The term hip dysplasia means poor development of the formation of the hip joint, and describes a developmental disease in young dogs of many different breeds. Unsound hipjoints are a common problem in the larger breeds, and hip dysplasia can be a serious problem in any dog that is to be trained for a demanding activity.
Hip dysplasia is an inherited defect with a polygenic("many genes") mode of inheritance. The degree of hereditability is moderate in nature, meaning that the formation of the hip joints can also be modified by environmental factors such as over nutrition, excessively rapid growth, and certain traumas during the growth period of the skeleton. As with any quantitative trait, hip joint conformation can range from good to bad with all shades in between.
Signs of hip dysplasia cannot be detected in the new born puppy, but usually appear in the rapid growth period between four and nine months of age. Signs of the disease can vary widely from slight irregularities of gait to crippling lameness. Improvement or even apparent disappearance of lameness can occur as the dog matures, as a result of the joint stabilizing, inflammation subsiding, and musculature strengthening. However, the dysplastic dog will usually develop arthritis later in life.
Hip dysplasia may be diagnosed by X-ray between six months and a year of age, but this is not entirely reliable, and dogs intended for breeding should be X-rayed when fully mature in order to select for sound hips. Two years of age is considered to be the minimum age for accurate radiographic determination of desirable conformation.
X-rays should be sent to the Orthopedic Foundation for Animals (OFA - see below for address) in Columbia, Missouri, for a diagnostic evaluation. The charge is $15 for a preliminary evaluation (for dogs X-rayed prior to two years of age), and $20 for the assignment of a permanent OFA Registry number (for dogs two years of age or older). The Golden Retriever Club of America has a list of all Golden Retrievers that have been diagnosed free of hip dysplasia by the Orthopedic Foundation for Animals over the years (which is currently over 30,000 Goldens), available for a small fee.
The dysplastic dog should not be sued for breeding, but may well lead a long, happy, useful life. During the acute phase of the disease, your veterinarian may suggest rest and supportive care. Moderate and regular exercise, control of weight, and perhaps anti-inflammatory drugs, are helpful in the management of arthritis associated with hip dysplasia in the older dog. Many Goldens with hip dysplasia will show no outward signs at all until perhaps 7 or 8 years of age when muscle tone decreases and arthritis and wear and tear on the joint become more noticeable.
Goldens and other breeds of retrievers often seem to have high pain thresholds, and do not show signs of pain when other breeds might be very uncomfortable. An X-ray does not always show you how your dog feels, as many dysplastic Goldens are completely unaware that they have a problem!
There are a number of orthopedic problems in addition to hip dysplasia which sometimes occur in the growing dog. Among these are panosteitis, osteochondritis dissecans, luxated patella, and other problems. It is suspected that there may well be some hereditary predisposition to such conditions, so even though surgery may be able to correct some of these problems, there is some question whether dogs affected with any of these conditions should be considered for breeding.
Hereditary cataracts are a common hereditary eye problem in the Golden Retriever breed. (Cataract by definition is any opacity within the lens of the eye.) At lease one type of hereditary cataract appears at an early age in affected Goldens, and while these may or may not interfere with the dog's vision, some do progress into severe or total loss of vision. There are also non- hereditary cataracts which sometimes occur, and examination by a Board-certified veterinary ophthalmologist is necessary to determine if the cataract is or is not of concern from a genetic standpoint. If there is any question, the dog is certainly not to be recommended for breeding.
A few families of Goldens carry genes for Central Progressive Retinal Atrophy (CPRA) which is progressive deterioration of the light-receptive area (retina) of the eye, and may result in complete blindness at a fairly young age. There are also other eye defects, such as retinal dysplasia, that prevent consideration of a dog as a breeding animal.
Eyelid and eyelash problems also may occur in the breed; some with an hereditary basis, and some sometimes due to other factors. Entropion and ectropion are the turning in or turning out of the eyelids. Trichiasis and distichiasis involve eyelashes or hairs rubbing on and irritating the eye. Surgery may be needed to correct these problems, and while it is a fairly simple procedure, such dogs should not be bred and are ineligible to be shown under AKC rules.
Nuclear sclerosis, the "bluish haze" of the eye seen in older dogs, is a normal part of the age-related change in the lens of the eye and is NOT a problem.
Examination of breeding stock should be done annually, until at least eight years of age and preferably longer, as hereditary eye problems can develop at varying ages. The examination should be made by a Board-certified veterinary ophthalmologist, who has the special equipment and training needed to properly examine the dog's eyes.
