Protecting Your Dog against Lyme Disease

By Dr. Kim Everson, DVM

 

As I sit writing this column on a below-zero February day, deer ticks and Lyme disease may not seem a timely topic. However, every day in practice I encounter misinformation about ticks and the diseases they spread, the most prevalent falsehoods relating to tick “season” and risks to the average pet. As Wisconsinites we like to believe that our reward for months of wind chill and drab landscapes is protection against the creepy crawlies commonplace in warmer climates.  This may be true in many ways, but not when it comes to ticks.

Tick season in Wisconsin is basically whenever there is no snow cover – even when it is cold! In fact, many dogs are exposed to Lyme disease in the late fall (November and December) or early spring when we let our guard down and have either discontinued or have not resumed our flea and tick preventatives. At these times of year, we humans are so bundled up we do not see ticks on ourselves, but our dogs are exposed as they wander through fields, marshes and woods. Deer ticks—the type of tick known to transmit Borrelia burgdorferi bacteria that causes Lyme disease—are teeny and not easy to spot. By the time you might notice a deer tick, it has become plumped up with its blood meal and has already transmitted the Borrelia bacteria to your dog.

Dogs that have been bitten by a Borrelia-infected deer tick will test positive as soon as two to five weeks later on a simple blood test run in the veterinary clinic. Once a dog has been exposed to Borrelia it is considered “infected” but it may not develop clinical Lyme disease. A variety of protocols exist for how to handle a dog that tests positive for exposure to B. burgdorferi. Additional bloodwork or urine tests may be ordered, especially if the dog is acting sick. Many veterinarians including myself will prescribe antibiotic treatment for any dog with a positive test result, because removing as many bacteria as possible from the dog’s bloodstream is beneficial long term.

How serious is Lyme disease in dogs? Most dogs infected by B. burgdorferi do not go on to develop Lyme disease. Dogs that do become ill typically have a high fever, severe lameness that shifts from one limb to another and flu-like symptoms. In rare cases, the bacteria invades a dog’s kidneys, an often fatal complication. If caught early, dogs with Lyme disease usually respond quickly to simple antibiotic therapy. Unfortunately, the bacteria may “hide out” in joints, kidneys and other tissues and cause recurrent illness later in life.

Fortunately for dogs, there are highly effective vaccines available to prevent Lyme infection. Which dogs should receive the vaccine? I believe every Wisconsin dog is at risk for exposure to disease-carrying deer ticks, but farm dogs, hunting dogs and those that spend time camping or hiking are at particular risk. Any dog that has tested positive for Borrelia or other tick-borne bacteria or has had ticks removed is an excellent candidate for Lyme vaccination. Previous natural exposure to Borrelia is NOT protective against future re-infection.

Lyme vaccination in dogs requires two injections several weeks apart initially, then annual boosters long term. Because it takes at least two months for the dog’s immune system to develop protective antibodies against potential future infection, vaccination is not immediately protective. Therefore, even though Wisconsin is buried in snow and frigid winds are blasting, now is the perfect time to start protecting your dog against Lyme disease.

 

Originally printed in farm news column, Fond du Lac Reporter, February 22, 2015