Amphibian biology is intricate, and there are many inter-related factors that need to be understood before establishing successful Conservation Breeding Programs (CBPs). Nutritional needs of amphibians are highly integrated with disease and their husbandry needs, and the diversity of developmental stages, natural habitats, and feeding strategies result in many different recommendations for proper care and feeding. This review identifies several areas where there is substantial room for improvement in maintaining healthy ex situ amphibian populations specifically in the areas of obtaining and utilizing natural history data for both amphibians and their dietary items, achieving more appropriate environmental parameters, understanding stress and hormone production, and promoting better physical and population health. Using a scientific or research framework to answer questions about disease, nutrition, husbandry, genetics, and endocrinology of ex situ amphibians will improve specialists’ understanding of the needs of these species. In general, there is a lack of baseline data and comparative information for most basic aspects of amphibian biology as well as standardized laboratory approaches. Instituting a formalized research approach in multiple scientific disciplines will be beneficial not only to the management of current ex situ populations, but also in moving forward with future conservation and reintroduction projects. This overview of gaps in knowledge concerning ex situ amphibian care should serve as a foundation for much needed future research in these areas.

Medical records of three male and three female callitrichids of four species (Leontopithecus chrysopygus, Leontopithecus rosalia, Callithrix argentata argentata, Callithrix kuhlii) diagnosed with cholelithiasis were reviewed. Ages of affected animals at the time of diagnosis ranged from 2-14 yr. Definitive antemortem diagnosis of cholelithiasis was made in four of the six cases. Chronic weight loss, lethargy, and weakness were seen in all cases. Chronic intermittent diarrhea was seen in three cases. Icterus and abnormal gait were each present in two of the animals. Hematologic and serum biochemical abnormalities included leukocytosis in five cases, elevated bilirubin (direct and indirect) in four cases, and anemia in four cases. Radiographic evidence of choleliths was observed in three cases. Surgical removal of choleliths was successfully performed on two animals. Full necropsies were performed on all cases, and choleliths were believed to contribute to morbidity in all cases. However, inflammatory bowel disease was determined to be the primary cause of weight loss and mortality in at least three animals. All choleliths analyzed were pigment stones, two being primarily composed of cystine.

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The success of ex situ survival assurance populations as tools for amphibian conservation depends on the health and reproductive success of founder populations. Necropsy examination and histopathology of animals that die in assurance populations are useful for the identification of population-limiting disease problems and can help to direct applied research efforts in areas such as amphibian husbandry and nutrition. This study reviewed postmortem findings in 167 frogs from 13 species that died in a large Panamanian rescue and survival assurance population between 2006 and 2011. Common problems identified in long-term captive animals, especially in Atelopus species, were epithelial squamous metaplasia suggestive of vitamin A deficiency and a polycystic nephropathy resembling lesions seen in laboratory animals with electrolyte imbalances. Metabolic bone disease was a significant contributor to morbidity in captive-bred juvenile frogs of Gastrotheca cornuta, Hemiphractus fasciatus, and Hylomantis lemur. Findings common to multiple species included poor overall nutritional condition that was sometimes attributable to maladaptation to captive husbandry and epidermal hyperplasia and hyperkeratosis possibly reflecting environmental skin irritation. Infectious diseases and endoparasitism were most common in recently captured animals and included chytridiomycosis and Rhabdias sp. lungworms. Applied research efforts to improve sustainability of survival assurance populations should focus on elucidating optimal husbandry practices for diverse species, improving methods for nutritional supplementation of cultured insects and examination of the role of water composition in disease development.

Two adult Wied's marmosets (Callithrix kuhlii) presented with jaundice, anemia, and weight loss. Death of one individual was attributed to renal tubular necrosis; liver and kidney were positive for Leptospira antigen by immunohistochemical (IHC) staining. The second animal was negative for antigen by IHC staining, but serologically positive for Leptospira borgpetersenii serovar ballum with an eightfold titer increase in paired samples, and was euthanized because of unresponsiveness to treatment. Environmental contamination by mice was suspected as the Leptospira source.