Patellar Luxation in the
Cavalier King Charles Spaniel

Cavalier King Charles spaniels may suffer from a recurring hereditary condition which causes luxating patellas. The disorder is believed to affect as many as 20% of cavaliers. The patella is the dog's knee cap. It should be located in its groove in the center of the stifle (knee joint) of the femur (upper leg bone). A luxating patella is a knee cap that moves out of its groove. Genetic conditions which cause patellar luxation are a shallow groove, weak ligaments, and misalignment of the muscles and ligaments between the femur, patella, and tibia (lower leg bone).

If the condition is not corrected, it will degenerate: the patella's ridges will wear, its groove will become shallower, and the cavalier will become progressively more lame. Arthritis will prematurely affect the joint, causing a permanently swollen knee with poor mobility.


Symptoms & Diagnosis

Veterinarians can check for patellar luxation by manipulating it. The dog is examined awake and the veterinarian classifies its degree of luxation. Adult cavaliers should be evaluated annually, and puppies should be examined at 6-8 weeks of age prior to their release to the new owners.

The Orthopedic Foundation for Animals (OFA) has a diagnosis protocol and registration for examining dogs for patellar luxation.

Grades of Patellar Luxation



-- medications

Dogs with milder grades of luxation often are prescribed non-steroidal anti-inflammatory drugs (NSAIDs), such as such as carprofen (Rimadyl), meloxicam (Metacam), firocoxib (Previcox), mavacoxib (Trocoxil), and aspirin to relieve the pain but not any but not the deterioration.

-- surgery

Veterinary orthopedic surgery usually is required to correct more severe stages of the condition, such as Patella SurgeryGrade 3 or 4. The groove may be surgically deepened to better contain the patella. The patella itself may be tied down laterally (on its outside), to prevent it from deviating medially (toward the inside). The bony protuberance at the point the quadriceps tendon attaches to the tibia may be cut off and then re-attached in a more lateral position.

Recovery from patella surgery includes a lot of downtime, resting in a crate, with very limited physical activity, for as long as the surgeon recommends.

Water Therapy-- alternative therapies

In some cases, non-traditional therapies such as holistic healing or homeopathy, including acupuncture, and joint supplements such as Glyco-Flex II by VetriScience, may be useful alternatives to conventional medicine and surgery. Some physical therapy, such as hydrotherapy (swimming) (right), may also be prescribed. Dogs with patellar luxation should not be over-weight.


Canine Patella DiagramBreeders' Responsibilities

The Canine Inherited Disorders Database recommends that any dogs with patellar luxation not be bred, nor should their parents or littermates. Because of the strong hereditary relationship, all cavalier King Charles spaniel breeding stock should be examined by qualified veterinarians at least annually and cleared for patellar luxation, the closer the examination to the breeding the better.

The Cavalier King Charles Spaniel Club, USA (CKCSC,USA) recommends that, prior to breeding any cavalier, the dog have no evidence of patellar luxation from an evaluation by a licensed veterinarian.  The American Cavalier King Charles Spaniel Club (ACKCSC) states that "Cavaliers used for breeding should have within normal limits patellas as determined by an OFA examination at age one. The patellas should be reevaluated as the Cavalier ages."

The Canine Health Information Center (CHIC) is a centralized canine health database sponsored by the AKC/Canine Health Foundation (AKC/CHF) and OFA. The CHIC, working with participating parent clubs, provides a resource for breeders and owners of purebred dogs to research and maintain information on the health issues prevalent in specific breeds.

AKC's national breed clubs establish the breed specific testing protocols. Dogs complying with the breed specific testing requirements are issued CHIC numbers. The ACKCSC requires that, to qualify for CHIC certification, cavaliers must be screened for patellar luxation (OFA).


Related Links


Veterinary Resources

Control of Canine Genetic Diseases.  Padgett, G.A., Howell Book House 1998, pp. 198-199, 246.

Guide to Congenital and Heritable Disorders in Dogs.  Dodds WJ, Hall S, Inks K, A.V.A.R., Jan 2004, Section II(235).

Complications Associated with Corrective Surgery for Patellar Luxation in 109 Dogs. Gareth I. Arthurs and Sorrel J. Langley-Hobbs. Vet. Surg. Aug 2006; 35:559.

Patellar luxation. Greg Harasen. Can Vet J. 2006 August; 47(8): 817–818. Quote: "Congenital luxation of the patella represents one of the most common orthopedic conditions in small animal practice. Medial luxations account for 75% to 80% of cases in all breeds. The majority of patients are small breed dogs including ... cavalier King Charles spaniels. ... The overwhelming majority of patellar luxation are congenital and certainly hereditary, although a mode of inheritance has not been described."

Breed Predispositions to Disease in Dogs & Cats (2d Ed.). Alex Gough, Alison Thomas. 2010; Blackwell Publ. 52.

Genetic Connection: A Guide to Health Problems in Purebred Dogs, Second Edition. Lowell Ackerman. July 2011; AAHA Press; pg 134. Quote: "Table 9.10 -- Breeds at Risk for Patellar Luxation on the Basis of a Large-Scale Epidemiologic Study: ... 8. Cavalier King Charles spaniel -- odds ratio 9.1."