Crypto calf infections more prevalent in recent years
The cryptosporidia infection is the last thing suckler farmers want occurring as the calving season progresses.
A recent report from the veterinary services of the Department of Agriculture, Food and the Marine, and the Department of Agriculture, Environment and Rural Affairs in Northern Ireland revealed that up to 40% of calf mortality in the first six weeks is scour-related.
At farm level, cryptosporidium parvum is becoming more prevalent, and apart from the obvious lack of thrive and potential for high mortality rates, it is both expensive and time consuming to control an outbreak.
It can also infect humans through cryptosporidium-contaminated water supplies; the citizens of Galway and surrounding areas suffered from this back in 2007.
Clinical signs
Calves from five to 35 days old are susceptible, but it generally occurs in the second week of life.
Characteristically, calves will get a persistent diarrhoea that is extremely difficult to cure.
The infection will cause severe damage to the lining of the gut wall, and destroy the ability of the animal to absorb nutrients.
Calves will become lethargic, stop drinking and can become dehydrated quickly.
Once infected, calves will after four days begin to shed vast quantities of oocytes in their scour.
This leaves the environment heavily contaminated for other calves that then become infected.
Treatment
Because of the damage to the gut lining, it is important that calves are kept on milk and electrolyte therapy, so that they are kept nourished, and do not become dehydrated.
The only licenced product that can be used therapeutically or as a preventative is Halocur. Where there is a problem, calves should be given Halocur in the first 24 hours after birth, and it must be continued daily for a further seven days.
Once one calf is treated in the herd, all subsequent new born calves should be treated for the remainder of that calving season.
Your typical 45kg-50kg calf will need 10ml per day for eight days. Treating calves with Halocur will interrupt the life cycle of the cryptosporidium, reducing the challenge to the calf, and the number of oocytes shed declines.
Once cryptosporidia gets into a herd, it can be difficult to remove it, so many herds will just routinely treat all calves after they are born.
Prevention
Isolate scouring calves immediately from the group.
They are a huge source of infection. Adequate colostrum will safeguard calves against secondary infections such as rotavirus and coronavirus.
Hygiene and cleanliness are critical. Calving boxes, feeding buckets, boots, and stomach tubes need to be properly cleaned and disinfected. Consult your vet on what is the most effective disinfectant to use.
You should use a disinfectant that is effective against the oocytes from this protozoan parasite when cleaning out sheds and pens.
Remember, antibiotics are ineffective, and you cannot vaccinate against cryptosporidia.
Veterinary assistance
If you suspect cryptosporidia infection in your calves, prompt action is vital.
Consult with your veterinary surgeon immediately about your suspicions.
It is also important that a scour sample is taken to your local vet and sent to a veterinary laboratory to identify the causal organism and verify that it is cryptosporidia. Treatment will very much depend on the outcome of the sample test results.
