Cats may limp on one leg for many reasons including foreign objects stuck in the paw that you can remove yourself. Other injuries correct themselves with rest and warm compresses while more serious injuries require a veterinary visit for diagnosis and treatment.
Examine your cat to obtain information on the cause of his limp. Have your kitty lie down and look at the affected limb starting from the paw and working your way up his leg to his torso. Gently look for signs of the area that is hurting him by rubbing your hand lightly over all areas of his paw, between his toes and up his leg. Your cat likely will wince or pull back from you when you find the affected area.
If your cat has long hair, you may need to trim the hair around his foot to examine it. Use a small pair of rounded tip scissors and trim the hair so it doesn't overlap his paw pad. If your cat won't sit still or you are uncomfortable trimming around his paws, take your cat to your vet. Remove any foreign objects from the paw pad or between the toes, such as a sticker or a bee stinger with a pair of tweezers. Watch the area for signs of infection including swelling, hot skin at the site of the foreign object removal, blood or pus. If the paw looks infected, take your cat to your veterinarian for antibiotic treatment.
Torn or Broken Toenails
Cats "sharpen" their claws on objects to remove the outer nail sheaths and reveal the smooth, sharp claws underneath them. A cat who suffers from a torn or broken toenail will limp. If your cat has a lateral tear from the tip of the claw extending upward or a break in a toenail that causes it to bleed, apply styptic powder to stop the bleeding and take your cat to your veterinarian. Severe tears and short breaks require your cat to be sedated and your veterinarian to trim the nail higher than the affected area. Your cat most likely will travel home with a cute new bandage on his foot and possibly antibiotics to prevent infection.
Soft Tissue Trauma
Sprains, strains and pulled muscles occur in cats from jarring the soft tissue. These injuries are all evident by a limping cat. If your cat winces when you touch a certain area of his leg, and is stiff, but exhibits no other signs of pain, he most likely has soft tissue trauma. Warm compresses and rest can heal these injuries with complete recovery in about two weeks. If the limp continues and does not vanish or diminish during this time, seek veterinary help.
If you cat has a severe limp, cannot bear weight on a foot or suffers distress and pain, seek immediate veterinary care. These can be signs of a broken bone, torn ligaments or dislocated joints that require medical care.