Subcutaneous choriocarcinomas in captive Amargosa voles ().

Spontaneous choriocarcinomas are rare, highly vascular, malignant trophoblastic tumors that occur in humans and animals. This report describes the unusual spontaneous presentation of 4 choriocarcinomas within the subcutaneous tissues of 4, multiparous but nongravid, Amargosa voles () from a captive breeding colony. Two subcutaneous neoplasms were composed of multifocal discohesive and infiltrative aggregates of medium to large trophoblasts and cytotrophoblasts within a fibrovascular stroma.

Diet composition analysis provides new management insights for a highly specialized endangered small mammal.

The critically endangered Amargosa vole (Microtus californicus scirpensis) is found only in rare marsh habitat near Tecopa, California in a plant community dominated by three-square bulrush (Schoenoplectus americanus). Since the earliest research on the Amargosa vole, the existing paradigm has been that these voles are obligatorily dependent on bulrush as their only food source and for the three-dimensional canopy and litter structure it provides for predator avoidance. However, no prior research has confirmed the diet of the Amargosa vole.

DISEASE AND PATHOLOGICAL CONDITIONS OF AN ENDANGERED RODENT, , IN A CAPTIVE-REARING FACILITY AND IN THE WILD.

Causes of morbidity and mortality and a survey of infectious disease agents were collated from wild and colony-raised endangered Amargosa voles (). Six voles from the wild and 295 voles in the captive-breeding colony were included in the study upon identification of an infectious agent during screening, identification of clinical signs of disease, or finding a pathological condition or infectious agent on necropsy. Findings included 28 significant or incidental pathological conditions of seven organ systems and 19 parasitic, viral, bacterial, or fungal agents.

Conservation Implications of Shifting Gut Microbiomes in Captive-Reared Endangered Voles Intended for Reintroduction into the Wild.

The Amargosa vole is a highly endangered rodent endemic to a small stretch of the Amargosa River basin in Inyo County, California. It specializes on a single, nutritionally marginal food source in nature. As part of a conservation effort to preserve the species, a captive breeding population was established to serve as an insurance colony and a source of individuals to release into the wild as restored habitat becomes available.

ERADICATION OF A TROPICAL RAT MITE ( ORNITHONYSSUS BACOTI) INFESTATION FROM A CAPTIVE COLONY OF ENDANGERED AMARGOSA VOLES ( MICROTUS CALIFORNICUS SCIRPENSIS).

  Staff at a university laboratory responsible for management of a captive insurance colony of endangered Amargosa voles ( Microtus californicus scirpensis) discovered an outbreak of tropical rat mites ( Ornithonyssus bacoti) infesting 106 voles. This bloodsucking mesostigmatid mite typically occurs in laboratory settings and can cause weight loss, wounds, or other negative impacts on health. The source of the infestation was likely feral rodents, and the route was suspected to be straw bedding.

Apical Elongation of Molar Teeth in Captive Microtus Voles.

Molar apical elongation (MAE) was the leading cause for euthanasia or death in a captive breeding colony of endangered Amargosa voles ( Microtus californicus scirpensis). Clinical signs included ocular discharge, abnormal mastication, dyspnea, abnormal mentation, weight loss, and death. Although the severity varied, all molars in all quadrants were affected.

Successful care and propagation of the endangered amargosa vole (Microtus californicus scirpensis) in captivity.

The Amargosa vole (Microtus californicus scirpensis) is a highlyendangered rodent endemic to a small stretch of the California portion of the Amargosa River basin in Inyo County's Mojave Desert. Although the Amargosa vole has survived in this naturally fragmented ecosystem for thousands of years, recent habitat degradation due to land development, water drainage, and marsh exploitation has further isolated the species and reduced its available habitat. As part of a conservation effort to preserve the species, a captive breeding population was established in 2014 to serve as an insurance colony and as a source of individuals to release into the wild as restored habitat becomes available.