Limping in our companion animals can be caused by many different things. Trauma and overexertion are probably involved in the vast majority of cases. The possibility of genetic diseases including knee ligament tears, patella knee ligament luxation, as well as hip dysplasia need to be evaluated by a veterinarian. With foreleg lameness, genetic conditions of the elbow, shoulder and long bones may be involved in puppies under 18 months of age. However, in certain older pets, degenerative joint disease, autoimmune arthritis, and infectious arthritis such as those carried by ticks (i.e lyme, ehrlichia, rocky mountain spotted fever) may play a role. Traumatic fractures will also lead to clinical signs of limping. Pets with spinal cord disease, especially disc disease anywhere along the spine, may show signs of leg lameness, stiffness, or weakness. In middle aged and older pets, especially in large breeds, bone cancer also needs to be ruled out in those cases of chronic lameness.
Limping may cause varying degrees of pain, as well as fever in severe cases. Pets with infectious causes of limping, such as tick-borne diseases, may suffer from various blood disorders and problems in the bone marrow, including low red blood cell counts and low platelet counts. This may result in bleeding, weakness and shock. Lyme disease may lead to problems in the brain, heart or kidneys. One-sided limping may result in problems in other limbs as a result of a shift in weight bearing, as well as problems with the spinal cord.