Variability in Weight and Histological Appearance of the Prostate of Beagle Dogs Used in Toxicology Studies

Abstract

This review was performed to assess variations in weight and histologic appearance of the prostate of untreated male beagle dogs between 23 and 108 weeks of age, from two breeding centers. Data from 125 control beagle dogs from twenty-seven regulatory toxicology studies were used. Age, terminal body weight, and prostate weight were analyzed. Prostate sections were examined microscopically, and histological changes-such as development of acini, amount of secretion, and patterns of dilation and inflammation-were recorded and graded when appropriate. The influence of age, terminal body weight, and source on the weight and histological appearance of the prostate, and the degree of interanimal variation were evaluated

Prostate and Testes

“…Contrast radiographic studies (cystography, urethrography) are also important adjuncts that can corroborate ultrasonographic findings as well as provide additional information, such as subtle urethral irregularities and prostatic reflux. 2,3,13,17,[20][21][22][23][24][25][26][27][28] Studies have shown a positive correlation between prostate size and parameters related to body size and age in intact dogs 24,26 but not in neutered dogs. enlarges at sexual maturity secondary to hormone influences, becoming progressively more intraabdominal in location.…”

“…Interstitial cell tumors are composed of small nodules that may be singular or become confluent to form large nodular masses; they are poorly encapsulated and are yellowish, soft, and greasy on cut surface. [68][69][70][71][72] The ultrasonographic appearance of testicular neoplasms varies and is not specific for tumor type (Figures 17-33 to [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. Sertoli cell tumors often cause testicular enlargement and are associated with feminizing syndrome and bone marrow suppression due to high estrogen production.…”

Body and major organ sizes of young mature microminipigs determined by computed tomography

“…The results clearly showed the smallness and anatomical traits of microminipigs, and suggested their great potential as a large animal model for biomedical research and for medical training. The 10-month-old TOYO beagles used in this study, which were slightly larger than the beagles produced by Marshall Farm, NY, USA (average 8.7 AE 1.1 kg at 9-10 months of age), but similar in size to the beagles produced by Harlan France (average 11.3 AE 1.0 kg at 9-10 months of age) or by the Centre of Laboratory Animals Production, Havana, Cuba (average male 11.8 AE 1.9 kg and female 10.3 AE 1.7 kg at 8-10 months of age), 15,16 were standard size beagles and were appropriate as a reference for understanding the sizes of microminipigs. Therefore, researchers and technicians who have used beagles in experimental studies or medical training should be able to easily image the body and organ sizes of microminipigs.…”

Male Genital Tract

“…33 It is usually fairly non-specific but may be associated with squamous metaplasia of the glandular epithelium (see below). 24 24,34 A detailed study of laboratory beagles of up to 108 weeks of age by Dorso and colleagues showed that inflammation tended to be either lymphoid limited to the connective tissue and the periurethral zone or subacute involving acinar epithelium.…”

“…18 The ampullary glands associated with the vas deferens, located on the dorsal surface of the urethra, are lined by columnar epithelium and are also recognized by intensely eosinophilic staining secretions. 24 Despite the relative homogeneity of the dog prostate gland, regional differences in the response of the prostatic epithelium to hormonal influences are reported. A number of schemes have been proposed.…”