Major force is necessary to rupture a joint and displace the bones. Such
injuries usually are the result of falls, fights with other animals, or car
accidents. The cat may also be in shock and
have internal bleeding from injured organs. Signs of dislocation are sudden
pain with the inability to bear weight on the limb. There is an observable
shortening of the limb when compared with the opposite side.
The hip is the most commonly dislocated joint in the cat. It
can be recognized by signs of pain on movement of the hip, a gritty sensation,
and shortening of the leg by about 1 inch (25 mm). Other joints less frequently
dislocated are the patella (kneecap), hock, and jaw. A dislocated kneecap
occurs with some frequency in the Devon Rex; the breed has a hereditary
predisposition. It is also seen in Maine Coon Cats.
Toxoplasmosis is a disease caused by the parasite Toxoplasma gondii, which can be found in garden soil and raw meat. Cats can get toxoplasma infection by killing and eating infected prey. The disease can also be passed on from cats to humans.
In this cat with a dislocated hip joint, the affected right leg is shorter
than the left one.
Treatment: Veterinary examination is necessary to rule out an associated
fracture and to replace the joint in its socket. Treating other injuries may
take precedence, because a dislocated joint is not life threatening. Replacing
a joint in its socket often requires sedation or anesthesia, and the cat may
need to wear a splint or wrap to hold the joint in place for a short time while
the damaged tissues heal. If a joint has been dislocated for a long time,
surgery may be required to replace it or, in extreme cases, the involved joint
may need to be removed; for example, in some hip dislocations the femoral head
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"