Tick-borne Infections in Animals
*Updated 30th September 2014
From the Canine Vector-Borne Disease Site:
After a tick bite, Borrelia burgdorferi disseminates by active movement of the bacteria through the tissue. Therefore, even early infections require full dose antibiotic to penetrate all tissues in adequate concentrations to be bactericidal to the organism.
There is no universally effective antibiotic for treating Lyme borreliosis. The choice of medication used and the dosage prescribed will vary for different individuals based on multiple factors. These include age, weight, gastrointestinal function, blood levels achieved, and patient tolerance.
*Tetracyclines, including doxycycline (treatment of choice) and minocycline, are bacteriostatic unless given in high doses.
*Penicillins are bactericidal. Amoxicillin has been shown to be more effective than oral penicillin V. Because of its short half-life and need for high levels, amoxicillin is usually administered along with probenecid.
*Cephalosporins of the third generation have been shown to be effective in penicillin and tetracycline failures. The third generation cephalosporin ceftriaxon is able to cross the blood-brain-barrier.
Duration of treatment
The spirochete has a very long generation time (12 to 24 hours in vitro and possibly much longer in living systems) and may have periods of dormancy, during which antibiotics will not kill the organism. Therefore, treatment has to be continued for a long time.
It has been observed for humans that symptoms will flare in cycles every four weeks. It is thought that this represents the organism’s cell cycle, with the growth phase occurring once per month. As antibiotics will only kill bacteria during their growth phase, therapy is designed to brake at least one whole generation cycle. This is why the minimum treatment duration should be at least four weeks (also for dogs).
If antibiotics are effective, over time these flares will lessen in severity and duration. But a persistent infection with Borrelia even after antibiotic therapy is commonly reported in dogs.
(vaccination & prevention also covered in the link below plus useful maps of tick-borne infections) http://www.cvbd.org/en/tick-borne-diseases/lyme-borreliosis/treatment/
* Updated 29 August 2014
LYME DISEASE and its implications for humans and dogs
Some excellent tips on protection & a run down on some of the complex issues such as testing & treatment (UK) – the section on dogs further down the page..
Lyme disease: hidden dangers on a country walk
Lyme disease is common in moorland areas. It may seem relatively safe walking your dog in the countryside, but there are a number of unexpected hazards that can be present in these surroundings. They include Lyme disease, which occurs virtually throughout the entire northern hemisphere, outside the tropics. Much still remains to be learnt about this illness, which is spread by a type of tick called Ixodes.
It is more of a problem in certain areas than others, with moorland regions ranging from the New Forest to the Scottish Highlands in the UK being especially hazardous. This is where ticks are likely to be most numerous, as they will survive well here, hidden in the dense vegetation, even during a dry summer.
For more on the article go to:
Please note that the tip on smothering the tick isn’t always advisable, remove them gently with fine tipped tweezers or a tick twister as smothering can agigate the tick & may cause added risk of infection if they inject stomach fluids before they release… http://www.ticktalkireland.org/howtoremoveaticksafely.html
Did you know that the Irish dogs website sells tick twisters in Ireland?
Check them out at: http://store.irishdogs.ie/products/O%27Tom-Tick-Twister-Tick-Remover-for-Dogs%2C-Cats%2C-Horses-%26-Humans-%28Pack-of-2%29.html
* Updated 03 June 2014
Molecular evidence of tick-transmitted infections in dogs and cats in the United Kingdom.
Shaw SE1, Binns SH, Birtles RJ, Day MJ, Smithson R, Kenny MJ.
Vet Rec. 2005 Nov 19;157(21):645-8.
PCR analysis was used to determine the prevalence of tick-transmitted infections in 120 systemically ill dogs and 60 cats recruited over a period of three months from 52 veterinary practices in the UK. The animals had not travelled outside the UK and had one or more of the following clinical criteria: acute or recurrent pyrexia, anaemia and/or thrombocytopenia, polyarthritis/muscle pain, splenomegaly/lymphadenopathy, and intraocular inflammation with systemic signs. Blood samples from the animals were tested for the presence of DNA from Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum by using simple PCR targeting. B. burgdorferi sensu lato was detected in five dogs and two cats, and A. phagocytophilum was detected in one dog and one cat. These results provide the first molecular evidence of naturally occurring B. burgdorferi sensu lato infection in cats in the UK and confirm that A. phagocytophilum infection is present in cats. There were no statistically significant associations between the infections and the clinical signs shown by the dogs and cats.
PMID: 16299364 http://www.ncbi.nlm.nih.gov/pubmed/16299364
Animal Health Ireland on Redwater Fever in Cattle July 2013 (PDF)
Ticks kill sheep
Date:November 12, 2013
Source:Bioforsk – Norwegian Institute for Agricultural and Environmental Research
In some lamb herds, a mortality rate of 30 percent has been recorded, with no predators involved in these losses. The situation is so serious that the sheep industry could be under threat. It is therefore crucial to identify the causes and implement preventative measures. The answer may be found somewhere within the genetics of the sheep and the course of the disease, assessment and control of tick populations and biological control of ticks.
More at: http://www.sciencedaily.com/releases/2013/11/131112091015.htm
• Check out this interactive map on the spread of Lyme and co-infections for dogs in the U.S.
Also includes details on tick-borne diseases that can affect your pooch, including:
Rocky Mountain spotted fever
PCR-BASED SURVEY OF TICK-BORNE DISEASES IN THE UK/IRELAND
European Society for Veterinary Internal Medicine, 2001
Department of Clinical Veterinary Science, University of Bristol, UK
http://www.bris.ac.uk/acarus/esvimabst.htm (NB: link now broken but kept for reference!)
Extracts of report below:
A PCR-based survey of UK/Irish dogs and cats was undertaken to obtain
a preliminary picture of the distribution and presence/prevalence of
tick-borne infections. Blood samples from 180 systemically ill animals
(120 dogs and 60 cats) from 41 practices distributed throughout UK and
Ireland were collected during September-October, 2000. The study was
stratified according to clinical signs and each sample was tested by
PCR for Ehrlichia, E. phagocytophila, Borrelia and Bartonella DNA.
Simple PCR targeting of genus- or species-specific regions of rRNA
genes (Ehrlichia), housekeeping genes (citrate synthetase and gltA in
Bartonella), virulence factors (ospA in Borrelia) or multicopy
sequences (epank1 in E. phagocytophila) was used.
DNA of endemic tick-borne pathogens was detected in 6.6% of sick dogs
and 5% of sick cats. Borrelia burgdorferi sensu lato was detected in 5
% and E. phagocytophila in 0.8 % of canine samples. In sick cats, 3.3%
were infected with B. burgdorferi sensu lato and 1.6% were infected
with E. phagocytophila. No samples were positive for Bartonella DNA
using PCR. However, in a larger separate survey of cats studied here,
11% were positive for Bartonella henselae using culture.
Retrospective study of UK samples submitted for PCR diagnosis
A rapid PCR-based diagnostic service for arthropod-borne diseases in
companion animals has been developed at the University of Bristol. PCR
methodology used is as described for the PCR-based survey. Between
January 2000 and May 2001, 100 blood samples from ill non-travelled UK
dogs and cats were PCR tested. Of 89 samples tested, 6 dogs were
positive for E. phagocytophila (6.7%). Of 68 tested for Borrelia, 2
dogs (3%) were positive and of the 66 samples tested for Bartonella, 2
dogs (3%) were positive.
