Cats and dogs can become infected with Borrelia burgdorferi, a type of bacteria that is transmitted by ticks without ever developing symptoms of Lyme disease. Where Lyme disease is common, cats may test positive for exposure to the bacteria despite not showing any signs of disease.
Transmission of Lyme Disease
Ticks become infected with the bacteria by feeding on infected mice and other small animals. When an infected tick bites other animals, it can transmit the bacteria to these animals. Lyme disease is transmitted by the deer tick (blacklegged tick) and a group of other closely related ticks, the exact species varying by location. The deer tick is a small tick and may bite animals and people without being easily detected.
Cats that spend a lot of time outdoors, in areas with bush or tall grass are most at risk of being infected with Lyme disease.
However, it is important to remember that ticks can be carried into yards on other animals, so even cats that don’t roam far could potentially be bitten by a tick (and if you have dogs, ticks can hitch a ride into the home on the dogs). There is currently no evidence that Lyme disease is spread by direct contact between animals, including between infected pets and their owners.
Symptoms may include:
- limp (may shift from leg to leg)
- stiffness, pain
- decreased appetite
Because so many cats do not develop symptoms after infection with B. burgdorferi, the diagnosis of Lyme disease must be made on a combination of factors, including history (especially exposure to ticks), clinical signs, finding antibodies to B. burgdorferi bacteria, and a quick response to treatment with antibiotics. An antibody test is not enough to make a diagnosis on its own because not all cats that are exposed to B. burgdorferi get sick, and the antibodies can persist in the blood for a long time after exposure.
Another diagnostic test such as blood tests, urine tests, x-rays, and sampling of joint fluid, may be done as well to check for more serious effects of Lyme disease such as kidney disease and to rule out other conditions that can cause similar signs and symptoms.
Treating Lyme Disease
Treatment with antibiotics usually produces a rapid improvement in symptoms. If there are more serious issues that might be secondary to Lyme disease, such as kidney disease, a longer course of antibiotics along with additional medications is usually necessary.
Prevention of Lyme Disease
Tick control is extremely important for the prevention of Lyme disease (and other diseases that can be transmitted by ticks).
Check outdoor cats daily for ticks and remove them as soon as possible, since ticks must feed for at least 12 hours (possibly 24-48 hours) before transmitting the bacteria causing Lyme disease. Be careful handling ticks, as they are potentially infective to people, too.
Products that kill ticks can be used; be sure to follow your veterinarian’s advice when using these products. Keep grass and brush trimmed in your yard, and in areas where ticks are a serious problem, you can also consider treating the yard for ticks.
If your pet is showing any signs of continuous illness, please consult a veterinarian as quickly as possible.