Dealing with GSD Hereditary Health Problems

 

In this chapter

• Knowing which health problems are more common in GSDs than other breeds
• Understanding the treatment options if your dog suffers from one of these conditions
• Recognizing hereditary eye and ear problems
• Screening for skeletal problems
• Dealing with digestive, neural, cardiovascular, and immunological problems

Every pure breed of dog is predisposed to its own set of health problems, because every pure breed has its own subset of genes. In some breeds, selection for particular traits may inadvertently cause certain health problems. In other cases, a small number of dogs were used to found a breed, and if one of those dogs happened to carry a gene for a health problem, the problem could have become widespread throughout the breed due to the restricted gene pool. Finally, in breeds that have been extremely popular, careless breeding by owners who are unaware of health problems can cause genetic disorders to become more widespread.

Like all popular breeds, the German Shepherd has hereditary predispositions to several health problems. In this chapter are some of the more common problems that seem to have a hereditary basis in GSDs. Chances are you won’t ever have to worry about most of them, but just in case you become worried about your dog’s symptoms, I’ve organized this chapter by system of the body for easy reference.

Skeletal Problems

The skeletal system is the framework for your dog’s body. Many large dogs, including German Shepherds, are predisposed to skeletal problems that can lead to lameness.

Hip dysplasia

Hip dysplasia is the most well known hereditary problem of dogs, and the German Shepherd has been the poster child for this disorder. The GSD is far from being the most affected breed, however.

Hip dysplasia occurs when the ball of the femur (thigh bone) does not fit properly in the socket of the pelvic bone, as shown in Figure 12-1. The fit is affected both by the depth and shape of the socket and by the laxity of the joint. With pressure on the joint, such as the pressure that occurs when a dog walks or runs, the combination of laxity and a shallow socket allows the ball of the femur to pop in and out of the socket. This movement further deteriorates the rim of the socket, worsening the condition. This is why early diagnosis and treatment are important.

Hip radiographs can diagnose dysplasia before outward signs of the disorder can be perceived. In the United States, radiographs are most often rated by either the Orthopedic Foundation for Animals (OFA) or the Pennsylvania Hip Improvement Program (PennHip).

The OFA is the most common hip certification. A panel of specialists subjectively rates radiographs based on a number of specific joint characteristics. A dog with “normal” hips (which includes ratings of excellent, good, and fair) receives an OFA number. Borderline ratings indicate that a dog should be rechecked in another six to eight months. Dysplastic hips include ratings of mild, moderate, and severe.

Ratings are not given until dogs are 2 years old, but you can obtain a preliminary rating at an earlier age. Doing so can be important if you are buying or selling a young adult or if you want to initiate early therapy.

FIGURE 12-1: Hip dysplasia.

PennHip evaluation is available at a much younger age. It is based on objectively measured degrees of joint laxity, reported as a Distraction Index (DI), with lower numbers reflecting tighter (better) hips. PennHip–approved veterinarians must take the X-rays by using special procedures.

Breeders disagree about which method is better; thus many breeders elect to have two radiographs taken at the same time, submitting one to each registry. The only bad choice is no certification at all.

The “a” stamp given to German dogs includes those with normal, near-normal, and “still-permissible” hips, with the latter category including some mildly to moderately dysplastic dogs. Thus the “a” stamp is less informative and more inclusive than OFA or PennHip certification.

AN OFA NUMBER DECIPHERED

A dog with normal hips receives an OFA number, such as GSD23101G24MT. GS stands for German Shepherd Dog; 23101 means that this dog is the 23101th GSD to receive an OFA number; G stands for “good” (it could also be F for fair or E for excellent); 24 stands for the dog’s age in months when X-rayed; M stands for male (F for female); and T stands for tattooed (M stands for microchipped).

Hip dysplasia becomes progressively more crippling and painful. Mild cases may not need specific treatment, but dogs with more severe cases can live full lives if they’re given timely surgery. If the condition is detected in a young dog before secondary changes (osteoarthrosis) have occurred, a procedure called a triple pelvic osteotomy (TPO) can be performed. In a TPO, the orientation of the dog’s hip socket is surgically changed, allowing the femur head to fit better into the socket.

