Easing the burden of coccidiosis
This spring has posed many challenges on farms throughout the country. Tommy Cox, Teagasc DairyBeef 500 Advisor, writes that one such challenge which can be particularly prevalent on some calf rearing farms is coccidiosis.
Coccidiosis is caused by protozoa and will tend to present as a problem in calves between three weeks and nine months of age.
Coccidia are single-celled parasites that can infect a wide range of animals. These organisms are host specific, meaning they won’t pass from one species of animal to the other but will pass between the same species. These parasites affect the small and/or large intestine, where they damage the intestinal wall.
Sub-clinical infection often occurs on some farms, where animals show very little symptoms and will recover with time, but they will as suffer a performance set back. In more severe cases, symptoms include a watery scour with the presence of blood due to damage of the gut lining. Damage to the intestine reduces the calf’s ability to absorb fluids and nutrients and so calves that are infected can become dehydrated and, as a result, rapid treatment is required.
Prevention
Like with any disease, prevention is always better than the cure. At present, there is no vaccine available to give protection against coccidiosis, therefore management practices are the only way to prevent a potential outbreak.
Good hygiene is crucially important in preventing an outbreak. Keeping bedding changed and keeping fresh straw under calves at all times helps prevent build up. Preventing the build-up of faecal contamination around feed and water troughs, or any area where calves congregate, is also important to preventing an outbreak. Mixing of different ages of calves should be avoided, as younger calves will be more susceptible to the disease.
If you have had a problem, make sure sheds are cleaned and disinfected with a strong disinfectant between batches of calves. Disinfectant choice that kills oocytes is critical.
A farm-specific disease
Coccidiosis is totally farm specific. Some farms may require treatment in the shed or on pasture where other farms require treatment at both stages. Where there’s a history of coccidiosis on the farm, vigilance is required.
Good management of coccidiosis involves allowing the calves to be exposed to the parasite to develop immunity but at the same time avoiding disease and poor performance. Taking dung samples from a number of animals within the group is also advised as animals failing to exhibit clinical signs may have a high oocyte burden.
Herds that have an ongoing problem with coccidiosis will often dose calves with anti-coccidial products that contain the active ingredients diclurazil/toltrazuril as a prophylactic. When treating, the best time to administer the product of choice is one week before expected clinical signs. This will allow some exposure to the parasite and allow immunity to develop. Diclurazil-based products enables natural immunity to develop. Toltrazuil products are only licensed to be used in calves less than 80kg due to with environmental contamination with the product.