Lyme Disease – Protect Your Pet to Protect Yourself

Return to Article List

Q: My dog was recently diagnosed with Lyme Disease, after extensive x-rays and testing. What can you tell my about this disease?

A: Lyme Disease is caused by a bacterial organism called Borrelia burgdorferi. It was first documented in Old Lyme, Connecticut, thus the name, and it is still very prevalent in the Northeast. It is transmitted by ticks, and in this area the deer tick, Ixodes scapularis, is the primary host. Wildlife, such as deer, raccoons, and even birds, can act as natural reservoirs, and it has been documented to cause disease in humans, dogs, and, to a lesser extent, cats, cattle and horses.

Serological studies have shown that up to 50% of dogs in endemic areas have antibodies to B. burgdorferi, indicating exposure to the organism. A local study done in the early 1990’s showed that 73% of raccoons trapped in Shelby County, TN had antibodies to Lyme disease. Luckily, only 5-10% of infected dogs will develop clinical signs. The incubation period is two to five months from the time of infection to the onset of clinical signs.

In dogs, as in humans, the clinical symptoms of Lyme Disease (also known as borreliosis) can be very vague, but include joint pain (often in more than one joint), fever, malaise, and lymph node enlargement. In rarer circumstances, it can lead to kidney damage (Labrador and Golden Retrievers have been shown to have a breed predilection to this), and neurological and heart disease.

Diagnosis is best made by blood tests looking for antibodies to the organism, or for the organism itself. Dogs vaccinated for Lyme Disease may show a positive antibody titer from the vaccine, but a true positive can be determined using paired serology or a Western Blot test. PCR testing amplifies the DNA from the organism, and can often detect it in blood or joint fluid even if only very few organisms are present. Attempting to culture the organism is expensive and usually unrewarding. A negative test of any type never fully rules out the possibility of infection.

Borreliosis is best treated by tetracycline or beta-lactam antibiotics, such as doxycycline or amoxicillin. Due to the slow growth of this organism, a prolonged course of antibiotic therapy is recommended, usually 21-28 days. Most dogs will show clinical improvement in only one or two days after therapy is initiated, but it is important that they gat the full course of medication. Dogs that experience a relapse usually respond equally well to a second course of therapy.

Prevention is best accomplished through preventing tick exposure. Products such as Frontline and Preventic Collars work well in keeping ticks off of dogs. There are a lot of other products on the market that contain permethrins and organophosphate insecticides that work equally well, but the high instance of side effects from these products keeps me from recommending them when there are safer products available. Vaccinating your pet will also help prevent disease, should it be bitten by an infected tick. This option should be discussed with your veterinarian. Should you find a tick on your pet, remove it immediately, because it has to be on the animal for 24-48 hours before disease transmission can occur.

Keeping ticks off of your pet will help keep them out of your environment and away from yourself and your family.

For more information on Lyme Disease, contact one of the following organizations:

• The Lyme Disease Foundation – www.lyme.org
• The American Lyme Disease Foundation, Inc. – www.aldf.com/Lyme.asp
• The Lyme Disease Association, Inc. – www.lymediseaseassociation.org
• The Lyme Disease Network – www.lymenet.org

Return to Article List