Older dogs or dogs with more advanced dysplasia are better candidates for total hip replacement, similar to the same procedure in humans. The ball of the femur is replaced with a metallic ball, and the socket is replaced with a Teflon cup.

A third procedure, which is less effective in large dogs, is simply to remove the head of the femur. Although it’s less expensive than other surgical treatments, this surgery is not a good choice for young, active dogs. However, it may be a reasonable choice for an older dog who needs only to be comfortable walking around the house.

Elbow dysplasia

Elbow dysplasia occurs in many breeds, including the German Shepherd. Several different types of developmental problems can cause it; in GSDs, the cause is most often ununited anconeal process (UAP). The anconeal process is a small finger of bone that normally attaches to the head of the ulna (one of the long bones of the forearm) and works to stabilize the elbow by fitting snugly in a notch in the humerus (upper arm), where it hinges with the ulna.

In some dogs, the anconeal process never attaches properly to the ulna (see Figure 12-2), so the dog’s elbow can shift from side to side when the dog puts weight on it. The anconeal process breaks loose, floats around, and causes irritation to the elbow.

FIGURE 12-2: Elbow dysplasia can cause lameness in GSDs.

A dog with elbow dysplasia has varying degrees of lameness of the front legs that originates in the elbow joint, which may be swollen and painful. Radio-graphs can diagnose the condition. To treat this condition, a vet surgically removes the loose piece.

CHECKING YOUR DOG’S ELBOW CLEARANCE

The Orthopedic Foundation for Animals (OFA) maintains a registry for elbows, and all German Shepherd breeding stock should have an OFA elbow clearance. Dogs over 2 years of age with normal elbows are assigned a breed registry number. Abnormal elbows are assigned either Grade I, II, or III, with Grade III being the most severely affected. About 20 percent of the German Shepherds who have had their elbows X-rays submitted to OFA have been rated as dysplastic; most of them are Grade I.

Panosteitis

Panosteitis is an inflammation of the long bones resulting in lameness. The lameness often shifts from leg to leg. It is most common in growing dogs of large breeds, including German Shepherds. Symptoms may come on suddenly, usually at between 5 and 10 months of age, although some GSDs (unlike other breeds) may develop the condition at up to 2 years of age. The exact cause is not known, but the prognosis for a full recovery is excellent. Treatment consists of limiting exercise and giving the dog analgesics to help control pain — see your vet for details.

Osteochondrosis dissecans

Osteochondrosis dissecans (OCD) is lameness that occurs when a flap of cartilage becomes detached from the bone. Lameness starts gradually at around 7 to 10 months of age and gradually worsens. The most common site of the lameness is in one or both shoulders, but almost any joint can be affected. Sometimes absolute rest (meaning restriction to a cage) for several weeks helps, although lameness may actually worsen with rest. It gets better with mild exercise and is worst with heavy exercise. Surgical repair is usually preferable and is especially satisfying with OCD of the shoulder.

Pituitary dwarfism

Although technically an endocrine disorder rather than a skeletal disorder, pituitary dwarfism — failure to grow normally due to a lack of growth hormone — has profound effects on the skeleton. Caused by a simple recessive gene, it occurs more often in German Shepherds than in any other breed. You first notice affected dogs at about 2 months of age, when they’re smaller than their litter mates. Their coats are wooly, lacking guard hairs, and often hair is missing from their bodies but remains on the heads and legs. Their bark may be shrill, and the dogs may be more difficult to housebreak as a result of retarded mental development.

Specialized testing can lead to a positive diagnosis. This condition is treated with growth hormone replacement, but treatment must be started early, will not totally cure the dog, may have side effects, and can be expensive.

Neural Problems

The neural system is the computer and wiring of the body. Neural problems can cause lack of coordination, paralysis, pain, and numbness.