These preliminary data suggest significant exposure of UK/Irish
companion animal populations and possibly their owners, to infected
arthropod vectors. Ehrlichia phagocytophila, Borrelia and Bartonella
spp are human pathogens and companion animals may act as sentinels for
human infection (10). In addition, the presence of E. phagocytophila
infection in dogs and cats in UK and Ireland has been confirmed.
Molecular evidence of Borrelia infection in dogs is confirmed and is
reported for the first time to our knowledge, in cats. The Borrelia
genospecies involved in infection will be further characterised using
restriction fragment length polymorphism analysis. Canine Bartonella
infection is reported for the first time in Europe and the canine
Bartonella DNA will be sequenced.
Tick-borne disease in pets (BADA-UK)
Includes the following:
Anaplasma and Ehrlichia species parasitize the white blood cells of many animal species. Learn the symptoms of infection in dogs, cats and horses.
Babesia species parasitize the red blood cells of their hosts. Find which species can affect our companion animals and how infection can be treated.
Bartonella infections are often found in cats and dogs without any apparent symptoms but sometimes they do get sick. Learn what tests and treatment are currently used.
Borreliosis can cause serious disease in pet animals. Find out how an infection can be diagnosed and treated.
Effects of tick-borne disease on the canine immune system
The tick-borne diseases are caused by intracellular organisms, that is organisms that reside inside of cells in the animals they infect. Most are hemoparasites, inhabiting blood cells. Several can inhabit several different kinds of cells including those other than blood cells.
For whatever reason, perhaps their ability hide within the hosts cells, these organisms have profound effects on the immune systems of their host. They seem to cause immune system dysfunction, and often appear to suppress the hosts immune system at the same time they are triggering autoimmune reactions. Immune system depression manifests as lack of antibodies and vulnerability of the infected animal to secondary infections.
Autoimmune reactions are the hallmark of tick-borne disease. There may be autoimmune destruction of blood cells or blood cell progenitors in the bone marrow. Joints are inflamed and swollen and fluid tapped from affected joints has all the characteristics of autoimmune poly arthritis. Affected dogs may suffer from autoimmune disorders such as inflammatory bowel syndrome, myositis, and uveitis. Many affected dogs are reported to suffer from skin “allergies”, another indication of immune system dysfunction.
What are the early symptoms?
Rickettsial infections go through three stages: acute, sub-clinical, and chronic.
The acute stage occurs within a few weeks of infection. Dogs may appear to be suffering from “flu,” exhibiting low energy, lack of appetite, fever, swollen lymph nodes, and even nasal discharge. Other manifestations may include, but are not limited to:
low platelet count
swollen lymph nodes
discharge from the eyes
lameness, joint pain and swelling
unexplained weight loss and/or loss of muscle mass
increased water consumption
Neurological symptoms may also be seen, including (but not limited to) seizures.
Blood work may reveal elevated liver enzymes and low total blood protein levels. Low platelets are a hallmark of ehrlichiosis, however extremely high red cell, white cell, or platelet counts have also been reported. Hemolytic anemia is a hallmark of babesiosis, but may occur with other tick-borne diseases. Not all dogs with ehrlichiosis will have low platelets; not all dogs with babesiosis will have anemia. Infected dogs with any of these diseases may have normal CBC values.
Dogs with babesiosis may be vulnerable to hypoglycemia. Any dog diagnosed with babesiosis, should have blood sugar levels checked as hypoglycemia concurrent with babesiosis worsens the prognosis for recovery (Keller et al., 2004).
Most infected dogs will have more than one, but not all of these signs of infection. During the acute phase the symptoms may be severe or may be so mild as to go unnoticed.
Can a dog be infected, but have no symptoms?
Yes. Acute stage symptoms may be so mild that symptoms are not recognizable. Following the acute stage of infection, untreated dogs may enter a sub-clinical stage. In this stage the dog is asymptomatic and appears healthy. The sub-clinical stage can last for weeks or years. If a dog has a strong immune system, it may be able to keep the organisms in check, thus maintaining a sub-clinical state for quite a long time. Eventually the dog may experience stress that weakens the immune system enough that the infection becomes active again, and the dog enters a chronic stage of infection.
What are the chronic stage symptoms?
In chronic stage infections, the organism may penetrate brain and central nervous system tissues, internal organs (liver, spleen, kidneys), reproductive organs (uterus or testes) and bone marrow. A tremendous number of symptoms are possible, making accurate diagnosis difficult. Symptoms and signs are serious and may be life-threatening including:
Chronic Stage Symptoms
low platelets (thrombocytopenia)
low white cells
bone marrow failure
muscle wasting / weight loss
enlarged spleen and/or liver
abnormal thyroid function
seizures & other neurological disorders
severe non-regenerative anemia and thrombocytopenia (i.e. low platelets), seizures, muscle wasting, kidney failure, enlargement of the spleen, cardiac abnormalities, and bone marrow hypoplasia. Neurological symptoms have been documented for almost all rickettsia species. Many of these infections can trigger a wide array of autoimmune processes in the body: autoimmune facial paralysis, immune-mediated polyarthritis, inflammatory bowel syndromes, chronic ear and skin infections and “allergies”. Thyroid hormone and thyroid auto-antibody levels may be abnormal. There is anecdotal evidence to suggest these infections may be responsible for a variety of reproductive disorders including sterility, abnormal heat cycles, and resorbtion of litters. There is no scientific proof as yet, however a number of dog owners and veterinarians who have direct experience with rickettsial infections suspect that they may have the potential to trigger the development of lymphosarcoma. Ehrlichia canis has been associated with meningitis and uveitis in dogs (Panciera at al., 2001, Massa et al., 2002), and Leishmania has been associated with uveitis (Pena at al., 2000).
Tick-borne infections are commonly misdiagnosed. Symptoms may be very similar to blastomycosis and Valley Fever. Tick-borne infections may be misdiagnosed as lupus, lymphosarcoma, leukemia, autoimmune hemolytic anemia, epilepsy, myositis, brucellosis, inflammatory bowel disease, encephalitis and “autoimmune disease.”
What you should know about tests for tick-borne diseases
There are two major types of tests available for tick-borne diseases: direct tests such as PCR testing look for direct evidence of the presence of the organism itself, whereas indirect tests such IFA titer, ELISA and Western blot tests look for the presence of antibodies against a particular organism.
Indirect Testing Methods
Indirect antibody tests are most commonly used as they are more easily available from commercial testing laboratories and are less expensive. These tests analyze for the presence of antibodies against specific organisms. High levels of antibodies are believed to indicate active infection. The problem is how to interpret negative or low level positive results. A negative result is generally interpreted to mean the dog is not infected, although it could also mean the dog’s body simply has mounted no immune defense against the infecting organism. Low levels of antibodies may indicate a poor immune response against an active infection, or past exposure to the organism but no active infection.
