The results of a urinalysis and routine blood work (a complete blood count and serum biochemistry profile) are almost always normal in dwarf dogs, unless they also happen to have some unrelated medical disorder or disease. Usually, the physical appearance of the dog, its breed and its history are sufficient to enable the veterinarian to make a presumptive diagnosis of genetic dwarfism with some degree of confidence. Radiographs (X-rays) of the short legs, and of the skull and spine if they also appear abnormal, probably will show atypical growth of both cartilage and bone. A definitive diagnosis of dwarfism can be made by taking bone biopsies and submitting the samples to a laboratory for microscopic evaluation by a veterinary pathologist.
Pituitary dwarfism can be diagnosed through hormonal testing of blood samples. The veterinarian will be looking for the level of growth hormone in circulation; pituitary dwarfs will have very low circulating levels of that particular hormone. Computed tomography (CT scan) and magnetic resonance imaging (MRI) can also be used to identify the tiny pituitary cysts which commonly are present in the pituitary gland of pituitary dwarfs.
It is not difficult to identify canine dwarfs, especially in breeds where the traits associated with dwarfism are considered to be desirable. In other breeds, X-rays and bone biopsies are probably the most reliable methods to diagnose the nature and extent of the dog’s skeletal abnormalities.