Cauda equina syndrome

Cauda equina syndrome is more common in large breeds, particularly German Shepherds. No screening tests are available, and a hereditary component, if any, is not known.

Technically, cauda equina syndrome can result from several abnormalities, but narrowing of the lumbosacral vertebral canal is the most common. When this canal narrows, it presses on the spinal nerve roots within the canal, resulting in pain and perhaps incontinence and paralysis of the hind legs. The pain is focused in the pelvic area; the dog also feels pain when he lifts his tail or extends his hind legs rearward. Pain during defecation is a common symptom as well. The muscles of the hind limbs may waste away, and the dog may drag his toes. These signs may come on slowly, over a period of months, and are often confused with signs of hip dysplasia and degenerative myelopathy.

Specialized X-rays or other imaging techniques are required for diagnosis. Electromyography provides the most definitive diagnosis. Mild cases can be treated with rest and medicine, but most cases tend to progress. Veterinarians usually see better results with surgical correction, which requires a good deal of postoperative commitment from the owner.

Remember

Because of the pain involved in this condition, prompt attention is essential. Degenerative myelopathy Degenerative myelopathy is a progressive disease of middle-aged and older dogs in which the dog gradually loses control of his hind limbs. The condition is painless but progressive. The earliest signs may include dragging a foot slightly or occasionally placing the top of the foot on the ground. Dogs may have difficulty rising or lying down. More obvious signs follow, including increasing clumsiness, weakness, and partial paralysis. Eventually, the hind limbs become completely nonfunctioning. The feet must be monitored for sores that can form due to being dragged. Ultimately, the front legs also become affected and paralyzed. Finally, the brain stem is affected, resulting in death. (Most dogs are euthanized before they reach this point.)

Although the cause of DM is unknown, some experts speculate that it may be an autoimmune condition in which the immune system attacks part of the nerve fibers in the spinal cord of the mid-back region. Specifically, the part that is destroyed is the myelin sheath, the fatty insulating covering of the nerve fiber that is important in conduction of nerve impulses. This same part of the nerve fiber is destroyed in the human condition of multiple sclerosis. Spinal fluid proteins may help differentiate DM from other spinal problems.

Stress and inactivity seem to worsen this condition. No cure is available, but a special diet, supplements (including vitamins B and E and epsilonaminocaproic acid), physical therapy, and exercise may help slow or perhaps even halt its progression. The earlier DM is detected and treated, the better the prognosis. Unfortunately, the early signs often go unnoticed or are confused with those of hip dysplasia, delaying the start of treatment.

Digestive Problems

German Shepherds are predisposed to several digestive problems, the most life threatening of which is gastric dilatation volvulus.

Gastric dilatation volvulus

Gastric dilatation volvulus (GDV), also known as bloat or gastric torsion, is a life-threatening emergency in which gas and fluid become trapped in the stomach, as shown in Figure 12-3. It is most common in large, deep-chested breeds, including German Shepherds.

FIGURE 12-3: Gastric dilatation volvulus.

Warning!

Symptoms include distention of the abdomen, unproductive attempts to vomit, excessive salivation, and restlessness. A dog with these symptoms needs to go to the emergency clinic immediately — not tomorrow, and not even an hour from now.

The veterinarian will try to pass a tube into the stomach so that gases can escape. Often, the stomach has twisted and rotated on its axis, though, so the tube can’t get into the stomach. These dogs require emergency surgery to save their lives. The rotation of the stomach cuts off the blood supply to the stomach wall (and sometimes other organs), which will die and subsequently kill the dog if surgery isn’t performed quickly. During surgery, the veterinarian should tack the stomach in place to prevent future rotation. Dogs who bloat once often continue to do so.

In the largest study of bloat to date, several factors affecting bloat emerged. Dogs who are fearful, eat fast, and eat only one meal a day are more likely to bloat. Stress seems to precipitate a bloating episode. Dogs with stable temperaments, and dogs who eat some canned food and table scraps, are less likely to bloat. A dog with a close relative who has had the problem is more likely to have the problem, suggesting a hereditary component.

