Beef and Lamb New Zealand is reminding farmers to be alert as cases of salmonella and leptospirosis rise in the wake of Cyclone Gabrielle.
Leptospirosis lives in water and spikes of the disease are often seen after flood events, while bad weather can also increase the spread of salmonella.
Beef and Lamb senior advisor for biosecurity and animal welfare Will Halliday said both diseases are already rearing their heads on the east coast of the North Island.
He said people who come into contact with an infected animal's urine were most at risk of contracting leptospirosis, but the bacteria can also live in urine-contaminated soil and water.
"Healthy, well-grown animals were more likely to spread leptospirosis to people through their urine, posing a risk during milking, calving, lambing, shearing, or slaughtering and processing stock."
Halliday said all mammals - such as humans - can be infected by leptospirosis, and the industry was seeing an increased number of cases in dogs.
"It can enter the body through scrapes and wounds and through the mucous membranes, so It's important for farmers to protect themselves from animal urine by wearing protective clothing, covering wounds, and washing thoroughly after handling animals."
Halliday said free-standing water or puddles can be a source of leptospirosis on farms.
"This can include puddles around water troughs where animals may have urinated."
The symptoms include headaches, flu-like symptoms and muscle and gut pain, but can present in a number of ways.
Halliday said cases of salmonella are also on the rise.
"The best form of prevention of salmonella and leptospirosis is for farmers to vaccinate their animals to stop people getting sick, prevent infections and reduce stock loss.
"Vet clinics in the region are up running, so farmers shouldn't hesitate to organise vaccinations," he said.