The past few years have seen an increase in cases of Lyme Disease in Minnesota, and we have had a number of dogs test positive at our clinic over the past year.  Veterinarians are still learning how Lyme disease affects dogs and the best steps for prevention and treatment.

Symptoms: Lyme disease is caused by a spiral-shaped bacteria called Borrelia burgdorferi.  These bacteria are passed from wild animals to people and dogs by deer tick bites.  In 80% of people bitten by an infected tick, a rash, fever and flu-like signs develop within several days.  Many of these people go on to have long-term joint pain, with some developing even neurological or cardiac abnormalities.  Unlike people, dogs seem to be quite resistant to the effects of Borrelia infection and only 5-10% of dogs infected go on to develop disease.  Disease generally includes joint pain, fever and swollen lymph nodes weeks to months after infection.  The most serious long-term effect is kidney disease in a small percentage of dogs.

Testing: There is a new very accurate blood test that tells us if a dog has been infected with Borrelia bacteria.  While most infected dogs do not go on to develop disease, knowing if a dog has been exposed gives us information about the prevalence of the bacteria and deer ticks in our local area.  In dogs with joint pain this is an important test to determine appropriate treatment.  Beginning next spring our standard heartworm test will also include a test for Lyme disease and Ehrlichiosis (another tick-borne disease of dogs).

Treating: For dogs that test positive for Lyme disease, we recommend antibiotic therapy for 3 weeks.  If the dog is actually showing signs such as joint pain and fever, improvement is seen within a few days.  The Borrelia bacteria are very good at hiding in the body, however, and dogs may be infected for years, even after treatment, without any symptoms of the disease.  Because dogs with "silent" infections may go on to develop kidney disease years after infection, annual screening for protein in the urine is recommended for dogs with positive Lyme tests.  Early detection of abnormal protein in the urine lets us make dietary changes which can help keep the kidneys healthy as long as possible.

Prevention: The first mode of prevention is effective tick control.  Deer ticks are the size of a pin head, so most owners don't find the ticks on their dogs.  The tick must be attached to the dog for 48 hours to transmit the bacteria.  Fortunately there are several flea/tick control products available, such as Frontline topical liquid, that kill the tick or cause it to drop off the dog before infection can occur.  In general, flea and tick collars are minimally effective in preventing tick attachment.  Another mode of prevention is annual Lyme vaccination.  The current protocol at our clinic is to vaccinate dogs that will be traveling to areas with high incidence of Lyme disease.  Vaccination should be discussed with your veterinarian.  For more Lyme disease information, please visit here.