A widely recognised specialist in animal welfare science and ethics has raised questions around the cloning of horses.
Dr Madeleine Campbell, an honorary lecturer with London’s Royal Veterinary College, discusses a series of issues around horse cloning in a review published online this week in the journal, Equine Veterinary Education. Her piece is entitled, “Is cloning horses ethical?”
Campbell qualified as a vet from the college in 1996 and completed a doctorate in equine reproduction in 2003. She completed a masters degree in medical ethics and law in 2012 and was this year recognised as a European specialist in animal welfare science, ethics and law by the European College of Animal Welfare and Behavioural Medicine.
“For some people, cloning horses and other species is unethical because cloning goes beyond the limits of how far man ought to interfere with nature and is therefore simply morally repugnant,” she said.
“Such arguments are hard to refute, because they are a matter of moral conscience. However, the concept of ‘an affront to dignity’, which forms part of some moral objections to cloning, seems a weak ethical reason for branding cloning ethical.”
She continued: “Concerns about the health and welfare of recipient animals gestating and giving birth to clones and about the short, medium and long-term health and welfare of cloned farm animals provide compelling reasons to consider cloning unethical on cost-benefit grounds.
“What little evidence exists so far suggests that some welfare problems which are prominent in the cloning of farm animals, particularly fetal oversize and dystocia [obstructed labour], do not occur with such significance in horses,” she added.
“However, other reported problems, particularly those occurring in equine neonates [newborns] and foals, render use of the technique ethically dubious.”
Campbell suggested the onus was on all those providing commercial equine cloning services to provide a stronger evidence base for ethical decision-making about equine cloning by collating data about the short, medium and long-term health of cloned horses.
“This will require collaboration not only between specialist centres, but also with veterinarians who are not specialists in cloning, but who provide healthcare for cloned offspring throughout their lives.”
Somatic cell nuclear transfer
Campbell says somatic cell nuclear transfer (SCNT), or “cloning”, is currently being offered as a commercial method of horse reproduction in countries including the European Union, the United States, Australia, New Zealand and South America.
In 2012, it was estimated that there were 100–200 cloned horses worldwide.
“It is likely,” she said, “that the number of cloned horses being born per year is small.”
She noted 2015 research that reported 20 viable cloned foals had been produced over four years in South America, whilst another 2015 study estimated that 2 to 5 cloned foals were born each year in Europe.
“Cloning is not allowed by international studbooks registering racing Thoroughbreds. The American Quarter Horse Association is another notable example of a studbook which refuses to register clones,” she noted.
“Studbooks which will register clones include the majority of Warmblood stud books and the World Breeding Federation for Sport Horses.
“It is probable that cloning has been used in horses of various breeds being used for the disciplines regulated by the Federation Equestrian Internationale (FEI), although the FEI does not have data on which horses competing under FEI Regulations are clones.”
Reasons why owners choose to clone horses include the production from a competitively successful castrated male animal of an entire male clone which can be used for breeding, the attempted ‘recreation’ of a favourite animal, and attempted duplication of a successful competition horse.
She noted that in 2012 the FEI changed its rules to allow clones and the offspring of clones to compete.
“However, the European Commission in December 2013 tabled proposals to ban the use of the cloning technique in the EU for farm animals and the import of such animal clones.”
The proposals of the European Commission included horses used for agricultural production purposes, but allowed exemptions for “animals kept and reproduced exclusively for other purposes such as research, the production of medicinal products and medical devices, the preservation of rare breeds or endangered species, sporting and cultural events.”
This, she said, effectively excluded horses used for purposes other than agricultural production from the proposed ban on cloning.
In October 2015, the European Parliament amended the European Commission’s proposal to remove the exemption from the ban for sporting and cultural events.
“This means that should the European Parliament’s amendments be agreed in regulation negotiations with the European Council, cloning of all horses except those of endangered breeds for which no other method of reproduction can be used will be banned in the EU. However, cloning of horses for all purposes will continue to be allowed in many other countries.”
Campbell examined the general ethical arguments against the cloning of animals of all species and analysed whether they applied to horses.
Examining moral issues around cloning, Cambell said: “There is undeniably something fundamentally different about cloning compared with all other assisted reproductive techniques (ARTs), since cloning aims to reproduce an existing animal, whereas all other ARTs aim to produce a novel animal.
“The idea that there is something fundamentally wrong with cloning, that it is somehow beyond the realms of moral acceptability, pervades the literature on cloning in man and is often expressed as ‘an affront to human dignity’.
“These concerns quite probably do reflect public sentiment, but are poorly defined.
“Interestingly, there is a similarly poorly defined public repugnance with the concept of cloning animals, which might be characterised as an ‘affront to the animal’s dignity’.”
Campbell noted that a 2006 investigation into public attitudes to animal cloning found that “moral assessment is the most important factor behind the level of support”; that people were concerned about “violation of the integrity of animals that cloning might constitute” and that “cloning seems to cross an invisible border between the natural and the unnatural”.
She commented: “Whilst public unease about animal cloning based on ill-defined notions of ‘dignity’ undeniably exists, such unease is not necessarily a strong ethical reason to ban cloning, either of horses or of any other species.”
Looking at cloning for conservation, Campbell said any ethical justification for allowing cloning to facilitate conservation would have to be based on a cost-benefit argument that any costs to individual animals were outweighed by a perceived benefit of preserving the species.