Since antibodies may persist in the bloodstream for months or years following an infection, the presence of antibodies is not unequivocal evidence of active infection. The tick-borne organisms are notorious for causing immunosuppression and there is anecdotal evidence that infected dogs may have low or zero antibody levels. Low antibody levels or negative antibody test results are not conclusive evidence for lack of infection.
One probable reason for negative test results for dogs whose symptoms strongly suggest tick-borne disease is that the dog was not tested for the right species. Antibody tests are very specific for the exact species of tick-borne organism. Only a few species create “cross-over” problems, where antibodies from one species cause a false positive reading when testing for a different species. Typical test “panels” only test for a few species of the many tick-borne organisms that may infect dogs.
IFA (indirect fluorescence assay) titers are the most reliable type of titer test to run for tick-borne diseases. IFA tests analyze for the presence of antibodies. Results are reported as a ratio, indicating how far the sample could be diluted and still have a positive reading for the presence of antibodies. The higher the ratio, the greater the abundance of antibody in the dog’s blood. Tests are specific for the exact species. IFA tests are available for almost all species of tick-borne organisms that infect dogs, and are available from a great many commercial laboratories. As with all testing, it is important to use a reputable laboratory that uses careful lab procedures and quality control.
Veterinarians now have available to them a simple in-house test kit that tests for Borrelia burgdorferi (Lyme Disease), Ehrlichia canis, and canine heartworm, all in the same test kit. These test use the ELISA antibody testing method. They are fast and inexpensive, but not 100% reliable for Borrelia and Ehrlichia. (the heartworm part of the test appears to be reliable) The test is called the SNAP 3Dx. A positive reading on the SNAP test for Lyme Disease or E. canis should be considered accurate. A negative reading does not necessarily mean the dog is free of those infections. E. canis is the only Ehrlichia species tested for on this test, and dogs can be infected by many other Ehrlichia species.
International experts discuss threats posed by ticks and fleas
16. April 2010 02:51
As experts from around the world met in New York this week they discussed the need for greater understanding of the threat posed by ticks, fleas and sand flies. Leading scientists called on veterinarians and dog-owners around the world to take action to protect dogs and humans from potentially lethal diseases.
Ticks, mosquitoes, fleas and, in some countries, sand flies are critical in the transmission of diseases to both dogs and humans, including life-threatening conditions such as Lyme Disease, Leishmaniasis and other important diseases such as Ehrlichiosis. “These so-called CVBDs (canine vector borne diseases) that were once considered exotic or unusual are now commonly extending their distribution thanks to the increase in pet travel and, in part, to changes in climate,” stated Professor Gioia Capelli of the Parasitology and Ecopathology laboratory, Experimental Institute for Animal Diseases Control of Northern Italy (IZSVe). “Today, with the very latest highly sensitive diagnostic techniques, known as PCR and serology tests, we are able to accurately detect these infectious agents, improve diagnosis and rapidly grow our understanding of these life threatening diseases. Also, DNA-based techniques look set to provide useful information for treatment.”
For more go to: http://www.news-medical.net/news/20100416/International-experts-discuss-threats-posed-by-ticks-and-fleas.aspx
Map of Human vs Dog Lyme cases 2000:2006
Prevalence of selected infectious agents in cats in Ireland
Journal of Feline Medicine & Surgery
Volume 12, Issue 6, June 2010
1 University Veterinary Hospital School of Agriculture, Food Science & Veterinary Medicine, University College Dublin, Ireland
2 College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO., Ireland
Vector-borne bacterial and rickettsial agents and Toxoplasma gondii, are common organisms in cats. Some are potentially zoonotic or may be transmitted via blood transfusion. The current study investigated the prevalence of these agents in cats from Dublin, Ireland, for which no published data exists. Whole blood (n = 116) and sera (n = 83) samples were obtained from 121 cats. DNA was extracted from blood and assayed using polymerase chain reaction techniques for Anaplasma species, Bartonella species, Ehrlichia species, Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’, ‘Candidatus Mycoplasma turicensis’ and Rickettsia species. IgG and T gondii IgG and IgM serum antibodies were detected by enzyme-linked immunosorbent assay. DNA consistent with B henselae (3.4%), B clarridgeiae (0.8%), both Bartonella species (0.8%), C M haemominutum (12.9%), or M haemofelis (2.5%) was amplified from 24/116 blood samples (20.6%). Antibodies to T gondii and Bartonella species were detected in 28 (33.7%) and 22 (26.5%) of 83 sera, respectively.
Pets And Owners At Risk From Lyme Disease in The New Forest
Posted by: Richard L on: 10 August 2009
NB link now broken but kept for reference!
As the PDSA warns us that the 150% increase in suspected cases of Lyme Disease could be the tip of the iceberg, we remind you how to avoid Lyme Disease and what symptoms to look out for.
Lyme disease is transmitted by a tick bite that carries the bacterium Borrelia burgdorfei. It transmits the bacterium to you as it feeds on your blood. It can spread to humans, dogs and cats, plus some other species. Symptoms include a rash, fever, lameness and fatigue as well swollen lymph glands and nerve damage.
Ticks are very small (about the size of a poppy seed) and can easily be overlooked. Most ticks are not infected with the bacteria that cause Lyme disease. Even if a tick is infected, it does not spread the bacteria in the first few hours of its feed, so there is a very low risk of infection to both pets and humans if a tick is removed quickly.
A tick bite usually looks like a lump with a small scab on the skin surface at the site of the bite. Most people with Lyme disease then develop a reddish skin rash in a ring shape, and this may be the only sign of infection. The rash spreads out from the site of a bite after three to 30 days. Other common symptoms of early Lyme disease include tiredness, headache, joint pains and flu-like symptoms.
Early detection and treatment of the disease helps to relieve the symptoms and shorten the illness. For this reason, it is important to be aware of the symptoms, particularly the rash, so that treatment can be given early.
Pet owners are advised to prevent themselves being bitten by covering up when in woods or long grass – and to check their pets after walks for signs of ticks.
Some areas are more prone to infected ticks. In the UK, Lyme disease occurs mainly in the New Forest, Salisbury Plain, Exmoor, the South Downs, parts of Wiltshire and Berkshire and Thetford Forest. It’s also found in the Lake District, the Yorkshire Moors and the Scottish Highlands and Islands. Elsewhere, areas of high incidence are the United States, France, Germany, Austria, Sweden, Czech Republic, Slovakia, Slovenia, Croatia, Romania, Bulgaria and the Baltic republics. Peak times of the year for tick bites are late spring, early summer and autumn.
Unfortunately, some of the symptoms of Lyme Disease are similar to those of Swine Flu, but the characteristic rash should help to confirm a diagnosis. Symptoms can vary from patient to patient and sometimes there are no symptoms at all.
In around 70-80% of cases, the first sign of infection is usually a rash known as erythema migrans. The rash appears between one and four weeks after the bite. It spreads gradually from the site of the tick bite and can cover much of the trunk of the body. Other symptoms include:
* headache, and
* aching muscles and joint,
* stiff neck, and
* swollen glands.
If you suspect that you have been bitten by a tick and you have the symptoms described above, see your GP or call NHS Direct.
