Hereditary Problems

HEREDITARY PROBLEMS

The vast majority of dogs of all breeds (as well as mixed breeds) can live, long healthy lives if given proper care and routine veterinary attention.  However, any dog can fall victim to a wide range of acquired problems, just as humans can.  Each pure breed of dog has its own particular hereditary problems, some minor, some impairing, and some possibly fatal.

The Golden Retriever is no exception and unfortunately, the problems multiply with indiscriminate breeding.  Failure to screen for hereditary problems before breeding often results in the “doubling up” of unfavourable genes, and the results are distressing for the buyer and dog alike.  The following, while not all inclusive, are some of the more common hereditary problems that may be encountered in Goldens.

HIP DYSPLASIA

The term hip dysplasia means poor development in the formation of the hip joint, and describes a developmental disease in young dogs of many breeds.  Unsound hip joints are a common problem in the larger breeds, and hip dysplasia can be a serious problem in any dog.

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 poor 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 newborn puppy, but usually appear in the rapid growth period between four (4) and nine (9) 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 stabilising, inflammation subsiding, and muscular strengthening.  However, the dysplastic dog will usually develop arthritis in later life.

The only accurate means of determining the condition of the hip joint is by x-ray examination.  Sedation will be needed to restrain the dog so that a diagnostic film can be made, as positioning of the hips is of great importance.  Signs of hip dysplasia found on x-ray include shallow sockets, irregular shape of the femoral heads, looseness of the joint, and degenerative joint disease or osteoarthritis.

Hip dysplasia can sometimes be diagnosed by x‑ray between six (6) and twelve (12) months 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.  Fifteen (15) to eighteen (18) months of age is considered to be minimum age for accurate x-ray determination of desirable conformation.

X-rays should be submitted for scoring by the Australian Veterinary Association or other Australian Canine Scoring Schemes.

The dysplastic dog should not be used 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 older dog.  Many Goldens with hip dysplasia will show no outward signs at all, until perhaps seven (7) or eight (8) years of age when muscle tone decreases and arthritis and wear and tear on the joint becomes 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 how your dog feels, as many dysplastic Goldens are completely unaware that they have a problem.

EYE DISEASE

Hereditary cataracts are a common hereditary eye problem in the Golden Retriever.  “Cataract” by definition is any opacity within the lens of the eye.  At least 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 sight.  There are also non‑hereditary cataracts which sometimes occur, and examination by a 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 progressive retinal atrophy (PRA) 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 occur in the breed, some with an hereditary basis, others are sometimes due to other factors.  Entropion and ectropion is the turning in or turning out of the eyelids.  Distichiasis involves eyelashes 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 with.

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 (8) years of age and preferably longer, as hereditary eye problems can develop at varying ages.  The examination should be conducted by a veterinary ophthalmologist, who has the special equipment and training needed to properly examine the dog’s eyes.

OTHER ORTHOPAEDIC PROBLEMS INCLUDING ELBOW DYSPLASIA

There a number of orthopeadic problems besides hip dysplasia which may also 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 disposition to such conditions, so even though surgery may correct some of these problems, there is some question whether dogs affected with any of these conditions should be considered for breeding.

Nevertheless, when purchasing puppy, it is important to ensure that the parents have been screened by x-ray for elbow dysplasia.

HEART CONDITIONS:  SUB-AORTIC STENOSIS

Like humans, dogs can and do suffer from heart problems.  Of particular concern in the golden retriever is Sub-Aortic Stenosis (SAS), a condition basically caused by a faulty valve in the aorta.  At this point in time SAS is regarded as an hereditary condition.  Dogs severely affected by this condition may not survive puppyhood, or, if they survive early life, may suddenly collapse and die prematurely.   When choosing a puppy it is important for you to know that its parents have been screened by a specialist veterinary practitioner for hereditary heart conditions.

EPILEPSY

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.  One or perhaps two isolated seizures do not necessarily constitute a problem, but dogs subject to recurring seizures should not be bred.  Often the veterinarian can recommend medication which will control the seizures, although medication is not always effective, and many dog owners are not always willing to try and live with this problem