While the Orthopedic Foundation for Animals (OFA) continues to place most of its attention on hip dysplasia, today’s OFA mission, “To improve the health and well-beings of companion animals through a reduction in the incidence of genetic disease,” reflects the organization’s expansion into other inherited diseases.
OFA orthopedic evaluations take about one hour at Animal Health Services. Your pet may be given a mild sedative and will then proceed to our digital radiology department, where a doctor and technician will take radiographs of your pet’s relevant body parts. Once the radiographs are complete, we allow your pet to recover from the sedative until they are ready to walk out of the office.
Once the digital radiographs are taken and reviewed by OFA, we will notify you of the results within 14 to 21 business days.
Hip dysplasia is a terrible genetic disease because of the various degrees of arthritis (also called degenerative joint disease, arthrosis and osteoarthrosis) it can eventually produce, leading to pain and debilitation.
No one can predict when or even if a dysplastic dog will start showing clinical signs of lameness due to pain. There are multiple factors that can affect the severity of clinical signs and phenotypic expressions (radiographic changes), such as caloric intake, level of exercise and weather. However, radiographic changes won’t necessarily reflect changes to the dog’s pain levels. Many dysplastic dogs with severe arthritis still run, jump and play as if nothing is wrong, and some dogs with barely any arthritic radiographic changes are severely lame.
Elbow dysplasia is a general term used to identify an inherited polygenic disease in the elbow. Three specific etiologies make up this disease, and they can occur independently or in conjunction with one another.
These etiologies include:
- Pathology involving the medial coronoid of the ulna (FCP)
- Osteochondritis of the medial humeral condyle in the elbow joint (OCD)
- Ununited anconeal process (UAP)
Studies have shown the inherited polygenic traits causing these etiologies are independent of one another. Clinical signs involve lameness, which may remain subtle for long periods of time. No one can predict at what age lameness will occur in a dog due to a large number of genetic and environmental factors, like the degree and severity of changes, rate of weight gain and amount of exercise. Subtle changes in gait may be characterized by excessive inward deviation of the paw, which raises the outside of the paw so that it receives less weight and distributes more mechanical weight on the outside (lateral) aspect of the elbow joint, moving weight away from the lesions located on the inside of the joint. Range of motion in the elbow is also decreased.
While the exact mode of inheritance is unknown, osteochondrosis (OCD) is considered to be an inherited disease. Affected individuals show a disruption in ossification of the cartilage mold beneath the articular cartilage of the joint. This results in aseptic necrosis, and when the weakened area collapses, the articular cartilage fractures cause lameness.
OCD has been reported to occur in the shoulder, elbow, stifle, hock and spine and can be unilateral or bilateral. Most affected dogs that develop clinical signs are less than one year of age.
OCD is seen in many breeds, but it appears to be more common in breeds with larger body types. It is also seen more frequently in males than females.
The patella, or kneecap, is part of the stifle joint (knee). In patellar luxation, the kneecap luxates, or pops out of place, either in a medial or lateral position. Bilateral involvement is most common, but unilateral is not uncommon. Animals can be affected by the time they are 8 weeks of age.
The most notable finding is a knock-knee (genu valgum) stance. The patella is usually reducible, and laxity of the medial collateral ligament may be evident. The medial retinacular tissues of the stifle joint are often thickened, and the foot can be seen to twist laterally as weight is placed on the limb.
Legg-Calve-Perthes Disease (LCP)
Legg-Calve-Perthes Disease (LCP) is a disorder of hip joint conformation. In dogs, it is most often seen in miniature and toy breeds between the ages of 4 months to a year.
LCP occurs when the blood supply to the femoral head is interrupted, which results in avascular necrosis, or the death of the bone cells. Followed by a period of revascularization, the femoral head is subject to remodeling and/or collapse, creating an irregular fit in the acetabulum, or socket. This process of bone cells dying and fracturing, followed by new bone growth and remodeling of the femoral head and neck, can lead to stiffness and pain.
LCP is believed to be an inherited disease, although the mode of inheritance is not known. Because there is a genetic component, it is recommended that dogs affected with LCP not be used in breeding programs.
Breeds most at risk for Legg-Calve-Perthes disease:
Affenpinscher, Australian Terrier, Bichon Frise, Border Terrier, Boston Terrier, Cairn Terrier, Chihuahua, Cocker Spaniel, Dachshund, Fox Terrier, Jack Russell Terrier, Lakeland Terrier, Manchester Terrier, Miniature Schnauzer, Miniature Pinscher, Pomeranian, Pekingese, Poodle, Pug, Schipperke, Scottish Terrier, Shetland Sheepdog, Silky Terrier, Welsh Terrier, West Highland White Terrier, Yorkshire Terrier.