Dogs that have been examined by a Board-certified veterinary ophthalmologist and found to be free of hereditary eye disease can be registered with the Canine Eye Registration Foundation (CERF - see below for address). CERF assigns the dog an number which, when properly understood, helps to make eye clearances more meaningful. For example, CERF GR1857/89-102 means that this dog was the 1,857th Golden Retriever to be registered with CERF; that the most recent examination indicating this dog free of hereditary eye disease was done in 1989; and that the dog was 102 months old at the time of the examination.
Dogs with hereditary eye disease should not be used for breeding.
Canine von Willebrand's Disease is an inherited deficiency in one of the clotting factors of the blood. It is similar to hemophilia in some respects, but may appear in either male or female. Carriers may show no overt symptoms of the disease, but their progeny can have severe bleeding problems. There is a blood test available which will identify dogs with the VWD trait; complete information can be obtained from Dr. W. Jean Dodds, New York State Department of Health, Division of Laboratories and Research, Albany, New York 12201. The laboratory will test, free of charge, properly prepared samples sent to Dr. Dodds.
As von Willebrand's Disease in Golden Retrievers is considered an incomplete dominant, dogs carrying the trait (whether showing symptoms or now) will pass it on to half of their offspring, even if bred to a mate free of the trait. If VWD carrier animals are bred, it is recommended that they be bred only to mates that test free of this gene, and that their progeny be tested for VWD. Animals clinically affected with VWD should not be bred.
Dogs affected with VWD may have symptoms varying from very mild to severe or lethal. These bleeding problems include prolonged bleeding from toenails cut too short, hemorrhage from even minor surgical procedures, lameness, hematomas, stillbirths or early death of newborn puppies, intestinal bleeding, and so on. The bleeding primarily involves mucosal surfaces (gastrointestinal tract, nose- bleeds, blood in the urine, vaginal or penile bleeding) and is aggravated by stress situations (other physiological, pathological, emotional or hormonal conditions).
This is a generalized metabolic disease characterized by atrophy or malfunction of the thyroid glad. Clinical symptoms include obesity, lethargy, and/or coat problems. Affected animals may also have various reproductive problems, including irregular or absent estrus (heat cycle), and lack of fertility in both male and female.
Diagnosis of hypothyroidism is by laboratory tests measuring levels of T3 and T4 (produced by the thyroid gland) in the blood. Treatment consists of daily administration of thyroid supplement orally and, when successfully treated, the prognosis is excellent and the dog's lifespan is normal, although the dog may require lifelong thyroid supplementation.
There is some question whether dogs requiring supplementation should be bred, as early hypothyroidism may be hereditable.
Many clinically normal, healthy Goldens may test slightly under the accepted range of "normal" T3 and T4 levels, and it is quite possible that the normal values for this breed may be slightly lower than the values used for the general canine population. In the absence of definite clinical symptoms of a thyroid deficiency as determined by a veterinarian, or of an abnormal response to TSH (thyroid function test), supplementation is probably not required for the animal with slightly low T3 T4 levels. Indiscriminate use of thyroid supplementation should be avoided; it can cause problems as well as remedy them.
Seizure disorders may arise from a variety of environmental factors including viral infections, other diseases, and trauma. In some cases there is no ascertainable cause other than perhaps some inherent factor resulting in a low threshold to the stimuli setting off the seizures. While an isolated seizure does not necessarily constitute a problem, dogs subject to recurring seizures should not be bred; low seizure threshold is inherited. A veterinarian can prescribe medication to control recurring seizures, but medication is not always completely effective. Epilepsy generally does not affect a dog's health or longevity; the condition is much more traumatic for the owner than the dog.
Hereditary heart disease, most commonly Subvalvular Aortic Stenosis (SAS), is known to occur in the Golden Retriever breed. All prospective breeding animals should be examined by a board-certified veterinary cardiologist or by an Internist with cardiovascular training. if a murmur is detected on auscultation, additional diagnostic tests are available and may be recommended; however, even if the results are negative, this does not conclusively rule out heart disease, as some mild but hereditary forms may be undetectable except on necropsy. Animals with hereditary heart disease should not be used for breeding.
CERF - Canine Eye Registration Foundation
c/o VMDP, Allen Warble
South Campus Courts, Building C
Purdue University
West Lafayette, IN 47907
(317) 494-8179
OFA - Orthopedic Foundation for Animals
2300 Nifong Blvd.
Columbia, MO 65201