Pituitary dwarfism in dogs
The pituitary dwarfism in dogs is a disease characterized by degeneration of the pituitary gland and the resulting lack of pituitary hormones ( growth hormone deficiency ) is characterized and a genetic defect underlies. Due to the lower amounts of growth hormone and thyroxine in the blood, growth comes to a standstill at around three to eight weeks of life, whereby the dwarfs are not disproportionate.
The genetic defect that causes pituitary dwarfism in the German Shepherd Dog is also the cause of the Saarloos Wolfdog and Czechoslovakian Wolfdog , as this disorder was observed for the first time after German Shepherd dogs were crossbred.
Clinical picture
Affected dogs have a fox-like appearance with widely spaced ears, a pointed snout and a slight overbite, and they also blink more intensely in bright sunlight. Untreated dogs keep their puppy fluff or lose their fur completely. Cover fur usually only develops on the head and foot regions.
The dwarfs suffer from a variety of clinical illnesses far worse than skin or coat problems. For example, the lack of growth hormones also leads to poor kidney development, which can lead to chronic kidney failure. The lack of TSH leads to an underactive thyroid, which makes the animal slow and clumsy. The lack or deformity of the sexual organs can be another consequence of the changed hormone composition. The insufficiency of the gonadotropins leads to a unilateral or bilateral cryptorchidism . Female dwarfs go into heat but do not ovulate .
Heredity
Dwarfism is an autosomal - recessive disorder that develops only in dogs that have inherited the mutated gene from both parents; these are referred to as P / P (positive / positive). Heterozygous carriers of this mutated gene (N / P, ie negative / positive) are clinically healthy and externally indistinguishable from unaffected animals, but transmit the disease to their offspring. If two heterozygous dogs (N / P) are mated, theoretically 25% of the offspring will be completely healthy (N / N), 50% will be carriers (N / P) and 25% will inherit the mutated gene from both parents and become dwarfed suffer (P / P) or die already intrauterine or shortly after birth.
It is assumed that only about 10% of the affected animals (P / P) survive and only in individual cases (depending on the treatment) become older than four years.
The birth of dogs with this serious disease should be avoided from the outset by not pairing any carriers with one another. Diagnosis is only possible through a gene test, which all relevant laboratories now offer. If this test were used on all breeding animals, the pituitary dwarfism could be completely eliminated.