Sporting Breed Related Medical Problems
Many conditions appear to be especially prominent in Sporting breeds. Sometimes it is possible to identify the genetic basis of a problem, but in many cases, we must be satisfied with merely identifying the breeds that are at risk and how their conditions can be identified, treated and prevented.
Following are some conditions that have been recognized as being common in Sporting breeds. However, this listing can never be considered complete, as more research is being done every day. Also, many genetic conditions may be common in certain breed lines, but not in that breed or the sporting breed group in general.
ACRAL LICK DERMATITIS
Few things are as frustrating to veterinarians as dealing with acral lick dermatitis (lick granuloma), a problem caused by a dog licking incessantly at a spot on its leg. Some recent research has shown that there may be some nerve deficits in dogs that develop this condition. Other research has suggested that boredom may be a precipitating cause that eventuates in a compulsive behavior. Treatment is often frustrating because, without knowing the cause, it is difficult to predict the chances of success. Most therapies use anti-inflammatory agents, but a variety of other options exist, which should be discussed with your veterinarian.
BLOAT (GASTRIC DILATATION VOLVULUS)
Bloat occurs when the stomach becomes distended with air. The air gets swallowed into the stomach when susceptible dogs exercise, gulp their food/water or are stressed. Although bloat can occur at any age, it becomes more common as susceptible dogs get older. As the stomach fills with air it can twist on itself and impede the flow of food within the stomach as well as the blood supply to the stomach and other organs. This twisting (volvulus or torsion) not only makes the bloat worse, but also results in toxins being released into the bloodstream and the death of blood-deprived tissues. These events, if allowed to progress, will usually result in death in four to six hours.
Bloat can't be completely prevented, but there are some easy things to do to greatly reduce the risk. Feed a premium product that minimizes the risk of expanding in the stomach, like Nature's Recipe. Don't leave food down for dogs to eat as they wish; rather, feed two to three small meals. Prevent gulping by placing chew toys in the bowl, if necessary, so your dog has to work harder for the food. Do not allow exercise for one hour before and after meals.
Cataracts refer to an opacity or cloudiness on the lens and ophthalmologists are careful to categorize them on the basis of stage, age of onset and location. Many dogs adapt well to cataracts, but cataract removal surgery is available and quite successful if needed. Affected animals and their siblings should obviously not be used for breeding, and careful ophthalmologic evaluation of both parents is warranted.
ELBOW AND HIP DYSPLASIA
Elbow dysplasia doesn't refer to just one disease, but rather an entire complex of disorders that affect the elbow joint. Several different processes might be involved, including ununited anconeal process, fragmented medial coronoid process, osteochondritis of the medial humeral condyle or incomplete ossification of the humeral condyle. The most common condition reported in Sporting breeds is ununited anconeal process. Elbow dysplasia and osteochondrosis are disorders of young dogs, with problems usually starting between 4 and 7 months of age. The usual manifestation is a sudden onset of lameness. In time, the continued inflammation results in arthritis in those affected joints.
Hip dysplasia is a genetically transmitted developmental problem of the hip joint that is common in many breeds, and sporting breeds are no exception. Dogs may be born with a "susceptibility" or "tendency" to develop hip dysplasia but it is not a foregone conclusion that all susceptible dogs will eventually develop hip dysplasia. All dysplastic dogs are born with normal hips and the dysplastic changes begin within the first 24 months of life although they are usually evident long before then.
It is now known that there are several factors that help determine whether a susceptible dog will ever develop hip dysplasia. These include body size, conformation, growth patterns, caloric load and electrolyte balance in the dog food.
The management of dogs with elbow dysplasia is a matter of much debate and controversy. Some recommend surgery to remove the damaged cartilage before permanent damage is done. Others recommend conservative therapy of rest and pain-killers. The most common drugs used are aspirin and polysulfated glycosaminoglycans. Most veterinarians agree that the use of cortisone-like compounds (corticosteroids) creates more problems than it treats in this condition. What seems clear, is that some dogs will respond to conservative therapies, while other need surgery. Surgery is often helpful if performed before there is significant joint damage.
If you start with a pup with less risk of hip dysplasia you can further reduce your risk by controlling its environment. Select a food with a moderate amount of protein avoiding the super high protein and calorie diets. Also, feed your pup several times a day for defined periods (e.g., 15 minutes) rather than leaving the food down all day. Use controlled exercise for your pup rather than letting him run loose. Unrestricted exercise in the pup can stress the joints which are still developing.
If you have a dog with hip dysplasia, all is not lost. There is much variability in the clinical presentation. Some dogs with severe dysplasia experience little master. pain while others that have minor changes may be extremely sore. The main problem is that dysplastic hips promote degenerative joint disease (osteoarthritis or osteoarthrosis) which can eventually incapacitate the joint. Aspirin and other anti-inflammatory agents are suitable in the early stages; surgery is needed when animals are in great pain, when drug therapy doesn't work adequately, or when movement is severely compromised.
