Pituitary Dwarfism

Affected dogs will have a proportionately small stature and coat abnormalities including a puppy-like (lanugo) coat that lacks most primary or guard hairs. The skin may appear thin and dark (hyperpigmented) with signs of inflammation. Dogs may experience gradual hair loss and delayed or absent tooth development. There may also be reproductive abnormalities.

Clinical signs may be visible as early as a few weeks of life, but coat abnormalities and small size may not be clear until puppies are older. Affected dogs may need to be intensively nursed and hand-reared, which may lead to hypopituitarism being undiagnosed and labeled as “failure to thrive.”

Clinical history, genetic testing, and laboratory testing can be used in conjunction to diagnose Pituitary Dwarfism. Because this form of Pituitary Dwarfism is the result of combined pituitary hormone deficiency, in most affected dogs there is also secondary hypothyroidism.

One or more hormones may require supplementation as prescribed by your veterinarian.

Talk to your vet about your dog’s pituitary dwarfism result so you can discuss potential hormone deficiencies and the best plan for ongoing monitoring and treatment.

Some dogs with this condition may remain small but otherwise live comfortably with proper care and regular check-ins.

Provide a calm environment and consistent daily routines to support your dog’s energy and comfort.

Feed a balanced diet appropriate for their size and activity level, and monitor for any changes in coat quality, appetite, or activity that could indicate a hormonal imbalance.

This variant was first identified in Karelian Bear Dogs.

Penetrance: Pituitary Dwarfism is inherited in an autosomal recessive manner, meaning that affected dogs must have two copies of the variant to show clinical signs from it.

Gene

POU1F1 Intron 4

Inheritance type

recessive

Clinical category

Endocrine

Citations

1. Kyostila et al 2021
2. Andresen and Willeberg 1977

• Karelian Bear Dog