Cats and Dogs: Two Neglected Species in this Era of Embryo Production in Vitro?

Abstract

Contents During the last decades, in vitro fertilization (IVF) has become a routine technique in most domestic animals. However, in the dog the technique has lagged behind, with to date not a single pup born after IVF. In cats, healthy kittens have been born, but in fewer numbers than in cattle and horses. In pet animals, research in reproduction has mainly been focused on contraception, although recently, the introduction of new drugs especially marketed for cats and dogs will probably expand fertility research in carnivores towards the previously neglected area of assisted reproduction. In particular, the dog remains a real challenge for the reproductive biologist, due to the low meiotic capacity of canine follicular oocytes. In cats, oocyte maturation is less of a problem and embryo production rates comparable to those of cattle can be achieved. The domestic cat is a valuable model for endangered felids and it can even be used as a recipient for wild felid embryos. In this short review, we list some of the problems associated with the implementation of IVF in dogs and cats in relation to their reproductive characteristics, and we discuss the state‐of‐the‐art of IVF in several other domestic species such as cattle, horses and pigs.

In vitro fertilisation in domestic mammals—a brief overview

“…However, the domestic cat is an excellent model for other feline species, and almost all large cats are threatened by extinction at least to some extent. Only a few domestic kittens have been born after IVF ( 26 , 27 , 56 ). When a genetically important animal unexpectedly dies, gametes can be collected and either directly subjected to IVP or frozen for future use.…”

“…When a genetically important animal unexpectedly dies, gametes can be collected and either directly subjected to IVP or frozen for future use. For cats, between 40% and 80% of the COCs mature to MII phase, and the proportion of cleaved embryos developing in vitro can reach 70% ( 56 ) but is usually lower. In SLU Uppsala, we have used the domestic cat as a model to increase the number of spermatozoa that can be salvaged from the testicles after removal.…”

40 years of bovine IVF in the new genomic selection context

“…Therefore, as early as the late eighties, obtaining hundreds of embryos per experiment using slaughterhouse material was a true possibility. This almost unlimited source of oocytes in cattle and pigs was instrumental to the development of better techniques and culture conditions compared to other species where progress has been slower like horses and IVF is still limited by the sperm failure to fertilize in vitro requiring injection of spermatozoa into the oocyte (Leemans et al 2016) or pets where seasons and physiological peculiarities alter the success of IVF (Van Soom et al 2014).…”

Effect of Different Reproductive Stages and Culture Times on Domestic Cat <i>in Vitro </i> Oocyte Maturation

“…Several assisted reproduction techniques have been implemented in companion animals, such as artificial insemination, cryopreservation of germ cells (sperm, oocytes, and embryos), in vitro embryo production (IVEP), and embryo transfer [4]. IVEP in wild cats can be an important tool for those oocytes recovered from ovaries obtained by Ooforo-Salpingo-Hysterectomy (OSH), due to medical or post-mortem reasons [5], and help the conservation of threatened and endangered species [6].…”