New strain of salmonella in sheep – vets advise on prevention

Advice on dealing with a newly emerging strain of salmonella in sheep has been issued by the Animal and Plant Health Agency (APHA), following identification in two UK flocks.

The outbreaks were classified by Public Health England as Salmonella typhimurium t5 3225, which has left sheep appearing “dull with diarrhoea” and has resulted in high mortality.

The strain can affect pigs, horses, dogs, cattle and wildlife, as well as humans – with the cause of the outbreak currently unknown.

In a statement, the APHA said proper hygiene when cooking meat was essential to stop cross-contamination and infection in humans. 

Veterinarians have advised that good biosecurity and flock health practices are key to keeping the bacterium from infecting flocks.

Veterinary advice should also be sought on antibiotics treatment options. A vaccine is available in cattle, but little is known about its use and it is not licensed in sheep.

See also: Sheep flock health and welfare must-haves for less than £20

Outbreak prevention advice

SAC Consulting Veterinary Services investigation officer Katrina Henderson told Farmers Weekly biosecurity measures are critical to keep the strain off farms.

She said the organism can be introduced by infected livestock, equipment, machinery, personnel, contaminated feed, watercourses, birds and rodents. 

“Stressors and reduced feed intake can predispose animals to infection,” she said. “Wet weather, transport, alterations in diet, worm burdens and poor nutrition will all increase the likelihood of clinical disease.”

  1. Avoid purchasing as much as possible and buy from known sources. Avoid multiple sources.
  2. Good cleaning and disinfection is required (see “Cleaning and disinfection”, below).
  3. Protect feed stores from rodents and birds where possible and ensure clean water is available.
  4. Limit the number of people and machinery entering the farm and ensure good cleaning and disinfection of any unavoidable entries.

Cleaning and disinfection 

Defra-approved chlorocresol disinfectants are effective against salmonella at the following dilution rates (disinfectant: water).


Dilution rate











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