Calf scour is a major cause of disease in young calves and a cause of significant economic loss on many farms. Scour can result from non-infectious (e.g. nutritional) or infectious causes. Often there is a combination of factors involved and the occurrence of disease is influenced by environmental and management factors. In the mid 90’s, an SAC study in the Inverness area found the cost to the farmer of an outbreak of scour to be over £3000 (including increased farm labour, drugs, decreased weight gain of calves, calf deaths).
In Scotland in 2003 the main causes of scour (as diagnosed by a lab) were Cryptosporidiosis (35%), Rotavirus (33%) and Coronavirus (20%). Other causes included E. coli, coccidiosis and Salmonella.
- Rota & Coronavirus: these viruses damage the intestinal lining resulting in impaired digestion and absorption of nutrients. Scour occurs between the ages of 4 days and 3 weeks of age.
- Cryptosporidiosis is caused by a single-celled protozoan organism, which attacks the cells of the intestinal wall. Scour occurs in calves from 4 days to 3 weeks of age. This organism can also affect humans so good hygiene is essential.
- E. Coli K99 causes disease from a very early age –within the first few days of life. This bacterial infection leads to rapid fluid loss but is less damaging to the intestinal wall.
- Coccidiosis causes bloody diarrhoea, ill thrift and straining to defaecate in older calves (between 3 weeks and 6 months of age).
- Salmonella can be a cause of scour as well as septicaemia, joint ill and pneumonia. Again, salmonella can affect humans, so good hygiene is very important.
FLUIDS: The aim of treatment is primarily to prevent dehydration. A calf needs a surprisingly big volume of fluid over a 24-hour period and this requirement is further increased when taking into account the increased loss of fluid due to scour. A 50kg calf with bad scour, which is already slightly dehydrated, requires at least 8 litres of fluid per day to treat and prevent further dehydration. Warm electrolyte solutions such as Glutalyte® or Lifeaid® are ideal in this situation. You can also make up your own by adding 1 teaspoon of salt, 2 tablespoons of glucose and a pinch of baking soda to 1.5 litres warm water. Calves which are unable to get up or have a sunken eye are likely to need intravenous fluids (a drip) and should be seen by a vet.
TLC: The benefits of keeping the calf warm, dry and well hydrated is often underestimated!
NUTRITION: In the past, the recommendation was to take the calf off the mother until the scour had stopped. However, current thinking recommends that you should continue to feed milk despite the calf scouring, as milk helps to keep the cells of the gut wall alive, aiding in a faster recovery. Milk also provides the calf with much needed energy. Electrolyte sachets can be mixed through milk as well as through water.
ANTIBIOTICS: Because the most likely causes of diarrhoea in young calves are not bacterial, it is rare that antibiotics are necessary. In fact they can do more harm than good by killing off the ‘good bacteria’ in the gut and increasing the likelihood of developing antibiotic resistance. Calves with blood scour or which are suffering from other infections as well as scour (e.g. joint ill, pneumonia) do need antibiotics. Speak to a vet about when to use antibiotics and which ones are best for your particular case.
OTHER TREATMENTS: Giving Probiotic tablets/paste or giving the calf some natural probiotic yogurt can help the gut return to normal function quicker. Kaolin may be used to dry up the scour. In cases of coccidiosis (blood scour), calves may require a specific anti-coccidial treatment such as Vecoxan® or Baycox bovis®.
Serious cases of scour, cases of scour which do not clear up with the above treatment or outbreaks of scour should be investigated by laboratory testing. We are able to carry out some in-house testing at the practice which gives results very quickly. For other tests, we send samples to a lab and usually have results back within 5-7 days. The best samples to take are from fresh untreated cases – we can provide faecal collection pots for this. Please don’t bring it in a plastic glove!
Control of calf scour in the herd
The first step in control is finding out what infectious agents you are dealing with so faecal sampling or post-mortem of dead calves is essential.
There are a number of excellent vaccines available against the viral causes of scour as well as against E. coli (e.g. Rotavec Corona). These vaccines are given to the cow before she calves (read the data sheet for exact times as this varies depending on the vaccine). The cow produces antibodies in response to the vaccine which she then passes on to her calf in colostrum. Speak to a vet about choosing and using an appropriate vaccine in your herd.
Regular cleaning and disinfection of the calving pens prevents build-up and spread of infection, particularly towards the end of the calving season.
Newborn calves should receive 10% of their bodyweight in colostrum in the first 12 hours of life. After this time, the calf is no longer able to absorb the antibodies from the colostrum that allow the calf to fight infections. If it is not possible to get an adequate quality and quantity of colostrum from the calf’s mother, Locatim®, an oral solution can be given within the first 4 hours after birth. Alternatively, powdered colostrum can be given. Bought-in colostrum should never be used due to the risk of disease transmission, especially Johne’s disease.
When to call a vet!
A vet is always at the end of the phone even if it is just for advice. Calves which are severely dehydrated or unable to get up need to be seen by a vet urgently. If calves are not responding to treatment or if you are having outbreaks of scour, veterinary advice should be sought. Farm health plans can include specific action plans for future control of calf scour on your farm where this has been a problem in the past.
Call us at the surgery on 01786 430387.