Animal Health & Husbandry
1 January, 2026
Humidity concerns
DAIRY Industry development officer Bec Cameron is urging all farmers to be aware of the increased health risks for dairy cattle during wet and humid conditions.
With temperatures climbing as we make our way through summer, dairy farmers are encouraged to take proactive steps to protect herd health as humid, wet conditions can affect growth rates of young cattle – and decrease productivity.
“The risk of infectious diseases also increases in wetter conditions,” Ms Cameron said.
“The risk of mastitis rises when cows lie in muddy environments, allowing bacteria to enter the udder.
“Leptospirosis, a zoonotic disease, can spread through contaminated water, posing risks to both cattle and humans.”
She said clostridial diseases such as blackleg and pulpy kidney may also emerge after flooding or soil disturbance.
Pinkeye in cattle is a common summer and autumn issue in Victoria, mainly caused by bacteria and spread by flies, dust and grass seeds.
This can lead to tearing, squinting, swollen eyelids and cloudy corneas that can progress to ulcers and blindness, reducing weight gain and milk production.
“Treatment includes antibiotic eye ointments or injections and veterinarians can help identify the bacterial strain affecting the animal,” Ms Cameron added.
“Controlling flies, slashing pastures to reduce seed heads, providing shade, vaccinating before fly season and maintaining good nutrition (vitamin A, copper and selenium) can all help reduce the risk.”
She encouraged early detection and isolating affected animals to help limit spread and protect herd productivity.
“Facial eczema is prevalent in humid weather conditions, alongside the liver disease caused by cattle ingesting spores.
“The spores thrive in dead pasture during warm, humid conditions. The toxin damages the liver and can lead to photosensitisation, reduced milk yield and weight loss.”
According to Ms Cameron, subclinical cases may go unnoticed but still affect productivity.
Prevention is essential and includes monitoring spore counts through your vet, supplementing with zinc in consultation with your nutritionist or feed company, and managing grazing to reduce exposure.
Hoof health should also be a priority for farmers.
Lameness caused by softened hooves from prolonged exposure to moisture can increase.
Wet laneways and paddocks increase the risk of bruising, footrot and white-line injury.
These conditions reduce mobility, feed intake and milk production, which can lead to early culling.
Preventative measures include maintaining dry walking surfaces, regular hoof checks and prompt treatment of injuries.
Water quality should also be a priority.
Proactive management of troughs and water sources helps protect herd health and maintains productivity during challenging weather.