The Effects of Handling and Anesthetic Agents on the Stress Response and Carbohydrate Metabolism in Northern Elephant Seals

Free-ranging animals often cope with fluctuating environmental conditions such as weather, food availability, predation risk, the requirements of breeding, and the influence of anthropogenic factors. Consequently, researchers are increasingly measuring stress markers, especially glucocorticoids, to understand stress, disturbance, and population health. Studying free-ranging animals, however, comes with numerous difficulties posed by environmental conditions and the particular characteristics of study species. Performing measurements under either physical restraint or chemical sedation may affect the physiological variable under investigation and lead to values that may not reflect the standard functional state of the animal. This study measured the stress response resulting from different handling conditions in northern elephant seals and any ensuing influences on carbohydrate metabolism. Endogenous glucose production (EGP) was measured using [6-3H]glucose and plasma cortisol concentration was measured from blood samples drawn during three-hour measurement intervals. These measurements were conducted in weanlings and yearlings with and without the use of chemical sedatives—under chemical sedation, physical restraint, or unrestrained. We compared these findings with measurements in adult seals sedated in the field. The method of handling had a significant influence on the stress response and carbohydrate metabolism. Physically restrained weanlings and yearlings transported to the lab had increased concentrations of circulating cortisol (F11, 46 = 25.2, p<0.01) and epinephrine (F3, 12 = 5.8, p = 0.01). Physical restraint led to increased EGP (t = 3.1, p = 0.04) and elevated plasma glucose levels (t = 8.2, p<0.01). Animals chemically sedated in the field typically did not exhibit a cortisol stress response. The combination of anesthetic agents (Telazol, ketamine, and diazepam) used in this study appeared to alleviate a cortisol stress response due to handling in the field without altering carbohydrate metabolism. Measures of hormone concentrations and metabolism made under these conditions are more likely to reflect basal values

Alimentary Tract Duplications

Enteric duplications are rare development malformations that can occur anywhere along the alimentary tract from the tongue to the anus. To date, there is no unique classification that can explain their extremely variable onset, size, and location. Calder was the first to publish a report of alimentary tract duplications, back in 1773, describing a duodenal duplication. The term “intestinal duplication” was used for the first time by Fitz in 1884 but was not widely used until it became commonly used in 1937, thanks to Ladd and a further classification by Gross in 1953. Several terms had been used before then to describe such anomalies such as giant diverticula, enterogenous cyst, or unusual Meckel’s diverticula. The current nomenclature, as suggested by Ladd and Gross, depends on the anatomic location of the duplication in relation to the normal gastrointestinal tract