As we head into the colder months on the West Coast, lice infestations can become an increasing concern.
While common across New Zealand, the West Coast’s unique climate – cool, moist, and often wet – creates ideal conditions for lice to thrive.
Why should I worry about lice?
Lice aren’t just a nuisance, they can be a considerable stress factor. They can cause:
Skin irritation – Cows will be constantly scratching and may experience hair loss, particularly around the neck, shoulders and spine.
Reduced milk production – Discomfort can lead to stress and a decrease in milk yields.
Secondary infections – Scratching opens the door for bacterial infections.
Stunted growth – Calves can experience poor growth due to lice-related stress.
How do I control lice?
Regular monitoring – Look out for signs amongst your cows and calves.
Effective treatments – You can use pour-on treatments (pyrethroids or macrocyclic lactones), injections (such as ivermectin), or spray-on products. Be sure to follow guidelines and rotate drug families to avoid resistance.
Dry, clean housing – Ensure wintering barn and calf shed bedding is kept dry and buildings are well-ventilated to reduce lice prevalence.
Quarantine new stock – Isolate and inspect all cattle who arrive on farm before introducing them to the herd.
Signs of lice on a cow:
