Our two dogs just had their annual exams with our new vet. One was not previously vaccinated against Lyme Disease by the vet we used before. We live in Metrowest Boston and there are plenty of ticks around, even in our yard. Despite using flea and tick control, I have pulled several dead ticks off both dogs.
The new vet suggested we start vaccinating the unvaccinated dog against Lyme and we did. A booster is due in three weeks. Also, as part of their annual exams, shots and heartworm tests, the younger dog did test positive for Lyme Disease with a 4DX test.
The vet suggested that we had two choices of an additional specific objective test or we could start an antibiotic called Doxycycline. What should we do? E.Y.
Dear E.Y.,
I have no idea why your previous veterinarian would not have suggested vaccinating your second dog against Lyme Disease, especially given the prevalence of Lyme in the area.
Lyme Disease in dogs can cause shifting leg lameness as well as other far more serious problems such as Lyme nephropathy which ends up with destruction of kidney function leading to death.
The 4DX test that veterinarians do for dogs annually tests for heartworm, Lyme, Ehrlichia, and Anaplasmosis. The latter three are carried by ticks. Testing positive, as your dog did, does not necessarily mean that treatment is called for. It simply means that the dog has been exposed to the active Lyme bacterium called borrelia burgdorferi but is not necessarily actively infected.
If a dog is asymptomatic, some veterinarians choose not to treat, others do. Some do additional testing such as the quantitative C6 test which when the result is over a certain number (30), then most treat. Other follow up tests include checking for protein in the urine or urine protein:creatinine ratio. There is little harm to using a course of antibiotics and I usually err on the side of caution prescribing doxycycline at 5 mg/kg twice daily for 28 days.