Vet explains what could be behind coughing calves this summer

Every year the phone rings with the same complaint, “the calves are coughing.”

Normally I could set my watch by it. This year I’d want a crystal ball too.

It’s been a patchy summer – some counties baked through weeks of drought, others stayed close to normal.

That matters: parasite cycles follow local ground conditions, so nearby farms can face very different pictures right now.

Heat stress doesn’t cause a cough directly, but a panting herd has less in the tank immunologically.

Add animals recovering from summer scour, or on changed diets as feed gaps get bridged and there’s vulnerability with nothing to do with lungworm or a virus.

Meanwhile IBR, PI3 and coronavirus haven’t gone anywhere, with the usual bacterial suspects following behind.

Then there’s lungworm. Dry ground slows larval development, so drought-hit pastures may carry a lighter challenge for now.

But a proper break in the weather can trigger a rapid hatch and a sharp spike in pressure.

Naïve first-season grazers feel it hardest and an animal dosed during the dry spell isn’t necessarily covered once pressure surges – it may need treating again.

Not every cough is disease. Dusty hay or dusty alternative feeds like palm kernel can set a healthy animal coughing from pure irritation — no fever, no spread, no treatment beyond damping the feed down.

With that many explanations for one symptom, guessing isn’t good enough.

Test: faecal samples (a blunt tool for lungworm, as damage is usually done before eggs appear), bloods or swabs for viral causes and a proper multifactorial look at the group.

There’s no standard prescription this year – local conditions decide the risk, so talk to your vet.

Joaquim Canotilho, DVM

XLVets, Ormonde Veterinary Hospital, Kilkenny