Lyme Disease in Dogs

Lyme disease is a bacterial infection (Borrelia burgdorferi) named after Lyme, Connecticut, spread to dogs by deer tick bites. A tick must stay attached for 24 to 48 hours to transmit the bacteria, so prompt tick removal usually prevents infection. The good news: only about 5% of infected dogs ever show symptoms — most carry the bacteria without getting sick. When symptoms do appear, they show up weeks to months after the bite: shifting leg lameness, joint pain, fever, and lethargy, which usually respond quickly to antibiotics. Heart and neurologic problems are extremely rare in dogs. The most serious long-term concern is Lyme nephritis, a kidney disease that develops in a small number of infected dogs, which is why vets recommend screening urine for protein. Prevention centers on tick control: use a veterinary-recommended tick product that kills ticks before the 24–48 hour transmission window, check your dog after walks in grassy or wooded areas, and remove ticks promptly. Vaccines against Lyme exist in several forms and can prevent new infections, but whether to vaccinate depends on your dog's risk — discuss it with your vet. Call your vet if your dog limps, runs a fever, or seems lethargic after tick exposure, and ask about annual Lyme testing and tick prevention if you live in or visit tick country.