Differential Diagnoses by Clinical Signs—Crocodilians

Abstract

Stress and immunosuppression are often underlying factors for many diseases affecting captive crocodilians. Stress has been defined as "a physiological answer to a perceived threat that includes, but is not restricted to, increased adrenal secretion." 1 Stress is also thought of as any event that challenges homeostasis, and likely the response to that challenge involves more than an adrenal response. The autonomic nervous system, the hypothalamic adrenal axis, neuropeptides, neurotransmitters, and neuroimmunologic mediators all have a role in the response of the immune system to stress. 2 Studies in crocodilians have evaluated the stress associated with restraint, long-term corticosterone implants, cold shock, and stocking densities. 3-6 Lance et al. provide an overview of the physiology and endocrinology of stress in crocodilians. 7 Catecholamines, glucocorticoids, glucose, and lactate have been implicated in the stress response of crocodilians. In addition, an argument is made for immunosuppression on the basis of changes observed in the white blood cells. [3][4][5]7 Factors that influence stress in crocodilian and reptile species are reviewed by Rooney and Guillette. 1 Enough evidence exists to suggest that stress plays an important role in the physiology of crocodilians, and it may indeed predispose them to illness. Overcrowding, handling, excessive noise, diet changes, water and air quality, temperature irregularities, and more should all be considered as predisposing or confounding factors of disease.

Hematology, Biochemistry Reference Intervals, and Morphological Description of Peripheral Blood Cells for a Captive Population of Crocodylus intermedius in Colombia

“…Because reptiles and especially crocodilians do not exhibit early signs of discomfort or disease, routine observations are not practical or neither recommended. However, blood testing could offer more information and be performed twice per year for preventive medical programs ( 14 , 15 ).…”

“…Because reptiles and especially crocodilians do not exhibit early signs of discomfort or disease, routine observations are not practical or neither recommended. However, blood testing could offer more information and be performed twice per year for preventive medical programs (14,15). This leads to a frequent and tedious issue with reptiles; the lack of baseline information limits the application of diagnostic tools (16).…”

Yokenella regensburgei, a novel pathogen in farmed American alligators

“…have been isolated from antemortem and postmortem tissue samples in alligators with clinical disease and lesions; however, their pathogenic relevance is uncertain. 19,21 Their low prevalence suggests these bacteria did not play a main role in these cases.…”

“…21 Some of the most relevant bacteria are Mycoplasma alligatoris, Chlamydia spp., and Dermatophilus sp. 19,21 Here we report the pathologic and bacteriologic analyses suggesting a role of Yokenella regensburgei infection in acute fatal septicemia in farmed American alligators.…”