Managing calf scours

Calf scours is the most common disease of neonatal calves in New Zealand and is responsible for the greatest economic losses.

Scours result from a variety of causes including nutrition, stress events, and pathogens such as rotavirus, E.coli, cryptosporidium, salmonella, and coccidia. Irrespective of the cause, diarrhoea results from damage to the gut lining, reduced milk digestion, and altered gut microflora.

If you turn up to your sheds and find that your calves are scouring, don’t panic, there are a few simple steps we recommend that you take.


The first thing to do is isolate any sick calves to prevent the spread of any illness from these calves to your healthy ones. If over a third of a particular pen are scouring, isolate the whole pen in place. Always handle/feed the sick calves last (after you have fed the healthy ones) and remember not to share any equipment between pens. We also recommend implementing good biosecurity practices such as using foot baths and to regularly clean and disinfect pens, feeders and all other equipment.


Can they stand? Can they suckle? Is their rectal temperature abnormal (below 38 or above 39.3)? Is there blood in their faeces? Answering these simple questions can help guide your next steps.


If your calves are standing, suckling, have normal temperatures, with no faecal blood it’s likely you’re dealing with a nutritional/stress-related scour (or early-stage infectious scour). In this case, unless you are very risk averse, there is no urgent need for testing. Initiate electrolyte treatment and monitor progress. Feel free to get in touch if you’d like to discuss risk factors and preventative strategies for nutritional scours.

If your calves aren’t suckling, are weak, have abnormal temperatures, have bloody faeces, or aren’t responding to electrolytes then you may be dealing with an infectious issue. In this case we advise you to collect fresh poo from scouring calves into separate, clean, labelled containers/ziploc bags and bring these to the clinic for testing. If less than 10 are scouring then one to two samples should be representative, but if multiple pens are affected, bring at least one sample from each group.

Finding out what ‘bug’ we are dealing with early on into the problem allows us to best advise which treatments, disinfectants, and preventative strategies will be most effective for your calves, which will not only reduce your costs, but will also maximise their chances of recovery.

When to give us a call

  • If your calves are worsening/dying despite treatment.
  • For calves that are unable to stand and or/have lost their suckle reflex.
  • If you would like assistance with making improvements to your calf rearing systems/facilities.
  • For blood testing to check the adequacy of your farm’s colostrum management and/or rule out other infectious diseases including BVD.



Oral electrolyte therapy is the primary treatment for calf scours. If it is started at the first sign of scours and continued until full recovery, then it is typically successful in 95% of cases.

Fluids can be given by bottle for calves that are still drinking or via tube feeding for those without an appetite (remember to never tube feed milk in calves over 48 hours old). Aim to give scouring calves six to 10L of fluids daily to meet normal daily intakes plus account for ongoing losses via diarrhoea.

There are many electrolytes to choose from, but regardless of your product choice please follow all mixing instructions and check whether it can be added to milk, and if it cannot, please separate milk and electrolyte feeds by at least three hours. Totally Vets recommend using Totally Hydrated or Revive, as their formulation allows them to be safely and conveniently combined with milk as per the following protocol, without disrupting digestion.

Electrolyte Replacement Protocol


  • Normal milk feed with electrolyte added
  • If the calf does not drink, tube feed 2L of warm electrolytes made with water (no milk)
  • Place a fresh bucket of electrolytes in the pen for calves to help themselves


  • 2L of warm electrolytes


  • Normal milk feed with electrolyte added
  • If the calf does not drink, tube feed 2L of warm electrolytes made with water (no milk)


  • 2L of warm electrolytes

Most calves require three to five days of electrolyte therapy. As the scouring improves start skipping the electrolyte-only feeds but continue adding electrolytes to their milk. Some calves will produce loose faeces for a number of days post treatment due to ongoing inflammation of the gut lining, but if the calf is feeding well, hydrated and bright, no further action is necessary.