Influenza A Virus in Cattle

Influenza A is very much associated with infections in birds, pigs and humans. On this site we have already demonstrated that the virus can also infect mink, seals, whales, dogs, cats, horses, and bats.

It all shows that the Influenza A virus is much more versatile than previously thought. If it can infect so many species, we can ask the question: can it infect even more animals?
Sporadic cases of an acute fall in milk production, called ‘milk drop’, were investigated in a Holstein Friesian dairy herd in Devon. blood samples demonstrated[1] that rising antibody titres to human influenza A(H1N1) and human influenza A(H3N2) were associated with an acute fall in milk production. This study provides further evidence that influenza A persists in cattle and causes clinical disease.

Scientists[2] then tried to infect calves with Influenza A(H5N1) and they found that the virus had potential to infect calves. The animals did not fall visibly ill but could shed the virus. That means that there is a problem because in regions like Asia and Egypt, where the Influenza A(H5N1) virus is endemic and probability of contact between poultry, pigs and cattle is high, the virus might adapt, evolve and mutate more rapidly.

[1] Crawshaw et al: Significant rising antibody titres to influenza A are associated with an acute reduction in milk yield in cattle in Veterinary Journal - 2008
[2] Kalthoff et al: Experimental Infection of Cattle with Highly Pathogenic Avian Influenza Virus (H5N1) in Dispatches - 2008

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