Suppression of Fertility in Pre‐pubertal Dogs and Cats

Abstract

Contents Pre‐pubertal gonadectomy in dogs and cats is still controversially discussed because some consequences cause health problems. Nevertheless, postponement of puberty, that is, prevention of an increase in sexual hormones and thereby prevention of their manifold effects, is of major importance, not only in controlling overpopulation but also to preserve the genetic base for future breeding stock and pets. Therefore, alternatives for surgical suppression of fertility in pre‐pubertal animals were critically reviewed. As a promising alternative, the slow‐release GnRH agonist deslorelin and other GnRH analogues have been investigated. In female dogs and cats, puberty could be significantly postponed without initial flare‐up effect and without disturbance of body development. First trials to delay puberty in female and male cats by application of a 4.7‐mg deslorelin implant 24 h after birth so far are promising. In female dogs, a previous investigation showed that when the implant was inserted at the age of 4 months, the initial flare‐up effect was prevented. Body development was normal in the studies reviewed here, and with the 9.4‐mg implant, puberty was significantly delayed until the age of 21 months or older. In one study, bitches either received a 4.7‐ or a 9.4‐mg implant at the age of 4 months and the epiphyses were mostly closed before the time of first oestrus. Using a 4.7‐mg deslorelin implant in pre‐pubertal male dogs significantly postponed puberty, and age at puberty was >2 years when a 9.4‐mg implant was used. However, further investigations are required, especially concerning the effect of different GnRH agonist dosages and resorption rates on the duration of postponement of puberty as well as long‐term effects in both dogs and cats.

Desexing Dogs: A Review of the Current Literature

“…While these implants are not currently commercially available in North America, they are now widely used in veterinary practice in both Europe and Australia. Their use has also been suggested to delay the onset of puberty in both male and female dogs by several years [51][52][53].…”

Interval between Removal of a 4.7 mg Deslorelin Implant after a 3-, 6-, and 9-Month Treatment and Restoration of Testicular Function in Tomcats

“…Deslorelin is marketed as subcutaneous implants for use in male dogs to cause a reversible chemical sterilization through a desensibilization of hypothalamic GnRH receptors, which suppress pituitary gonadotropin secretion [2]. In male dogs, deslorelin causes a lowering of serum testosterone (T) concentration to undetectable levels, reduction of testicular volume and lack of sperm production from 6-8 to 24 weeks post-treatment [3][4][5][6]. A similar reversible long-term contraception was observed following the use of deslorelin implants in many species, such as ferrets, cats, wild carnivores, birds, and marsupials [7][8][9][10][11].…”

Persistência de frênulo peniano congênito em gato macho:

“…In fact, Gaytan et al (1988) verified relationship between balano-preputial separation and androgen production during sexual maturation in rats, since this fact does not occur when animals are castrated or when substances with antiandrogenic effects are administered (Yoshimura et al, 2005). Therefore, although the expected interval for a definitive diagnosis of this condition in cats is not described in literature, it is assumed that the animal in the present report was already at the age for the initial development of sexual maturity, since the presence of androgen-dependent penile spicules was observed (Carranza et al, 2014;Schäfer-Somi et al, 2014). Thus, it could be inferred that the present report is a case of persistence of penile frenulum.…”