Digestive physiology of the plains viscacha (Lagostomus maximus): A large herbivorous hystricomorph rodent.

Plains viscachas (Lagostomus maximus) are large South American, fossorial rodents susceptible to diabetic cataracts. Various aspects of their digestive physiology were studied in three different experiments with nine male and seven female adult animals and six different diets (total n of feeding trials = 35). Viscachas achieved mean retention times of 23–31 hr, which is of a magnitude also recorded in horses; these did not differ for solute or small particle (<2 mm) markers.

Occurrence of cataract and fatty liver in captive plains viscachas (Lagostomus maximus) in relation to diet.

An increased incidence of cataract and fatty liver in plains viscachas (Lagostomus maximus) was noted for many years at the Zurich Zoo (Switzerland). Based on elevated serum fructosamine and glucose, diabetes mellitus was diagnosed; and these parameters normalized when the diet of the animals was changed from a low-fiber to a high-fiber diet. In this present study, 177 necropsy reports from before and after the diet changes were evaluated for the incidence of cataracts and fatty liver.

Juvenile mortality in captive lesser kudu (Tragelaphus imberbis) at Basle Zoo and its relation to nutrition and husbandry.

Since 1956, when the Basle Zoo (Switzerland) initiated the breeding of lesser kudu (Tragelaphus imberbis), 43% of the lesser kudu juveniles died before reaching an age of 6 mo. In this study, the objective was to obtain the pathological findings, nutritional history, and family tree information in order to evaluate the influence of husbandry on juvenile mortality in these animals. The main cause of death was white muscle disease (WMD), diagnosed in 14 cases (26%) of the deceased juveniles.

Demonstrating coprophagy with passage markers? The example of the plains viscacha (Lagostomus maximus).

Coprophagy, or the ingestion of a certain fraction of the faeces, is a well-known strategy of small herbivores. However, the question of whether a particular species actually uses this cryptic strategy or not is not easily answered experimentally. In this study we introduce the use of ingesta passage markers as a tool to verify coprophagy in species where individual observation might be difficult.