Photo credit: MSD Animal Health
Cryptosporidium parvum (Crypto) is a gastrointestinal parasite that causes diarrhoea (scours) in calves, generally within the first four weeks of life. It is one of a number of pathogens that can cause diarrhoea in this age group, others include Rotavirus, Coronavirus, and Salmonella.
Typically, Crypto presents as mild to severe diarrhoea lasting several days. The worst cases often die quite quickly – sometimes as fast as 12 hours after onset of obvious clinical signs.
The parasite damages the gut lining, so even when calves do survive the disease, it can cause lasting damage to their ability to absorb nutrients. This effects growth rates going forward.
It can be one of the most challenging scours for farmers to manage when an outbreak occurs.
Infected calves shed billions of Crypto oocysts (single crypto cells) in their faeces around the shed, and as little as 17 of these oocysts are enough to infect another calf and cause disease.
Unfortunately, these oocysts are also almost impossible to remove from the environment with disinfectants. This means that once outbreaks start, they often spread through a calf shed swiftly. Farms that have experienced outbreaks will then generally have issues with the disease most seasons going forward.
If you have been unlucky enough to have suffered an outbreak you will already be well aware of the impact Crypto can have on a mob of calves.
Treatment options such as Halocur and Exagen have been available for some time to help fight Crypto, but these options will not stop the diarrheoa, and only limit the severity of clinical cases.
Excitingly, this year a new vaccine is available to help tackle Crypto in at-risk herds: Bovilis Cryptium.
Bovilis Cryptium works similarly to other scours vaccines (like Rotavec Corona). It is designed to be given to pregnant cows between 12 and 3 weeks pre-calving, and works to increase antibody levels in colostrum at calving. This immunity is then passed on to calves via the colostrum, setting them up to be better protected against Crypto exposure.
Cows will need two shots of Bovilis Cryptium, four weeks apart, their first time. Following that they'll only need one shot around the same time of year each season as a booster.
It’s important to mention that the vaccine itself is not going to be a silver bullet. Calves still need to get enough high-standard colostrum in a timely manner to receive the protection from the vaccine. So, improving the quality and quantity of colostrum your calves receive will help you get handle on Crypto.
If you would like to discuss a plan for vaccinating your herd with this new vaccine this season, please give the clinic a call or speak to your KeyVet.
