Canis ISSN: 2398-2942

Alimentary tract: neoplasia

Synonym(s): Gastrointestinal neoplasia, gastrointestinal tumors

Contributor(s): Trevor Bebchuck, Cheryl Hedlund


  • Neoplasia of gastrointestinal tract is uncommon.
  • Cause: Unknown. Transport and digestion of environmental carcinogens may contribute to development of cancer.
  • Signs: Variable depending on area involved; regurgitation or vomiting, diarrhea, weight loss, anorexia, lethargy, depression.
  • Diagnosis: Clinical signs, palpation, radiography, ultrasonography, endoscopy and ancillary tests.
  • Treatment: Surgical excision or biopsy and adjuvant chemotherapy and/or radiation therapy.
  • Prognosis:Good to grave. Good if complete resection is possible and metastatic sites have not developed. Grave if lesions are non-resectable or metastatic sites are non-responsive to adjuvant therapy.



  • Unknown for most tumors. Probably multifactorial.
  • Papovavirus is horizontally transmitted from dog to dog causing oral viral papillomatosis Skin: cutaneous papilloma.
  • Spirocerca lupi infestation predisposes to esophageal sarcomas Esophagus: neoplasia.
  • Chronic inflammation and irritation may predispose to squamous cell carcinoma.
  • Repeated exposure to insecticides may be carcinogenic.
  • Repeated exposure by transport and digestion of environmental carcinogens may contribute to the development of cancer.
    • Gastric carcinomas are experimentally induced by chronic oral dosing of nitrosamines.
    • Experimentally, N-ethyl-N'-nitro-N-nitrosoguanidine induces pancreatic duct adenocarcinoma.
    • Hepatic tumors have been experimentally induced with radiation and various chemicals including diethylnitrosamine, dichlorobenzidine, and aramite. Other implicated agents include aflatoxins, o-aminoazotoluene, aramite, Clonorchcis spp flukes, and various radioactive compounds including strontium-90 and cesium-144.

Predisposing factors


  • Breed and gender may predispose to some tumors.
  • Chronic parasitism.
  • Chronic exposure to carcinogens.
  • Obesity due to increased storage of carcinogens.


  • Mucosal trauma or irritation may allow carcinogens to penetrate the protective barrier.
  • Tumor growth involving the esophagus, stomach or intestines initially causes mild and vague signs, followed by signs of partial obstruction and then complete obstruction if left untreated.


  • Variable with region of the gastrointestinal tract and biological behavior of the specific tumor type.
  • Variable depending on the resectability of the tumor and the presence of metastasis.
    • Complete resection of benign tumors should result in normal life expectancy.
    • Shortened life expectancy may be anticipated if resection of benign tumors is incomplete or treatment of malignant tumors unsuccessful in controlling recurrence or metastasis.
  • Variable depending on the tumor's susceptibility to adjuvant therapies, radiation Radiotherapy and/or chemotherapeutic agents Chemotherapy: general principles Lymphoma: chemotherapy protocols.


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Cohen M, Post G S & Wright J C (2003) Gastrointestinal leiomyosarcoma in 14 dogs. J Vet Int Med 17 (1), 107-110 PubMed.
  • Swann H M & Holt D E (2002) Canine gastric adenocarcinoma and leiomyosarcoma: A retrospective study of 21 cases (1986-1999) and literature review. JAAHA 38 (2), 157-164 PubMed.
  • Takahashi T, Kadosawa T, Nagase M, Matsunaga S, Mochizuki M, Nishimura R & Sasaki N (2000) Visceral mast cell tumors in dogs: 10 cases (1982-1997). JAVMA 216 (2), 222-226 PubMed.
  • Tobin R L, Nelson R W, Lucroy M D, Woolridge J D & Feldman E C (1999) Outcome of surgical versus medical treatment of dogs with beta cell neoplasia: 39 cases (1990-1997). JAVMA 215 (2), 226-230 PubMed.
  • Crawshaw J, Berg J Sardinas J C, Engler S J, Rand W M, Ogilvie G K, Spodnick G J, O'Keefe D A & Henderson R A (1998) Prognosis for dogs with nonlymphomatous, small intestinal tumors treated by surgical excision. JAAHA 34 (6)451-456 PubMed.
  • Valerius K D, Powers B E, McPherron M A, Hutchison J M, Mann F A & Withrow S J (1997) Adenomatous polyps and carcinoma in situ of the canine colon and rectum: 34 cases (1982-1994)JAAHA 33, 156-160 PubMed.
  • Steiner J M & Bruyette D S (1996) Canine InsulinomaCompend Contin Educ 18 (1), 13-23 VetMedResource.
  • Kapatkin A S, Mullen H S, Matthiesen D T & Patnaik A K (1992) Leiomyosarcoma in dogs: 44 cases (1983-1988). JAVMA 201 (7), 1077-1079 PubMed.
  • Church E M, Mehlaff C J & Patnaik A K (1987) Colorectal adenocarcinoma in dogs: 78 cases (1973-1984). JAVMA 191 (6), 727-730 PubMed.

Other sources of information

  • Withrow S J (2001) Cancer of the gastrointestinal tract. In: Clinical Veterinary Oncology, 3rd ed. Eds S J Withrow and E G MacEwen.W B Saunders, Philadelphia. pp 305-353.
  • Gualtieri M, Monzeglie M G & Scanziani E (1999) Gastric neoplasiaVet Clin N Am: Sm Anim Pract 29(2), 415 - 440.
  • Simpson K W & Dykes N L (1997) Diagnosis and treatment of gastrinoma. Semin in Vet Med & Surg (Sm Anim) 12(4), 274-281.
  • Hammer A S & Sikkema D A (1995) Hepatic neoplasia in dogs and cats.Vet Clin N Am: Sm Anim Pract 25(2), 419-435.
  • Crow S E (1985) Tumors of the alimentary tractVet Clin N Am: Sm Anim Pract 15(3), 577-596.