Phalaris arundinacea (reed canarygrass) grass staggers in beef cattle.

Four adult mixed-breed beef cows from a cow-calf operation in West Virginia were referred to the Virginia-Maryland Regional College of Veterinary Medicine in March 2009 with weakness, ataxia, hind limb paresis progressing to lateral recumbency, and death within 2-3 days. Histologically, there was accumulation of light brown, granular pigment in neurons of the ventral gray horns of the spinal cord (more severe in thoracic and lumbar sections), brain stem, and pons, resulting in distortion and bulging of the cell body and displacement of the Nissl substance, suggestive of Phalaris sp. grass toxicosis.

Elution of metronidazole and gentamicin from polymethylmethacrylate beads.

Objective: To characterize the elution and bioactivity of metronidazole and gentamicin sulfate polymerized, individually and in combination, with polymethylmethacrylate (PMMA).

Study Design: In vitro experimental study.

Methods: PMMA beads containing metronidazole (3 concentrations), gentamicin sulfate, or metronidazole and gentamicin sulfate were immersed in 5 mL of phosphate-buffered saline in triplicate.

How to evaluate toxicant exposures.

Susceptibility of individual animals to any specific toxicant is influenced by many factors, including genetics, environment, age, gender, and preexisting disease. Because the relative influence of these factors on a specific toxicosis is often unknown and unmeasured, it is difficult to predict how an individual animal is likely to respond to a toxic challenge compared with the "average" animal in the population. Safety or uncertainty factors of 10 have been proposed to deal with intraspecies and interspecies variability in regard to LD50 values.

Cretinism in a North American black bear (Ursus americanus).

Congenital hyperplastic goiter and cretinism were documented in a 16 month-old male North American black bear (Ursus americanus). The cub was captured at approximately 8 months of age and maintained for an additional 8 months in captivity. Clinical signs included growth retardation, clumsiness, and facial dysmorphism.