Lyme Disease

Dear Dr. Jody:  I heard on the news yesterday that we now have Lyme disease in Alberta.  I do a lot of hiking and camping with my Sheltie, “Poncho”.  How can I protect him against Lyme disease, and should I worry about catching Lyme disease from him?

Lyme disease, also called Lyme borreliosis, was named after the town of Lyme, Connecticut, following its discovery there in 1975.  The condition is caused by bacteria called Borrelia burgdorferi, and is a vector-borne illness, meaning it is transmitted by insects or arthropods.  Hard-bodied ticks of the genus Ixodes are the primary vectors of Lyme disease.  Although Alberta has more than its fair share of tick species, until about five years ago Ixodes ticks were not known to inhabit this province.  For this reason, Lyme disease is much more common along the eastern seaboard of the United States where the Ixodes ticks are populous.

Alberta veterinarians who remove ticks from domestic animals are encouraged to submit them to the Government of Alberta.  This free service is provided by Alberta Agriculture as a means of monitoring the populations of tick species in this province.  It is through this surveillance that officials were able to quickly detect the movement of this particular tick into the province a few years ago.  A press release issued by the Government of Alberta on July 19, 2011 states that so far this year, five ticks have tested positive for Borrelia burgdorferi.  These five ticks were found on dogs and cats in the Calgary and Edmonton areas. 

A tick must attach to your pet and feed for at least 24 hours (some sources say at least 50 hours) for the disease to be transmitted.  Many ticks are still able to attach to your pet despite the use of tick repellent products, but most ticks are not able to stay on your treated pet for the length of time it takes to transmit the disease.  For this reason, most tick repellent products are effective at preventing the spread of the disease, even if a tick does hitch a ride on your dog for a short time.

Ticks that carry Lyme disease normally attach and feed in the summer months from May to August, and may even attach up until the late fall.  Pet owners who are concerned about Lyme disease are encouraged to use tick repellent products available from their veterinarians throughout spring, summer, and fall.  It is also prudent to inspect your dog for the presence of ticks following time spent outdoors in tall grass or in forested areas.  Ticks that have attached to your pet can be removed by grasping the tick firmly with tweezers as close as possible to the dog’s skin.  Pull back very slowly and steadily to maximize your chance of getting the tick out in one piece.  Avoid squishing the attached tick as this may inject the bacteria into your pet.  Your veterinarian can submit the tick to Alberta Agriculture to have it identified and tested for Lyme disease.  This is a free service at most veterinary clinics.

Weeks to months after exposure, dogs infected with Lyme disease manifest a variety of symptoms ranging from acute lameness and polyarthritis to fever, lethargy, and other non-specific signs.  Rarely, the kidneys, nervous system, skin, or heart can be affected. 

Diagnosis of Lyme disease can be challenging.  If your veterinarian suspects the illness in your pet, he or she may run bloodwork to try to detect the presence of anti-Lyme antibodies in your dog.  The presence of these antibodies does not confirm that your dog is currently suffering from Lyme disease, but it does show that your dog has been exposed to the illness at some point.  Based on the results of this test, your veterinarian may choose to treat your pet for Lyme disease with antibiotics. 

Fortunately, antibiotics are typically very effective at treating the disease.  Within 24-48 hours of the start of antibiotic treatment, affected dogs will begin to show improvement in their symptoms.  Occasionally, symptoms can recur weeks or months after the disease is treated.  The earlier the illness is detected and treated, the greater the chances that the pet can be cured without any long term effects.  The disease is not well-studied in cats. 

There is a vaccine against Lyme disease.  Because the illness is so new in Alberta, not all veterinary clinics carry this vaccine.  And because the likelihood of your pet becoming infected with Lyme disease is still extremely low, you may not need to vaccinate your pet.  To help determine whether your pet is at increased risk for Lyme disease, please discuss your pet’s lifestyle with your veterinarian.

You cannot catch Lyme disease directly from your pet; however, you can catch Lyme disease from tick bites.  For more information on Lyme disease in people, visit www.myhealth.alberta.ca.