|
Canine
Hermaphroditism
and Pseudohermaphroditism
|
|
A Hermaphrodite
is an animal in which the reproductive tissue of both sexes is
present.This condition
is very rare but it has been seen occasionally. In the womb the
reproductive system does not develop normally and in consequence they
end up with abnormal genitals and internal organs and are likely to be
sterile. Being a hermaphrodite rarely affects the quality of life
and doesn't normally cause any particular behavioural problems.
Abnormal internal organs should be removed in a neutering operation to
prevent further disease, as they can otherwise become cancerous and
abnormal genitals may need surgical treatment if they are likely to
interfere with normal urinary function.
True hermaphroditism is when
both
ovarian and testicular tissue are present in the same individual.
A lateral hermaphrodite has an ovary on one side and a testicle on the
other. A bilateral hermaphodite has an ovary and testicle (or combined
ovary-testis) on each side. 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
*************
|
What are
disorders of sexual development?
|
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
********************
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.