Introduction:
The cloning of equids was first reported by a collaborative group at Idaho and Utah Universities (Woods et al. 2003; Vanderwall et al. 2004). Subsequently, other groups have reported births of cloned foals (Hinrichs 2006; Galli et al. 2008). Cloning is now being offered commercially, and a small number of horse owners are using the technique for a variety of reasons. This presentation will summarise the current science of equine cloning; discuss the ethics of cloning horses in comparison to the ethics of cloning people; and finally discuss some ethical issues which pertain specifically to the cloning of horses.

The science of equine cloning
'Cloning' can refer to either therapeutic or whole animal cloning. Whole animal cloning involves creating a new individual animal whose chromosomal DNA is identical to that of the original or 'donor' animal. The process by which this is achieved is known as 'nuclear cell transfer' and has been described in detail elsewhere (Hinrichs 2006). Somatic cell nuclear transfer (SCNT) is the method commonly employed in animal cloning.
Current animal cloning techniques have associated welfare problems across species (Renard et al. 2001; Hinrichs 2006; Houdebine et al. 2008; Council 2012). These begin with high embryonic loss rates (EFSA 2010), and continue through to the adult stages of the lives of cloned animals (Renard et al. 2001). There are some species-specific differences in which abnormalities occur and the frequency with which they do so. The incidence of post natal abnormalities may be lower in equids than in other species (Galli et al. 2008). The main abnormalities resulting in welfare/ethical issues which have been reported across species are:
1. High rate of embryonic loss
2. Placental abnormalities
3. Fetal abnormalities during pregnancy
4. Dystocia
5. Neonatal weakness/septicaemia/inadequate immune system function
6. Systemic illness in young clones
7. Premature ageing of adult clones

Though a few groups have reported their own results, the industry incidence of such problems in commercial equine cloning programmes is currently unknown, and is the subject of an on- going research project being undertaken by this author. One review paper (Hinrichs 2006) reported a high rate of early embryonic loss, but a relatively low incidence of post natal abnormalities compared to some species. Umbilical problems requiring surgery, tendon contracture and a requirement for neonatal intensive care were cited as reported abnormalities in cloned foals.

Reasons for wanting to clone horses
1. Recreate a pet animal
2. Preserve rare genetic material
3. Replicate successful sports horse
4. Duplication genetic material of a successful competition gelding to create a stallion.

Do ethical considerations about reproductive cloning of people apply equally to equids?
The cloning of Dolly the sheep resulted in media speculation that cloning of humans would inevitably follow. Several countries, including the UK, made reproductive cloning of people illegal. An analysis of the arguments for and against human cloning goes some way to helping us to analyse the ethics of equine cloning.

Arguments in favour of human cloning
1. Reproductive liberty
2. Source of matching tissues/organs
3. Freedom of scientific enquiry
4. Sense of immortality
5. Eugenic selection
6. Treatment of infertility
7. Replacement of dead relative
8. Negative attitudes = clonism
9. A clone is no more the same as another person than a twin is.

Arguments against human cloning
1. An affront to human dignity
2. Allows eugenic selection
3. Instrumentalisation
4. Clones will live in the shadow of the original
5. Reduces genetic variation
6. Defies right to genetic individual identity
7. Safety
8. Effect on family relationships.

Specific ethical considerations relating to the cloning of equids
1. Arguments for biodiversity/preservation of rare breeds
2. Arguments for cloning geldings so that they can be used in the breeding pool
3. Legal issues which arise from cloning - identity
4. Competition issues which arise from cloning FEI.

Conclusion:
Many ethical arguments about human cloning are based around concepts of individual identity, family relationships, eugenics and reproductive autonomy which arguably do not apply to animals. The overriding reason for caution in condoning commercial equine cloning programmes at the present time is the on-going welfare problems arising from the technique of cloning itself, rather than abstract philosophical objections. It is likely that these welfare problems will become less significant as cloning techniques are refined. Collaborative research to establish the extent of abnormalities in cloned equine pregnancies, neonates, young animals and adults, and to investigate any causal links between variations in technique and the incidence of such abnormalities is essential in order that any ethical decision-making about equine cloning may be evidence-based. Until such time as that information is available, regulatory bodies should adopt a precautionary principle and err on the side of safe-guarding the welfare of equids.