What About Your Pet?
Senior Veterinary Surgeon Elaine Pendlebury said, “The number of suspected cases of Lyme disease in dogs and cats is just the tip of the iceberg, in my opinion. Pet owners may not consult their vet as they are often unaware of the dangers of tick bites and that an infected pet may need early antibiotic treatment.
“It is essential that owners are aware of the dangers of ticks, particularly during the summer months, because both you and your pet could be affected. Tick bites can be difficult to detect as they are relatively painless but symptoms of the infection can develop months, even years, after the tick bite.
“One way for owners to reduce the risk of Lyme disease in pets is to use tick control products as recommended or prescribed by their vet. They should also check their dogs for ticks regularly after a walk, and immediately consult their vet if their dog shows any of the signs of Lyme disease.
“When a pet has been in woods or long grass, owners should check the fur, using rubber gloves, as an infected tick can bite both the pet and the human. If an owner does find ticks on their pet then their vet can safely remove it and also give advice on how an owner could effectively do this in the future.”
PDSA vets also advise dog owners to cover up when walking their pets, particularly in the countryside or park. Owners should wear long-sleeved tops and full-length trousers and after a walk a person should check their armpits, groin, belly button, neck and head for ticks. The number of people being diagnosed with Lyme disease in the UK has also steadily risen over the past 10 years.
Lyme Vaccine Side Effects for Pets
The Lyme vaccine is an inoculation meant to provide protection against Lyme disease, which is transmitted by a tick bite. The necessity to protect pets against Lyme disease with a shot is highly debated because of the side effects associated with this vaccine.
Lyme Disease Explained
Lyme disease is a bacterial infection that’s transmitted by ticks when they bite their hosts. Not all ticks carry the bacterium that causes Lyme disease, Borrelia burgdorferi. It’s typically found on ticks that have had deer as a host and have stored the bacteria in their bodies. This disease can affect many of a pet’s systems: joints, skin, heart and nervous system.
The Lyme Vaccine
The Lyme vaccine isn’t without controversy as its safety, efficacy, and long-term side effects are questioned. There are two types of Lyme vaccines: bacterin and a recombinant vaccine. The bacterin vaccine has antigens that protect against Lyme disease and preservatives that are called “adjuvants”. The recombinant vaccine has an antigen made of an outer surface protein that helps prevent the transmission of Lyme disease.
Promoters of the vaccine state it benefits a pet by prompting his immune system to create antibodies that attack the proteins found on the outside of the bacteria. However, it is not recommended that a pet be given the vaccine to treat Lyme disease, acute or chronic. The manufacturers of the Lyme vaccine encourage pet owners and veterinarians to administer the shot every year. Many veterinarians that do provide this vaccine will typically only repeat a vaccination when a pet is at a higher risk of contracting Lyme disease.
Lyme Vaccine Side Effects
The side effects of the Lyme vaccine mimic those of the actual disease because of the proteins within it that pets aren’t typically exposed to. Experts have found this vaccine to cause arthritis, problems of the heart and nervous system, skin problems, and sudden kidney failure. Many veterinarians have reported that pets given the Lyme vaccine display all the symptoms of Lyme disease, but blood samples taken from the pets showed no evidence that the pets contracted the disease itself.
Research on the vaccine conducted on animals in a controlled environment found that those that were given a Lyme vaccine were more likely to develop arthritis. This discovery has made veterinarians extra weary of vaccinating pets that are predispose to an autoimmune disorder.
The adjuvants in the bacterin form of the Lyme vaccine are what experts believe causes the adverse side effects in the inoculation. The recombinant form of the vaccine is less likely to cause adverse side effects as it doesn’t contain adjuvants.
Many veterinary experts recommend that pet owners vaccinate a pet with the recombinant form of the Lyme vaccine if they feel it’s necessary for their animal companion to receive this shot. However, what most animal experts recommend instead of a Lyme vaccination are prevention techniques so a pet does not attract ticks. These techniques include using an insect repellent that’s safe for use on pets, spot treatments to repel and kill fleas and ticks, and antibiotic treatments for when a tick bite is noticed.
EPA: More pets injured by flea and tick products
By Matthew Daly
Associated Press Writer / March 17, 2010
Lyme Disease Treatment in Pets
Lyme disease can be treated with antibiotics, because the disease is caused by a bacterium that is introduced to your pet through a bite from a tick carrying the disease.
Antibiotics will be taken for a long period of time and some times and may not be very effective if your pet has had the disease for a long period of time. Sometimes, your veterinarian can switch the antibiotics so see if that may cure the disease. But, if your pet does get bitten again, the disease can reoccur.
So, the best treatment for lyme disease is in the prevention. Ticks can be found in many different areas and are just waiting for the next warm body. Keeping your pets out of thick brush and high grass will help them from getting ticks, but there are many products on the market today that can in fact keep ticks off of your pets or kill these pests if your pet already has ticks.
Bathing your pet or grooming your pet can also help in Preventing ticks on the time you connect to your pet. After your pet has been outside in, comb him completely and check the skin. This can be a lengthy process when you dog or cat has long hair. But it is well worth the time.
If you have a tick on your pet better and is a movement, then you will be able to remove easily. Make sure you kill the tick. If the tick has attached it is very important to remove it properly. You can use tweezers or your fingernails. Grabthe tick close to your pet‘s skin and pull straight out very firmly. Do not allow any of the contents from the tick on your skin or your pet‘s skin. Lyme disease can be transmitted through a cut on the skin. And yes, humans can also contract lyme disease.
Tick fears as dog dies from bite
Scientists believe a tick which can kill dogs has spread to the British mainland after a dog in Kent was bitten by the insect and died.
Janet Hunt, from Ashford, said she used to walk her dog Caffreys near railway lines used by Eurostar trains. Foreign trucks also park alongside the paths.
Caffreys died from the blood-born disease babesia, caused by a tick not previously known to be in the UK.
The disease was diagnosed by a research scientist at the University of Bristol.
The veterinary school is the only one of its kind able to use DNA to spot such rare types of blood-born disease.
“We don’t know how widespread this tick is in the UK,” said vet Dr Susan Shaw.
“We don’t know how many infected ticks there are in that area and we don’t know what the risk is for other dogs.”
The blood-sucking parasite lives around the Mediterranean but Caffreys never left the UK.
“These lorries from abroad might have something to do with the disease – I just don’t know,” said Mrs Hunt.
Safety warning for Cats
Tick- and flea-control products that are sold over the counter in pet shops and supermarkets often contain Permethrin, which is extremely harmful to cats. It can cause Feline Permethrin Toxicosis, which is potentially fatal. Cases of poisoning most commonly occur when people mistakenly use a product that is intended for dogs on their cat. Poisoning can also occur when the cat comes into contact with treated carpets, other soft furnishings and pet bedding. Sometimes cross-contamination occurs when a cat has close contact with a treated dog.
Some product ingredients may be dangerous to aquatic organisms. Check the manufacturers’ instructions before letting your pet come into contact with water.
