Hip Dysplasia

What is Hip Dysplasia?

We are placing the following article to our blog in order to educate and help owners and future dog owners find out what is Hip Dysplasia about ,how can be avoided and how can be treated. At this point we have to say that the best way to avoid a disease like that is to test both parents and ancestors before any breeding and only when the results will come out good to proceed to mattings. This is the only way together with other tests to responsible breeding and litters without problems.

 To understand hip dysplasia we must have a basic understanding of the joint that is being affected. The hip joint forms the attachment of the hind leg to the body and is a ball and socket joint. The ball portion is the head of the femur while the socket (acetabulum) is located on the pelvis. In a normal joint the ball rotates freely within the socket. To facilitate movement the bones are shap1ed to perfectly match each other; with the socket surrounding the ball. To strengthen the joint, the two bones are held together by a strong ligament. The ligament attaches the femoral head directly to the acetabulum. Also, the joint capsule, which is a very strong band of connective tissue, encircles the two bones adding further stability. The area where the bones actually touch each other is called the articular surface. It is perfectly smooth and cushioned with a layer of spongy cartilage. In addition, the joint contains a highly viscous fluid that lubricates the articular surfaces. In a dog with normal hips, all of these factors work together to cause the joint to2 function smoothly and with stability.

Hip dysplasia is associated with abnormal joint structure and a laxity of the muscles, connective tissue, and ligaments that would normally support the joint. As joint laxity develops, the articular surfaces of the two bones lose contact with each other. This separation of the two bones within the joint is called a subluxation, and this causes a drastic change in the size and shape of the articular surfaces. Most dysplastic dogs are born with normal hips but due to their genetic make-up (and possibly other factors) the soft tissues that surround the joint develop abnormally causing the subluxation. It is this subluxation and the remodeling of the hip that leads to the symptoms we associate with this disease. Hip dysplasia may or may not be bilateral; affectingboth the right and/or left hip

 

What are the symptoms of hip dysplasia?

Dogs of all ages are subject to hip dysplasia and the resultant osteoarthritis. In severe cases, puppies as young as five months will begin to show pain and discomfort during and after exercise. The condition will worsen until even normal daily activities are painful. Without intervention, these dogs may eventually be unable to walk. In most cases, however, the symptoms do not begin to show until the middle or later years in the dog's life. The symptoms are similar to those seen with other causes of arthritis in the hip. Dogs often walk or run with an altered gait. They may resist movements that require full extension or flexion of the rear legs. Many times, they run with a 'bunny hopping' gait. They will show stiffness and pain in the rear legs after exercise or first thing in the morning. They may also have difficulty climbing stairs. In milder cases dogs will warm-up out of the stiffness with movement and exercise. Some dogs will limp and many will become less willing to participate in normal daily activities. Many owners attribute the changes to normal aging but after treatment is initiated, they are surprised to see a more normal and pain-free gait return. As the condition progresses, most dogs will lose muscle tone and may even need assistance in getting up.

        

What are the risk factors for the development of hip dysplasia?

Hip dysplasia is caused by a subluxation in the hip joint. This creates abnormal wear and erosion of the joint and as a result arthritis and pain develop. The disease process is fairly straightforward; the controversy starts when we try to determine what predisposes animals to contracting the disease. Genetics: Researchers agree that hip dysplasia is a genetic disease. If a parent has hip dysplasia, then the animal's offspring are at greater risk for developing hip dysplasia. If there are no carriers of hip dysplasia in a dog's lineage, then it is highly unlikely he will not contract the disease. If there are genetic carriers, then he may contract the disease. We can greatly reduce the incidence of hip dysplasia through selective breeding. We can also increase the incidence through selectively breeding. We cannot, however, completely reproduce the disease through selective breeding. In other words, if you breed two dysplastic dogs, the offspring are much more likely to develop the disease but the offspring will not all have the same level of symptoms or even necessarily show any symptoms. The offspring from these dogs will, however, be carriers and the disease will most likely show up in their offspring in later generations. This is why it can be challenging to eradicate the disease from a breed or specific breeding line.

Nutrition: It appears that the amount of calories a dog consumes and when in the dog's life those calories are consumed have the biggest impact on whether or not a dog genetically prone to hip dysplasia will develop the disease.

 Experimentally, it has been shown that obesity can increase the severity of the disease in genetically susceptible animals. It stands to reason that carrying around extra weight will exacerbate the degeneration of the joints in a dog; including the hip. Dogs that may have been born genetically prone to hip dysplasia and are overweight are therefore at a much higher risk of developing hip dysplasia and eventually osteoarthritis. Another factor that may increase the incidence of hip dysplasia is rapid growth in puppies during the ages from three to ten months. Experimentally, the incidence has been increased in genetically susceptible dogs when they are given free choice food. In one study, Labrador Retriever puppies fed free choice for three years had a much higher incidence of hip dysplasia than their littermates who were fed the same diet but in an amount that was 25% less than that fed to the free-choice group.

