Vladimír Jekl, Assoc Prof MVDr, PhD, DECZM (Small Mammal Medicine and Surgery)
Jekl & Hauptman Veterinary Clinic - Focused on Exotic Companion Mammal Care, Mojmirovo namesti, Brno, Czech Republic
Small mammals play a very important role in zoo collections. Veterinary doctors facing various animal species, as some of them are herbivorous (e.g., lagomorphs), omnivorous (e.g., mice, rats), or insectivorous (e.g., hedgehogs, tenrecs), so a knowledge of anatomy, physiology, behaviour, diet, and common diseases of particular species are necessary. Also approach to these animals differ, as a rare species are treated as individuals and some (mice, rats, rabbits) are treated mostly as a colony.
Some rodents (mostly guinea pigs) and rabbits are commonly kept in children corners of the zoo and in some zoo’s children/people are in a direct contact (handling/feeding) with these species. In these cases, the prevention of zoonotic diseases (esp. dermatophytosis) is a must.
Rare or endangered species of small mammals are sometimes very difficult to breed and keep due to specific behaviour, dietary needs (e.g., Phloeomys pallidus, Phloeomys cumingi, Hypogeomys sp.), overfeeding (Lagostomus sp.) and lack of knowledge about common diseases. Also, handling and clinical examination can be problematic due to the animal size (e.g., Jaculus sp.) or behaviour (hedgehogs, tenrecs). The use of optimal anaesthetic protocol is an issue in many species. This author recommends using isoflurane as a safe anaesthesia; dark induction chamber is a preferred method of induction, especially in smaller and stress sensitive species. This method can be used also in wild small mammals in case of field studies. In larger animals, midazolam (0.2–0.6 mg/kg) can be used as a safe sedative agent. Lagomorphs and rodents kept in zoological gardens, which are native to particular countries (Spermophilus sp.), are bred and then reintroduced back to the wild to increase the animal population or as a part of a food chain (source of natural food) for predators (e.g., birds of prey).
Mice, rats, guinea pigs, and rabbits are used as a source of food for many reptilian and bird species. Small rodents for feeding are mostly bred in zoos, other species are bred outside of the zoo and are bought from different sources. Especially mice are the most commonly kept animal for feeding and the number of animals used for feeding per months can be more than 10.000 individuals making the mouse the most commonly kept animal in a zoo.
In summary, small mammals play a very important role in zoological gardens, as they are attractive species for expositions, non-aggressive animals in case of children zoos and they are used as feeding for many invertebrates and vertebrates.