Cryptosporidiosis was one of the most common diagnoses in cattle carcass submissions to the Animal and Plant Health Agency (APHA) in Great Britain last year1, prompting a leading cattle vet to call for more routine on-farm testing and vaccination to manage the disease.
APHA data1 revealed cryptosporidiosis 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.
Affecting calves from five days to two weeks of age Cryptosporidium parvum presents with symptoms such as colic (gut pain), 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 (oocysts) shed in the faeces of infected animals.
Vet Rob Drysdale from Bovine Health Solutions says Cryptosporidiosis can often be missed, and may be under-diagnosed on some farms, despite being the most common cause of infectious scour in the UK2.
Testing is crucial for accurate diagnosis. According to Mr Drysdale:
- Scours in calves under five days old are unlikely to be C. parvum.
- Scours in calves aged 5-10 days could be caused by C. parvum or rotavirus.
- Scours in calves from 10-20 days are most likely due to C. parvum.
“Without testing, farmers cannot manage the disease effectively,” he said. “If you don’t know the cause, you can’t implement the right solution.” He carries testing kits to help with a rapid calf side diagnosis while on the farm.
Once C. parvum is present on a farm, eradication is nearly impossible, making management essential. “C. parvum is essentially a disease of faecal contamination. Keeping calves clean, ensuring quality colostrum intake, and maintaining hygiene at calving and in housing are key,” he said.
Control
To control the disease, Mr Drysdale recommends:
- Maintaining hygiene at calving, using disinfectants effective against C. parvum.
- 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 with Bovilis Cryptium® 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.
Cost of C. parvum
The economic impact of C. parvum is substantial. Gut damage at an early age affects lifelong performance, with a recent UK study3 showing that calves infected within the first 16 days of life gained significantly less weight over six months, leading to a potential £161 reduction in sale price per calf. Additional costs include increased labour for managing sick calves.
Vaccination
Mr Drysdale believes vaccination is potentially more cost-effective than treatments for sick calves and at the same time is preventing disease and reducing labour costs.
“Vaccination can save farmers time and reduce calf losses,” said Mr Drysdale. “By vaccinating dams, farmers improve calf health, enhancing lifetime performance, earlier age to first calving, and increased milk production. Losing a heifer could cost the farmers in the short term but damage from Cryptosporidiosis might impact health and production leading to bigger longer-term losses.”
Mr Drysdale also reminded farmers of the risks to humans from C. parvum, with the potential for the zoonotic parasite to 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.
Vaccinating pregnant heifers and cows with Bovilis Cryptium® provides newborn calves with protection through colostrum, reducing clinical signs like diarrhoea. The two-dose primary vaccination course is administered 4-5 weeks apart in the third trimester, with a booster required in subsequent pregnancies.
Bovilis Cryptium® can be co-administered with Bovilis® Rotavec® Corona, which protects against rotavirus, coronavirus, and E. coli strains. “The protection of calves depends on adequate ingestion of colostrum and transition milk from vaccinated cows,” said Dr Baxter-Smith.
“Calves should receive at least three litres within six hours of birth and all calves should be fed colostrum and transition milk during the first five days of life. Calves gain protection against these pathogens by drinking the fortified colostrum from their vaccinated mothers,” explained Dr Baxter-Smith.
Farmers interested in further information should contact their local veterinary professional.
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