Friday, May 16, 2008
What you should know about Lyme disease in dogs dogs
Lyme disease is caused by a spirochete bacteria called Borrelia burgdorferi which is transmitted by the bite of the deer tick, Ixodes scapularis. The deer tick lives on several different species throughout its life cycle, including the white-footed mouse and the white-tailed deer. Both larval and nymphal forms of the ticks (which are roughly the size of a sesame seed) and adult forms, which are larger, can transmit the disease if they feed on a host for 48 hours or more.
Knowing the Lyme status of your dog every year is important for the humans who live with your pet. Dogs are sentinels of disease. If your dog has been exposed, you and your children also have a chance of exposure.
Signs of Lyme disease in dogs
Over 90% of dogs who are not maintained on regular tick control are thought to have been exposed to Lyme disease in endemic areas such as Carlisle. Of those exposed, fewer than 10% will become ill. Lyme characteristically causes a fever; large, swollen and painful arthritic joints; and swollen lymph nodes. Unlike humans, no “target lesion” is described in the dog. The acute arthritis responds remarkably well and quickly to a 30-day course of antibiotics.
The new concern with Lyme disease is the potential for some dogs with a long-standing and untreated Lyme infection to develop Lyme Nephritis, a condition that results from the body’s fight against the Lyme bacteria. Numerous proteins called immunoglobulins form as part of the immune response and get stuck in the kidney filter, causing the kidneys to fail.
Most veterinarians will perform a yearly Lyme test. For dogs testing positive for Lyme, it is important to understand how much Lyme is circulating in the blood stream and if the kidneys are affected. This is accomplished with both blood and urine testing: a special blood test called a C6 quantitative test and a urinalysis. Once the appropriate tests have been made, your veterinarian can decide if treatment with an antibiotic called doxycycline is indicated.
Preventing Lyme disease
Lyme and other tick-borne diseases are easier to prevent than to treat. The best means of prevention in your dog is to remove any attached ticks every day. Once a tick is attached and feeding, it takes over 24 hours to transmit Lyme disease The importance of a daily tick check cannot be overestimated.
In addition to physically removing the ticks, regular tick control is extremely important in a Lyme-endemic area. Some of the tick-control options that are effective and veterinarian recommended include Frontline™, a Preventic collar, Canine Advantix™ , and Promeris®. These may be combined or used more frequently than the label instructs when instructed by your veterinarian.
Tick control for the environment
In addition to treating your dog, you may want to consider treating your environment. Ticks generally will not inhabit a lawn but are usually found in the woods. Environmental treatments are available from professional exterminators, but with well water and many local beekeepers, this is a concern for Carlisleans. Natural, garlic-based environmental treatments may help, and tick tubes are also a happy medium between effective chemical tick control and environmental friendliness. These are waterproof tubes containing cotton balls treated with permethrins. If you scatter the tubes around the perimeter of your property, the white-footed mouse will use them as nesting material. The permethrins in the cotton balls kill the ticks on the mouse and do not penetrate the ground water.
Dogs can be vaccinated annually against Lyme disease. The most recent recommendations suggest vaccine for both positive- and negative-testing dogs. It is about 80% effective.
Some helpful web sites
The science of infectious diseases is constantly changing and veterinarians are only beginning to fully understand the repercussions of Lyme disease in the dog. Further information is available at:
, Information on Lyme disease from the veterinary information network,
•American Lyme Disease Foundation,
•, life cycle. ∆
Dr. Rule is a Carlisle resident and a veterinarian at Countryside Animal Hospital in Chelmsford, located 11 minutes from Carlisle center.
© 2008 The Carlisle Mosquito