Breed-Specific Genetic Problems Quiz

Answer: Early-onset Addison's disease

Addison's disease, in which the adrenal glands do not work properly, is common in several breeds, but usually occurs in older dogs. In tollers, the mode of inheritance is unknown, but it is suspected to be polygenic. Tollers are the only breed in which the disease regularly appears in puppyhood, sometimes as early as 4 months.

In addition, while Addison's disease in older dogs is very treatable, the disease in young tollers often does not respond well to medication and is fatal.

Answer: Gray collies

The disorder, an autosomal recessive, is often called "gray collie syndrome" for this reason. The disorder actually causes the color change in the coat to gray. It can be cured by a bone marrow transplant; this can actually cause the gray hairs to be replaced by normally-colored ones.

Answer: Cone degeneration (CD2 mutation)

Cone degeneration causes the cone cells in the eye to deteriorate, leading to day blindness. There is a DNA test to determine whether or not a dog carries the genes for the disease. Cone degeneration, with this particular mutation, is found in Alaskan Malamutes as well as in the pointer.

Answer: Canine leukocyte adhesion deficiency

This autosomal recessive disorder leads to death at an early age from overwhelming infections. There is no effective treatment. A DNA test exists to detect carriers of the disorder.

Answer: Congenital stationary night blindness

This disorder, in which the retinal pigment epithelium of the eye degenerates, was first discovered in Briards in Sweden. Gene therapy has been used to restore sight to affected dogs, and a DNA test exists to detect carriers of the disorder.

Answer: Storage disease

Storage diseases result from abnormalities in lysosomal enzymes, preventing them from doing their job of removing certain substances from cells. This results in the storage of inappropriate materials in the cells, leading to cell damage, especially to nerve and brain cells. Fucosidosis in Springers is an autosomal recessive and causes gradual motor and mental decline, leading to death. A DNA test exists to detect carriers of the disorder.

Many different types are found in a variety of animals as well as humans.

Answer: Inhibits normal blood clotting

This autosomal recessive disorder affects the production of thrombin, a protein necessary for clotting, by platelets. Dogs with this disorder may bleed easily and their blood may fail to clot properly, thus leading to hemorrhage. Some dogs are only mildly affected, others have severe bleeding problems. There is no cure.

Answer: Cardiovascular

Sick sinus syndrome is a malfunction of the sinus node, an area of the heart that acts as the heart's pacemaker. The mode of inheritance is unknown, and the treatment of choice is implantation of a pacemaker.

Answer: Siberian husky

As the disorder is X-linked, it is usually expressed in males, as males have only 1 X chromosome.

Answer: Gluten-sensitive enteropathy

Dogs with this disorder cannot tolerate gluten; the protein found in wheat. They develop severe diarrhea and lose weight. The symptoms disappear when the dog is fed a wheat-free diet. The method of inheritance is unknown.

Answer: Miniature schnauzer

Hyperlipoproteinemia, sometimes called hypercholesteremia, is common in the miniature schnauzer. When the dogs eat high-fat meals, they vomit and experience diarrhea and abdominal pain. The disease is treated by feeding a low-fat diet. The mode of inheritance is unknown.

Answer: Labrador retriever myopathy

This autosomal recessive disorder may cause mild to severe disability. Signs usually do not worsen after 6-8 months of age, and dogs may improve with age.

Answer: Chow chows

Dogs with myotonia have an awkward gait, difficulty moving, and stiff joints. Drug therapy may help affected dogs, and the condition usually does not worsen with age. This disorder is autosomal recessive in inheritance.

Answer: Meningitis

Usually seen in young beagles, beagle pain syndrome causes severe neck pain, depression and fever. The symptoms come and go. The disorder is treated with corticosteroids. The mode of inheritance is unknown.

Answer: It causes susceptibility to respiratory infections

Dogs with bullous pemphigoid suffer from large blisters, especially in the mouth, groin and armpits, that often become infected. The mode of inheritance is not known.

Answer: Immune system proteins

Complements are proteins that are vital to the functioning of the immune system. In affected dogs, complement 3 (C-3) is lacking. These dogs suffer from infections and immune-mediated kidney failure. The pattern of inheritance is autosomal recessive. There is no cure, but a DNA test exists to detect carriers of the disorder.

Answer: Basset hounds

In both humans and bassets, SCID is an X-linked recessive. There is no effective treatment in dogs.

Answer: Skin lesions

FSF involves an overproduction of interleukin-6, a cytokine that is involved with "priming" the immune response. It is a periodic disorder that comes and goes. It is treated with aspirin and with colchicine to help prevent amyloidosis, a severe side effect that can lead to kidney and liver failure.

Answer: Bronze discoloration of the skin

Dalmatian bronzing syndrome is probably related to excess production of uric acid, a trait that all Dalmatians share. Affected dogs have a patchy hair coat, bronze discoloration of the skin, and a susceptibility to skin infections. The mode of inheritance is unknown.

Answer: Zinc

Bull terriers with lethal acrodermatitis cannot metabolize zinc properly. This leads to stunted growth, skin lesions, and infections. Affected dogs usually do not live past puppyhood. The disorder is autosomal recessive.