Travelling the length and breadth of the country for the last number of weeks, there were many concerns farmers raised at our mart roadshows.

One front-runner for animal health was dealing with cryptosporidium in calves this spring. This is a small parasite affecting beef and dairy calves.

Managing the disease can prove very problematic and this article shares some tips for this spring.

The disease facts

  • Cryptosporidium parvum is the disease we see most often in calves and sometimes lambs. It is a parasite that can survive for up to one year in the environment. The infective oocysts have a thick shell making them resistant to heat, cold and many disinfectants.
  • The route of infection is faecal oral, meaning calves can ingest the parasite in small numbers (100 oocysts) causing infection. Infected calves will shed billions of oocysts in their dung. The cow is thought to be the initial reservoir or source for infections.
  • Infected calves shedding billions of oocysts must be isolated to remove the biggest source of new infections for other calves.
  • It causes a scour from damage done to the lining of the gut. This scour can last for five to seven days and take up to a week to recover from. Death occurs from weakness, fluid loss and secondary infections.
  • It can also affect humans, so care must be taken to reduce the risk of humans succumbing to the disease.
  • It generally affects calves between one and five weeks of age.
  • It can be diagnosed using rapid snap tests by your vet on the farm.
  • It is believed to survive well in water, so drinkers’ heights and hygiene are important. UV light is believed to kill the parasite in water.
  • There are no treatments available which effectively kill the parasite meaning that supportive care is the best option to help calves survive infections. This involves fluid therapy and continued milk feeding or keeping cows on calves.
  • Paramycetin is an antibiotic used in some countries to control and prevent the disease.
  • Due to the fact it causes inflammation in the gut, anti-inflammatories may play a role as part of the treatment. It makes sense as the disease can cause quite a bit of pain and colic symptoms.
  • Where you get infections with rotavirus scours at the same time, the disease can be more severe.
  • As a preventative, Halofuginone lactate can be administered orally for the first seven days of life to reduce the severity of disease.
  • Colostrum

    Colostrum is still really important.

    When we talk about controlling Cryptosporidium parvum, where colostrum management is poor, then we can see high mortality with cryptosporidium.

    For the suckler cow, it is key to get nutrition right pre-calving, feeding high protein and energy pre-calving to ensure good-quality colostrum.

    Get calves up quickly and tube- or bottle-feed colostrum to weak calves. With dairy calves, we really need to make sure they get three to four litres of colostrum quickly.

    With crypto in dairy calves, we need to pay close attention to hygiene around colostrum. Clean out any containers used to feed colostrum regularly.

    Bacteria

    The bacteria in colostrum can reduce how effective colostrum is. Remember, anywhere there is dung on feeding equipment we could have crypto.

    Colostrum is still the most important tool in minimising the severity of crypto infections.

    Remove

    If infected calves are producing billions of oocysts, we must isolate them from other calves early. Isolating your suckler dam and calf is also an option. Sometimes, if weather is favourable, then turnout is an option. Calves can also get infections outdoors.

    Hygiene

    With dairy calves, removing them or snatching them from calving pens is an effective way of reducing exposure to infection. We need to make sure that all utensils and feeding equipment are cleaned regularly with hot water and diluted hydrogen peroxide 3%. Where we use this, a cold clean rinse to wash off hydrogen peroxide is important. Cleaning sheds between batches is critical, which can be difficult in springtime. Some farmers have suggested having fewer problems with crypto on peat bedding but I have no evidence of this myself. Surfaces such as plastic or walls with paint that can easily be washed down help to remove oocysts from the environment.

    To clean sheds:

  • Remove any dung from shed (dung contains billions of oocytes).
  • Steam-clean all surfaces that calves are in contact with. This is up to 5ft on walls.
  • Disinfect the whole shed with foam. Get a foaming nozzle for power-washer. Some people use a small amount of foaming agent such as washing-up liquid. Always use a licensed disinfectant to kill the oocysts. My own personal favourite is hydrogen peroxide 3-4% with a foaming agent as it has a rapid kill.
  • Make sure to remove all calves when cleaning sheds.

    Feeding

    Where outbreaks occur in dairy herds, I will always look at feeding levels of milk. I will often push up feeding to six litres, or 900g of powder, twice daily as standard. With calves on OAD feeding, I have noticed symptoms and mortalities to be higher. With suckler calves, I also look at the feeding of cows to maximise milk outputs. This is my own opinion but with more feeding I have seen fewer symptoms and quicker recovery of sick calves.

    Control other infections

    Where there is a risk of rotavirus, I always advise vaccinating cows as this can reduce the severity of the crypto infections in calves.Halocour

    Using halofuginone for every calf at the beginning of the calving season definitely helps to control crypto. It is quite toxic on a calf’s stomach so follow the dose rate of 2ml per 10kg carefully. It needs to be given daily for seven days and with or just after a milk feed. This can be difficult to manage in suckler cows and calves.

    Cryptosporodium is probably the most frustrating disease I see in young calves. It takes time, effort and attention to detail to get on top of it.