Spring-born calves and autumn weanlings will be at an increasing risk of developing respiratory diseases as lungworm become more common.

Warm days, cool nights and regular rain showers provide ideal conditions for worm burdens to multiply, allied to the fact grazed grass makes up an increasing part of a calf’s diet in late summer.

When checking cattle daily, keep a close eye on young stock. Watch for early signs of respiratory problems that could trigger a pneumonia outbreak.


Things to look out for are calves breathing heavy, dull and lethargic appearance, reluctance to eat or suckle their dam, ears drooping, discharge from the nose and hard, frequent coughing.

Calves will also have a temperature when caught. Healthy calves will have a body temperature between 38.5 and 39.5 degrees. Anything above 39.5 degrees will be sick.

Avoid herding cattle late in the evening when temperatures are cooling down. Getting animals raised as temperatures cool is a recipe for disaster.


Effective worm control will reduce the risk or respiratory diseases, but be careful about which product you use if calves have a severe lungworm burden.

Using an ivermectin can sometimes trigger pneumonia, as there is a rapid parasite kill, putting calves under respiratory pressure as they expel dead worms from the lungs. Ask your vet for advice.

Vaccinating animals against respiratory diseases, such as IBR and pasteurella, can also benefit calf health going into the high-risk autumn period.

However, vaccines do not compensate for poor health management. But when combined with good practice, they greatly reduce the health risk to calves.

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