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Dedicated To the Total Presa Canario
Facts
about Canine Hip Dysplasia
The hip joint of the dog is made up of two parts- the femoral head (thigh bone) and the acetabulum (the socket of the pelvic bone). The acetabulum and the femoral head form a "ball and socket" joint. The femoral head surface is covered with a smooth articular cartilage. There is a thin layer of fluid (synovial fluid), which serves as a lubricant for the joint and nourishment for the articular cartilage, separating these opposing surfaces. Muscles encase the entire hip, stabilizing and allowing movement. The head of the femur is held in the acetabulum by the pelvic muscles, joint capsule, surface tension and the round ligament. Proper development of the joint still depends on the head of the femur being held firmly within the acetabulum until all parts are mature.
Many dysplastic dogs show observable signs between 3 and 15 months of age, while some can take up to 36 months. This is generally the severest form, characterized by marked pain and lameness. In others, a more chronic form with gradual onset increasingly becoming more affected in advanced age. In some cases the chronic form dog may be asymptomatic. Some of the signs are
Because the hip joint is weakened in a dog with CHD, it is more subject to injury with normal activity such as jumping off the couch or playing with another dog. Often times this results in acute lameness that the owner thinks was caused by the injury, when in fact it is the underlying CHD that has made the joint more susceptible to injury.
The only way to determine the conformation of CHD free or affected is by radiographic examination of the hips. Radiographic criteria of subluxation, shallow acetabulum, remodeling and/or secondary degenerative joint disease (DJD) are well documented. DJD of the hip is characterized by one or more of the following: cartilage damage, joint effusion, synovitis and bony remodeling. DJD is synonymous with osteoarthritis and its radiographic evidence is considered a diagnosis of CHD.
Joint
laxity (looseness of the joint) is a dynamic state that cannot
be determined by routine radiography. The joint may appear
radiographically normal but in actuality be loose.
Laxity is considered to be one of the earliest pathologic findings in CHD. Therefore, demonstration of laxity in young dogs from 3-6 months of age could be a diagnosis of CHD or possibly a predictor of dysplasia. Palpation of the hips is not accepted as a single method of diagnosing CHD. The use of a wedge or fulcrum (placed between the thighs to force the head of the femur out of the acetabulum) is used to determine the degree of radiographic subluxation. Some type of measurement criteria must be employed (Norberg, millimeters, distraction index, etc.) to demonstrate the amount of displacement of the femoral head when compared to a fixed anatomical structure or to a standard radiograph taken without a wedge or fulcrum. The use of the fulcrum has shown that some laxity is expected in a normal joint and that many dogs with laxity beyond a certain point later show characteristic radiographic evidence of CHD.
The
Orthopedic Foundation for Animals (OFA) is a not-for-profit
foundation established in 1966. They maintain a dysplasia
control registry as a voluntary service to register hip status
for Breed club affiliation is an important part of the OFA-By-Laws,
as OFA cannot control the frequency of CHD, as they have no
control over breeding. Only breeders who wish to use them as a
tool can reduce the instance of CHD in a breed.
Radiographs may be submitted to OFA at any age but only dogs 24 months of age or older at the time of the x-ray can qualify for an OFA registration number. Hip status of younger dogs will be evaluated on a consultation report only.
Each evaluation is independent- meaning that no radiologist knows the interpretation given by the others. These are then compiled into the final consensus.
To learn more about OFA, please visit their website at
PennHIP
stands for University of Pennsylvania Hip Improvement Program.
In 1983, Dr. Gail Smith a veterinary orthopedic surgeon and
bioengineer began to actively research a method for early
diagnosis of CHD. The PennHIP was founded as an extension of his
laboratory research.
PennHIP requires a certified PennHIP veterinarian to take the radiographs, and it must be done under heavy sedation or general anesthesia. It is policy that all radiographs taken be submitted to PennHIP for evaluation. This ensures that prescreening of radiographs and only sending the best for evaluation does not occur, resulting in an unbiased data base for the given breed.
To learn more about PennHIP, visit their website at www.vet.upenn.edu
Public Health Database for Presa Canarios
There are currently no firm statistics on the occurrence of CHD in the Dogo Canario. The original Island breeders did not x-ray their dogs, but relied on the functionality of the dog to determine it's health. Many lines of the breed were established before the necessity of radiographs to determine if CHD was present was well understood. The Club Espaņol del Dogo Canario conducted a survey in the late 1990's of 300 Island dogs to determine the percentage of CHD in the breed. Approximately 12% of the dogs fell into the Excellent to Good (A) category with 22% affected with various degrees.
The majority of the breed fell into the Fair to Borderline (B) rating. They are working towards requiring radiographs on all breeding dogs. In the USA, The Dogo Canario Club of America is working towards that same goal on stock used by American breeders. The Dogo Canario has a typical hip confirmation of a molosser dog with little angluation. At this time the breed averages more subluxation than is typically allowed by OFA examination, resulting in mild ratings on dogs that are otherwise normal. Dogs scoring OFA mild should be evaluated under the PennHip method to get a true reading of their subluxation. Dogs scoring at or under the current breed median, with no DJD, can be considered fit for breeding.
Canine hip dysplasia is an inherited genetic disease with a minor environmental roll in its expression in some circumstances. Some environmental factors can influence the expression of the disease and mask or exacerbate the symptoms. Some common factors are:
Non surgical methods of treatment for pain management may include, aspirin, phenylbutazone, non steroidal anti-inflamitories, steroids and Rimadyl (Pfzier). All of these drugs should be used under direct supervision of your veterinarian and all but aspirin are by prescription only.
Another product that is
showing great promise in alleviation of symptoms is glucosamine.
Liquid Health 5000, Adequan, Cosequin, Glycoflex are some brand name products which
contain this homeopathic substance. Vitamin C is controversial
but has been shown to help reduce inflammation.
Reduction in the weight of the dog and a modified exercise program
helps to lessen the stress on the dog's weakened joints. An
ideal exercise for a CHD affected dog is swimming, which doesn't
stress the joints. Keeping the dog mainly indoors and with
softer surfaces to lie on will also help to make his life more
comfortable. Surgical treatments are generally reserved for animals for when other treatments offer no relief. There are many surgical options that must be discussed with the advise of your veterinarian. He or she will recommend the best option for your dog.
This page is meant for informational purposes only. It is not meant to be an alternative for a diagnosis from your veterinarian. Always consult your veterinarian first regarding any questions about your dog's health.
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