Beef producers calving this autumn should be on their guard for coccidiosis, advises vet Jenny Hull, Black Sheep Farm Health, Rothbury, Northumberland.
Coccidiosis was prevalent this spring due to cold and wet weather, but could recur this autumn in completely different climatic conditions.
Dr Jenny Hull, a vet at Black Sheep Farm Health, Rothbury, Northumberland, says the long, dry summer could have affected the health and condition of autumn-calving suckler cows.
Dr Hull reports the recent death of calves born late this spring. She says: “This has been out of season but is probably a reflection of the dams’ nutrition and poor grazing conditions.
“We are not certain why, but coccidiosis is definitely on the increase. In recent years, many farmers have reported mild, pasty, grey scour in calves between six and nine weeks old, a classic symptom of the disease.
“It can almost go unnoticed until the end of an outbreak, although calves may have a dull coat and growth rates will be slow.”
Conversely, severe clinical coccidiosis can lead to the sudden onset of profuse diarrhoea containing mucus and flecks of blood.
Producers are advised to be vigilant and watch for the mild or severe symptoms, and those suspecting an outbreak should contact their vet. The dung can then be examined for oocysts, the stage of the coccidian parasite’s life cycle excreted by the animal and picked up from contaminated areas to reinfect others.
Ms Hull says: “The diagnosis should be made at the earliest opportunity to allow for early treatment.”
However, she notes clinical signs can often be seen before this oocyst shedding begins, in which case diagnosis can be based on symptoms and the age of calves.
“If you have coccidiosis diagnosed, treatment is likely to be recommended across the calf crop,” she says.
“Equally, if there has been a cocci problem on your farm this spring or in previous years, it is worth giving a strategic dose of a coccidiocide as a blanket treatment at about six weeks of age.
“This will give the animals protection, without impairing their ability to acquire life-long natural immunity against this disease,” she says.
For the long-term, Ms Hull recommends establishing husbandry practices which help avoid the disease in the future.
“Try to avoid grazing fields with known problems in previous years and practise good hygiene.
"This means, for example, using plenty of bedding for housed cattle or avoiding access to water courses or standing water and regularly moving feed hoppers to avoid the build-up of mud, both of which can be sources of infection for cattle outside.”
The economics of protecting against and treating for the disease can be well worthwhile, as coccidiosis can cause lower weaning weights in beef calves and, in extreme cases, lead to death.