Hypothyroidism is an often diagnosed endocrine (hormonal) problem in Sporting breeds. The disease itself refers to an insufficient amount of thyroid hormones being produced. There is a great deal of misinformation about hypothyroidism. Owners often expect their dog to be obese with the condition and otherwise don't suspect it. The fact is that hypothyroidism is quite variable in its manifestations and obesity is only seen in a small percentage of cases. In most cases, affected animals appear fine until they use up most of their remaining thyroid hormone reserves. The most common manifestations then are lack of energy and recurrent infections. Hair loss is seen in about one-third of cases.
Fortunately, although there may be some problems in diagnosing hypothyroidism, treatment is straightforward and relatively inexpensive. Supplementing the affected animal twice daily with thyroid hormone effectively treats the condition. In many breeds, supplementation with thyroid hormones is commonly done to help confirm the diagnosis. Animals with hypothyroidism should not be used in a breeding program and those with circulating autoantibodies but no actual hypothyroid disease should also not be used for breeding.
PATENT DUCTUS ARTERIOSUS (PDA)
Patent Ductus Arteriosus (PDA) is the most common congenital heart defect seen in dogs. This defect occurs when the normal fetal communication between the nonfunctional lungs and the aorta (major blood vessel leaving the heart) fails to close after birth. This results in the shunting of blood into the pulmonary artery (major vessel to the lungs) and flooding the lungs. At the same time the rest of the body is getting an inadequate amount of circulation.
Most puppies with PDA show no clinical signs early in life, but a heart murmur is detected upon examination for first vaccination. Other puppies may develop acute heart failure and have difficulty in breathing, exercise intolerance, or develop a cough. The diagnosis of PDA is normally made by the characteristic murmur, electrocardiogram (EKG) and chest radiographs (X-rays). Surgery is needed to correct the condition. The surgery should be done as soon as possible, ideally before five months of age to minimize secondary damage to the heart and lungs. There is over a 90 percent success rate with the surgery and if completed early enough, the prognosis is excellent that the dog will be able to live a normal life expectancy. If left uncorrected, the puppies usually do not live more than the first year or two.
PROGRESSIVE RETINAL ATROPHY (PRA)
Progressive retinal atrophy (PRA) refers to several inherited disorders affecting the retina that result in blindness. PRA is thought to be inherited with each breed demonstrating a specific age of onset and pattern of inheritance.
All of the conditions described as progressive retinal atrophy have one thing in common. There is progressive atrophy or degeneration of the retinal tissue. Night blindness occurs first because the rods (which are responsible for vision in dim light) are affected first. Visual impairment occurs slowly but progressively. Therefore, animals often adapt to their reduced vision until it is compromised to near blindness. Because of this, owners may not notice any visual impairment until the condition has progressed significantly.
Progressive retinal atrophy encompasses both degenerative and dysplastic varieties. This distinction may seem confusing to owners, but it is important to remember that there are many distinctly different disorders that can result in PRA.
Unfortunately there is no treatment available for progressive retinal atrophy, and affected dogs will eventually go blind. Fortunately, PRA is not a painful condition and dogs do have other keen senses upon which they can depend. Prevention is possible since breeding dogs should be screened annually.
Seborrhea is a primary defect in the skin's ability to replenish its supply of cells. Although the term seborrhea is loosely used for any greasy skin condition, Sporting breeds are prone to the primary inherited form of the disease. Most other cases that are referred to loosely as seborrhea are actually secondary to an underlying disease process such as allergies or hypothyroidism. Research to date has shown that the epidermal cells of affected animals have a greatly accelerated turnover rate, which causes them to collect in a haphazard fashion on the skin surface. The defect has been identified and is located in the skin itself. Thus, if a sample of affected skin were grafted onto a normal animal, the problem would persist in that defined area. Similarly, skin taken from a normal animal and grafted onto one with seborrhea would maintain skin normalcy in that particular area.
The result is an animal that is born normal but by early adulthood has started to develop greasy skin, a disagreeable odor and inflammation on the skin surface. The ears also often develop a waxy discharge. In time, there is thickened skin, loss of fur and variable itchiness. Secondary bacterial and yeast infections are commonplace.
Treatment is symptomatic and there are currently no cures. Frequent shampooing with antiseborrheic products (e.g., benzoyl peroxide, tar, selenium disulfide) is necessary. Some animals respond well to vitamin A derivatives (retinoids) such as etretinate. Affected animals should definitely not be used for breeding.
VON WILLEBRAND'S DISEASE
The most common inherited bleeding disorder of dogs is von Willebrand's disease. The abnormal gene can be inherited from one or both parents. If both parents are "clear," none of the pups will be affected. If both parents pass on the gene, most of the resultant pups fail to thrive and most will die. In most cases, though, the pup inherits a relative lack of clotting ability which is quite variable. Some dogs don't get diagnosed until they are neutered or spayed and they end up bleeding uncontrollably or they develop pockets of blood (hematomas) at the surgical site. There are tests available to determine the amount of von Willebrand factor in the blood and they are accurate and reasonably priced. However, determining carrier status is not straightforward and is very frustrating. Since hypothyroidism can be linked with von Willebrand's disease, thyroid profiles can also be a useful part of the screening procedure in older dogs.