Cryptosporidiosis– a common cause of scour in calves
- Cryptosporidiosis is the disease caused by infection with the protozoan parasite and is the commonest cause of calf scour in the UK. Cryptosporidium can also infect man and has been associated with mass water pollution incidents of drinking supplies( E.g. Lancashire 2015)
Healthy calves at 3-4 months of age with no history of crypto!
- Only one species, Cryptosporidium parvum, causes disease in cattle and generally only in neonatal calves. The typical age for crypto is in the first 4 weeks of life
- Clinical signs can range from mild scouring to calf death depending on the parasite burden, susceptibility and health status of the calves. The higher the dose the more severe the symptoms
- Nutritional or energy stresses on the calf will make the symptoms more severe.
- The life cycle of the parasite allows it to multiply rapidly in the host leading to the rapid spread of the disease as infected calves shed millions of parasites into the environment creating major breakdowns in calf rearing units
- The parasite survives well in the environment and is not killed by most standard disinfectants.FAM and Sorgene DO NOT control crypto.
- The parasite survives best in wet or damp conditions and can survive for more than a year in damp environments.
- Resistant to temperatures up to 60 Deg C and -20 Deg C. Steam cleaning is effective method of disinfection.
- Currently there is no vaccine available and treatment options are limited
How infectious is Crypto?
- The infective dose is 10 parasites! An infected calf can shed billions of parasites. One infected calf causes major contamination of the environment allowing infection to be spread to naïve calves through contaminated bedding, feeding utensils or feed troughs.
- Mixing ages is high risks. Older calves or any calf recovering from infection can infect younger calves and perpetuate the life cycle
Contaminated feed troughs are a common source of crypto and cocci contamination.
The life cycle
- The life cycle takes between 2 and 7 days to complete from the point of infection to shedding oocysts in the faeces. Infection can build up very quickly
How do I break the life cycle?
What treatment options are there?
- Treating affected calves is challenging. In severe cases the disease will cause death with typically a poor response to treatment in many cases. Prevention is the key.
- Halocur( prescription medicine supplied by us) can be used as a prevention by mixing with milk or dosing by mouth for the first 7 days.
- Any treatment must be controlled with improved hygiene, frequent bedding and using correct disinfectants frequently enough to break the life cycle.
Crypto can leak out of the pen into the passageways and contaminate where you walk and this can be a common source of infection to other calves
Pressure washing of hutches is essential to prevent cross contamination. Wash and disinfect!
Top tips to Reduce environmental contamination
- Steam cleaning of animal pens/calving areas – to kill oocysts
- Cleaning calving areas frequently – to reduce oocyst build up. Ideally every 2 weeks
- Deep and regular straw bedding – keeps animals clean/away from faeces
- Slurry and manure should be well fermented or composted prior to application on pasture.
- Build can occur under hutches and if on free draining hard core base the simplest option is to add more hard core to bury the Crypto.
- Ensure all troughs and buckets that can be contaminated with faeces are cleaned and disinfected as they can be the “point source” of infection
Wooden troughs are impossible to clean and are not ideal.
Calves well bedded down, calf jacket to reduce cold stress with a pen that can be readily disinfected will allow for good control of crypto
Plenty of bedding will help separate the calf from the parasite and improve drainage. Calves eat straw. Lets make sure they eat clean straw!
Maximising immunity and animal management
The three „Q‟s‟ of colostrum – Quickness, Quality and Quantity to maximize immunity of the calf to any diseases
Rehydration of sick calves with electrolytes is the central plank of scour treatment
Keep animals in age groups – do not mix older animals with younger animals to help prevent spread between ages
Quarantine scouring animals until 1 week after scouring stops as these calves are still infectious after they have recovered
Feed healthy animals first before handling sick animals
Controlling other scour pathogens such as Rotavirus is beneficial as combined infections are common and the stress of other infections can trigger more serious crypto problems.
Breaking the life cycle and reducing the challenge
Many of the common farm disinfectants such as FAM and Sorgene (if used at the manufacturer‟s recommended concentration) are NOT effective in killing Cryptosporidium oocysts.
All disinfectants work best after pressure washing or steam cleaning.
- 2-3% KenoTMCox – kills 99% oocysts after 2 hours contact time
- 2-4% Neopredisan – kills 99% oocysts after 2 hours contact time
- 10% Ox-Virin – reduced oocyst infectivity after 1 hour contact time
- 3% Hydrogen Peroxide – reduced oocyst infectivity after 4 minutes
If bedded on hard core applying a further layer of hard core on top or replacing the hard core using lime as a base will help reduce crypto and cocci pathogen load
When to call the vet for help?
We can help diagnose infection using simple tests at the practice allowing for same day results. Establishing a diagnosis can aid in defining the best way forward.
We can also blood sample 1-7 day old calves and check for immunity status
Most importantly we can help advise you to adopt a PVG control plan for calf scour which will deliver lasting economic benefits to your farm.
Phone us to create a calf infectious disease plan for your herd!
Cattle Handling Systems
Simple Cattle handling systems
Mark Martin of Limestone farm demonstrates his simple system for handling cattle using an old Tubar crush modified with IAE race. Mark also supplies IAE equipment and can advise on a system to suit you.