Abstract
Gastric carcinoma of dog has been known to be frequently induced by oral administration of N-Ethyl-N′-nitro-N-nitrosoguanidine (ENNG) solution mixed with a pellet diet.
In the present paper, clinicopathological findings on gastric carinomas induced by our method were described.
Gastric carcinomas were developed in all of 4 mongrel and 3 beagle dogs. Early gastric carcinomas in two of the 7 dogs were found and both early and advanced gastric carcinomas were developed in the remaining 5 dogs. Numerous metastases to intraperitoneal and distant lymphonodes were also detected in 4 dogs. Liver metastases were observed in two beagle dogs. In one of them, peritonitis carcinomatosa with ascites and metastases to the lungs, heart, bones and subdermal tissue as well as the liver were found.
Gastric carcinomas were frequently localized in the gastric antrum and the upper one-third of the stomach. The commonest type of carcinoma was protruded. Most of carcinomas were composed of tubular adenocarcinoma and signet-ring cell carcinoma. In the upper one-third of the stomach, most of the carcinomas were protruded with common histological type of well differentiated adenocarcinoma. On the other hand, there occured various types of protruded, flat and depressed carcinoma in the gastric antrum. Histologically, there was not any difference in incidence between well differentiated adenocarcinoma and poorly differentiated adenocarcinoma with signet-ring cell carcinoma.
All of advanced gastric carcinomas were over 20mm in diameter.
In mongrel dogs, most of carcinomas were well differentiated adenocarcinoma, whereas in beagle dogs the typical histological type was poorly differentiated adenocarcinoma with signet-ring cell carcinoma.
In a mongrel dog, it was interesting that the histological findings suggestive of malignat change from benign hyperplastic polyp were seen in a polypoid lesion.
