Abstract
Historically, cats have done very well at reproducing themselves and, for most of us, our first experience of using a scalpel as veterinary students was performing the easiest (and most available) surgery: spaying a queen or castrating a tom. Accordingly, over the majority of the past century at least, feline reproduction has been in the collective imagination as something to be blocked or stopped.
Meanwhile, reality was being turned upside down by the entrepreneurship of the cat fancy, by rising standards of living and changing demographics (including more people living alone), and by the impressive ability of cats to fulfill a variety of needs, including the need for companionship. In some countries (eg, the UK), cats have now overtaken dogs in terms of numbers of companion animals at home, 1 and there are data from the US to show that cat visits to veterinary clinics are rising at a higher rate than dog visits. 2 Yet, until recently, the only feline reproductive knowledge being imparted to veterinary students was how to neuter.
For pet cats, a neutered life in the home environment is still very much the norm – and certainly dexterity in spaying and castrating queens and toms remains an important asset in feline practice. However, (intact) cats have gained importance – principally for feline breeders, whose number and professionalism have dramatically increased in recent decades, but also in research, as models for the study of endangered feline species. Interestingly, the most powerful force driving the need for knowledge in feline reproduction has been one of the breeding and registration rules of the International Feline Federation (FiFe) stating that ‘Queens must not have more than three litters in 24 months’. Suddenly, the new challenge for feline practitioners became identifying a ‘reversible’ way of blocking reproduction, using hormones rather than scalpels.
Cloud, a domestic shorthair queen, kept intact owing to a heart condition precluding surgery. Following a mismating at the time of her pubertal heat she was treated with a progesterone antagonist to interrupt her pregnancy. She was subsequently managed with a long-acting GnRH agonist
This triggered the so-called ‘progestin saga’, whereby queens around the world were regrettably subjected to incorrect dosing of steroids; and, in turn, a huge number of case reports documenting progestin toxicity in cats appeared in the literature. More recently, the veterinary armoury has been enriched by several interesting new drugs for controlling reproduction, most notably gonadotrophin-releasing hormone (GNrH) agonists and antagonists but also zona pellucida vaccines, melatonin and dopamine agonists.
Reversible control of reproduction is clearly not the only topic of relevance for those of us who work with intact cats. Breeders are increasingly expecting us to be knowledgeable about normal pregnancy, pregnancy diagnosis, parturition and dystocia, neonatology and congenital/ inherited diseases. Moreover, they pose us very challenging questions: how to ensure health in a cattery, how to deal with fading kittens, when to opt for a caesarean section, how to resuscitate a neonate, and even how to solve fertility problems in queens or to assess breeding soundness in tom cats. All of these (and many more) questions are addressed in the six papers of this Special Issue of JFMS devoted to Feline Reproduction and Reproductive Problems. Further articles are in the pipeline and the series (available at bit.ly/JFMSreproduction) will grow as these come to fruition over the coming months.
The aim is to provide current information and stimulate readers to learn more about this fascinating field. I thank all of the authors, who have worked so hard to ensure that we, as feline practitioners, can play a vital role in helping our clients produce healthier and more fertile cats.