FMD

From Cow
Oral lesions in a cow infected with FMDV
Lesions on the tongue of a cow infected with FMDV
Hoof lesions in a cow infected with FMDV

Foot-and-mouth disease (FMD) is a highly infectious and sporadic notifiable viral disease of cattle worldwide.

Outbreaks occur in many countries worldwide, except Australia, Indonesia, North and Central America. In coutries where it is endemic, especially poorer countries where vaccinations stategies are limited, FMD causes massive animal loss and economic hardship for the cattle industry[1].

FMD virus is an aphthovirus (family Picornaviridae). The virus is relatively unstable outside the host and easily destroyed. Close contact between cattle is essential for spread of the disease, usually by aerosol transmission, fomites (recovered cattle, contaminated food, milking utensils, etc) or mechanical vectors such as dogs and cats[2].

Clinical signs

FMD is not a fatal disease and most affected cattle show clinical signs for 3 - 4 days followed by eventual recovery. The disease spreads rapidly in naïve cattle herds[3].

Fever, anorexia, reduced milk yield, and oral and hoof lesions predominate. Vesicles, erosions und ulcerations in the mouth and hairless parts of the skin, in particular on the feet, are visible[4]. Vesicles may also appear on teats, causing mastitis. Young calves may die due to FMD virus causing an acute pericarditis.

Diagnosis

Diagnosis must be confirmed by a government statutory body as this is a notifiable disease.

The disease must be distinguished from other causes of stomatitis including bovine mucosal disease, malignant catarrhal fever, rinderpest, peste des petits ruminants, contagious ecthyma, blue tongue, epizootic haemorrhagic disease, papular stomatitis and vesicular stomatitis.

Laboratory confirmation requires use of serology testing, ELISA[5] or PCR asaays[6].

Treatment

Slaughter of all affected and in-contact susceptible animals and strict restrictions on movement of animals and vehicles around infected premises is usually required[7].

In countries where FMD is endemic, vaccination protocols have been established to minimise outbreaks[8]. A systematic surveillance and communication network is essential to provide accurate information in controlling pandemics[9].

Experimental studies have shown that development of RNA interference (RNAi) genes can be used for cultivation of transgenic cattle immune to FMD virus[10].

References

  1. Bellet C et al (2012) Evaluating the efficiency of participatory epidemiology to estimate the incidence and impacts of foot-and-mouth disease among livestock owners in Cambodia. Acta Trop 123(1):31-38
  2. Orton RJ et al (2012) Risk of Foot-and-Mouth Disease spread due to sole occupancy authorities and linked cattle holdings. PLoS One 7(4):e35089
  3. Pandya M et al (2012) An alternate delivery system improves vaccine performance against foot-and-mouth disease virus (FMDV). Vaccine 30(20):3106-3111
  4. Teifke JP et al (2012) Foot-and-mouth disease and its differential diagnoses. Tierarztl Prax Ausg G Grosstiere Nutztiere 40(4):225-237
  5. Ayebazibwe C et al (2012) Application of the Ceditest® FMDV type O and FMDV-NS enzyme-linked immunosorbent assays for detection of antibodies against Foot-and-mouth disease virus in selected livestock and wildlife species in Uganda. J Vet Diagn Invest 24(2):270-276
  6. Howey R et al (2012) Modelling the within-host dynamics of the foot-and-mouth disease virus in cattle. Epidemics 4(2):93-103
  7. Merck Vet Manual
  8. Schley D et al (2012) Modelling the influence of foot-and-mouth disease vaccine antigen stability and dose on the bovine immune response. PLoS One 7(2):e30435
  9. Hui RK & Leung FC (2012) Evolutionary trend of foot-and-mouth disease virus in Hong Kong. Vet Microbiol 159(1-2):221-229
  10. Wang H et al (2012) Identification of short hairpin RNA targeting foot-and-mouth disease virus with transgenic bovine fetal epithelium cells. PLoS One 7(8):e42356