Even though it is uncommon in cats, lyme disease is known to be one of the most common tick-transmitted diseases in the world. Caused by a bacteria spirochete species of the Borrelia burgdorferi group, its dominant clinical feature in cats is lameness due to inflammation of the joints, lack of appetite, and lethargy. Some cats develop kidney conditions, and rarely heart or nervous system diseases.
Symptoms and Types
Many cats with lyme disease do not exhibit any symptoms. Those that do may have recurrent lameness of the limbs due to inflammation of the joints. Others, meanwhile, may develop acute lameness, which lasts for only three to four days but recurs days to weeks later, with lameness in the same leg, or in other legs. Better known as “shifting-leg lameness,” this condition is characterized by lameness in one leg, with a return to normal function, and another leg is then involved; one or more joints may be swollen and warm; a pain response is elicited by feeling the joint; responds well to antibiotic treatment.
Some cats may also develop kidney problems. If left untreated, it may lead to glomerulonephritis, which causes inflammation and accompanying dysfunction of the kidney's glomeruli (essentially, a blood filter). Eventually, total kidney failure sets in and the cat begins to exhibit such signs as vomiting, diarrhea, lack of appetite, weight loss, increased urination and thirst, fluid buildup in the abdomen and fluid buildup in the tissues, especially the legs and under the skin.
Other symptoms associated with lyme disease include:
Stiff walk with an arched back
Sensitive to touch
Fever, lack of appetite, and depression may accompany inflammation of the joints
Superficial lymph nodes close to the site of the infecting tick bite may be swollen
Heart abnormalities are reported, but rare; they include complete heart block
Nervous system complications (rare)
Borrelia burgdorferi, which is the bacteria responsible for lyme disease, is transmitted by slow-feeding, hard-shelled deer ticks. However, infection typically occurs after the Borrelia-carrying tick has been attached to the cat for at least 18 hours.
You will need to give a thorough history of your cat's health, including a background history of symptoms, and possible incidents that might have precipitated this condition, such as the areas in which your cat might have been. The history you provide may give your veterinarian clues as to which organs are being affected secondarily. A complete blood profile will be conducted, including a chemical blood profile, a complete blood count, and a urinalysis. Your veterinarian will use these tests to look for the presence of bacteria, parasites, and fungi in the bloodstream. Fluid from the affected joints may also be drawn for analysis.
The condition of the skin near the tick-bite site will be an important indicator of your cat's health as well, such as whether the wound is still open, or whether there are any fragments of the tick's body left in the wound.
There are many causes for arthritis, and your veterinarian will focus on differentiating arthritis initiated by Lyme disease from other inflammatory arthritic disorders, such as trauma. Immune-mediated diseases will also be considered as a possible cause of the symptoms, and an x-ray of the painful joints will allow your doctor to examine the bones for damage or disorder.