Growth Hormone-Responsive Dermatoses in Dogs
Dermatosis, or skin diseases, due to a deficiency of growth hormones are uncommon in dogs. However, there are two types of dermatosis that affect canines: pituitary dwarfism (seen at two to three months of age) and adult-onset hormone-responsive dermatosis (skin disease usually seen at one to two years of age).
Pituitary dwarfism is most often seen in German Shepherds, but has also been reported in Spitzes, Toy Pinschers, and Carnelian Bear Dogs. Adult-onset hormone-responsive dermatosis has been reported in Chow Chows, Pomeranians, Poodles, Keeshonds, Samoyeds, and American Water Spaniels. Though this mostly affects male dogs, it can be seen in both sexes.
Symptoms and Types
Pituitary Dwarfism (Signs at two to three months of age)
- Baldness on both sides of the torso, neck, and backs of the thighs
- Hair growth occurs over face and legs only
- Retained puppy coat is easily pulled out (or falls out)
- Skin is thin, scaly, and dark with blackheads
Adult-onset Growth Hormone-Responsive Dermatosis
- Baldness on both sides of the torso, neck, and insides and backs of the thighs, on the tail, on the underside of the abdomen, under the tail, and on the ears
- Hair present on the head and legs
- Hair easily comes out
- Tufts of hair regrowth at injury or tissue sampling sites
- Genetically recessive trait which results in an abnormally developed pituitary gland and lack of growth hormone production
- Unknown, possibly pituitary cancer
- Hereditary influence probable
Your veterinarian will want a complete medical history of the dog, so as to determine when the animal began showing signs of the dermatosis. He or she will conduct a physical physical exam on the animal to help categorize the skin disease as either adult-onset or pituitary dwarfism.
To test for a growth hormone deficiency, the veterinarian may send blood away to have its Somatomedin C concentrations measured, give an insulin response test, test for normal adrenal gland function, and take skin samples to be analyzed at the laboratory. If your veterinarian suspects pituitary dwarfism, he or she may test adrenal and thyroid function.