August 2017



Signalment (JPC #1879041):  Cow

HISTORY:  This cow was one of many from a herd with respiratory distress.

HISTOPATHOLOGIC DESCRIPTION:  Lung:  Diffusely, interlobular septa are markedly expanded up to 20 times normal by abundant edema, eosinophilic beaded fibrillar material (fibrin), and necrotic debris and are infiltrated by large numbers of degenerate neutrophils, with fewer macrophages and viable neutrophils.  The interlobular septa, small caliber vessels, and bronchioles are outlined and surrounded by numerous lymphocytes and plasma cells (lymphoid hyperplasia).  The surrounding alveolar spaces contain eosinophilic edema fluid, viable and degenerate neutrophils, plasma cells, histiocytes, lymphocytes, fibrin, and abundant necrotic debris.  Multiple contiguous alveoli coalesce and are expanded by clear space (emphysema).  Multifocally, alveolar septa are discontinuous with replacement by fibrin and necrotic debris (septal necrosis) or are expanded by lymphocytes, histiocytes, and edema.   Vessel wall architecture is multifocally replaced by abundant necrotic debris, fibrin, and similar inflammatory cells (necrotizing vasculitis).  Bronchi and bronchioles are multifocally filled with edema, fibrin, neutrophils, lymphocytes, and histiocytes.  

MORPHOLOGIC DIAGNOSIS:  Lung:  Pleuropneumonia, fibrinonecrotic and suppurative, diffuse, severe, with interlobular, alveolar and interstitial edema, lymphoid hyperplasia, and necrotizing vasculitis, breed unspecified, bovine.

ETIOLOGIC DIAGNOSIS:  Mycoplasmal pneumonia

CAUSE:   Mycoplasma mycoides subsp. mycoides (small colony type) (MmmSC)

CONDITION:  Contagious bovine pleuropneumonia (CBPP)











  1. Bras AL, Barkema HW, Woodbury MR, et al. Clinical presentation, prevalence, and risk factors associated with Mycoplasma bovis-associated disease in farmed bison (Bison bison) herds in western Canada. J Am Vet Med Assoc. 2017 May 15;250(10):1167-1175.
  2. Caswell JL, Williams KJ. Respiratory system. In: Maxie MG ed. Jubb, Kennedy and Palmer"s Pathology of Domestic Animals. Vol 2. 6th ed. Philadelphia, PA: Elsevier; 2016:551-554.
  3. Constable PD, Hinchcliff KW, Done SH, Gruenberg W. Diseases of the respiratory system. In: Veterinary Medicine, A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs, and Goats. 11th ed. New York, NY: Elsevier; 2017: 925-932.
  4. Gagea MI, Bateman KG, Shanahan RA, van Dreumel T, McEwen BJ, Carman S, et al. Naturally occurring Mycoplasma bovis-associated pneumonia and polyarthritis in feedlot beef calves. J Vet Diagn Invest. 2006;18(1):29-40.
  5. Janardhan KS, Hays M, Dyer N, Oberst RD, Debey BM. Mycoplasma bovis outbreak in a herd of North American bison (Bison bison). J Vet Diagn Invest. 2010;22(5):797-801.
  6. Jores J, Meens J, Buettner FF, Linz B, Naessens J, Gerlach GF. Analysis of the immunoproteome of Mycoplasma mycoides mycoides small colony type reveals immunogenic homologues to other known virulence traits in related Mycoplasma species. Vet Immunol Immunopathol. 2009;131(3-4):238-45.
  7. Le Boedec K. A systematic review and meta-analysis of the association between Mycoplasma spp and upper and lower respiratory tract disease in cats. J Am Vet Med Assoc. 2017 Feb 15;250(4):397-407.
  8. Lopez A, Martinson SA. Respiratory system. In: Zachary JF ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Mosby; 2017:532.
  9. Maunsell FP, Woolums AR, Francoz D, et al. Mycoplasma bovis infections in cattle. J Vet Intern Med. 2011;25(4):772-783.
  10. Pilo P, Frey J, Vilei EM. Molecular mechanisms of pathogenicity of Mycoplasma mycoides subsp. mycoides SC. Vet J. 2007;174(3):513-21. Pothmann H, Spergser J, Elmer J, et al. Severe Mycoplasma bovis outbreak in an Austrian dairy herd. J Vet Diagn Invest. 2015 Nov;27(6):777-83.
  11. Rodríguez F, Castro P, Poveda JB, et al. Immunohistochemical labelling of cytokines in calves infected experimentally with Mycoplasma bovis. J Comp Pathol. 2015 Feb-Apr;152(2-3):243-7.
  12. Thiaucourt F, Manso-Silvan L, Salah W, Barbe V, Vacherie B, Jacob D,et al. Mycoplasma mycoides, from "mycoides Small Colony" to "capri"- A microevolutionary perspective. BMC Genomics. 2011;12:114.
  13. Zachary JF. Mechanisms of microbial infections. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Mosby; 2017:170-171.

Click the slide to view.

Click on image for diagnostic series.

Back | Home | Contact Us | Links | Help |