Univ of Bristol – Acarus Labs for pets
The Acarus Unit has been set up for a number of reasons
* To provide a rapid diagnostic service for a number of arthropod-borne microbial diseases in companion animals, specifically: Babesiosis, Bartonellosis, Borrelliosis, Ehrlichiosis and Leishmaniasis
* To develop novel methodologies for the rapid identification of specific micro-parasites
* To develop research projects addressing the prevalence, ecology and epidemiology of these disease in the UK
* To raise awareness amongst veterinary practitioners on the subject of arthropod-borne diseases
* To establish a focus for the dissemination of information on these diseases for the scientific community
PCR TESTING FOR VECTOR-TRANSMITTED INFECTION
The Acarus laboratory specialises in polymerase chain reaction (PCR) testing for organisms transmitted by arthropod vectors (insects, ticks etc) including those that affect animals that have travelled into the UK from overseas destinations. Samples submitted to the Acarus laboratory are processed to extract DNA and then screened for the presence of gene sequences that are specific for the organism or organism group that is being investigated.
Two main PCR services are offered
1. PCR testing for individual organisms. These may be designed to be very specific for the target organism e.g. Anaplasma phagocytophilum and Bartonella henselae real time PCR
2. Combinations of PCR tests (“screens”) which have been constructed to cover several infections that may occur in particular travel destinations. The components of these screens require regular up-dating as the distribution of infection changes with animal/vector movement and climate change.
TESTS FOR INDIVIDUAL ORGANISMS/GROUPS (Aug 2009-2010)
Cost per PCR test : £30.00 + VAT
Anaplasma phagocytophilum (granulocytic ehrlichiosis) real time PCR
Babesia species conventional PCR
Bartonella henselae real time PCR
Bartonella species conventional PCR
Borrelia species conventional PCR
Ehrlichial species (imported) conventional PCR
Leishmania species real time PCR
Rickettsia species conventional PCR
Meningitis, cranial neuritis, and radiculoneuritis associated with Borrelia burgdorferi infection in a horse
Journal of the American Veterinary Medical Association
November 15, 2010, Vol. 237, No. 10, Pages 1180-1185
Frances M. James, MAVetMB, DACVS; Julie B. Engiles, VMD, DACVP; Jill Beech, VMD, DACVIM
Departments of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348. (James, Beech); Departments of Pathobiology, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348. (Engiles)
Dr. James’ present address is Donnington Grove Veterinary Surgery Oxford Rd, Newbury Berkshire, RG14 2JB, England.
The authors thank Dr. Julia Flaminio for assistance with immune function testing.
Address correspondence to Dr. James (firstname.lastname@example.org).
Case Description—A 12-year-old Thoroughbred was examined because of signs of depression, neck stiffness, and poor performance.
Clinical Findings—Physical examination revealed that the horse was dull, appeared depressed, was reluctant to raise its neck and head above a horizontal plane, and had a temperature of 38.5°C (101.3°F). No radiographic or scintigraphic abnormalities of the neck were found; however, high plasma fibrinogen concentration and relative lymphopenia were identified and the horse was seropositive for antibodies against Borrelia burgdorferi. Analysis of CSF revealed neutrophilic inflammation, and results of a PCR assay of CSF for B burgdorferi DNA were positive. Immunologic testing revealed severe B-cell lymphopenia and a low serum IgM concentration consistent with common variable immunodeficiency.
Treatment and Outcome—The horse responded well to do×ycycline treatment (10 mg/kg [4.5 mg/lb], PO, q 12 h for 60 days) and returned to normal exercise. However, 60 days after treatment was discontinued, the horse again developed a stiff neck and rapidly progressive neurologic deficits, including severe ataxia and vestibular deficits. The horse’s condition deteriorated rapidly despite IV oxytetracycline treatment, and the horse was euthanatized. Postmortem examination revealed leptomeningitis, lymphohistiocytic leptomeningeal vasculitis, cranial neuritis, and peripheral radiculoneuritis with Wallerian degeneration; findings were consistent with a diagnosis of neuroborreliosis.
Clinical Relevance—Nervous system infection with B burgdorferi should be considered in horses with evidence of meningitis and high or equivocal serum anti-B burgdorferi antibody titers. Evaluation of immune function is recommended in adult horses evaluated because of primary bacterial meningitis.
Map of canine vector-borne disease in the World
(can click on Europe to zoom in to one area, can also click on individual tick-borne diseases on the left to see clusters, ie Lyme & Anaplasmosis shows as endemic in UK & Ireland..)
Canine Lyme disease Know the facts (North America)
1. It is estimated that 50 percent of dogs are infected with Borrelia burgdorferi in endemic disease areas
2. Nearly 75 percent of unvaccinated dogs in endemic areas will eventually test positive, and each year some will develop Lyme disease
3. Dogs are 50 to 100 times more likely than humans to come in contact with disease-carrying ticks
4. More dogs are probably infected with Borellia burgdorferi than reported, as dogs will often show no signs of disease.
5. Dogs spend more time roaming in areas infested with ticks, especially in their own backyards
6. The threat of Lyme disease is probably greater in dogs than in humans
Go to www.dogsandticks.com for a U.S. map of the incidence of Borrelia burgdorferi infection and other tick-borne diseases.
Ticks are on the march in Britain
Press release issued 23 March 2011
The prevalence of ticks attaching to dogs in Great Britain has been mapped by scientists as part of a national tick survey. The findings reveal that the number of dogs infested with the blood-sucking parasites was much higher than expected. The study also confirms that a European tick species now exists in Great Britain.
The research, carried out by academics from the University of Bristol’s Veterinary Parasitology Group and published in the journal Medical and Veterinary Entomology, found that at any one time 14.9 per cent of dogs were infested with ticks.
More than 3,500 dogs were examined for ticks at 173 vet practices across Great Britain between March and October 2009. The researchers found that gundog, terrier and pastoral breed groups were more susceptible to getting ticks than others, and that longer-haired dogs were more susceptible to ticks than short-haired dogs.
Samples of a tick species only found previously in continental Europe were also found in locations in west Wales and south east England, adding to growing evidence that this tick, deemed as ‘exotic’, is now a permanent resident in Great Britain.
Professor Richard Wall, head of the Veterinary Parasitology Group at the University, said: “This is an important study because the results suggest that the risk of tick infestation is far higher in dogs than was previously thought. This has serious implications for the incidence of tick-borne disease. The study also confirms that a non-native species of tick, which is also a major disease vector in Europe, is now established in southern England. It will be of considerable interest to monitor its spread.”
Dogs can be infected with a number of tick-borne diseases, including Lyme disease. A non-native species of tick could help spread new diseases from Europe in the UK.
Current concerns over the potential impacts of changing climate and increased global movement of people and companion animals on the distribution of ectoparasites highlight the need for an accurate understanding of existing prevalence patterns, without which future changes cannot be detected.
Faith Smith, lead author on the study from the University’s School of Biological Sciences, added: “The study represents a major large-scale analysis of ticks in Britain – and the data could aid work to help predict the effects of climate change on tick distributions and disease spread.”
The study entitled ‘Prevalence, distribution and risk associated with ticks infesting dogs in Great Britain’, was funded by the Natural Environment Research Council [NERC] and Merial Animal Health Ltd.
Please contact Faith.Smith@bristol.ac.uk for further information.
