Cryptosporidiosis, also known as crypto, was one of the most common diagnosis in carcasses submitted to the Animal and Plant Health Agency (APHA) in Great Britain last year.
The data has prompted calls from vets for more routine on-farm inspections to manage the disease.
APHA data showed that crypto was the fourth most common diagnosis in Q1 and the second most frequent diagnosis during the same period from 2015 to 2024, highlighting the ongoing prevalence of the disease and its impact on calf health.
The disease affects calves from five days to two weeks and presents with a number of symptoms such as colic, reduced weight gain and feed intake, through to watery scour and dehydration.
Infection occurs when calves ingest the parasitic protozoan, C. parvum, which produces vast numbers of encysted eggs shed in the faeces of infected animals.
Vet Rob Drysdale from Bovine Health Solutions says cryptosporidiosis can often be missed, and may even be under-diagnosed on some farms, despite being the most common cause of infectious scour in the UK, according to the APHA.
Scour in calves under five days old are unlikely to be caused crypto, in calves five to 10 days old it is more likely to be caused by crypto, and in calves 10 to 20 days of age scour is most likely to be due to the parasite.
Drysdale said: “Without testing, farmers cannot manage the disease effectively, if you don’t know the cause, you can’t implement the right solution.”
To control spread of the disease, Drysdale recommends:
- Maintaining hygiene at calving and using disinfectants effective against crypto;
- Ensuring proper colostrum management, with clean equipment and timely feeding;
- Cleaning calf pens thoroughly and using appropriate disinfectants between uses;
- Avoiding mixing calves of different ages, limiting the age gap to seven days;
- Vaccination of pregnant heifers and cows to provide increased protection through colostrum.
“Most farms have some level of exposure to C. parvum, so reducing the subclinical load in calves is vital,” he added.
Drysdale said that he believes vaccination is potentially more cost-effective than treatments for sick calves.
He also reminded farmers of the human risk associated with the disease which can cause stomach problems.
Dr Kat Baxter-Smith from MSD Animal Health stressed the multifactorial nature of infectious calf scour.
“No single solution exists, but good biosecurity, vaccination, nutrition, and hygiene help minimise disease problems,” she said.
