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Canine Hermaphroditism
and Pseudohermaphroditism
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True hermaphroditism is when both
ovarian and testicular tissue are present in the same individual.
Pseudohermaphroditism is when the external genitalia is of the opposite
sex as the gonads
Signs
May be no overt problems
Surgical Treatment
Remove gonads.
Cosmetic surgery on external genitalia may be performed
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What are disorders
of sexual development?
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At fertilization, the sex chromosomes
are established as XX (the animal will be female) or XY (male). During
development of the embryo, ovaries develop if XX, and testicles if XY.
An abnormality can occur in chromosome differentiation (to produce XXY,
XXX, XO) - this is rare in dogs and is not thought to be inherited. Gonadal
intersex refers to developmental abnormalities in the gonads (ovaries and
testicles) despite a normal set of sex chromosomes. In some cases (pseudohermaphrodites),
the sex chromosomes in these dogs match the sex of the gonads, but the
genitals are abnormal. This is only seen (rarely) in females, and is generally
due to excess exposure to male sex hormones during development - ie. environmental
factors rather than an inherited condition.
Sexual reversal describes the condition where the chromosomal and gonadal
sex differ. Only XX sexual reversal has been seen in dogs. The dog may
be an XX true hermaphrodite (female chromosomes in a dog with both ovaries
and testicles), or XX male (female chromosomes, with testicles).
How is sexual reversal inherited?
XX sex reversal is an autosomal recessive trait in the American cocker
spaniel.
What breeds are affected by sexual reversal?
These conditons are seen (uncommonly) in the American cocker spaniel,
German short-haired pointer, beagle, basset hound, pug, Kerry blue terrier,
and Weimaraner.
For many breeds and many disorders, the studies to determine the mode
of inheritance or the frequency in the breed have not been carried out, or
are inconclusive. We have listed breeds for which there is a consensus among
those investigating in this field and among veterinary practitioners, that
the condition is significant in this breed.
What do disorders of sexual development mean to your dog & you?
Affected animals are infertile (so that your apparently female dog will
not come into heat), and may have chronic irritation in the genital area,
which may look abnormal to you.
How are disorders of sexual development diagnosed?
Your veterinarian will typically suspect one of these conditions when
s/he notices an abnormality such as clitoral enlargement or an abnormal penis
during physical examinataion of your dog, or if a breeding dog is being examined
for infertility.
To diagnose the specific condition requires that your veterinarian
evaluate both internal (generally at the time of spay) and external sex
organs, and send away a blood or other cell sample from your dog for karyotyping,
which identifies the chromosomes.
For the veterinarian: Dogs with XX sexual reversal may be XX true
hermaphrodites or XX males. These dogs can appear in the same family, and
result from the same genetic defect. XX true hermaphrodites have both ovarian
and testicular tissue. The degree of masculinization of internal and external
genitalia depends on the proportion of testicular tissue in the gonads.
XX males have a uterus, bilateral (usually undescended) testes, and
a prepuce that is located abnormally.
How are disorders of sexual development treated?
Affected animals should be neutered.
Breeding advice
Affected animals, their parents (carriers) and siblings (potential carriers)
should not be used for breeding.
FOR MORE INFORMATION
ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.
Resources
Mickelsen, WD, Memon, MA. 1995. Inherited and congenital disorders of
the male and female reproductive systems. In E.J. Ettinger and E.C. Feldman
(eds.) Textbook of Veterinary Internal Medicine, p. 1686-1690. W.B.
Saunders Co., Toronto.
Copyright
© 1998 Canine Inherited Disorders Database. All rights reserved.Revised:
December 14, 2001.
This database is a joint
initiative of the Sir James Dunn Animal Welfare Centre at the Atlantic
Veterinary College, University of Prince Edward Island, and the Canadian
Veterinary Medical Association.
reprinted
with kind permission from:-
Alice
Crook, DVM,Coordinator, Sir James Dunn Animal Welfare Centre, Atlantic
Veterinary College,University of Prince Edward Island, 550 University Ave.Charlottetown,
PEI C1A 4P3
http://www.upei.ca/cidd
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The above information is simply informational. It's intent is
not to replace the advice of a veterinarian nor to assist you in making a
diagnosis of your pet. Please consult with your own veterinarian for confirmation
of any diagnosis. Your pets life may depend on it.