Spontaneous Tumors in the Dunkin-Hartley Guinea Pig 2 3

Abstract

Seventy-nine spontaneous neoplasms in Dunkin-Hartley guinea pigs were observed over a 9-year period in the Fort Detrick guinea pig colony. Sixty-three of the neoplasms were found during approximately 8,500 necropsies performed on animals under 27 months of age. The remaining 16 tumors were in 34 breeders maintained after 27 months of age on a natural life-span study. Of this group, 10 (29.4%) developed neoplasms by the termination of the study, when the animals were 80 months of age. The skin tumor, trichofolliculoma, of which there were 29, comprised the largest tumor classification.

Spontaneously Arising Tumours and Tumour-like Lesions of the Cervix and Uterus in 83 Pet Guinea Pigs ( Cavia porcellus )

“…While Rogers and Blumenthal (1960), Ediger and Kovatch (1976) and Field et al (1989) investigated the occurrence of spontaneously arising tumours in thousands of laboratory guinea pigs, the present study reports tumours of the cervix and uterus in guinea pigs kept as pets. Genital polyps are rare in most species of small mammals and rodents, except in rats where they are the most common uterine neoplasm (Goodman and Hildebrandt, 1987a, b;Eiben and Bomhard, 1999).…”

“…In the current study, eight polyps were observed in the genital tract of guinea pigs. These were not mentioned in earlier surveys (Rogers and Blumenthal, 1960;Ediger and Kovatch, 1976;Sommerey, 2001).…”

“…In previous studies, no cervical tumours were diagnosed in guinea pigs (Rogers and Blumenthal, 1960;Ediger and Kovatch, 1976;Field et al, 1989;Sommerey, 2001). Adenomas and adenocarcinomas of endocervical glands have not even been documented in classification schemes (Mohr, 1997;Kennedy et al, 1998).…”

“…Endometrial adenomas are not listed in other studies of guinea pigs (Rogers and Blumenthal, 1960;Ediger and Kovatch, 1976;Field et al, 1989;Sommerey, 2001). In the three cases of endometrial adenocarcinoma, no metastases were found during necropsy examination.…”

“…This has also been described elsewhere. Leiomyomas were the most common benign tumour in guinea pigs, but leiomyosarcomas were not diagnosed by Ediger andKovatch (1976), Field et al (1989) or Sommerey (2001). In contrast, Rogers and Blumenthal (1960) found two leiomyomas, one leiomyosarcoma, one fibrosarcoma, one myxosarcoma and one undifferentiated sarcoma in the uteri of guinea pigs.…”