An anatomic and genetic study of canine cryptorchidism

Abstract

Twelve cases of cryptorchidism were found in a colony of Minature Schnauzer purebred and crossbred dogs. At least nine affected dogs were derived from the same sire directly or indirectly. Of 12 affected dogs, five cases were unilateral and seven were bilateral. Eight of the 12 cases were subjected to anatomic study. Fixation of affected organs was by vascular perfusion or immersion. Testes were separated from epididymides and both were weighed. All unilateral retained testicles were on the right side, and right sided bilaterally retained testes were always smaller than their left sided counterparts. With only one exception, ectopic testes were in the abdominal positon. Developmentally, the morphologic appearance of the epididymis of abdominal testes was very primitive in bilateral cases but nearly normal in the unilateral cases. Degree of inbreeding was greater for bilateral cases than unilateral cases. High incidence of cryptorchidism in this colony provided good evidence for hereditary nature of the condition in the Miniature Schnauzer dog. Morphologic observations were suggestive of a multiple gene defect.

Cryptorchidism in Florida Panthers: Prevalence, Features, and Influence of Genetic Restoration

“…Among these are maternal vitamin A deficiency (Wilson et al, 1953), in utero exposure to high levels of estrogen (Rajfer and Walsh, 1977), and genetic factors (McPhee and Buckley, 1934;Claxton and Yeates, 1972;Cox et al, 1978). ruled out vitamin A deficiency as a likely cause of congenital deformities, including cryptorchidism, in Florida panthers.…”

Cryptorchidism in common eutherian mammals

“…It is also possible that at least some cases of cryptorchidism in common animals result from fetal exposure to endocrine disruptor agent. Despite limited size of studies, there is no doubt that brother-sister matings of dogs or pigs over several generations increases incidence of cryptorchidism (Cox et al 1978, Mikami & Fredeen 1979, McPhee & Buckley 1984. There also is anecdotal opinion that cryptorchidism is familial in some sire lines of horses and pigs.…”

“…This is too simplistic. Approximately 25 years ago, the notion of a single locus gene problem gave way to acceptance of a polygenic recessive model, based on relatively small studies with pigs (Sittmann & Woodhouse 1977, Rothschild et al 1988; dogs (Cox et al 1978, Nielen et al 2001; and also for men (Czeizel et al 1981). Unfortunately, techniques of modern molecular genetics have not been applied to sub-human species with a sufficient incidence of cryptorchidism to justify a study of gene abnormalities (e.g.…”

Criptorquidectomía laparoscópica en dos perros utilizando bisturí ultrasónico

“…La orquiectomía bilateral es el tratamiento de elección en estos pacientes, ya que el criptorquidismo se reconoce como una condición heredada, ligada al sexo autosómica recesiva de rasgo poligénico (1,8). También los testículos retenidos se constituyen en factor de riesgo para el desarrollo de neoplasia testicular (13.6 a 14.3 mayor probabilidad de desarrollar tumores que los testículos escrotales) (3,4), además, los testículos retenidos en el abdomen, presentan un riesgo incrementado de torsión cuando desarrollan neoplasias (9).…”