New study highlights gaps in calf scour control on British farms

The findings come from MSD Animal Health’s Five Point Plan Cryptosporidiosis Control Questionnaire, designed to help farmers and vets pinpoint weak areas on-farm and build a ‘margin of safety’ against infectious scour. 

Calf cryptosporidiosis, caused by the protozoan parasite Cryptosporidium parvum (C. parvum), is now the most common cause of infectious scour in Great Britain. It is widespread on both dairy and suckler units and typically affects calves between five and 14 days of age. 

Scour costs the UK cattle industry an estimated £11 million per year, with gut damage reducing growth, feed efficiency, and lifetime performance, alongside the immediate welfare and mortality losses.  

Due to its scale and impact, the UK National Office of Animal Health (NOAH) classifies calf scour, including cryptosporidiosis, as a Category 1 disease, meaning prevention should be prioritised. 

Once C. parvum is present, eradication is virtually impossible, as infected calves can shed billions of oocysts – with as few as 17 capable of causing infection. Effective management is therefore critical. 

Five Point Plan

To support farmers, MSD Animal Health developed a Five Point Plan focusing on: 

Dr Kat Baxter-Smith, veterinary advisor at MSD Animal Health, said that the questionnaire highlights both progress and areas needing improvement. 

“Lower scores show where changes will have the most impact. By covering all five areas, farmers can build their margin of safety and get scour properly under control.” 

Colostrum management 

One of the most notable findings was that almost half of the farms were not testing total proteins in calf bloods to check for adequate colostrum transfer. 

“Testing total proteins is quick, inexpensive, and gives an immediate indication of whether colostrum management is working,” Dr Baxter-Smith explained.  

“Colostrum is the foundation of a calf’s immune system – it’s the only way newborns receive antibodies to fight disease in the crucial first weeks. If colostrum management isn’t correct, calves start life with lower protection, making them far more vulnerable to scour and other infections.” 

Isolation of sick calves 

Another area flagged was the inconsistent isolation of sick calves. Twenty-one farms isolated scouring calves only sometimes, while six never did. 

“Isolation is one of the simplest and most effective ways to prevent disease spread but is often overlooked. 

“Once a calf shows scour, it’s already shedding billions of oocysts. Keeping that calf with healthy animals increases infection pressure. 

“Ideally, sick calves should go to a clean, well-bedded isolation pen with separate feeding equipment and handled last. Even small steps – separate buckets, disinfecting boots and clothing – make a big difference. Isolation protects the rest of the group and is an important part of the margin of safety farmers can build,” said Dr Baxter-Smith. 

Progress 

The survey also highlighted positive practices. Most farms had effective rehydration protocols, grouped animals by age, and fed colostrum in the correct quantity and timeframe. 

“Managing cryptosporidiosis is multifactorial – it’s about stacking good practices together. 

“The aim isn’t to overhaul everything, but to fine-tune what’s being done well and strengthen weaker links,” Dr Baxter-Smith added. 

Vaccination 

Vaccination is a vital tool in scour prevention. Bovilis Cryptium, the world’s first vaccine for cryptosporidiosis, boosts antibodies in the dam’s colostrum. 

Administered to pregnant cows in the third trimester, it requires two doses four to five weeks apart, with the final dose completed at least three weeks before calving.  

For subsequent pregnancies, a single booster is needed. It can be given alongside Bovilis Rotavec Corona, which protects against rotavirus, coronavirus, and E. coli F5 (K99) and F41. 

“By vaccinating cows in late pregnancy, antibodies against C. parvum are passed to the calf via colostrum,” Dr Baxter-Smith explained. “Calves should receive at least three litres of colostrum within six hours and continue with colostrum and transition milk for the first five days. Used alongside good colostrum management and hygiene, vaccination can help significantly improve calf health, welfare, and farm efficiency.” 

Take action 

Dr Baxter-Smith encourages farmers to use the Five Point Plan and work with their vets to assess farm practices. 

“This questionnaire is a practical tool to identify gaps, track improvements, and ensure no area is overlooked. By combining all five elements of the plan, farmers can protect their calves, reduce losses, and improve herd productivity,” she concluded. 

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