Zuclopenthixol decanoate toxicity

A psychopharmaceutical describes a drug that has an impact on the mental state of the user. These medications are often used preventively to modify the behavioural response to stress in ungulate prey species, for example, to facilitate transportation and/or introduction
into a new area, group or herd. Zuclopenthixol is a long-acting neuroleptic (LAN) or antipsychotic agent that has been used to facilitate wildlife translocation in conservation projects. In human medicine, this drug is used to treat psychiatric disorders including schizophrenia and psychosis. It is a long-acting dopamine D1 and D2 receptor
antagonist, with a duration of action of 3–4 days (acetate ester) up to 2–3 weeks (decanoate) in wild ungulates, depending on the pharmaceutical formulation (Swan, 1993; Read, 2002).
Our understanding of equine behaviour and in particular learning theory, has deepened over the past few years. We now recognise that most problematic behaviours can quickly be resolved with appropriate training (McLean & Christensen, 2017; Pearson, 2019) and this knowedge should markedly reduce the need for psychopharmaceutical use during the routine management of horses. Yet, as this knowledge is still not embedded into mainstream equestrianism, and considering we know most people overestimate their understanding of horse behaviour (Warren-Smith & McGreevy, 2008; Wentworth-Stanley, 2013;
Pearson et al., 2020), psychopharmaceuticals remain an attractive option to many. Moreover, some problematic behaviours coincide with marked levels of emotions such as fear, which impairs a horse's ability to learn. By directly reducing fear, judicious psychopharmaceutical use
may optimise retraining, improve welfare and maximise safety.