Tests show cattle may be susceptible to human flu
By Jessica Buss
CATTLE may be suffering from the same influenza virus that is common in humans and other animals.
A report in the Vet Record, Dec 5, 1998, from the Vet Lab Agency at Weybridge, Surrey and Starcross, Devon, says antibodies to influenza type A virus, which affects humans, have been detected in cattle from outbreaks on two farms. These farms are said to be unrelated.
Report authors say affected cattle suffer increased respiratory rates and lung sounds, anorexia, nasal discharge, a cough and, in milking animals, severely reduced milk yields.
A MAFF spokesman says the likelihood is that these animals have had influenza A, but so far researchers have not managed to isolate the active virus in an animal. Until the actual virus is found it is difficult to find out where it came from and how infectious it is to other animals and humans, he says.
"Influenza A is known to affect a lot of animal species, including pigs and poultry, in many countries in eastern Europe and Asia. But until now there has been no clear evidence of it in cattle."
But he believes this is the first time the antibody has been looked for in UK cattle. Cattle symptoms were similar to flu in humans and one of the vets involved asked if it could be the same. When animals were tested antibody was detected but no virus.
Antibodies occur after fighting a virus. But researchers do not know how severely affected infected animals were, how widespread it is, how it affects a herd or how contagious it is. Further research hopes to answer these questions, but that will not be possible until the virus is found.
Somerset vet Bobby Moore of the Glynswood Vet Centre, Chard, has seen cattle in which influenza virus antibodies were isolated.
He reports seeing herds with one or two cases, and suggests investigating animals with an unexplained milk drop for virus antibodies where acetonaemia or disease such as leptospirosis are discounted. Not all affected animals suffer severe respiratory disease.
"The milk drop seen can be significant; in the worst case yield dropped from 40 to 20 litres. Affected cattle can be of any age or stage of lactation. They have a high temperature for 24 hours, but it is rarely above 103.5F," says Mr Moore.
"It takes five to 14 days for animals to return to normal, whatever form of treatment is used."
In the meantime, MAFF suggests applying good husbandry practices to any sick animal and consulting your vet. Isolate sick animals, keep them warm with plenty of bedding and ensure a good supply of water. When they have influenza they will normally recover after a few days.
Mr Moore says there are many potentially infectious diseases, so it is wise to take care with children around animals and to follow normal hygiene precautions, such as washing after handling animals. *
• Antibody recently identified in cattle.
• Symptoms appear similar to humans.
• Cows may have unexplained milk drop.
• Animals recover in five to 14 days.