Pituitary Anatomy Diagram

The pituitary gland is a small gland located within the skull just beneath your dog’s brain. Pituitary dwarfism is genetic, and if your dog is affected by this condition, they will fail to grow normally. Dogs that have pituitary dwarfism are also at risk of developing additional health concerns as they mature, such as kidney disease.

These dogs are often affected by hypothyroidism, meaning they do not produce enough thyroid hormone. If you think that your dog may have pituitary dwarfism, talk to your veterinarian for information and advice.

Diagnosis

Pituitary dwarfism is suspected based on the dog’s breed and clinical signs. German Shepherds are, by far, the most commonly affected breed. Dogs with pituitary dwarfism grow at a much slower rate than normal dogs and do not reach full size. These dogs often keep their puppy coats and may have hair loss on both sides. Skin infections may develop, and changes like skin darkening and scaling can be seen.

Dogs with pituitary dwarfism may develop neurological signs later in life. The underlying abnormality causes a cyst to form in the pituitary, which can enlarge and cause neurological abnormalities. Affected dogs can also have incorrect formation of the first two vertebrae (bones in the spine), leading to spinal cord damage. Neurological signs include abnormal behavior, lack of balance, strange gait, neck pain, or a tilted head.

Additional diagnostic tests should be done to confirm pituitary dwarfism since other conditions can also cause poor growth. Appropriate treatment depends on a correct diagnosis. The measurement of insulin-like growth factor-1 (IGF1) is very helpful, but it is not perfect. Genetic testing is used to diagnose breeds known to have a genetic cause. Blood work, imaging studies, hormone analyses, and genetic tests can help your veterinarian come to a final diagnosis.

Treatment

Because pituitary dwarfism is caused by an inability of the pituitary gland to produce hormones, this disease is treated by providing hormonal replacement therapy. By replacing some of the important hormones that your dog is missing, their body functions more normally. This treatment will not allow the dogs to grow to full size, but if treatment is initiated early enough, it will help them grow significantly more than if they were untreated. Hormonal replacement will also help with coat and skin abnormalities. Growth hormone replacement is typically not available, unfortunately. Progesterone treatment can stimulate growth hormone production, but it can have severe adverse effects.

Although not proven, initiating this type of treatment may reduce your dog’s chances of developing kidney disease due to pituitary dwarfism.

Dogs that experience hypothyroidism along with pituitary dwarfism should also be treated with L-thyroxine, which is the thyroid hormone that the dog is not producing on their own.

Additionally, if your pet develops a skin infection, appropriate antimicrobial treatment should be given.

Prevention/Prognosis

Dogs that receive appropriate hormonal replacement therapy have a better prognosis than those that do not, and any skin and coat issues are usually resolved within six to eight weeks.

If dogs are young enough when treatment with growth hormone or progesterone is started, they can grow in height, although normal stature is not typically achieved. Dogs that receive treatment have a longer life expectancy than those that do not, but it may not be a normal length. L-thyroxine therapy may be the most important therapy for extending survival. Neurological abnormalities that develop (brain or spine) can be life-limiting.

Without treatment, dogs with pituitary dwarfism usually live three to five years.

Genetic screening can be done before breeding dogs to eliminate the risk of having a litter affected by this disease. Dogs with pituitary dwarfism are typically infertile, but if fertile, breeding would be discouraged as they are likely to pass this condition on to their puppies.