What to look for -
- Signs vary with the number of flies and the sensitivity of animal
- Skin irritation
- Heavily infested cattle try to dislodge the flies by rubbing against trees, posts or buildings
- Constant rubbing may lead to hair loss and skin abrasions
- Damaged skin can become infected or attract other flies
Cause – a blood sucking fly
Buffalo fly is widespread in the tropical and sub-tropical regions of Australia. Adult buffalo flies spend their lives on cattle and survive by sucking blood from their hosts. Female flies lay eggs around the edges of fresh cow pats. These eggs hatch and the larvae move into the manure where they develop into adult buffalo flies. Fly numbers build up in spring and summer.
Animals likely to be affected
Cattle of any age.
Other diseases with similar signs
Skin lesions may be confused with other causes of skin irritation.
Confirming the diagnosis
Buffalo flies are easily identified, but if in doubt catch several flies and show them to a neighbour or local vet. It is important to distinguish them from screw-worm fly, which is not currently present in Australia, but occurs in tropical countries to our north. Screw-worm fly differs from buffalo fly as it burrows into the flesh of animals and results in wounds containing large numbers of maggots. IF YOU SEE UNUSUAL FLY INFESTATIONS NOTIFY YOUR VET.
Spread of the disease
Buffalo flies can readily spread within a mob, over a fence or from introduced animals.
Risks to people
Buffalo flies sometimes bite people but are not known to transmit any infectious diseases.
A number of chemicals are effective against buffalo fly and can be applied via ear tags, pour-ons or sprays. Manufacturers’ withholding periods must be observed to avoid chemical residues in dairy products. Buffalo flies may become resistant to a particular product if it is used frequently.
To reduce the build-up of resistance chemical use should be limited to periods when fly numbers are very high, and insecticides should be changed periodically.
Plans are available on the internet for a buffalo fly trap that removes flies from cattle, then traps and destroys them. To be successful, cows must pass through the trap several times a day.
www.mla.com.au Tips and Tools, Animal Health and Welfare