ABSTRACT
The development of a potential pharmaceutical requires establishing a risk profile that involves animal testing before human exposure. A pathologist is responsible for evaluating a representative list of tissues from study animals during the long, comprehensive toxicology screening process. This chapter includes the historical control data from 26 to 52 weeks of chronic toxicity studies with Gottingen minipigs. The mouse is also a commonly used species for toxicology testing. The purpose-bred beagle dog is the most commonly used large animal species in nonclinical safety studies. The highest incidence of spontaneous findings in the 26-week studies occurred in the adrenal glands, kidneys, Harderian glands, muscle, liver, and stomach for the transgenic mouse. In the dog, the most frequent observations occurred in the pituitary gland and prostate of males, consisting of focal to multifocal inflammatory cell infiltrations, and pituitary gland cysts arising from the craniopharyngeal pouch, mainly involving the pars distalis.
