From Dog

Splenitis in dogs is an inflammatory or infectious disease of the spleen, usually associated with enlargement (splenomegaly).

Splenomegaly is most commonly observed during routine anesthetic procedures due to the chemical relaxation of intrasplenic smooth muscles induced by drugs such as acepromazine, thiopentone and propofol. Splenomegaly in this situation is considered a nonpathological process[1].

The spleen acts primarily as a blood filter and sequestration of generalized septicemia or parasitemia precludes it to inflammatory and infectious disease.

Primary infection may also be attributed to necrosis associated with splenic tumors.

Causes of splenitis and splenomegaly include:

- Pyruvate kinase deficiency
- Canine infectious hepatitis
  • Bacterial septicemia
- Cholangiohepatitis[2]
- Mycobacterium avium[3]
- Pyometra
- Phialemonium spp[4]
- Monocillium indicum[5]
- Anaplasma spp[6]
- Babesia gibsoni[7]
- Bartonella spp[8]
- Echinococcus spp[9]
- Ehrlichia spp
- Gnathostoma spp
- Leishmania infantum[10]
- Rangelia vitalii[11]
- Theileria spp
- Immune-mediated hemolytic anemia
- Immune-mediated neutropenia
- Rheumatoid arthritis
- Doberman hepatitis
- Splenic tumors

Clinically affected dogs often present with acute-onset nonspecific signs such as anorexia, vomiting. A palpably enlarged spleen is usually obvious on digital manipulation of the abdomen.

Blood tests may reveal leucocytosis if the underlying pathology is an infectious splenitis.

A differential diagnosis would include splenic contracture post-anesthesia, splenic hematoma, mast cell tumor[13] and secondary lymphoma[14], mast cell tumor and hemangiosarcoma[15].


  1. Baldo CF et al (2012) Effects of anesthetic drugs on canine splenic volume determined via computed tomography. Am J Vet Res 73(11):1715-1719
  2. Forrester SD et al (1992) Cholangiohepatitis in a dog. J Am Vet Med Assoc 200(11):1704-1706
  3. O'Toole D et al (2005) Fatal mycobacteriosis with hepatosplenomegaly in a young dog due to Mycobacterium avium. J Vet Diagn Invest 17(2):200-204
  4. Simpson KW et al (1993) Systemic mycosis caused by Acremonium sp in a dog. J Am Vet Med Assoc 203(9):1296-1299
  5. Mackie JT et al (2004) Granulomatous lymphadenitis and splenitis associated with Monocillium indicum infection in a dog. J Vet Diagn Invest 16(3):248-250
  6. Cockwill KR et al (2009) Granulocytic anaplasmosis in three dogs from Saskatoon, Saskatchewan. Can Vet J 50(8):835-840
  7. Trotta M et al (2009) Clinicopathological findings, molecular detection and characterization of Babesia gibsoni infection in a sick dog from Italy. Vet Parasitol 165(3-4):318-322
  8. Varanat M et al (2011) Molecular prevalence of Bartonella, Babesia, and hemotropic Mycoplasma sp. in dogs with splenic disease. J Vet Intern Med 25(6):1284-1291
  9. Sharif MA et al (2009) Primary perisplenic hydatid cyst. J Coll Physicians Surg Pak 19(6):380-382
  10. Freeman KS et al (2010) Leishmaniasis in a dog native to Colorado. J Am Vet Med Assoc 237(11):1288-1291
  11. Da Silva AS et al (2013) Canine rangeliosis: the need for differential diagnosis. Parasitol Res 112(3):1329-1332
  12. Schnier LM (2010) A case of splenic torsion with progressive anemia and thrombocytopenia. Can Vet J '51(5):527-529
  13. Book AP et al (2011) Correlation of ultrasound findings, liver and spleen cytology, and prognosis in the clinical staging of high metastatic risk canine mast cell tumors. Vet Radiol Ultrasound 52(5):548-554
  14. Eberle N et al (2012) Splenic masses in dogs. Part 1: Epidemiologic, clinical characteristics as well as histopathologic diagnosis in 249 cases (2000-2011). Tierarztl Prax Ausg K Kleintiere Heimtiere 40(4):250-260
  15. Rossi F et al (2013) Metastatic cancer of unknown primary in 21 dogs. Vet Comp Oncol Jan 7