NON-INFECTIOUS DISEASE
2.1 Diabetes mellitus
Diabetes mellitus has been diagnosed in several zoohoused black-footed tree rats (Mesembriomys gouldii), and greater stick-nest rats in a zoological collection (Lendon et al.
2015). In all cases, animals were considered overweight. Clinically, rats have high blood glucose, glu- cosuria and ketonuria and many present with cataracts. Control of the diabetes (normal blood glucose and no glucosuria) has been achieved with dietary modification and strict weight control in all but one animal. However, in all cases the cataracts have been irreversible (Lendon et al. 2015).2.2 Leukaemia
Myelogenous leukaemia was incidentally diagnosed in a spinifex hopping-mouse that had been euthanased because of traumatic injury. Histological examination of the spleen showed numerous polygonal cells with large, donut-shaped nuclei, marked anisocytosis and anisokary- osis, and moderate mitotic figures. Also present were giant cells with abnormal nuclei. The humeral bone marrow revealed cells of the granulocytic lines in various stages of maturation containing similar donut-shaped nuclei with little to no development of the erythrocytic cell line present. No evidence of retroviral infection was identified as a cause of leukaemia in this case (ARWH 2018 case no. 6337.1).
2.3 Papillomatosis
Large gastric papillomas were identified in a plains mouse euthanased because of wounds sustained from conspecific aggression. On gross necropsy the oesophagus was markedly dilated secondarily to the papillomas obstructing the entrance to the stomach. As a result, the oesophagus was filled with rotting food. No evidence of a viral aetiology was identified in the formation of the papillomas and it is thought that debilitation caused by this pathology made the animal more susceptible to aggression (ARWH 2018 case no. 10269.1).