Intersex can be divided into two main types: true hermaphrodites and psuedohermaphrodites.
In true hermaphrodite, phenotypes can be XX males (normally XY) with testes and normal external genitalia, XX males with testes and ambiguous genitalia, and XX true hermaphrodites with ovotestes and ambiguous genitalia. XX males are reported in upwards of 20 breeds. An enlarged clitoris is a consistent clinical observation, 90% of which contain ossified tissue consistent with an os penis. XX disorders of sexual development in the dog can be sporadic but will often display familial clustering; pedigrees are usually consistent with patterns of autosomal recessive heredity but are sometimes described as autosomal dominant.
Female hermaphrodite dogs normally display clitoromegaly but otherwise may appear normal except for some increase in abdominal size.
Pseudohermaphrodites often display a combination of genitals such a fleshy mass protruding from the vulva. Upon operation the ovaries appear to have testicular growth associated with them and are known as ovotestes. Pseudohermaphroditism is also associated with Sertoli cell tumor and cryptorchidism.
Clinical signs are often difficult to determine as most are diagnosed during routine desexing procedures.
Treatment in most cases is elective neutering.
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