Calf Scours (NCD)
NEONATAL Calf Diarrhoea (NCD) is one of the most common and frustrating diseases of cattle, mainly in calves less than six weeks of age.
Outbreaks of NCD can be costly for producers as treatment is time consuming and neonatal death represents a substantial loss of profit from the cow. Survivors have subsequent reduced growth rate, weaning weight and difficulty attaining an adequate joining weight.
NCD usually results from a combination of three factors: adverse environment, poor host immunity and a high challenge from the infectious agents, although serious impairment of any one of these factors can result in a NCD outbreak.
“Adverse environment” relates to the conditions the neonate is being raised in.
Stress from weather, lack of shelter, high stocking rates with gross faecal contamination and heavy pick up of infectious agents all contribute to NCD outbreaks.
Healthy calves can be subclinically infected and amplify environmental contamination.
All major gastrointestinal pathogens are commonly carried by asymptomatic adult cows and faecal shedding of these pathogens tends to increase around parturition.
Many other animals, birds and flies are potential vectors of cryptosporidium and salmonella.
Feral animals and domestic pets are potential reservoirs of Rotavuirus.
“Poor host immunity” relates predominately to failure of colostral (initial maternal milk) transfer from the cow to the calf within the first 12 hours of birth and the immune status of the cow.
A neonatal calf should receive at least four litres of colostrum in this 12 hour period.
“The degree of challenge” is the potential exposure, intake and dose of the pathogen involved.
In a disease outbreak there is an amplifying effect with each new, infected animal incubating and then shedding the infectious agent in increasing numbers.
The infectious cause of NCD can be quite varied. The most common pathogens associated with NCD in suckling beef cattle in southeastern Victoria are Rotavirus and Cryptosporidia (protozoa).
Other major causes of NCD in juvenile bovines in both beef and dairy herds include: Coronavirus, Coccidia and Giardia protozoa, E.coli, Salmonella, Clostridial and Yersinia bacteria.
Treatment should be directed at the most common derangements seen in NCD; dehydration, acidosis, sepsis and hypoglycaemia.
Contact your vet for information if you suspect NCD in your calves.