Positive Lyme test without symptoms

Q: Barney, my 5-year-old terrier mix, tested positive for Lyme disease. He has never been sick, and his physical exam and the rest of his lab work (blood and urine) were normal.

My veterinarian recommends we start Barney on a tick preventive and have him vaccinated against Lyme, but she says he doesn’t need an antibiotic. Am I wrong to want him to have an antibiotic?

A: The blood test for Lyme disease measures antibodies to Lyme bacteria. A positive test indicates Barney was exposed and that he mounted an immune response by producing antibodies, but it doesn’t mean he has Lyme disease.

Lyme disease is characterized by a sudden onset of lameness that shifts from one leg to another, loss of energy and loss of appetite. A dog with Lyme disease usually has a fever and may lose protein through the kidneys.

For these dogs, an antibiotic such as doxycycline is warranted. In dogs that have been exposed but are not sick, an antibiotic may do more harm than good. However, tick prevention is recommended to decrease exposure in the future.

To guide veterinarians in making treatment decisions for dogs like Barney, Lyme disease experts examined all relevant research and last year updated the American College of Veterinary Internal Medicine’s Lyme consensus statement.

Editor’s Note: Lyme disease prevention month in May is a great time for a refresher on prevention. Here are five facts about Lyme disease in dogs you may not know.

Lee Pickett, V.M.D. practices companion animal medicine. Contact her at askdrlee@insurefigo.com.