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available, one could argue that, following the precautionary principle, cloning horses is unethical on welfare grounds, since it seems that there are more problems associated with embryos, fetuses and foals created using SCNT than there are with foals conceived using other equine ARTs. The caveat to this ethical argument is that many of the
problems associated with cloning (in all species) are probably related to technique, particularly in vitro culture conditions (van Wagtendonk-de Leeuw et al. 2000). Interestingly, culture conditions which cause large offspring syndrome and abnormal clone phenotype in ruminants, seem not to have the same effects when used for nonruminant embryos (Hill 2014). No data is currently available about any possible correlation between SCNT techniques and particular problems in horses, but it seems reasonable to expect that in horses, as in other species, problems are likely to diminish as techniques improve (Hinrichs and Choi 2015). Paradoxically, techniques will not improve unless cloning continues. This is an argument if equine cloning is to continue to be allowed for those clinics undertaking equine cloning to undertake anonymised and collated reporting on the health and welfare of equine clones at all stages of their lives. Given the small numbers involved, such reporting could operate on a voluntary basis in the equine sector, with due attention to client confidentiality and commercial sensitivities. In order to acquire data about medium and long-term effects, owner cooperation would be required. Collated reporting would increase the evidence base about health and welfare issues experienced by equine clones and, importantly, any correlation between technique and such problems. Such evidence would simultaneously make it much easier to judge whether on welfare grounds equine cloning is or is not currently ethical and provide an evidence base for improving technique so as to minimise negative effects in future.
Cloning and sporting ethics
Consideration should be given as to whether there are any additional ethical arguments which might apply to cloning horses but not to cloning other species. One argument around the ethics of cloning which applies to horses and racing dogs, but not to farm animals species, concerns sporting ethics. Although cloned horses have been allowed to compete freely in some disciplines, such as polo, the FEI initially prohibited cloned horses from competing, on the grounds that (i) identifying clones by DNA testing would be problematic, and (ii) cloning conferred a competitive advantage, which violated the spirit of fair play. There is no convincing argument that cloning is unethical
based around identification. Despite concerns that some sports horses are not DNA tested and that the FEI’s ban on cloning was therefore unenforceable (http://
internationalanimallaw.com/node/784, accessed 08.01.2016) the vast majority of equine studbooks now use DNA analysis to identify and register horses and would thus be capable of identifying clones and registering them as such. Given that clones do not normally look physically identical to the donor animal or to each other, and that microchipping of horses is commonplace (in some countries, a legal requirement), distinguishing between a cloned and a donor animal or between two clones with identical DNA should not be problematic.
Concerns that cloning confers an unfair competitive
advantage are, at the least, unproven. In the one report on racing cloned animals against their noncloned peers, the cloned animals’ performance was mediocre (http://www.
thehorse.com/articles/16552/cloned-mules-race-into-history). The FEI does not record clones competing under its rules and does not have data on the competitive success of clones compared with nonclones (G. Akerstrom, personal communication). However, to date, there has been no media coverage reporting that cloned horses have won important FEI events. There is no convincing evidence that equine cloning is
unethical because of reasons relating to sporting ethics. This is consistent with the fact that the FEI reversed its ban on clones competing in 2012.
Ethical issues facing veterinarians undertaking cloning
Finally, this article considers the ethical dilemmas which might face veterinarians whose clients ask them to become involved in equine cloning. Cloning is a very specialised technique, performed in a small number of centres worldwide. The involvement of most veterinarians is therefore likely to be limited to taking a skin biopsy from a donor animal, to provide the nuclear material necessary for the SCNT process and possibly to providing neonatal and later healthcare for cloned offspring. All ARTs are ethically unusual in that, unlike most
veterinary procedures, they are usually undertaken with no expectation of improving the health or welfare of the animal on which they are performed. In this respect, cloning is no different from commonly used equine ARTs such as artificial insemination and embryo transfer. Depending on the AR technique, the health and welfare of up to three animals (a donor animal, a recipient animal who gestates and gives birth to the foal and the foal itself) should be considered. In terms of the direct effects on the donor animal, there is
nothing inherently ethically different about a veterinarian subjecting a donor animal to a skin biopsy for SCNT than there is about a veterinarian subjecting a donor animal to another ART such as embryo retrieval; both are mildly stressful/painful procedures for which analgesia and sedation can be provided (Campbell and Sandoe 2015), which are not expected to offer any direct benefit to the donor animal. As discussed above, however, cloning is associated with risks to the health and welfare of cloned foals. Such risks have not been proven in foals created by other equine ARTs (Campbell and Sandoe 2015). The risks to foals produced by cloning may provide veterinarians involved in undertaking skin biopsies for SCNT with grounds for questioning the ethical justification of being involved in such procedures, albeit that the direct negative welfare effects on the donor animal on which the skin biopsy is being performed are mild and can be alleviated.
Conclusion
Arguments about unfair sporting advantage are unconvincing grounds for considering equine cloning unethical. There is no evidence that eating either cloned horsemeat or cloned meat from other animals poses a public health risk. However, all cloned meat ought to be clearly
©2016 TheAuthors EquineVeterinary Education publishedbyJohnWiley&Sons Ltdonbehalf of British EquineVeterinary Association
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