Effects of a Slipped Knee Cap
Patellar luxation is a common, mildly to severely painful condition in domestic dogs. Basically, the patella (kneecap) slips out of place for some reason, resulting in lameness, weakness and pain. It is most commonly seen in young miniature and toy breeds, although any age, gender or breed of dog can develop the disorder.
Symptoms of Patellar Luxation
Patellar luxation causes intermittent and chronic hind limb weakness, lameness and pain. The clinical signs of this condition can vary from dog to dog depending upon their pain tolerance and the severity of the displacement, but the symptoms typically include one or more of the following:
- Intermittent lameness, which may range from partial to complete non-weight-bearing lameness in one or in both hind legs
- Loss of range of motion in one or both hind legs
- Abnormal carriage of one or both hind legs
- Abnormal function of one or both hind legs
- Temporary paralysis of the stifle (knee) joint
- Pain when moving (or when the stifle joint is manipulated manually)
- Difficulty rising
- Reluctance to run or jump
- Swelling at or around the stifle
The signs seen by owners will vary depending on the severity of the patellar displacement, the amount of degenerative osteoarthritis involved, the particular dog’s pain tolerance level and the existence and extent of any other stifle abnormalities, such as cranial cruciate ligament rupture or tear. Some dogs develop an unusual “skipping” gait that waxes and wanes depending on the degree of pain they are experiencing.
Dogs At Increased Risk
All dogs are susceptible to patellar luxation. However, it is most frequently seen in young toy and miniature breeds - especially Poodles, Yorkshire Terriers, Pomeranians, Pekingese, Chihuahuas and Boston Terriers. Females are at a slightly higher risk of becoming affected than are males, although the reason for this is unclear.