Malignant rectal neoplasms are usually adenocarcinomas in dogs and lymphosarcomas in cats. Adenocarcinomas are slow growing and infiltrative. Local or systemic metastasis may develop before tenesmus, dyschezia, hematochezia, or diarrhea is seen. Surgery is the treatment of choice for adenocarcinomas, but it may be unrewarding because metastasis has usually occurred before the diagnosis. Cats with rectal lymphosarcoma are treated medically with antineoplastic drugs.

Last full review/revision March 2012 by Stanley I. Rubin, DVM, MS, DACVIM