Histological Findings in Captive Madagascar Hissing Cockroaches (Gromphadorhina portentosa) and a Literature Review

Madagascar hissing cockroaches (MHC, Gromphadorhina portentosa) are members of the Blaberidae (giant cockroaches) family of the Insecta class. They are native to the African island of Madagascar where they live within leaf litter on the rainforest floor. Due to their large size, relative tameness, and general easy keeping, they have become popular in classrooms, zoological collections, museums, research laboratories, and as private exotic pets; however, descriptions of diseases of MHC in the literature are rare. The objective of this study is to describe and characterize postmortem histological findings in 18 captive MHC from a single zoological collection. In this retrospective study, 18 (4 females and 14 males) adult MHC necropsies were submitted to Northwest ZooPath between 2016 and 2020 for evaluation. The main organs with histological lesions were chitinous gut (foregut and/or hindgut; n = 17), tracheae (n = 15), fat body (n = 14), ventriculus (midgut) (n = 13), body wall (n = 12), Malpighian tubules (n = 12), and hemolymphatic sinuses (n = 12). All animals had inflammatory lesions affecting various organs. Inflammatory lesions typically consisted of aggregates of hemocytes with variable amounts of melanization and/or encapsulation. Bacterial, fungal, and parasitic infections were common and variably associated with hemocytic inflammation. Many of these organisms may represent symbiotic organisms of the MHC that cause opportunistic infections. This study contributes to the current knowledge of pathological findings and disease response of MHC and reviews diseases reported in multiple cockroach species.

Invertebrate Oncology: Diseases, Diagnostics, and Treatment

Neoplasia is a documented occurrence across invertebrate taxa, but challenges remain with regard to tumor diagnosis and treatment. Literature reports of neoplasia are frequent in mollusks and insects, infrequent in Cnidaria and crustaceans, and are yet to be documented in Porifera and echinoderms. A significant contribution could be made by veterinary practitioners documenting and treating neoplasms in invertebrates. Traditional methods of veterinary diagnosis are encouraged, but the anatomy and tissue biology of each invertebrate species need to be considered. Most neoplasms described in the invertebrate literature have been considered benign, making external lesions potentially amenable to surgical resection.

Tarantula and Hermit Crab Emergency Care

Tarantulas and hermit crabs are commonly kept pets and are underappreciated in veterinary medicine. Safe handling, biology and husbandry, diagnostic techniques, anesthesia, fluid therapy, disorders, and euthanasia are covered in this article. Current research is applied to these topics to keep practitioners abreast with the best medicine for these creatures.