Active dogs can have a range of issues with their joints and bones, and if yours is experiencing pain or discomfort it can often show up as skipping or hopping, particularly in the hind legs. 

One or both legs can be affected, and in the case of both legs, the dog might bunny hop for a time. 

The most common cause of this strange behaviour is a slipping or dislocating of the patella, or kneecap, best known as a luxating patella, or patella luxation. 

Patella Luxation 

Patella luxation describes a condition where the patella is unstable and becomes displaced, usually to the inside of the knee, known as medial patella luxation, but occasionally to the outside, known as lateral patella luxation. 

Dog knees are very similar to human knees but on a smaller scale, and the patella sits over and in front of the knee joint and slides up and down in a groove on the lower end of the femur. 

When the groove is too shallow to hold the kneecap, instability occurs, and the kneecap can slide out of place. 

Patella luxation most often affects small breeds of dog such as poodles, chihuahuas and other toy breeds, but it can occasionally affect bigger breeds. 

What Causes Patella Luxation? 

There are various causes of patella luxation but the main cause in small dogs is congenital, often due to the breeding process that has changed their anatomy over time to produce the cute, pocket-sized dogs that people love so much. 

Trauma can also be a cause, particularly if your dog is a bigger breed and not typically predisposed to patella luxation. 

Different Grades of Patella Luxation 

Some dogs can be more affected by patella luxation than others and the condition is divided into four grades from mild to severe: 

  • Grade 1 – the patella occasionally slips out of place but quickly slips back into place by itself 
  • Grade 2 – the patella is displaced more often but still returns to the correct position by itself 
  • Grade 3 – The patella slips often and stays that way, usually until it is manually moved back into place 
  • Grade 4 – the patella has moved out of place and cannot be manually moved back.  

Grades 2, 3 and 4 produce varying degrees of lameness. 

Treating Patella Luxation in Dogs 

It’s the sliding around of the dog’s patella that makes the dog skip, limp, hold the affected leg up, or shake, and it tends to get worse as the dog ages. 

Dogs suffering from any grade of patella luxation other than grade one will most often require specialist surgery to repair the knee. 

Sydney Animal Hospital and Specialist Vet 

Sydney Vet Specialists is dedicated to providing quality 24 hour veterinary care for your pets, as well as specialist services for a wide range of conditions. 

To speak to one of caring, professional team members, call us on 02 9197 5800, or contact us online 

Book an appointment for your pet between Monday and Friday 8:30am-6pm or call us for emergency veterinarian services and after hours care.