Tip

To be on the safe side, avoid other suspected risk factors. You should

• Feed your dog several small meals instead of one large meal a day.
• Include some canned food or table scraps.
• Not allow your dog to gulp food.
• Not allow your dog to be stressed around mealtime.
• Restrict your dog’s water for an hour after eating.
• Avoid letting your dog run or jump for an hour after eating.
• Premoisten the dog’s food, especially foods that expand when moistened.

Pancreatic exocrine insufficiency

Some German Shepherds eat voraciously yet fail to gain weight. In GSDs, this problem is often due to a lack of a pancreatic enzyme. Affected dogs produce a large volume of feces because they don’t digest food efficiently. Your veterinarian can examine your dog’s feces for excess fat and get a preliminary diagnosis, but a blood test is needed for definite diagnosis. You can treat these dogs by adding enzyme powder to an easily digested food, but you must treat them for the rest of their lives.

Inflammatory bowel disease

Dogs that have chronic diarrhea may be suffering from inflammatory bowel dis- ease (IBD), a syndrome that may be due to a number of problems. In general, the condition involves hypersensitivity to substances in the bowel. Other symptoms may include vomiting, weight loss, unproductive attempts to defecate, and mucus in the stool. In extreme cases, anemia may result. The exact symptoms vary according to what part of the bowel is involved.

Vets usually run blood tests to rule out other possible causes, and fecal tests to rule out parasites. They diagnose IBD with a biopsy of the bowel mucosa. Feeding a controlled diet sometimes helps, and in some cases suppressing the immune system with drugs is helpful as well. Other drugs may also be useful.

A dog suffering from this condition should be fed a diet that’s free of additives and preservatives and contains an adequate but not excessive amount of protein. The protein should come from a single source that the dog has no prior experience eating. Added dietary fiber may also be helpful. Because there’s no such thing as an inherently hypoallergenic food, you may have to search for a novel source of protein. Lamb and rice foods used to be touted as hypoallergenic, but a dog is now likely to have eaten lamb previously. Your veterinarian can suggest sources of protein (such as venison, duck, or rabbit) that your dog may not have eaten.

Circulatory Problems

Disorders of the heart and blood are among the most common serious problems in dogs. In comparison to many other breeds, German Shepherds have healthy circulatory systems. They do have their predispositions, however.

Subvalvular aortic stenosis

Subvalvular aortic stenosis is a congenital heart defect in which the opening between the left ventricle and the aorta is abnormally narrow, obstructing the blood flow. The condition occurs most often in large breeds. Severe cases cause death by 3 years of age. In less-severe cases, the signs may not be noticeable, although some dogs may be weak and collapse when exercising. A veterinary cardiologist diagnoses the condition with an ultrasound. Open-heart surgery is the treatment of choice, but it’s expensive and risky.

Patent ductus arteriosis

One of the most common congenital heart defects in dogs, patent ductus arteriosis is seen more frequently in GSDs than in other breeds. During fetal life, the lungs are not functional, so a vessel (the ductus arteriosis) allows blood to bypass the lungs. This vessel normally closes shortly after birth, but in some dogs it remains open, allowing blood to leak through it and placing a strain on the heart.

Affected dogs have a heart murmur and can be diagnosed conclusively with an ultrasound. Surgical correction is necessary to cure the condition. Left untreated, heart failure can result.

Hemophilia

Hemophilia is a hereditary blood clotting disorder occasionally found in German Shepherds. Affected dogs lack a factor needed to clot blood properly. Symptoms include pockets of blood beneath the skin, bleeding into the joints (causing lameness), and internal bleeding. Excessive bleeding during surgery or after a toenail is cut too short may be the first signs you notice. Blood tests can provide a definite diagnosis.

Immunological Problems

Your dog’s immune system is his defense against microscopic intruders. Sometimes a dog’s immune system isn’t strong enough, and sometimes it is misdirected. In either case, problems can arise.

