Peer-reviewed veterinary case report
Dog with extra hind paw and both male and female genitalia
By Paquet, Marilène et al.·Published in Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc·2011·McGill University, Canada·View original on PubMed →
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Original publication title: Atypical caudal duplication with phenotypic sex reversal in a dog.
- Species:
- dog
Plain-English summary
A male German Shepherd Dog mix was brought in for chronic limping on his left hind leg, which was not bearing weight. Upon examination, the vet found severe joint issues and what looked like a second paw. Surprisingly, the dog had both male and female reproductive organs, which is very unusual. After amputating the affected leg, tests showed that the dog had a genetic condition causing this duplication and the presence of both sets of genitalia. The dog was diagnosed with a rare condition called atypical caudal duplication, and while the situation was complex, the surgery helped alleviate his pain.
People also search for: dog limping left leg · German Shepherd with two sets of genitalia · chronic lameness in dogs · dog leg amputation recovery
Abstract
A male German Shepherd Dog mix was presented for chronic non-weight-bearing lameness of the left hind limb. At clinical examination, the dog's left hind limb had severe joint contractures, with the presence of what appeared to be a second paw. The dog also had 2 sets of external genitalia of opposite phenotypic sex; a complete male reproductive tract with a left retained testicle and a right descended testicle, as well as rudimentary female external genitalia including a hypoplastic vulva with a blind-end vagina and a hypertrophied clitoris. The female genitalia were located on the proximal posterior third of the deformed limb. Following amputation of the hind limb, gross pathologic analysis revealed a duplication of the fibula, tarsal, and metatarsal bones, digits, and appendices. The supernumerary structures and female genitalia were concluded to represent a parasitic twin. As conjoined or parasitic twinning of non-identical twins is thought to be impossible, the presence of genitalia of opposite phenotypic sex appeared paradoxical. Polymerase chain reaction analyses were therefore performed to determine the genotypic sex of both animals, which revealed the presence of the Y chromosome in all tissues, including the female genitalia. The non-masculinization of the external genitalia in the parasitic twin was presumed to be the result of an embryonic developmental defect. On this basis, a diagnosis of atypical caudal duplication (parasitic twinning) with phenotypic sex reversal was made.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/21908371/