Table 29-2.

Relative Prevalence of Large Intestinal Tumors in Dogs and Cats^*

Colonic Neoplasm	Dog	Cat
Carcinoma	80	134
Lymphoma†	46	80
Mast cell tumor	1	0
Rectal plasmacytoma	97	0
Leiomyoma‡	7	1
Leiomyosarcoma§	15	8
Rectal papillary adenoma	582	0

^*Based upon 183,178 canine and 50,232 feline surgical biopsies from Canadian private veterinary hospitals, interpreted by a single pathologist, 1995-2009 inclusive.

^†Tumors limited to the large intestine, based on surgical assessment or imaging.

^‡Predominance of endoscopic samples probably underestimates true prevalence.

^§Not reviewed to distinguish from gastrointestinal stromal tumor.

Source: Histovet Surgical Pathology, Guelph, Ontario, Canada.