Tom Downes gives us our case of the month – Lungworm.
I was called to examine a down, dehydrated February-born dairy heifer that had gone downhill rapidly over two days. The rest of the group seemed bright and well.
When I examined her she had a slightly increased heart rate. increased breathing rate and diarrhoea but seemed remarkably bright. The group hadn’t been wormed for a while and were due a faecal egg count (FEC). There were some concern about potential toxicity as they were on fairly rough grazing with some noxious weeds around.
Despite the unusual presentation, I leapt to a likely diagnosis of gut worms and confidently took a faecal sample back to the practice to confirm this. Poisoning was certainly a possibility but is quite uncommon and as one of our lecturers once put it “if you hear hooves, think horses before zebras”.
My early confidence and optimism was sadly short lived. Firstly, I did a FEC on the muck sample and failed to find a single worm egg. I had to conclude that there was in fact no worm burden. I called to relay this back to the farmer and was promptly told that she had died after I left. Determined to establish what had happened I decided to perform a on-farm post mortem (PM). 20 minutes in, I was starting to sweat and with little hope of reaching a conclusive diagnosis, I opened up her lungs and airways last. As soon as I did all became clear! They were filled with bloody froth and adult lungworms as you can see from the picture to the right.
I strongly advised that he treat the remainder of the group ASAP and in future consider using vaccination.
In summary, it is very unusual to see lungworm this early in the year and especially in heifers during their first grazing season. So be vigilant! Especially if you have moved away from blanket worm treatment and are worming strategically.