The surgical use of these drugs is therefore limited to preanesthetic use. Other anesthetic overdoses by injection will also work. Acceptable physical methods of euthanasia are stunning followed by decapitation, and pithing followed by decapitation. Pithing involves severing the spinal cord at the base of the brain by inserting a sharp needle and rapidly moving the needle in a circular motion. An accurate diagnosis requires a knowledge of the species, its normal appearance, and its length of time in captivity.
Amphibians tend to show similar symptoms for a variety of disease states.
Body condition may be evaluated by looking for prominence of the skeleton and palpation of musculature and abdominal contents. Skin scrapings and gill biopsies are useful to detect fungal, bacterial and parasitic infections. Focal and nodular lesions should be biopsied, Gram's and acid-fast stained and cultured. Hematology has limited value because of the lack of normal data, plus wide variations due to sex, season, and hydration levels. A fecal exam can detect protozoan and metazoan parasites, but significance depends upon the type and extent of infestation with presence of clinical signs.