Welfare of exotic pets - evidence: scoping review

Conclusion

The published evidence for the welfare of exotic pets in Scotland has mostly been collected on animals in zoos and laboratories, or from farmed fishes, cephalopods and decapods. Data on health and disease in pet animals are mostly individual case reports in veterinary clinics. However, more investigation and reviews have been carried out, where behavioural problems occur in commonly kept species (e.g., African grey parrots) and are obvious and distressing to owners (e.g., aggression, feather-damaging behaviour).

The supply of exotic pets in Scotland is largely dependent on captive breeding, which is generally considered preferable to capture from the wild, as the risk of disease and parasitism is lower, the impact on wild populations is less and young can become familiar with humans at an earlier stage. The evidence assessed in this review indicates that wild-caught exotic pets are not common in Scotland, but information on the illegal wildlife trade (with a focus on conservation) may be available and is outside of the scope of this review, if studies do not analyse the welfare of the traded animals. The importation of captive-bred animals from outside the UK, which are transported long distances (especially in the case of fishes) is regulated to some degree (e.g., by IATA), but has rarely been investigated, with notable exceptions e.g., ball pythons (Green et al., 2020). Captive breeding presents several risks: Lack of genetic diversity which amplifies the presence of congenital diseases (e.g., African pygmy hedgehogs, lemurs, ball pythons), dystocia (e.g., marmoset, tamarins, green iguanas), difficulty in replicating breeding environments (clownfishes) and providing for the nutritional requirements of young (e.g., macaws, clownfishes and koi carp fry).

The sources targeted in this review (mostly published papers in scientific journals and care guides developed by experts) include very few data on conditions in commercial premises, except where data are held and made available by public bodies (such as APHA and DEFRA), or investigations have been carried out by welfare organisations. Parental care of captive-bred offspring is often preferable to hand-rearing and this is well understood in primates and parrots, but in birds of prey imprinting of birds onto humans is considered important to allow training. Early removal from parents can result in behaviours that are difficult to manage, such as loud and persistent calling for food, or aggression directed towards owners. Carnivores, which have not been domesticated, do not exhibit neoteny (retention of juvenile characteristics into adulthood) and therefore show adult behaviours, such as scent-marking, aggression and fear of humans. However, no objective assessments of the welfare of wild carnivores in private ownership were found.

Transport stress, where reported, is mostly due to restraint and can be reduced with preparation, including positive reinforcement and calm handling by familiar individuals. This is appropriate when animals travel with their owners, but not when animals are moved by courier or in mass transit (e.g., wild-caught fishes, cephalopods and decapods). Studies of the effect of human presence on stress in non-domesticated species often only happens in zoos and laboratories, although fear of humans is mentioned anecdotally in advice by hobbyist organisations on taming (e.g., birds of prey, squamates). Where it is well known that animals are not amenable to handling, or likely to benefit from interacting with humans, this is reflected in advice provided by the RSPCA.

The social needs of group-living animals may be complex and it is widely accepted that social animals should not be kept singly. In some cases the welfare of animals kept in isolation in laboratories has been assessed (e.g., African grey parrots, squirrel monkeys), whereas in others the isolation of individuals in captivity (especially males) has not been investigated (e.g. African pygmy hedgehogs, Siamese fighting fish, tegu lizards, Hermann’s tortoises).

Case reports of health and disease often focus on rare and novel findings, rather than giving an overview of the prevalence of disease in the pet population. Broadly, veterinary care guides are more informative than published studies in understanding the common conditions affecting each species, but the lack of specific data means that information on what is common may not be recent or may only represent a snapshot of admissions to a single veterinary centre. Establishing links between poor husbandry or lack of understanding of the species kept as pets, as well as signs of disease and behavioural indicators of poor welfare, are frustrated by lack of data collection on the conditions in which animals are kept.