“Yet is there an absolute benefit in species preservation? Is biodiversity necessarily a good thing? Is the loss of some species (or in the case of horses, breeds) not simply a normal Darwinian mechanism?
“The consequences of cloning to increase or preserve biodiversity could themselves have ethical implications; cloning a woolly mammoth, for example, is now feasible, but the consequences in terms of impact on the environment, habitat, other animals and on the welfare of the animal itself (reintroduced to an environment so different from the one which its species last inhabited) are unknown.
“Whilst it may seem a subjective shame to lose some of the equine rare breeds, the argument that they perform an environmental function which no other breed can do is tenuous. Indeed the environmental function of some rare breeds, such as the Suffolk Punch, has decreased significantly with the mechanisation of agriculture.
“Although governments may face legal obligations under the United Nations Convention on Biological Diversity to promote biodiversity, the ethical imperative to do so by subjugating the welfare of individual animals to the desire to preserve an equine breed is unconvincing.”
Looking at welfare-based reasons, Campbell said current cloning techniques result in recognised welfare problems. Problems associated with cloning across a variety species, but particularly cattle, include placental abnormalities during pregnancy, foetal abnormalities, obstructed labour related to large offspring in farm animals, neonatal weakness/disease, systemic illness/disease in cloned animals and premature ageing of adult clones.
One of the main reasons behind the European Commission’s decision in late 2013 to propose a ban on the cloning of food animals was the fact that farm-animal cloning was viewed as a risk to animal welfare, Campbell noted.
“If concerns about the health and welfare of clones and their dams provide a convincing ethical argument against cloning of farm animals, does the same argument apply to horses?”
Campbell traversed published evidence on embryo loss in equine cloning, foetal abnormalities, obstructed labour and neonatal health, concluding: “It is clear that the evidence base about health and welfare issues associated with cloning using SCNT is much less robust for horses than for farm animal species.
“The broad summary from the little data available seems to be that equine cloning is associated with high rates of embryonic loss; some incidence of fetal abnormalities (although this appears to be lower than that recorded in farm animals) and a requirement for neonatal intensive care.
“In contrast to farm animals, dystocia [obstructed labour] attributable to oversized foetal clones does not seem to be a significant problem in horses.
“It is difficult to know whether some abnormalities in neonatal and foal clones, for example limb deformities, are truly attributable to the cloning process, because such problems are not uncommon in foals anyway. To date, there have been no long-term studies on the health and welfare of cloned horses.
“Further research is clearly needed to increase the evidence base on the short, medium and long-term health and welfare effects of equine cloning.
“Until such evidence is 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.”
Campbell said the caveat to this ethical argument was that many of the problems associated with cloning (in all species) were probably related to technique, particularly in vitro culture conditions.
“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.
“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.”
Campbell noted that owner co-operation would be required to get data about medium and long-term effects of cloning.
“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.”
Campbell noted that one argument around the ethics of cloning which applied to horses and racing dogs, but not to farm animals, concerned 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,” she said.
“Despite concerns that some sports horses are not DNA-tested and that the FEI’s ban on cloning was therefore unenforceable, 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.”
She continued: “Concerns that cloning confers an unfair competitive advantage are, at the least, unproven. In the one report on racing cloned animals against their non-cloned peers, the cloned animals’ performance was mediocre.
“The FEI does not record clones competing under its rules and does not have data on the competitive success of clones compared with non-clones. However, to date, there has been no media coverage reporting that cloned horses have won important FEI events.”
Campbell said there was no convincing evidence that equine cloning was 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 for vets
Campbell said all assisted reproductive techniques were ethically unusual in that, unlike most veterinary procedures, they were usually undertaken with no expectation of improving the health or welfare of the animal on which they were performed.
“In this respect, cloning is no different from commonly used equine assisted reproductive techniques such as artificial insemination and embryo transfer,” she said.
Given that cloning is carried out only a small number of centres worldwide, the involvement of most veterinarians was likely to be limited to taking a skin biopsy from a donor animal, to provide the nuclear material necessary for the cloning process. and possibly to providing later healthcare for cloned offspring.
“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 assisted reproductive techniques.
“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.”
Food safety issues
Looking at food safety concerns, Campbell said there was undoubtedly public concern about the health implications of consuming clones or their products.
“Scientific evidence suggests that such concerns are unfounded. Although this evidence relates to ruminants rather than to horses, it is hard to see why health risks in man should be associated with eating cloned horse-meat when there are none associated with eating cloned meat derived from other species.
“The European Commission has indicated that a ban on cloning food-producing animals is not justified on food safety grounds and there is no evidence that this does not apply to horses as well as ruminants.”
Campbell noted that, in the US, Argentina and Brazil, unlabelled cloned animals and their products were now allowed in the food chain and can be exported.
“Cloned meat is primarily beef, but no data is available on the consumption of cloned horse-meat.
“Some consumers feel that it is unethical to clone animals even if eating cloned produce is safe. Cloned meat entering the food chain unlabelled does therefore raise an ethical issue about transparency, relating to consumers’ rights to know what they are eating. This would apply equally to horse-meat or other types of meat being produced by cloning.”
“Arguments about unfair sporting advantage are unconvincing grounds for considering equine cloning unethical,” Campbell concluded.
“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 labelled to enable consumers to select against it on moral grounds.”
Is cloning horses ethical?
M. L. H. Campbell