Immunoglobulin A deficiency

The immune system of a normal German Shepherd has a lower amount of immunoglobulin A (IgA) than is found in most other breeds. IgA is important for mucosal immunity, especially of the respiratory, gastrointestinal, and genital tracts. This lowered IgA may be related to some health problems, including bacterial overgrowth in the small intestine, although its significance is not known.

Autoimmune diseases

Autoimmune diseases occur when a body’s own immune system turns against parts of itself. Specific types include autoimmune hemolytic anemia, autoimmune thrombocytopenia, systemic lupus erythematous, and discoid lupus erythematosus, among many others. No screening tests are available, and the hereditary component, if any, is not known.

Other German Shepherd problems, such as perianal fistulas, pannus, and degenerative myelopathy, may have an autoimmune component. Treatment is with drugs to suppress the immune system. A variety of autoimmune problems that strike all breeds include the following:

• Autoimmune hemolytic anemia, in which the body destroys its own red blood cells, leading to severe anemia. Affected dogs may be feverish, be lethargic, and have whitish gums.
• Autoimmune thrombocytopenia, in which the body destroys its own platelets, leading to spontaneous bleeding. Signs may include petechia (small red spots on the surface of the gums and skin and within the eye).
• Systemic lupus erythematosus, which affects many organ systems. Symptoms may include a recurring fever, arthritis in several joints, and small ulcers of the skin on the face or toes.
• Discoid lupus erythematosus, in which ulcers arise on the nose and face. They are aggravated by exposure to ultraviolet light.

Warning!

All of these conditions require prompt veterinary attention. Treatment is usually with drugs that suppress the immune system.

Pannus

Pannus may be yet another autoimmune disease, in which a triggering factor (which seems to be ultraviolet light) causes the body to destroy its own corneal cells. Also known as chronic superficial keratitis or German Shepherd Dog keratitis, pannus is a chronic inflammation of the eye’s cornea, the normally clear outer surface. It most often appears in young to middle-aged dogs, first appearing as a reddish area around the rim of the cornea, usually of both eyes. The pigmented area gradually expands toward the center of the cornea, leaving the affected areas covered with a brownish surface. Without treatment, the cornea will become opaque and the dog will become blind. Treatment consists of avoiding ultraviolet light (even fitting the dog with sunglasses) and instilling immunosuppressive drugs into the eyes.

Perianal fistulas

Perianal fistulas (also known as anal furunculosis) are chronic draining tracts in the tissue around the anus. They occur more often in German Shepherds than in any other breed. The exact cause is not known, but the condition may be related to an autoimmune problem, the configuration of the tail in which the broad tail is seated snugly over the anal area, or an overabundance of sweat glands around the anus. Symptoms may include open sores around the anus, foul odor, constipation, painful defecation, weight loss, and lethargy. Affected dogs may lick their anal region more than is normal.

Left untreated (and sometimes even with the best of treatment), dogs with perianal fistula can suffer so much pain that they must be euthanized. Antibiotics won’t cure the problem, but they can help with secondary infections that often arise from fecal contamination. Drugs to suppress the immune system are also usually prescribed. Surgical excision of the affected tracts, and sometimes amputation of the tail, may help, but a chance of fecal incontinence exists. Several types of surgical procedures are available; owners of affected dogs should seek the best surgical center to perform the operation.

Cancer

Cancer occurs relatively frequently in all breeds of dogs. Some breeds seem to be predisposed to certain types of cancer; unfortunately, the German Shepherd is one of them.

For example, hemangiosarcoma, a malignant cancer of the circulatory system, is seen more often in GSDs than in any other breed. No screening tests are available, and the hereditary component, if any, is not known. Most often, hemangiosarcoma occurs as a tumor on the spleen or heart. As the tumor grows, internal bleeding may occur. Affected dogs may suddenly appear disoriented, collapse, and exhibit signs of hypovolemic shock. They may also be extremely thirsty. Perhaps most noticeable, their gums may be almost white.