Pics on site:
A map illustrating the prevalence of ticks attaching to dogs in Great Britain
An image of a male (small) and female (large) tick mating
An image of a male (small) and female (large) tick mating
This is an important study because the results suggest that the risk of tick infestation is far higher in dogs than was previously thought. This has serious implications for the incidence of tick-borne disease. The study also confirms that a non-native species of tick, which is also a major disease vector in Europe, is now established in southern England. It will be of considerable interest to monitor its spread.
Professor Richard Wall, head of the Veterinary Parasitology Group
The Common Shrew (Sorex araneus): A Neglected Host of Tick-Borne Infections? [JOURNAL ARTICLE]
Vector Borne Zoonotic Dis 2011 Mar 31.
Bown KJ, Lambin X, Telford G, Heyder-Bruckner D, Ogden NH, Birtles RJ
Abstract Although the importance of rodents as reservoirs for a number of tick-borne infections is well established, comparatively little is known about the potential role of shrews, despite them occupying similar habitats. To address this, blood and tick samples were collected from common shrews (Sorex araneus) and field voles (Microtus agrestis), a known reservoir of various tick-borne infections, from sites located within a plantation forest in northern England over a 2-year period. Of 647 blood samples collected from shrews, 121 (18.7%) showed evidence of infection with Anaplasma phagocytophilum and 196 (30.3%) with Babesia microti. By comparison, of 1505 blood samples from field voles, 96 (6.4%) were positive for A. phagocytophilum and 458 (30.4%) for Ba. microti. Both species were infested with the ticks Ixodes ricinus and Ixodes trianguliceps, although they had different burdens: on average, shrews carried almost six times as many I. trianguliceps larvae, more than twice as many I. ricinus larvae, and over twice as many nymphs (both tick species combined). The finding that the nymphs collected from shrews were almost exclusively I. trianguliceps highlights that this species is the key vector of these infections in this small mammal community. These findings suggest that common shrews are a reservoir of tick-borne infections and that the role of shrews in the ecology and epidemiology of tick-borne infections elsewhere needs to be comprehensively investigated.
Lyme Disease and Pets
(link now broken but kept for reference)
Lyme disease can affect individual pets differently. Some animals may display no symptoms. Other animals may develop fever, loss of appetite, painful joints, lethargy, and vomiting. If left untreated, the spirochete may damage the eyes, heart, kidneys, and nervous system. Lyme disease has been diagnosed in humans, dogs, cats, horses, goats, and cattle. Other species may also be at risk.
Cats may show lameness, fever, loss of appetite, fatigue, eye damage, unusual breathing, or heart involvement. Many cats do not show noticeable symptoms, despite being infected.
Infected dogs may be lethargic, have a poor/loss of appetite, or a fever (103° – 105 ° F). Dogs may also experience lameness shifting from one joint to another, fatigue, kidney damage or failure, heart disorders, or neurologic involvement (e.g. aggression, confusion, overeating, seizures). Dogs can be infected with the Lyme bacterium but not exhibit any noticeable symptoms. Dogs appear to have the same expression of disease as humans, therefore, humans have been considered an animal model for dogs. Transplacental transmission has occurred in dogs.
Many cattle do not display signs of Lyme disease; those that do may have lameness, painful or swollen joints, fever, laminitis, or weight loss. A skin rash may be present on the udder of infected cows. Bb has been found to exist in urine and colostrum of infected cattle; therefore, the possibility of transmission between cows should be considered. The Lyme bacterium has also been found in blood, milk, synovial fluid, and spontaneously aborted fetal tissue. Bb can survive in frozen milk, but is killed during pasteurization.
Infected horses generally do not have a fever, but may have lame or stiff joints, laminitis, depression, or refuse to eat. This bacterial infection may be a cause of moon blindness or loss of vision. There have been reports of spontaneous abortion and encephalitis in horses infected with Bb. Neurologic signs include head tilt, difficulty swallowing, or aimless wandering. Transplacental transmission occurs. Colts born to infected mares have displayed birth defects. Many horses may be infected with the spirochete, but display no symptoms.
PROTECTING YOUR PET
1. Apply tick-killing chemicals to your animals in order to protect them from disease spreading ticks. Sprays and dips containing permethrins and pyrethrins kill ticks on dogs, cats, and horses. Precautions should be taken when applying insecticides as some animals may be sensitive to the chemicals. Follow the manufacturer’s instructions.
It is a good idea to wear rubber gloves during application. Tick collars will help discourage ticks from attaching to your pet(s). Never apply multiple repellents on your pet. A mixture of different chemicals on your pet could make the animal very sick.
2. Take precautions to guard against ticks when entering tick habitat, such as grassy, shrubby, wooded, or beach grass areas. Cut/mow grassy areas regularly to reduce tick habitation.
3. Treat the environment with insecticides designed specifically for ticks. To avoid contaminating water, experts recommend spraying at least 75 feet away from a well.
4. Conduct frequent Tick-Checks! Examine animals closely in order to detect embedded ticks.
5. Remove attached ticks properly and promptly to reduce the chance of transmission of the LD bacterium. Place fine point tweezers around the tick’s mouthparts (the place where the tick is attached) and gently pull upwards until the tick detaches. Do not use your bare fingers!
Disinfect the bite site and tweezers after removal. Wash your hands. Place the tick, along with several blades of grass, into a small container (e.g. a clean screw-cap pill bottle or a zip-lock bag) for later examination. Call your veterinarian to determine if there is a local place where the tick can be tested. Label the container with: the date, name of pet, type of animal, owner’s name, address and phone number.
6. Have your animal(s) examined as soon as possible if you notice any symptoms of disease; the sooner a disease is diagnosed, the easier it is to treat.
7. Vaccines are available for dogs (in North America)
ARTHROPOD-BORNE INFECTIOUS DISEASES (by Acarus Labs, Bristol)
The diseases we work on are caused by bacteria (similar to E. coli) or much larger, more advanced organisms called protozoa (like amoeba or the agent that causes malaria). They are all transmitted by biting arthropods (ticks, fleas or flies).
Babesiosis is a tick-borne disease of companion animals, humans and food animals of worldwide significance. The disease is caused by protozoan organisms of the genus Babesia (sometimes called “piroplasms” due to their pear-like shape when seen within red blood cells). Of particular significance to us are the species B. canis and B.gibsoni, which can infect dogs, and B. felis, B. cati and B. pantherae which are found in cats.
The Babesias are protozoans, somewhat similar to those causing malaria and sleeping sickness. They have a complex two-host life cycle whereby they reproduce sexually in their tick host and asexually in mammals. The organisms replicate inside host red blood cells and cause a spectrum of disease ranging from no symptoms to a fulminant, acute disease, which may be fatal. Disease symptoms are usually due to the widespread destruction of red-blood cells with the concomitant release of haemoglobin and organisms into the blood stream. The major symptoms are fever, anaemia, haemoglobinuria (dark red, haemoglobin-containing urine), jaundice, lethargy and, in severe cases, acute collapse with multiple organ failure.
