Thinking ahead coughing cows



Over the last year, I’ve been lucky to talk with hundreds of dairy farmers around animal health issues. I also have had many conversations with vets around the country in relation to animal health challenges, they encountered. One problem that keeps reoccurring, is that of lungworm and coughing cows at pasture.

In December I said the number one animal health challenge of 2019 for me was lungworm. Particularly in dairy cows and young stock. These cases on a dairy farm can cost up to €150.00 per case. It was not unusual in my conversations, to hear of big jumps in daily yields after dosing.

While not every coughing cow is lungworm, it seems to be the common denominator in many herds. It also can open the door for other viruses and bacteria that cause pneumonia.

This has been further complicated in dairy herds by the limitations of products licensed for lactating animals. For milking cows this one product is eprinomectin, this is in pour-on or injectable form.

This means that we have only one product (eprinomectin) being used repeatedly on some farms. All parasites are smart and will develop resistance to repeated exposure. Where some herds are now dosing cows at grass four or five times in the summer with eprinomectin this is not sustainable.


Not every farm is affected, but in some workshops I’ve done already this January, coughing cows have come up time and time again.

Why is it a problem?

  • Lungworm is a parasite that likes the same conditions as any efficient grass-based dairy farm. Think about it?
  • Mild and wet weather is good for growing grass and parasite lifecycles.
  • Good utilization (low grazing where the larvae maybe)
  • Rotations which mean cows hit the same places over the summer quite regularly. They can also be followed by youngstock.
  • With an increase also in contract rearing, it can be these returning replacements that might not have had exposure or immunity developed.
  • Very regular dosing of young stock meaning that immunity may have not developed to the parasite.
  • It is complicated also by reinfection syndrome where immunity in some animals wears off.

Lungworm vaccination

I have been very interested in where the lungworm vaccine can play a role in any control program. There is also now a very real appetite from farmers to know more about how this product fits in lungworm control programs.

This is an oral vaccine not yet widely used, It is one of the oldest vaccines available but is not used on many problem farms.

I do know on the farms where we are dosing (eprinomectin) cows every summer, greater than 3-4 times a year this is simply not sustainable.

Focus group

I am involved with MSD animal health this spring in building a campaign around lungworm awareness and knowledge.

As part of this, I am looking to meet with dairy farmers, about discussing current parasite control and future challenges. It is simply looking at what are the current on-farm limitations around parasites and particularly lungworm.

I will be hosting this discussion on the 10th of February with a small focus group.

We are looking for dairy farmers who have been dealing with coughing cows

  • Treating cows with (eprinomectin) more than 3 times last summer
  • Having lots of issues with coughing cows every year
  • Farms who  have been dealing with lungworm issues in young stock


Over the next 7 days, I’m inviting farmers to express an interest in this workshop discussion. In simple terms, it is a look at current protocols and challenges.

Please email your interest before 3/2/20 to  with

  1. Your name
  2. Brief description of your enterprise
  3. Your vet’s name
  4. If you have treated your cows more than 3 times in 2019 with eprinomectin (how often).


This is not going to be about creating plans for farmers, but looking at challenges and discussing the practicalities around potential solutions.

A venue will be decided based on interest received, and geographical locations of the respondents.

The closing date for interest is Monday the 3rd of February. The proposed date for the discussion will be the evening of 10/2/20.




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