Feasibility of combined upper and lower gastrointestinal endoscopic biopsy in the common marmoset (Callithrix jacchus) to evaluate gastrointestinal diseases.

BACKGROUND: Chronic gastroenteropathies, including gluten sensitivity and marmoset wasting syndrome, frequently occur in captive colonies of common marmosets (Callithrix jacchus). Early identification and diagnosis of affected animals are desirable. Endoscopic examination of the colon in marmosets is described, but the small intestine can harbor significant mucosal lesions not representing those in the colon. Evaluating the small intestine currently requires invasive surgical biopsies due to the small patient size, carrying a risk of severe complications. METHODS: Endoscopic intubation and multisite biopsy of the duodenum/proximal jejunum are demonstrated in 10 marmosets under general anesthesia. RESULTS: Esophagogastroduodenoscopy with colonoscopy efficiently aid in examining the gastrointestinal tract and obtaining an antemortem histologic diagnosis in marmosets with chronic gastrointestinal signs. CONCLUSIONS: This minimally invasive technique is feasible in marmosets. Future investigations into the pathogenesis of chronic gastroenteropathies will benefit from these data, leading to improved animal welfare and better individual and colony health management.

Testicular biopsy in psittacine birds (Psittaciformes): comparative evaluation of testicular reproductive status by endoscopic, histologic, and cytologic examination.

Knowledge of the reproductive cycle of male parrots is important for examining the male genital tract and for successful breeding, especially of endangered species. To evaluate different diagnostic methods and criteria concerning the classification of reproductive stages, we examined 20 testicular samples obtained at necropsy in psittacine birds of different species and testicular biopsy samples collected from 9 cockatiels (Nymphicus hollandicus) and 7 rose-ringed parakeets (Psittacula krameri) by endoscopy 4 times over a 12-month period. The testicular reproductive status was assessed histologically and then compared with the macroscopic appearance of the testicles and cytologic results. The histologic examination was nondiagnostic in 19 of 59 testicular biopsy samples. By contrast, the cytologic preparations were diagnostic in 57 of 59 biopsy samples. The results of the cytologic examination coincided with the histologic results in 34 of 38 biopsy samples and 18 of 20 necropsy samples. Macroscopic parameters displayed some differences between reproductive stages but provided an unreliable indication of the reproductive status. These results suggest that microscopic examination of a testicular biopsy sample is a reliable method for evaluating the reproductive status of male parrots and is preferable to the macroscopic evaluation of the testicle. Cytologic examination provides fast preliminary results, even when the histologic preparation is not sufficient for evaluation, but results may be erroneous. Thus, a combination of histologic and cytologic examination is recommended for evaluating testicular reproductive status.

Testicular biopsy in psittacine birds (Psittaciformes): impact of endoscopy and biopsy on health, testicular morphology, and sperm parameters.

Histologic examination of a testicular biopsy sample may be required to evaluate the reproductive status of male psittacine birds. The purpose of this study was to evaluate the viability of testicular sampling from live birds by assessing the impact on the birds' health, testicular integrity, and sperm quality. Testicular biopsy samples were obtained by endoscopy 4 times during 12 months from 9 cockatiels (Nymphicus hollandicus) and 7 rose-ringed parakeets (Psittacula krameri). Only 2 of 16 birds showed testicular cicatrization or divided testicular tissue after a single endoscopy. Further complications, such as damage to the air sacs or bleeding, predominantly occurred in subsequent endoscopies. In both species, endoscopy and testicular biopsy caused only minor or transient effects on sperm production and sperm quality. These results support that a single testicular biopsy is a viable method for evaluating the reproductive status of male psittacine birds.