Added: Dec 5, 2008
From: AnimalsandNature
Duration: 0:33
Hip dysplasiaDescription:Hip dysplasia occurs when there is insufficient stability to keep the head of the femur (the "ball") within the acetabulum (the "socket") of the hip joint. This may be due to stretching of the joint capsule or weakness in the surrounding muscles, or a failure of the "socket" to develop properly. Because of this instability the hip joint develops abnormally, remodelling of the bones occurs and new bone is deposited around the joint (used to be called arthritis - now called degenerative joint disease). The result is hindleg weakness, pain and functional disability.Cause:It may surprise people to learn that the cause of hip dysplasia is not known ! Hip dysplasia is a complex (called polygenic or multigenic) disease with many factors involved in the cause. The most important are genetic and environmental factors but, based on detailed analysis of inheritance in German Shepherd dogs the disease is only described as being moderately heritable in that breed.Contributing factors are :Breed - genetic inheritance, BUT specific genes not yet identified. Also multiple genes involved (polygenic).Body size - low prevalence - ancestral dog size; greater prevalence -large/giant breedsBody type - low prevalence - slender and fit. Low subcutaneous fat content (1-2%); greater prevalence- giant breeds, heavy conformation, with acromegaly. Relatively high subcutaneous fat content(5-10%).Growing pattern - rapid growth rate and excessive weight gain (above the average for the breed) can both increase the likelihood of hip dysplasia occurring.Increased activity has been associated with increased likelihood of developing hip dysplasia. Possibly increased activity exposes the animal to increased chance of injury, or to excessive biomechanical forces which alter the stability of the hip joints.Muscle disorder - a muscle disease (developmental myopathy of the pectineus muscle) has been described in German Shepherd puppies with hip dysplasia, but a direct link between the two conditions was not proved, though it may have been present.Hormone - experimentally a female hormone (the oestrogen relaxin) can induce hip dysplasia due to relaxation of supporting ligaments in dogs, including greyhounds. However there is no evidence of a naturally occurring role for the hormone in the cause of the disease.Diet does not seem to be important except when excessive calorie intake occurs resulting in too rapid a rate of growth or excessive weight gain.Breed Occurrence:Hip dysplasia affects humans (1.3 children in every 1000) and ALL domestic animals including cats and dogs. Body size is an important factor and one of the of the highest prevalence's of the disease is in large and giant breeds of dog in which over 30% of some breeds may be affected. The disease is less common in dogs with a body size similar to the ancestral dog and it is rare in undomesticated animals.In the USA screening XRays have indicated that in some breeds over 20% are affected by hip dysplasia including - in descending order : St Bernards (43.2%), Newfoundlands (39.9%), Bullmastiffs (34.5%), English Setters (32.1%), Gordon Setters (32.1%), Old English Sheepdogs (29.9%), English Springer Spaniel (27.3%), Akita (27.1%), Chesapeake Bay Retriever (25.7%), Golden Retriever (27.5%), Norwegian Elkhound (25.6%), Rottweiler (25.4%), the German Shepherd Dog (25.1%), Giant Schnauzer(24.2%), Standard Poodle (23.6%) and the Brittany Spaniel (22.4%). (Reference Riser WH et al J Am Vet Med Assoc (1974) 165:79)Continue video #2....
Channel: Animals
Tags: artificial cats dog dysplasia hip hip.
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