Intrahepatic cholangiocarcinoma in a captive meerkat (Suricata suricatta)

Cholangiocarcinoma with carcinomatosis in a sugar glider

A 7-y-old, castrated male, leucistic sugar glider (Petaurus breviceps) was presented because of a progressive history of lethargy, ataxia, diarrhea, and anorexia. Abdominal ultrasound revealed fluid in the abdomen and an infiltrative mass in the liver. Due to a poor prognosis, euthanasia was performed. Postmortem examination revealed a focally extensive, infiltrative, off-white, firm mass in the liver with adhesion to the omentum, mesentery, gastric serosa, and diaphragm. The remaining hepatic parenchyma was diffusely yellow. Histologically, the hepatic mass was consistent with metastatic cholangiocarcinoma (cholangiocellular carcinoma) with proliferation of neoplastic epithelial cells surrounded by marked desmoplasia. Neoplastic cells expanded and infiltrated the adjacent omentum, mesentery, and the serosal surfaces of the stomach, kidney, and small and large intestines. To our knowledge, cholangiocarcinoma has not been reported previously in a sugar glider.

Pathology and causes of death in captive meerkats (Suricata suricatta)

BACKGROUND

Meerkats (Suricata suricatta) are endemic carnivores of southern Africa and, although currently listed as "least concern" by the International Union for Conservation of Nature (IUCN) red list, there is evidence of a significant decrease in wild populations mainly attributed to effects of climate change. Little is known about diseases associated with mortality in captive meerkats.

AIM

To characterise macroscopic and microscopic lesions that accounted for the death or euthanasia in a series of captive meerkats.

MATERIAL AND METHODS

Eight captive meerkats submitted for post-mortem examination between 2018 and 2022.

RESULTS

Three animals died unexpectedly without clinical signs, 2 exhibited neurological signs, 2 collapsed after con-specific fighting and 1 showed gastrointestinal signs. Common pathological findings of this study that may be related to the death of captive meerkats included foreign bodies (trichobezoars or plastic materials) within the alimentary tract, traumatic penetrating injuries or starvation associated with abnormal social behaviours (bullying and con-specific attacks), verminous pneumonia and systemic atherosclerosis. Common incidental findings included pulmonary edema and congestion, cholesterol granulomas, pulmonary adenomas and vertebral spondylosis.

CONCLUSIONS

Non-infectious diseases outreach infectious diseases as causes of mortality in captive meerkats including, foreign bodies within the alimentary tract, con-specific attacks and systemic atherosclerosis, which is described for the first time. These data should raise concern about appropriate husbandry (e.g. environmental enrichment, cleaning of facilities and diet formulation) by zookeepers and emphasise the need for further study of meerkat mortality in both captive and wild populations.

Procyonidae, Viverridae, Hyenidae, Herpestidae, Eupleridae, and Prionodontidae

This chapter covers the diseases and pathology of multiple taxonomic groups within the order Carnivora including Procyonidae several of the Feliformia carnivores. The overwhelming majority of knowledge about disease pathogenesis for these species is biased toward raccoons and concern for disease spread to humans and companion animals. Procyonids and feliform carnivores are ubiquitous in their environments and share habitat and environmental resources with other nondomestic and domestic carnivores and humans. As reservoirs for a number of important multispecies or zoonotic pathogens, surveys for pathogens that may be harbored or vectored by several of the species in this chapter, for example, raccoons (e.g., canine distemper virus, rabies, and leptospirosis) and civets (e.g., SARS coronavirus), have been active areas of investigation. Unfortunately, less research has focused on the potential effects of these pathogens on their hosts.

Anaplastic mandibular carcinoma in a meerkat (Suricata suricatta)

An 8-yr-old female slender-tailed meerkat (Suricata suricatta) presented with a necrotic sublingual mass and osteolysis of the mandible. After 1 mo of palliative care, the meerkat was euthanized. The mass was diagnosed histologically as an anaplastic carcinoma with extensive rostral mandibular destruction. Immunohistochemistry for vimentin and cytokeratin was validated in this nontypical species and showed that neoplastic cells expressed both mesenchymal and epithelial characteristics, suggestive of a primitive and poorly differentiated tumor. A review of 150 adult slender-tailed meerkat histopathology reports showed a 2% prevalence of orofacial neoplasia, suggesting that oral neoplasms are uncommon in meerkats.

Hepatocellular carcinoma in captive slender tailed meerkats (Suricata suricatta): 5 cases

Hepatocellular carcinoma was diagnosed in five slender tailed meerkats (Suricata suricatta) housed at the Smithsonian Institution's National Zoological Park between 1980 and 2013. Animals included four females and one male, ranging from 7 to 15 yr of age. Common clinical signs included weight loss and lethargy. Three of the neoplasms originated from the right medial liver lobe and were located adjacent to or partially incorporated in the gall bladder. Three animals had solitary masses, and two animals had multiple hepatic masses; all were characterized by polygonal to round neoplastic hepatocytes arranged in a trabecular pattern with smaller regions of varied solid, adenoid, and rarely peliod cell patterns. Hemorrhage and necrosis often with cystic degeneration was noted in all five cases. There was no evidence of metastatic disease in any of the cases examined.