Reversible control of reproduction in tom cats: medical options for manipulating libido and fertility

Abstract

Background: There has been a growing interest in alternatives to surgery for controlling reproduction in tom cats, and the resultant medical options add to a practitioner’s toolbox when handling these cases in clinical practice. It is important, however, that when suggesting these drugs, veterinarians have a good understanding of their mode of action, and their correct use and dosage. Clinical relevance: Breeders increasingly wish to be able to switch on/off the reproductive ability of their tom cats in a controlled manner. In addition, in small animal medicine, there has been concern from some academics, and a growing number of pet cat owners, about potential long-term effects of surgical sterilisation. Further, for some cats surgical castration may not be possible due to health conditions that mean anaesthesia is unsafe. In all of these scenarios, medical alternatives to surgery can prove useful. Equipment and technical skills: No special equipment or technical skills are required. A good knowledge of the medical alternatives to surgical sterilisation for controlling reproduction in a tom, and making sure the patient is a suitable candidate, are, however, important for ensuring the cat’s health during and after treatment and the owner’s satisfaction. Audience: This review is aimed principally (but not exclusively) at veterinary practitioners working with cat breeders who seek a temporary arrest in their tom cat’s reproduction. It may also help practitioners with clients who would like an alternative to surgery or with cats where anaesthesia for surgical castration is not possible. Evidence base: Advances in reproductive feline medicine have resulted in improved knowledge of medical contraception. This review draws on scientific evidence-based papers that report on the mode of action, length of efficacy and potential side effects of different methods of medical contraception, as well as the authors’ own clinical experience.

Successful parturition and lactation after a deslorelin implant removal in a pregnant cat

“…Given the uncertain effects of deslorelin implantation on pregnant queens, performing ultrasound examinations to exclude pregnancy is essential before administration of the implant. Queens living with intact males, even if chemically castrated, need to be especially considered given the wide range of durations of deslorelin-induced anoestrous in tom cats (6-18 months) 17 and queens (4-38 months). 12…”

Male animal sterilization: history, current practices, and potential methods for replacing castration

“…Hormones, including steroids and synthetic peptides, have been explored for controlling male reproduction. However, the focus has been on reversible contraception for both men and domestic or wildlife animals ( 21 , 156 , 182 , 197 , 403–406 ) rather than inducing sterility. For instance, anabolic steroids such as testosterone undecanoate can be used alone or with a progestin to temporarily suppress gonadotropins, leading to azoospermia, or the absence of sperm.…”

“…GnRH agonists and antagonists, which suppress gonadotropin synthesis and secretion, have been widely tested in domestic and wildlife animals. GnRH agonists, such as deslorelin, have been used successfully for temporary inhibition of reproduction in both males and females ( 20 , 92 , 152 , 156 , 186 , 408–415 ). Suprelorin® (Virbac) is commercially available in Australia, New Zealand, and Europe for contraception in male dogs.…”

Gene-Based Therapy: A New Approach to Feline Induced Sterilization?

“…Melatonin treatments are not used in males, as the effects of photoperiod on male reproductive function are less evident [26,27]. Male cats usually show light to moderate seasonal changes in sperm quality [27], but libido is not largely affected, and they retain breeding ability [28] unless the negative photoperiod is extended [29]. The effects of melatonin treatment in male cats mimic season-associated changes in gonadal function [30].…”