Tick-Borne Disease in Dogs ( Dr. Danowitz)

In our area of New  Jersey ticks are a concern, both for humans as well as animals.  Of the many diseases that ticks carry, several are transmissible to both species.  Although very small and seemingly fragile, ticks are actually tremendously hardy parasites, capable of surviving through a wide range of climate conditions.  This is one of the reasons that OCVH, FVH & NPVH advocate treating our pets with a flea/tick preventative all year round in our area.

To learn about the tick life cycle, please click here:

http://www.youtube.com/watch?v=0g_lt0FcQag

Of all the diseases that ticks can transmit to dogs, four are most prevalent:  Lyme Disease, Ehrlichiosis, Anaplasmosis and Rocky Mountain Spotted Fever. We have seen cases of all 4 of these conditions at OCVH and our family of practices over the past year, so they are present in our area!

 

LYME DISEASE

Lyme Disease is one of the most common tick-transmitted diseases in the world.  It is caused by microscopic bacteria called spirochetes, which ticks ingest when feeding on wildlife or other dogs that are infected with the spirochete. The tick then spreads the infection to another animal when it bites them looking for its next blood meal. The species of tick that transmits Lyme Disease is Ixodes Scapularis (Deer Tick).

 

Despite all the research into Lyme Disease in both human and veterinary medicine, there are many aspects of the disease that still remain a mystery.  Dogs that are exposed to Lyme Disease can exhibit a variety of clinical signs, ranging from no signs at all to an irreparable kidney failure and death. The most common clinical signs are joint inflammation leading to lameness, fever, and lethargy or depression.  Many dogs test positive for Lyme Disease and never develop clinical signs of the disease. Kidney disease secondary to Lyme Disease seems to be more prevalent in Labrador Retrievers, Golden Retrievers and Burmese Mountain Dogs.

How is it diagnosed?  There are several blood tests that can detect Lyme Disease.  Our heartworm test, called an Accuplex, also screens for exposure to Lyme Disease as well as 2 other tick-borne diseases.  Often if your dog is diagnosed with Lyme Disease the veterinarian may recommend a urine sample to make sure the kidneys are not affected, as well as, other more specific blood tests.  Test results, in combination with any clinical signs that the dog has, is considered before initiating treatment.  The treatment for Lyme Disease is a long course of an antibiotic, typically either doxycycline or amoxicillin.

In some patients it is impossible eradicate the organism from the body no matter what antibiotic is used. Therefore, even with appropriate treatment, the signs of disease may flare-up again in the future.

 

EHRLICHIOSIS

Ehrlichiosis is another bacterial organism transmitted to dogs through a tick bite.  The Brown Dog Tick (Rhipicephalus), the Lone Star Tick (Amblyomma) and the American Dog Tick (Dermacentor) have all been linked to the transmission of this disease.

Clinical signs associated with Ehrlichiosis vary greatly, but can include fever, loss of appetite, weight loss, enlarged lymph nodes, eye and nasal discharge, lethargy, difficulty breathing and swollen limbs.  The disease can progress to the nervous system, causing muscle twitching and other neurologic problems. Long term, blood platelet levels (cells that assist with clotting) may drop to dangerously low level and become life-threatening without treatment. Diagnosis of Ehrlichiosis can be made with the Accuplex blood test, as well as other blood tests available at our laboratory.  Doxycyline for at least 4 weeks is the treatment of choice for this serious disease.

 

ANAPLASMOSIS

Anasplamosis is another type of bacterial disease transmitted by ticks, including both the Brown Dog Tick (Rhipicephalus) and the Deer Tick (Ixodes).  In general, Anaplasmosis causes milder clinical signs when compared to Lyme Disease or Ehrlichiosis.  Clinical signs can include: fever, depression, weakness, lameness, reluctance to move, loss of appetite, enlarged lymph nodes and enlarged spleen. Anaplasmosis can also lead to low platelet numbers, much like Ehrlichiosis.  Diagnosis can be made with the Accuplex blood test. The treatment of choice for animals showing clinical disease is doxycycline, although often this disease is self-limiting and some animals never progress to the clinical state of needing treatment.

 

ROCKY MOUNTAIN SPOTTED FEVER

Rocky Mountain Spotted Fever (RMSF) is a potentially fatal disease of both dogs and humans due to an intracellular bacterium called Rickettsia. It is transmitted by the American Dog Tick (Dermacentor), the Brown Dog Tick (Rhipicephalus) and the Lone Star Tick (Amblyomma).  In humans, RMSF is often associated with a rash from the tick bite; however, in dogs a rash is much less common.  Clinical signs of infected dogs include: fever, loss of appetite, lethargy, reluctance to move, stiffness or swelling of joints, enlarged lymph nodes and neurological signs.  Destruction of platelets can lead to bleeding and severe inflammations of blood vessels.  In some dogs the disease is self-limiting, while in others it can become a fatal condition. Diagnosis of RMSF is through a special blood test. The treatment of choice once again for this disease is doxycycline.

 

PROTECTION FROM TICKS AND THEIR DISEASES

So how can we protect our furry companions from these diseases?  There are 2 main ways: vaccination and topical preventative.  The only tick-borne disease that we have a vaccination for is Lyme Disease. The Lyme vaccine that is available, although not 100% effective in preventing the disease in all dogs does dramatically reduce the chances of infection and can minimize the seriousness of Lyme Disease in a large majority of the pets that receive the vaccine before they are bitten by ticks carrying the Lyme bacteria.

We recommend the Lyme vaccination for all dogs in our area.

 

 

Topical tick preventative has become a cornerstone in our efforts to prevent the spread of

these four diseases.  Often these products are also designed to kill and / or prevent flea infestations as well.  Although there are several products on the market that kill ticks, the product preferred by the veterinarians at OCVH, FVH & NPVH for dogs is Vectra 3D.

Vectra 3D, in addition to killing fleas and ticks, has the extra bonus of repelling the ticks, making it less likely that they even attach to the dog.  Please see the video below:

http://www.youtube.com/watch?v=lmhth6fKtGQ

Protect your canine companion from these diseases by having them vaccinated annually against Lyme Disease and protecting them year-round from tick and flea infestations by using Vectra 3D.

 

William Danowitz DVM

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