If the tumor is on the spleen, the spleen can be removed. Not all tumors of the spleen are malignant, so it’s a good idea to have a biopsy done and wait for the results before making a decision. If the tumor is malignant, or if it is on the heart, treatment is usually unrewarding. Unfortunately, most dogs with hemangiosarcoma succumb either to its primary effects (internal bleeding that cannot be stopped) or to cancer spread to other organs.

Osteosarcoma (bone cancer) occurs more frequently in large breeds, including the German Shepherd. It develops most often on a long bone of a leg and can sometimes be seen as a lump. More often, the owner first notices the dog limping; osteosarcoma is very painful. Owners face the terrible decision of amputation that must be made quickly, as time is of the essence to prevent the spread to other parts of the body. Dogs adjust to the loss of a limb fairly easily, but factors such as age, weight, arthritis, and other joint problems factor into how well the dog can cope with only three legs. Unfortunately, even with the best therapy, survival time for dogs with osteosarcoma is usually only a few months.

Mammary gland tumors are among the most common cancers in dogs, occurring mostly in females who were not spayed early in life. Spaying after the age of 2 years doesn’t impart the protection from mammary cancer that earlier spaying does. Approximately 50 percent of all mammary tumors are malignant. Therapy may include surgical excision and chemotherapy.

Lymphosarcoma is another of the more common cancers in dogs. This cancer affects the blood and lymph systems; symptoms may include swelling of the lymph nodes, especially in the lower neck area and behind the “knees.” Chemotherapy can extend the lives of many affected dogs.

Parasites and Infectious Diseases

Some dog breeds are more prone to certain infections or parasites, perhaps because of immune system differences. Many breeds are predisposed to developing demodicosis due to mites. German Shepherds are also more susceptible to fungal infection (aspergillus) and protozoal infection (ehrlichiosis). The following sections explain these conditions and their treatments.

Demodicosis

Demodicosis (also known as demodectic mange or red mange) is a type of mange that’s caused by increased susceptibility to the demodex mite. Most dogs have some mites, but in some dogs the mites proliferate and cause the dogs’ hair to fall out. Demodicosis often runs in families and seems to be passed from dams to offspring, although the exact hereditary nature is unknown. See Chapter Taking Care of a Sick Shepherd for more information about this condition.

Aspergillosis

When most people think of fungal diseases, they think of relatively minor problems. Many fungal diseases are deadly, however, and aspergillosis is one of them. The fungus aspergillus is found in soil and decaying vegetation throughout the world. Dogs inhale the spores, and usually nothing happens. In some dogs, however, the fungus colonizes the nasal passages, gradually causing the bone to deteriorate. These dogs have a nasal discharge, often tinged with blood. They may also sneeze and have a painful nose.

In some dogs, the fungus spreads into internal organs, causing disseminated aspergillosis. More cases of disseminated aspergillosis are seen in German Shepherds than in any other breed. Affected dogs may lose weight, appetite, and energy and may also experience fever, lameness, back pain, or paralysis.

Infected dogs must receive veterinary attention. Treatment of nasal aspergillosis is involved and expensive but can be successful. Treatment of disseminated asper gillosis, unfortunately, is far less satisfactory.

Ehrlichiosis

Ehrlichiosis (also called tick fever or tropical canine pancytopenia) is an underdiagnosed yet serious disease that’s spread by ticks. Some reports contend that GSDs are more susceptible to being chronically affected by the disease. Symptoms may include lethargy, loss of appetite and weight, fever, and spontaneous bleeding. Often, no strong signs of disease are present. Owners may complain that the dog just doesn’t seem as playful or is not quite right. Other symptoms may include coughing, arthritis, muscle wasting, seizures, and anemia. The point is that no one or two symptoms of themselves suggest erlichiosis as an initial diagnosis. A vet makes the definitive diagnosis by getting a blood titer, in which antibodies to the disease are found.

Ehrlichiosis wreaks its havoc by parasitizing the dog’s white blood cells, crippling the immune system. If diagnosed early, it can be treated effectively. If not, it can be fatal. If your dog has a host of seemingly unrelated symptoms, make sure that your vet rules out ehrlichiosis.

by D. Caroline Coile, PhD