Lyme disease is pretty rare in cats but when it does happen it can be devastating. As many cats do not venture into the great outdoors, it is much less likely that you’ll encounter feline borreliosis than that your dog will pick up a tick and become infected. However, even indoor cats can end up with Lyme disease if you, your kids, or the family dog brings an infected tick into the house which then drops off and goes on to bite your cat.
Of course, cats are stoic animals, for the most part, and so it can be hard to tell that they’re sick until they’re very sick indeed. Many cats don’t show any symptoms of Lyme disease, while others develop a shifting lameness in their legs. This is due to inflammation in the joints, and the lameness may come and go, lasting around three or four days and then recurring weeks later in the same leg or a different leg.
Typically, a cat with Lyme disease and lameness will have swollen joints that are warm to the touch and painful. It can, therefore, be tricky to assess a cat with Lyme disease as they will not want their limbs to be touched. Fortunately, most cats with Lyme disease are able to be successfully treated with a short course of antibiotics.
Feline Borreliosis Symptoms
Other potential symptoms of Lyme disease in cats include:
- Lack of appetite
- Lethargy and depression
- Stiffness and walking with an arched back
- Sensitivity to being touched, especially on the legs
- Breathing issues
- Fever and swollen lymph nodes (often near the tick bite)
- Atrioventricular heart block or carditis
- Neuroborreliosis (leading to dementia-like behaviour)
Serious Effects of Lyme Disease in Cats
Cccasionally kidney conditions can arise in cats with Lyme disease, and in rare cases cats may develop heart problems or nervous system disorders. Unfortunately, few people think to get their cat tested for Lyme disease, especially if the cat rarely ventures outdoors. This can mean that a cat continues to suffer with a suspected kidney issue or feline dementia that is entirely treatable.
Where kidney problems do develop as a consequence of Lyme disease this may lead to glomerulonephritis, if left untreated. This condition involves inflammation and dysfunction of the kidney’s glomeruli, i.e. the filtration system that determines what substances stay in the body and which are eliminated in the urine. If the condition persists then kidney failure will eventually occur and the cat will show symptoms such as vomiting, diarrhea, lack of appetite and weight loss, increased urine output, increased thirst, and oedema (fluid build-up) in the belly, under the skin and in the legs.
Risk and Prevalence of Feline Lyme Disease
Lyme disease in cats can be fatal, especially as it can easily go unrecognised and, therefore, untreated until serious heart or kidney issues develop. Although rare and generally confined to the northeastern states of the US and Canada, Lyme disease has occurred in every US state and no cat is immune to infection, with no feline Lyme disease vaccine available. A cat-safe tick repellent can be used before kitty heads outdoors, however, but it is important not to simply use any old tick repellent as cats can be extremely sensitive to these products and may end up sicker than if they did get infected with treatable Lyme disease.
Checking for Ticks
Many cats who spend the winter indoors enjoy a little yard time in spring, summer and fall and a roll in the grass is all it takes to pick up a tick carrying the Lyme disease bacteria. Ticks are also more active during warmer weather, and like to climb up to the top of tall grasses and wait for passing animals to transfer to their fur and burrow in to feed. Grooming a cat after they’ve been outside is the best way to check for ticks, which should be removed immediately using the procedure outlined in this video.
Diagnosing Cats with Lyme Disease
If in doubt, it is best to take the cat to the vet to have a tick removed safely. In general ticks attached for less than 18 hours will not have had a chance to transmit Lyme disease bacteria to a cat, although ticks also carry other infectious organisms that can cause diseases in cats. Ensuring a full account of your cats whereabouts and activities outdoors can help your veterinarian assess their risk of Lyme disease and other illnesses, and cats suspected of having Lyme disease will have a blood test to check for infection. Swollen joints may also be tested to see if the synovial fluid is infeted.
Some cats that develop swollen joints do so because of osteoarthritis or immune-mediated arthritis, for which the treatment would be significantly different to that for Lyme arthritis in cats.