JPC SYSTEMIC PATHOLOGY

INTEGUMENTARY SYSTEM

November 2016

I-V11

 

Signalment:  (JPC #1848605):  Breed and age unspecified goat

HISTORY:  None

MICROSCOPIC DESCRIPTION:  Mucocutaneous junction, lip (per contributor): Multifocally, there is epidermal hyperplasia with acanthosis (up to 10× normal thickness) and elongated, anastomosing rete ridges.  Multifocally within the stratum spinosum, keratinocytes are markedly swollen and often contain clear intracytoplasmic vacuoles (ballooning degeneration) and pyknotic nuclei. Multifocally, keratinocytes contain one or more 2-10um, round to oval, brightly eosinophilic intracytoplasmic viral inclusion bodies. Within the superficial stratum spinosum and stratum corneum, there is neutrophilic exocytosis and multifocal clusters of neutrophils admixed with cellular and karyorrhectic debris, and abundant serum (microabscesses).  There is minimal multifocal spongiosis of the epidermis.  Overlying the affected epidermis is mild erosion with replacement by a thick serocellular crust composed of keratin, protein fluid, degenerate neutrophils and numerous mixed bacteria.  Within the dermis there are numerous dilated small caliber blood vessels and lymphatics separated by clear space (edema), fibrin, and moderate numbers of perivascular neutrophils, histiocytes and lymphocytes.

MORPHOLOGIC DIAGNOSIS: Mucocutaneous junction, lip (per contributor):  Cheilitis, proliferative and erosive, focally extensive, moderate, with epithelial eosinophilic intracytoplasmic viral inclusion bodies, serocellular crust and intraepidermal microabscesses, breed unspecified, caprine.

ETIOLOGY:  Ovine parapoxvirus (orf virus)

ETIOLOGIC DIAGNOSIS:  Parapoxviral dermatitis

CONDITION:  Contagious ecthyma

SYNONYMS: Contagious pustular dermatitis, soremouth, orf (Old English for "rough"), infectious labial dermatitis, scabby mouth, lippengrind, farmyard pox (human)

GENERAL DISCUSSION:

PATHOGENESIS

TYPICAL CLINICAL FINDINGS

TYPICAL GROSS FINDINGS

Rarely, lesions may extend into the alimentary and respiratory tracts, causing severe gastroenteritis and bronchopneumonia

TYPICAL MICROSCOPIC FINDINGS

DIFFERENTIAL DIAGNOSIS

Gross lesions

COMPARATIVE PATHOLOGY

REFERENCES

  1. Buttner M, Rziha, HJ. Parapoxvirses: From the lesion to the viral genome. J Vet Med. 2002;49(1):7-16.
  2. Casey MJ, Robinson JHM, Sammin DJ. Severe facial oedema associated with orf in an Irish sheep flock. Vet Rec. 2007:161(17):600.
  3. Mauldin EA, Peters-Kennedy J. Integumentary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 1. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:617-618.
  4. Hargis AM, Myers S. Integumentary system. In: Zachary JF, Pathologic basis of Veterinary Disease. 6th ed. St. Louis, MO: Mosby Inc; 2016:1124. 
  5. Kitching RP. Orf. In: Infectious Diseases of Livestock. 2nd ed. Cape Town, Southern Africa:Oxford University Press; 2004:1282-1285.
  6. Muller G, Groters S, Seibert U, Rosenberger T, Driver J, Konig M, Becher P, Hetzel U, Baumgartner W. Parapoxvirus infection in harbor seals (Phoca vitulina) from the German North Sea. Vet Pathol. 2003:40:445-454.
  7. Radostits OM. Diseases caused by viruses and chlamydia. In: Radostits OM, Gay CC, Hinchcliff KW, Constable PD, eds. Veterinary Medicine: A Textbook of the Diseases of Cattle, Sheep, Pigs, Goats, and Horses. 10th ed. Philadelphia, PA: Saunders Elsevier; 2007:1418-1421.
  8. Scott, DW. Viral and protozoal skin diseases. In: Color Atlas of Farm Animal Dermatology. Oxford, England:Blackwell Publishing Ltd; 2007:125-126.
  9. Tomaselli M, Dalton C, Duignan PJ, Kutz S, van der Meer F, Kafle P, Surujballi O, Turcotte C, Checkley S. Contagious ecthyma, rangiferine brucellosis, and lungworm infection in a muskox (Ovibos moschatus) from the Canadian Arctic, 2014. J Wildl Dis. 2016;52(3):719-24.
  10. Thurman RJ, Fitch RW. Images in clinical medicine. Contagious ecthyma. N Engl J Med. 2015;372(8):e12.
  11. Vikoren T, Lillehaug A, Akerstedt J, Bretten T, Haugum M, Tryland M. A severe outbreak of contagious ecthyma (orf) in a free-ranging musk ox (Ovibos moschatus) population in Norway. Vet Microbiol. 2008:127(1-2):10-20.


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