Diarrhoea in adult cattle

Page last updated: Wednesday, 19 August 2020 - 12:43pm

Please note: This content may be out of date and is currently under review.

There are a variety of possible causes of diarrhoea in adult cattle and they are often different to the common causes of diarrhoea, or scours, in calves. If diarrhoea is causing a production loss in your herd, it is important to try to define the problem and then diagnose the underlying cause. Depending on the cause, your veterinarian may recommend different treatment and prevention options.

What is diarrhoea?

Diarrhoea, or scours, occurs when intestinal fluids are not absorbed appropriately in the intestines. Usually these fluids are mostly reabsorbed and only a small amount is passed in the faeces. Anything that affects the intestines' ability to absorb fluid may result in diarrhoea.

Causes and risk factors

Where diarrhoea is the most obvious sign, the primary causes can be thought of broadly in two different groups, nutritional and infectious.

Nutritional causes include:

Infectious causes include:

It is important to remember that some infectious causes of diarrhoea, such as Salmonella and Yersinia, can potentially affect humans. Always practise high levels of hygiene when dealing with sick cattle.

There are many other diseases where diarrhoea presents as a secondary issue. Some of these include:

  • liver disease
  • peritonitis (e.g. hardware disease)
  • heart failure
  • chemical or plant poisonings (e.g. lead or nitrate)

Be aware of the potential for emergency diseases and how to report them

Diarrhoea can also be a sign of certain emergency animal diseases not present in Western Australia. If any of these diseases became established in WA, market access for animals and animal products could be severely impacted. Early diagnosis of an emergency animal disease is vital to allow rapid eradication of the disease and re-establishment of market access.

If you see any unusual signs of disease, abnormal behaviour or unexpected deaths in stock, including diarrhoea, call:

  • your private vet
  • a Department of Primary Industries and Regional Development (DPIRD) veterinary officer or
  • the Emergency Animal Disease hotline on 1800 675 888.

For more information about emergency animal diseases, see the EAD webpage and the reportable animal diseases webpage.

How to diagnose the cause of diarrhoea

Early diagnosis of disease and treatment are essential to minimise production and stock losses. A vet can help diagnose the cause of diarrhoea by collecting faeces, blood or post-mortem samples for laboratory analysis.

DPIRD provides subsidised veterinary investigations for any livestock disease with high stock losses or similar disease signs to an exotic or reportable disease. For more information about disease investigation subsidies, see the webpage: Significant Disease Investigation Program.

For more information about DPIRD's livestock health surveillance program, watch this short video: Animal health surveillance in Western Australia.

Treatment

Treatment decisions for cattle suffering from diarrhoea should be made in consultation with your vet. Dehydration and electrolyte losses can occur rapidly when diarrhoea is present. Depending on the cause of diarrhoea, treatment options may include responsible use of antibiotics or anthelminthics, anti-inflammatories, rehydration fluids, vaccination, mineral supplementation and ration management.

Note that antibiotics are only useful if the cause is a bacterial infection. Unnecessary use of antibiotics can contribute to development of antimicrobial resistance. See the antimicrobial resistance webpage for more information.

Prevention

Identifying the cause of diarrhoea in the herd will allow you to make a sound plan about how to prevent or minimise the effect. This can include reviewing rations, grazing plans, worm management and biosecurity practices.

Bacterial diarrhoea in adult cattle

Salmonella and Yersinia are two types of bacteria that can potentially cause diarrhoea in adult cattle.

What is bacterial diarrhoea?

Bacterial diarrhoea occurs when susceptible cattle are exposed to enough bacteria to cause an infection. The bacteria cause damage to the intestines and diarrhoea follows.

Causes of bacterial diarrhoea

Salmonella

Salmonella is a common cause of diarrhoea in adult cattle. Animals are usually affected suddenly, are quiet, off feed, have a fever and foul-smelling diarrhoea. The signs may range from mild to severe and abortions can also be seen with Salmonella infections. Often an animal carrying the bacteria but showing no signs of illness is the source of spread in a herd. These animals will intermittently shed the bacteria in their faeces when stressed. Faecal contamination of feed and water sources are common routes of spread, particularly in feedlots.

Yersinia

Yersinia is another bacteria that is occasionally the cause of diarrhoea, and usually affects only single animals, however, outbreaks can occur in yearling animals after severe winter weather. Cattle with Yersinia infections are often depressed, growing poorly with diarrhoea that does not smell.

Both Yersinia and Salmonella are bacteria that can potentially infect humans. High levels of hand hygiene should be practised when managing animals with diarrhoea.

Johne's disease in cattle

Johne's disease is one reportable bacterial cause of diarrhoea in adult cattle. See the DPIRD JD in cattle webpage for more information on testing and surveillance for this disease in WA.

Be aware of the potential for emergency animal diseases

Certain emergency animal diseases not present in WA can also present with diarrhoea. If any of these diseases became established in WA, market access for animals and animal products could be severely impacted. Early diagnosis of an emergency animal disease is vital to allow rapid eradication of the disease and re-establishment of market access.

If you see any unusual signs of disease, abnormal behaviour or unexpected deaths in stock, including diarrhoea, call:

How to diagnose bacterial diarrhoea

Early diagnosis of disease and treatment are essential to minimise production and stock losses. A vet can help diagnose the cause of diarrhoea by collecting faeces, blood or post-mortem samples for laboratory analysis.

DPIRD provides subsidised veterinary investigations for any livestock disease with high stock losses or similar disease signs to an exotic or reportable disease. For more information about disease investigation subsidies, see the webpage: Significant Disease Investigation Program.

Treatment of bacterial diarrhoea

Cattle with diarrhoea can quickly become dehydrated and those with Salmonella infections require prompt treatment. Decisions about the treatment of bacterial diarrhoea should be made in consultation with your vet. Outbreaks of bacterial diarrhoea require close management and a plan should also be discussed.

Treatment options may include antibiotics, anti-inflammatories and rehydration fluids, while management practices such as isolating unwell animals, waste management, pest control and nutrition can be considered more broadly.

Prevention of bacterial diarrhoea

Good biosecurity and management practices are the best prevention for bacterial diarrhoea in adult cattle. Ensuring that cattle are in good health reduces their susceptibility to becoming infected while examination and quarantine practices are good ways to make sure you are not introducing unwell cattle into your herd.

DPIRD veterinary contacts

See the webpage: DPIRD Livestock Biosecurity contacts.

Contact information

Livestock Biosecurity