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A few years ago, I was taught a harsh lesson about the importance of timeliness by an outbreak of lungworm in young cattle.
I had taken the written claims on the side of the pour-on box a bit literally and left it too long between applications. This resulted in housed calves being treated when carrying a substantial burden, and they subsequently coughed up so many dead lungworms that most of them developed pneumonia.
This incident scared the life out of me and I vowed never to get caught like that again.
For the next two or three years, the employed strategy has been to wait until a few calves in the batch began to cough slightly, then hit them with one of the clear pour-on products.
It seemed to work, and very often the length of time between treatments coincided with the famous five-week gap that was often talked about as a sure-fire method of keeping this nasty parasite at bay.
Second season
However, the in-calf heifers (during their second grazing season) were a different matter altogether and I have always been far more relaxed in my approach to parasitic control with them. Until this summer.
The vets have been talking for ages now about over-control of lungworm in calves during their first season, leaving them vulnerable for the following year, and even as cows coming into the parlour.
I thought I had this problem well controlled, because I was waiting until calves showed signs of a light worm burden before treatment, thus giving them some essential immunity for the years ahead.
With the benefit of hindsight, it seems I was just a little too laid-back with the bigger heifers and noticed a slight cough among them during the third week in July.
I can only guess that they had picked up some sort of heavy infestation sometime towards late June or early July, because after nonchalantly plastering them with Ivomec pour-on, the coughs of them for days afterwards would have frightened you. So much so that three of them needed a shot of antibiotics from the vet to control a high temperature.
That cough only receded slowly, and they were treated again three weeks later and again five weeks after that. It is only recently that they’ve stopped sounding like a 40-a-day person first thing in the morning.
In hindsight, these older heifers should have received some sort of lungworm control in late June or early July.
Vet advice
Having been metaphorically caught with my trousers down, I spoke to the vet to try and ascertain what exactly had happened.
Sometimes it is best just to ask a veterinary surgeon when to treat your animals, because if you want to understand the nuances of what was happening in your pasture, he’ll explain it in language that a Killinchy farmer will never understand.
For anyone of a more cerebral disposition than me, you might want to fully understand the complexities of the Pilobolus fungi and the role it plays in something known as ‘re-infection syndrome’ (even the vet admitted it is complicated).
And if you fully digest words like ‘sporangium’, ‘carotenoid pigments’, and ‘calcium oxalate crystals’, then maybe farming isn’t really the ideal career for you.
The upshot of this lungworm lesson is that I’ll have to tighten up on my control measures next year. The strategy of waiting until there are signs of infection may be playing with fire.
I can back this up with clear evidence because a batch of calves were treated in late September, despite not one of them coughing, even after running up the field.
However, after treatment, there is a slight husky bark running through the group and the vet assures me that is simply them coughing up dead lungworm from the depths of their bronchioles. Who’d have thought it, eh? Sixty years of age and still getting it wrong.
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