The most common call a vet receives is scoury calves. In the last three years I have seen a notable increase in crypto scours, probably due the fact we are testing all the samples now.

In my experience, I am also seeing crypto on its own or in conjunction with rotavirus/coronavirus. I would estimate about 40% or more of calf scours I see have crypto involved. Crypto is not a bacteria or a virus, it is a protozoan parasite, so control is slightly different. We usually see it in calves from 1-4 weeks of age. Antibiotics have no effect on crypto, in fact I think they can make it worse.

What I have found is crypto on its own can lead to quite bad scours with the calves contracting rotavirus as well. This can lead to high mortalities. Where the real problems occur is where colostrum feeding is below par and hygiene is poor, I have seen up to 20% mortality in some of these situations.

Signs of crypto

The clinical signs are usually profuse yellow/green diarrhoea, weakness and dehydration. The crypto gets into the lining of the intestine and will reduce the absorption of nutrients, causing a secretory diarrhoea which will lead to calf going downhill quickly.

Always test samples to confirm the pathogen you are dealing with. It can take a calf up to one week to recover their full appetite following a bad infection. I usually make a diagnosis on farm with a rapid scour test kit and sometimes send samples to the regional lab also.

Spread

Crypto is spread through faeces or in the environment. Oocysts can be found anywhere there are faeces, including from the faeces of the cow. These oocysts are extremely resistant and can survive for long periods in the environment as well. If you are in the middle of an outbreak then huge numbers of oocysts are being produced by sick calves, leading to huge infection pressure or exposure to healthy calves.

Treatment

I have tried everything but unfortunately there is no silver bullet solution. It is important to keep the calves on milk rehydrate orally with 2 x 2litres of warm electrolyte solution twice daily in between milk feeds. For recumbent or weak calves, you should seek veterinary attention. Halocour can be given as a treatment, but this only works for me when introduced very early on.

For healthy calves it is so important not to bring them into infected environment and start halocour treatment to prevent the severe clinical signs. Talk to your own vet about using halocour to get the best results.

I have no magic cures or preventions, but I do know where we have implemented strict hygiene protocols we have seen a big decrease in the incidence of the disease.

When cleaning calf sheds, I draw up a standard operating procedure between batches to reduce the oocysts in the environment. I find the best control is drawing up a written plan which can be referred to and adapted on a monthly basis by the farmer/vet. There are no quick fixes, so patience and compliance will see the best results. You and your vet are a team, the opposition is the crypto, and victory will come through an organised and consistent approach.

The main aim is a long term control plan

Colostrum feeding

This gives the calf the best chance of fighting any of these new-born scours. This is an area where you have to be regimental if you are having problems feeding 3 litres in three hours.

Hygiene

Clean clean clean. Disinfect calf feeders, utensils, stomach tubes or any other equipment and yourself very regularly. For example, I will disinfect calf feeders daily and have a disinfection point set up at calf house door.

Wear gloves when dealing with infected calves. Crypto can affect humans and be picked up from calves so take great care dealing with faeces from infected animals. I have seen two cases of farmers getting nasty infections from crypto off infected calves.

Avoid faeces build up in the environment. Change fresh straw bedding regularly under calves.

When cleaning sheds or pens, you must first clean all faecal matter from walls and floors with power hose. There can be no compromise in this area - you must have the sheds spotless. Where there are lots of crevices, these sheds can be very difficult to clean thoroughly. I find clean smooth surfaces the best for disinfecting; this is worth noting if ever upgrading calf housing.

Follow up with intensive steam cleaning of the whole environment and spray appropriate disinfectant on all areas of the house. I use is a product called Kilcox Xtra, but talk to your own vet about disinfection.

If possible, sheds should be left dormant for up to four months. In the middle of an outbreak this type of cleaning should be carried out to the best of your abilities depending on your set up. The main aim is for the following calving season to reduce the environmental exposure.

The calves

Calves should stay in individual pens in the first two weeks help control the spread of the disease. The calf should also be removed from the cow as soon as possible after calving. Having the calving pens cleaned and limed with regular fresh straw bedding helps

You should never mix age groups of calves, especially in the middle of an outbreak. Feed younger calves first and then the older ones. Isolate sick calves immediately and move to sick pens. These animals should be fed separately

As a control, start halocour from birth for seven days with milk feed to reduce shedding after talking to your own vet.

There are alternative treatments, however this is decision for you and your own vet to make. I have used only the established options here, but I am trialling alternatives myself. This might seem over ambitious in a real life working farm, however the closer you stick to this advice the more quickly you will control this very frustrating disease.

Remember, crypto can affect humans so take great care and appropriate hygiene measures yourself. Under no circumstances should children or older sick individuals be around calves with cryptosporidium.