With temperatures rising above normal levels in recent weeks, fly strike has become a problem for sheep farmers.
What is it -
A mysasis condition, Flystrike occurs when sheep are infected with a number of different fly species. These act as external parasites on the sheep, causing a parasitic infection in the sheeps body via fly larvae/maggots.
One inside, the maggots will grow whilst feeding on the sheeps muscle tissue and/or flesh. Fly strike generally occurs on an average of 80% of sheep farms, meaning it is a serious problem.
There are many signs that your sheep have succumb to fly strike, such as a loss of condition, reduced wool clippings, transmission to other animals and in extreme cases, even death.
Early signs that a sheep may be infected include agitation, a strong odour, foot stamping, body nibbling/itching, matted coloured wool, green or wet patches on the wool. Wool patches will begin fall off the animal as the infection develops.
When it occurs -
Flystrike normally occurs during the warm humid weather periods, with temperatures steadily above 9 degrees.
This is the ideal temperature for fly species to thrive. In fact, changeable weather patterns experienced this side of the world in recent years have only led to the earlier start to fly season. This means that the season lasts longer than it used to, causing more and more strain for farmers.
Blowfly season in temperate regions is June to September. It will be seen mostly in unshorn sheep in June and in lambs from July to September.
When sheep are attacked by these flies, they lay eggs on dirty wool or open wounds on the animal. The female flies can lay up to 3,000 eggs in the space of three weeks. Any damage can be done to the animal after only a 24 hour period. Therefore, to say prevention is key would be a severe understatement.
After the eggs hatch, the maggots burrow their way down through the dirtied wool and in under the sheep’s skin, where they will feed on flesh or tissue. As the maggots develop, they continue to lay news eggs on sheep, new or infected. Maggots can develop in as little as five days before they fall off the sheep and burrow into the soil to form pupae, which can cause a problem in one year’s time.
Fly strike can be prove deadly for sheep, with ammonia poisoning a probability.
If an animal is found to be infected with fly strike, it should immediately be removed from the flock and its wool shorn as close to the skin as possible around the affected area. The area should then to be treated with insecticides to kill any remaining maggot, with soothing cream then applied to the affected skin.
Keeping up to code with farm hygiene practices is one of the best preventative methods.
Clearing your farm and farmlands of any dead vegetation, faecal material or rotting carcasses will drastically improve your chances of preventing fly strike. This is because they gain protein from dead flora and fauna, enabling them to thrive.
Preventing diseases such as foot rot, skin diseases, scour, infected cuts and urine soaked wool on sheep is also vital in preventing fly strike. All of the above mentioned ailments, tend to attract blow flies. Therefore the correct steps should be implemented to prevent them.
Recently shorn sheep are seldom struck with fly strike, as flies are attracted to heavier wool coats. This is due to sheep sweating more during summer months with big coats, thus creating the perfect unhygienic environment for the flies. The docking of lambs tails at weaning is also another measure taken by some farmers to prevent infestation.
Effective animal health care, such as crutching and trimming, can also further help in the control of flystrike, while some farmers even use fly traps to limit the number of flies. Otherwise, the only other alternatives are medicinal. There are many chemical treatments available through your vet, which can be successfully used to prevent a case of fly strike. Plunging and dipping sheep is one such method that can protect sheep for up to eight weeks, though this will have to repeated thereafter.
It’s that time of year again, but have you sufficiently protected your flock?