Bacteria of the genus Bartonella are found in the blood of many wild rodents and larger mammals, such as deer, throughout the world. In these natural hosts, infection with the bacteria does not appear to influence fitness. However, the transfer of these bacteria to domestic animals and humans can result in disease.
Bartonella appear to be transmitted from one animal to another by a range of biting insects, particularly fleas, although ticks have also been implicated. The disease can also pass, to humans at least, by direct inoculation e.g. by scratching or biting by heavily infected animals (thus giving rise to “cat scratch disease” a problem in immuno-compromised humans).
Bartonellosis (infection with Bartonella) is largely an infection of cats where it causes a wide spectrum of problems dependent on the underlying health of the animal, although current work is investigating its association with disease in other companion animal species. It appears that many animals carry Bartonella but remain symptomless. When stressed or immuno-compromised cats may develop fever, anaemia, heart and liver problems and neurological signs.
Borreliosis (sometimes known as Lyme disease) is caused by bacteria called Borrelia. Several species of this organism exist in Europe and all cause disease when transmitted to dogs and humans (and, less commonly, to cats, and horses). These organisms are adapted to live in rodent and wildlife reservoirs in which they cause no apparent problems. When ticks which harbour the organisms bite an animal, the bacteria are transmitted into the host with tick saliva and multiply in the bloodstream.
It appears that only certain types of ticks (known as Ixodes) can transmit Borrelia. Unfortunately the most common UK tick, the sheep tick (Ixodes ricinus), is one of these.
In humans the typical disease progression is a red rash around the tick bite which resolves and is followed by flu-like symptoms and arthritis. In animals the rash is not usually observed and the first signs of illness are that the animal appears “off-colour”; this lethargy and anorexia is often accompanied by lameness due to arthritic changes in the joints.
The infection is managed with antibiotic therapy but prevention is better than cure – evidence suggests that the ticks do not infect their host for 24 to 72 hours post-attachment. Removal of the ticks in this time frame should forestall the disease as would use of an effective acaricide (i.e. tick-killing preparation).
Ehrlichiosis is caused by a small bacterium (a rickettsia) from the genus Ehrlichia. These bacteria are predominantly passed from animal to animal by ticks in a similar manner to the transmission of Lyme disease. Once in the bloodstream the bacteria invade white blood cells (or platelets) where they multiply.
The clinical manifestations of ehrlichiosis are very varied, ranging from general loss of condition with intermittent fever to more organ specific pathology such as arthritis or eye problems. There are two major types of Ehrlichia which differ in the type of white blood cells they infect. The monocytic Ehrlichia (generally E. canis) tends to give rise to a chronic disease, whereas the granulocytic Ehrlichia (E. phagocytophila) causes a much more acute disease with high temperatures, anorexia and reluctance to move in infected animals. Both types cause depletion of clotting factors in the blood resulting in severe haemorrhage in some cases.
Leishmaniasis is a disease caused by protozoans of the genus Leishmania, and is transmitted by biting sandflies. Once in the body the organism lives inside macrophages, cells of the immune system. The disease is a major human health problem in parts of Africa, The Middle-East, South America and is widespread in the Mediterranean basin. The disease is a bigger problem in dogs than cats and a lot of work is being carried out to see if dogs are a natural reservoir of the disease in some areas.
Dogs infected with Leishmania tend to develop a chronic, systemic disease with a variable course of development. The commonest symptoms are weight loss and lack of endurance, lymphadenomegaly (“swollen glands”) and skin disease, particularly around the eyes. If caught in the early stages the disease can be successfully controlled by chemotherapy, but the organism is good at hiding and so repeated courses of therapy may be necessary throughout the animal’s life.
Acquisition of Borrelia burgdorferi by Ixodes ricinus ticks fed on the European hedgehog, Erinaceus europaeus L.
Exp Appl Acarol. 1994 Aug;18(8):485-91.
Gray JS, Kahl O, Janetzki-Mittman C, Stein J, Guy E.
Department of Environmental Resource Management, University College Dublin, Ireland.
A hedgehog, Erinaceus europaeus, was found to be heavily infested with larval and nymphal Ixodes ricinus in a forest park in Co. Galway, Ireland. A large proportion of the ticks that engorged and detached were infected with the spirochaete, Borrelia burgdorferi, the causative agent of human Lyme borreliosis. The identity of these spirochaetes was confirmed by immunofluorescent assay with B. burgdorferi-specific monoclonal antibody and by polymerase chain reaction test and they were transmitted from the hedgehog to laboratory-reared ticks and from the ticks obtained from the hedgehog to gerbils (Meriones unguiculatus). The high infection rate of the larvae that fed on the hedgehog in comparison with unfed larvae from the same habitat was interpreted as strong evidence that this host species is reservoir competent. Since hedgehogs can evidently feed adult ticks as well as many immature stages, they may well have an important role in the ecology of Lyme borreliosis in some habitats.
PMID: 7628256 [PubMed – indexed for MEDLINE]
Dr. Bettina Wagner developed new techniques for testing for Lyme Disease that are more accurate, specific, and sensitive than previous tests.
“The bacteria that cause Lyme disease are particularly difficult to detect,” explained Dr. Bettina Wagner, Harry M. Zweig Assistant Professor in Equine Health, who teaches in the Department of Population Medicine and Diagnostic Sciences.
“After infection they tend to hide where they can’t be detected. They bury in the joints of dogs, causing arthritis or lameness. In humans and horses they also burrow into the nervous system, in the spine or even the brain, causing pain, paralysis, or behavioral alterations. By the time such clinical signs appear, the bacteria are usually not in circulation anymore.”
“We can now not only distinguish between infection and vaccination, but also between early and chronic infection stages,” Wagner noted. “That was not possible before. You were able to say whether an animal was infected, but not when it was infected, or how far the infection had developed.”
The test and information it provides can help veterinarians make advanced decisions about treatment. After the long treatment period ends, veterinarians usually conduct follow-up testing to see if it was successful. With the information the new multiplex test can give us about the stage of the disease in an animal, we know what to expect after treatment and can better measure its success.
Tick-borne disease on Irish farms – 23-04-2011
By Micheal Casey
#Mícheál Casey from the Department of Agriculture’s Regional Veterinary Laboratory service, outlines the common tick-borne diseases affecting Irish livestock
Ticks are blood-sucking parasitic members of the Arachnidae – the same class of eight-legged arthropods as spiders. Diseases transmitted by ticks are a major cause of economic loss, disease and deaths in farmed animals worldwide.
Although there is only one species of tick that affects Irish livestock – the ‘castor bean tick’, Ixodes ricinus – it can act as a vector for a range of diseases. All references to ticks in this article refer to this tick.
Ticks have some fairly precise environmental requirements, especially when they leave the relative shelter of the base of the vegetation. They find a new host by ‘questing’, where they climb to the tips of the vegetation and grab onto any animal (or person) that passes.
They need mild and moist conditions for questing, which are provided in late spring and in autumn in a typical Irish year, resulting in clearly defined spring and autumn peaks in tick-borne diseases.
On some farms the ticks have become adapted to one or the other season, while on other farms both peaks are seen.
This disease is caused by a bacterium (Ehrlichia phagocytophila) and is normally mild and transient. Although this is not commonly diagnosed, it is probably the most important tick-borne disease in Ireland.
