Induction of canine deciduoma in some reproductive stages with the different condition of corpora lutea.

Bitches were examined to see whether canine deciduoma could be induced at some reproductive stages with the different conditions of corpora lutea by inserting a silk suture into the uterine lumen. The bitches stimulated in the early and middle stages of diestrus or in unilateral pregnancy corresponding to these diestrous stages formed deciduoma at a high induction rate, however, no difference in the strength of decidual reaction between the pregnant and diestrous stages was recognized. On the other hand, no reaction could be seen in bitches in late diestrus, the late stage of unilateral pregnancy or the post partum repair phase in which stromal decidual cells similar to those of the rodentia can be seen. In already implanted uteri, however, no deciduoma was formed in the interplacental areas. Even though the corpora lutea were functional, new additional stimulations were not accepted at the interplacental area in which the uterine horn had already been influenced by fertilized ova. From these results, it was suggested that in the dog as well as the rodentia, the endometrium has to be under the influence of functional corpora lutea in order to form deciduoma.