SMEDI

Porcine parvovirus
Virus classification
Group: Group II (ssDNA)
Family: Parvoviridae
Genus: Parvovirus
Species: Porcine parvovirus
Porcine enterovirus
Virus classification
Group: Group IV ((+)ssRNA)
Family: Picornaviridae
Genus: Enterovirus
Species: Porcine enterovirus

SMEDI (an acronym of stillbirth, mummification, embryonic death, and infertility) is a reproductive disease of swine caused by porcine parvovirus (PPV)[1] and porcine enterovirus. The term SMEDI usually indicates porcine enterovirus, but it also can indicate porcine parvovirus, which is a more important cause of the syndrome.[2] SMEDI also causes abortion, neonatal death, and decreased male fertility.

From an economic standpoint SMEDI is an important disease because of the loss of productivity from fetal death in affected herds.[3] Initial infection of a herd causes the greatest effect, but losses slow over time. The disease is spread most commonly by ingestion of food and water contaminated with infected feces and occasionally through sexual contact and contact with aborted tissue.[4] A vaccine is available (ATCvet code: QI09AA02).

Pathogenesis

This depends on the age of the animal affected and the efficiency of its immune system. Colostral protection lasts up to 5 months of age, after which it decreases to an all-time low to increase yet again at about 12 months of age.

Therefore, it is important to note that the virus is particularly dangerous for the sow in her first gestation, which would be at 7–8 months of age, as she would have a particularly low antibody count at this age and could easily contract the virus via copulation.

Lesions

Histologically, the pregnant sow suffers lesions in the myometrium due to the infiltration of monocytes. The fetus presents: retarded growth, congestion of superficial vessels which may be associated with hemorrhage and dehydration which results in mummification of the fetus.

References

  1. Fenner, Frank J.; Gibbs, E. Paul J.; Murphy, Frederick A.; Rott, Rudolph; Studdert, Michael J.; White, David O. (1993). Veterinary Virology (2nd ed.). Academic Press, Inc. ISBN 0-12-253056-X.
  2. Carter, GR, Wise, DJ Flores, EF (2006). "Picornaviridae". A Concise Review of Veterinary Virology. Retrieved 2007-03-31.
  3. Kohler H (1983). "Pathophysiology of gravidity". Nord Vet Med 35 (3): 140–50. PMID 6683837.
  4. Carter GR, Wise DJ (2006). "Parvoviridae". A Concise Review of Veterinary Virology. Retrieved 2006-06-10.
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