Feeding a diet that has too much or too little calcium or other minerals can also have a detrimental effect on the development of the hip joint. However, with today's complete and balanced dog foods this has become a rare occurrence. The practice of feeding home-made dog foods is popular with some dog owners. These diets must be carefully monitored for proper nutritional balance; not only for calcium and the other essential minerals but for all nutrients.

Exercise: Exercise may be another risk factor. It appears that dogs that are genetically susceptible to the disease may have an increased incidence of disease if they over-exercised at a young age. But at the same time, we know that dogs with large and prominent leg muscle mass are less likely to contract the disease than dogs with small muscle mass. So, exercising and maintaining good muscle mass may actually decrease the incidence of the disease. Moderate exercise that strengthens the gluteal muscles, such as running and swimming, is probably a good idea. Whereas, activities that apply a lot of force to the joint are contraindicated.

How is hip dysplasia diagnosed?

The diagnosis of canine hip dysplasia is typically made by combining: clinical signs of arthritis and pain, a complete physical exam, and radiographs (x-rays). If a dog is showing outward signs of arthritis, there are usually easily recognized changes in the joint that can be seen on radiographs. In addition, the veterinarian may even be able to feel looseness in the joint or may be able to elicit pain through extension and flexion of the rear leg. Regardless, the results are straightforward and usually not difficult to interpret.However, about half of the animals that come in for a determination on the health of their hip joints are not showing physical signs, but are intended to be used for breeding. The breeder wants to ensure that the animal is not at great risk for transmitting the disease to his or her offspring. There are two different testing methods that can be performed. The traditional is OFA testing. The other relatively newer technique is the PennHip method.

                        

How do we prevent hip dysplasia?

When it comes to preventing hip dysplasia, there is only one thing that researchers agree on; selective breeding is crucial. We know that through selectively breeding animals with certified hips, we can significantly reduce the incidence of hip dysplasia. We also know that we can increase the incidence of hip dysplasia if we choose to use dysplastic animals for breeding. Breeding two animals with excellent hips does not guarantee that all of the offspring will be free of hip dysplasia, but there will be a much lower incidence than if we breed two animals with fair or poor hips. If we only bred animals with excellent hips it would not take long to make hip dysplasia a rare occurrence. If owners insisted on only purchasing an animal that had parents and grandparents with certified good or excellent hips, or if breeders only bred these excellent animals, then the majority of the problems caused by hip dysplasia would be eliminated. For someone looking to purchase a dog, the best way to lower the possibility of getting an animal that develops hip dysplasia is to examine the incidence of hip dysplasia in the litter's lineage. It is best to examine the parents and grandparents out to three or four generations.

 

References and Further Reading

Beale, BS. Use of nutraceuticals and chondroprotectants in osteoarthritic dogs and cats. In Mandelker, L (ed). Veterinary Clincis of North America Small Animal Practice: Nutraceuticals and other Biologic Therapies. WB Saunders Co, Philadelphia, PA 2004; 34(1):271-289.

 

Demko, J; McLaughlin R. Developmental orthopedic disease. In Renberg, WC (ed). Veterinary Clincis of North America Small Animal Practice: General Orthopedics. WB Saunders Co, Philadelphia, PA 2005; 35(5):1111-1135.

 

Johnston, A; Budsberg, C. Nonsteroidal anti-Inflammatory drugs and corticosteroids for the management of canine osteoarthritis. Veterinary Clinics of North America Small Animal Practice: Osteoarthritis. WB Saunders Co., Philadelphia, PA 1991; 27(4):841-862.

 

Kapatkin, S; Mayhew, D; Smith, K. Canine hip dysplasia: Evidence-based treatment. Compendium of Continuing Education for Practicing Veterinarians. August 2002.

 

Mclaughlin, M; Roush, K. Symposium on medical therapy for patients with osteoarthritis. Veterinary Medicine. February 2002.

 

Mclaughlin, M; Roush, K. Symposium on alternative and future treatment modalities for osteoarthritis. Veterinary Medicine. February 2002.

 

Smith, GK; Pastor, ER; Powers, MY; Lawler, DF; Biery, DN; Shafer, FS; et al. Lifelong diet restriction and radiographic evidence of osteoarthritis of the hip joint in dogs. Journal of the Veterinary Medical Association 2006; 229(5):690-69

2015

January

2014

January

2013

January

January

January

News