Firstly, it is very common; so common, in fact, that most herds have a high level of resistance and most infection occurs in young and bought-in animals. As the name suggests, animals run a temperature for a couple of days, lose their appetite, they may cough a little and milk yield of cows drops significantly.
The reason for the significance of tick-borne fever is the brief but severe immunosuppression that accompanies infection with the organism. Affected animals are very susceptible to other infections at the time of infection, and vaccines for other diseases that are administered at the time of tick-borne fever infection will not take effect.
Furthermore, if the tick that infects the animal is also carrying one of the other tick-borne diseases, then infection is more likely and the ensuing disease may be more severe.
Tick-borne fever is a hidden but important factor in every other tick-borne disease.
This parasite, Babesia divergens, is carried by ticks and is capable of being transmitted from one generation of tick to the next, so a reservoir of infection can be maintained on pasture even when no livestock have grazed that pasture for several years.
Once inoculated into the bloodstream, the organism replicates rapidly in red blood cells, which are ruptured as each generation of the parasite emerges. Animals run a high temperature which then falls rapidly, often below normal, as the disease progresses. Affected animals become dull, lose their appetite, become slow and may have difficulty standing or walking as the disease progresses. The oxygen-carrying haemoglobin is released from the ruptured red blood cells and passes through the kidneys and out in the urine, giving it a characteristic reddish brown colour and giving the disease its common name – ‘redwater’. The heart races as the body tries to compensate for the loss of circulating blood cells. Deaths can occur due to heart failure, kidney failure or anaemia, and blood transfusions may be required in the treatment of the most severely affected cases.
Drugs that prevent multiplication of the parasite are administered, but it is the effects of disease that are the most difficult to treat – anaemia, dehydration (and associated constipation).
One unique feature of redwater is the ‘reverse age immunity’ phenomenon. Calves are resistant to the disease until they are about six months of age. After that, the resistance an animal has to redwater in later life will depend on whether they were exposed to the disease as calves. Animals that have no resistance tend to develop a very severe form of the disease, and many farms routinely protect bought-in animals with a drug that gives protection for about four weeks. If this is given just before peak tick activity, there is a good chance that the animal will be bitten, infected and develop resistance without getting the disease, while protected by the drug.
Redwater seems to be decreasing in incidence and in severity in recent years. Partly, this is due to improved pasture management, which eliminates tick habitat. It also seems likely that the widespread use of Ivermectin-type products may have had an impact on tick productivity.
This is a disease of young lambs, which is caused by a common skin bacterium, Staphylococcus aureus. These bacteria are inoculated from the skin surface by the tick as it bites and get into the bloodstream causing septicaemia (blood poisoning). While the lamb’s blood carries the bacteria around the body, the tick will frequently be infecting the animal with tick-borne fever, which results in the bacteria ‘seeding’ the internal organs and tissues, especially the liver and the joints. A second septicaemia, often fatal, may occur at this stage. Affected lambs become slow and stiff and will die if untreated.
Q fever is caused by bacterium, Coxiella burnetti, and is very similar to tick-borne fever. Little is known about Q fever in Irish farm animals, largely because of the unavailability of diagnostic tests. It is known to occur here, and is tick-transmitted. It is likely to be behind some abortion outbreaks in sheep and cattle and may have an immunosuppressive role in a wide range of diseases
This bacterial tick-borne disease caused by Borrelia burgdorferi is strongly associated with deer, and the infection risk for humans and animals is highest in woodland and nearby pasture.
It is ‘one to watch’ as our wild and farmed deer population grows. It causes a fever and rash and can progress to cause central nervous system disease, arthritis and blood vessel damage in humans.
Again, little is known about the disease in Ireland, as it is rarely diagnosed, although blood testing shows that exposure to infection is common.
This is a serious and potentially fatal disease in humans, so it is very important to seek medical attention if any relevant symptoms are seen after a tick bite.
This virus causes encephalitis (brain inflammation) in sheep and is often fatal. It tends to occur in ticks in well-defined areas and is best controlled on affected farms by sourcing replacements from home-bred animals, or at least from within those areas.
A common feature of many tick-borne diseases is the strong, often life-long, immunity that results from infection. As a result, strong herd immunity develops, and very little disease tends to occur in stable, closed herds, even in heavily infested areas.
The exception here would be tick pyemia in lambs, where certain farms have a problem year after year unless they control the ticks.
Control of ticks requires the recognition and elimination of ideal tick habitat. Because ticks require mild, moist conditions, they are usually found at the base of dense vegetation. Ideal conditions for ticks occur where grass is growing through one or two years of dead previous growth (areas ungrazed for several years), and there is a moist decaying mat of old vegetation at the base of the sward. This is something to watch for when renting grazing land that may have been fallow for some time.
Control is achieved by minimising this phenomenon and by keeping animals fenced out of likely areas. Good pasture management and the rotation (where possible) of forage and grazing areas should minimise the amount of tick habitat.
The use of acaricides (chemicals that kill ticks) with residual effect will give protection against ticks for several weeks, and is a common practice, as a way to protect cattle or lambs during periods of peak risk.
However, preventing tick bites will also prevent the acquisition of immunity, so these animals will continue to be vulnerable once the protection offered by the acaricide wears off.
Another useful control measure is to source replacements within the herd, or at least locally, so that they will have been exposed to the range of tick-borne diseases that occur in that area.
Great care is needed when introducing animals from tick-free farms to areas where they will face a significant challenge, as these animals will have no immunity to tick-borne disease.
http://www.farmersjournal.ie/site/farming-Tick-borne-disease-on-Irish-farms-12922.html NB: link now broken but kept for informational purposes!
Vet Pathol. 2011 Apr 1. [Epub ahead of print]
Lyme Neuroborreliosis in 2 Horses.
Imai DM, Barr BC, Daft B, Bertone JJ, Feng S, Hodzic E, Johnston JM, Olsen KJ, Barthold SW.
Lyme neuroborreliosis-characterized as chronic, necrosuppurative to nonsuppurative, perivascular to diffuse meningoradiculoneuritis-was diagnosed in 2 horses with progressive neurologic disease. In 1 horse, Borrelia burgdorferi sensu stricto was identified by polymerase chain reaction amplification of B burgdorferi sensu stricto-specific gene targets (ospA, ospC, flaB, dbpA, arp). Highest spirochetal burdens were in tissues with inflammation, including spinal cord, muscle, and joint capsule. Sequence analysis of ospA, ospC, and flaB revealed 99.9% sequence identity to the respective genes in B burgdorferi strain 297, an isolate from a human case of neuroborreliosis. In both horses, spirochetes were visualized in affected tissues with Steiner silver impregnation and by immunohistochemistry, predominantly within the dense collagenous tissue of the dura mater and leptomeninges.
PMID: 21285382 [PubMed – as supplied by publisher]
Canine Lyme Disease and Seizures
Canine Lyme disease can be a serious medical condition. Lyme disease is spread to humans and animals by the bite of a deer tick. Once infected with Lyme disease, your dog may suffer from a number of symptoms. If Lyme disease is not treated, these symptoms can progress to serious neurological disorders..