On Monday, October 23, I wrote about a mystery illness that has been popping up among sheep flocks here and there. We’ve seen it here, and I’ve gotten multiple calls from shepherds who have heard that I’ve been trying to figure it out – they have seen it in their flocks, too. It isn’t particularly common (our flock has seen it in about 10-15% of our lambs over the past six months or so), but the fact that I’ve never seen it before in seventeen years of shepherding made me want to figure this out. It was especially intriguing that I was hearing about it at other farms, and they’d never seen it before either – and there were no sheep moving between these many flocks. It was a mystery – but one that I really wanted to solve.
A few weeks ago, I collected fecal samples from Quiana and Quella and delivered them to my vet. He took a portion to check for internal parasites, but as I suspected, there was nothing remarkable to find since we had recently dewormed these two lambs. He sent the remainder of the samples off to Iowa State University in hopes that they could culture a bacteria that would answer my many questions. It was honestly a long-shot, since fecal matter is full of bacteria, so culturing what was there would result in a lot of bacterial growth not necessarily having to do with the illness. Yet, we thought that was our next step, so off went the samples, and I began the long wait for results.
On Monday of this week, I got a call from my vet – the results were in! Unfortunately, it was as we expected: they cultured nothing that wouldn’t or shouldn’t be present in healthy sheep manure. My vet, Rik, and I talked a bit about our next step, but the path wasn’t clear to either of us. I told him I would call him back if I needed his help again for this or if I figured anything out, and I hung up.
As is my habit when I am stymied, I then called my friend, Maggie, of Tawanda Farms in California. Maggie and her business partner Carol have had their flock for about as long as we have, so they have a wealth of experience when it comes to sheep – and Maggie has a back ground in science having been a science teacher years ago. She and I tend to think in similar ways, so I gave her a call to update her on this mysterious illness. They haven’t seen it in her flock yet, but I knew that if we bounced ideas around, I might find another path to follow to rule in or out something new – and I was right. As we spoke, Maggie suggested we take another route.
I had told her that we had tried a number of antibiotics that we use when sheep get sick, and none of these had brought the lambs to health. There was only one antibiotic that seemed to do the trick, and that was Draxxin; a single dose eliminated the fever and started the lamb making pellets within about 24 hours. It was like magic. Maggie’s thought was to compare the active ingredient in the Draxxin and look for which bacteria it was effective, and compare that to the antibiotics that didn’t work and which bacteria they were intended to kill. Doing this would rule out a whole lot of bacteria and what was left would be the list of possible causes for our mystery illness. It was a very good idea!
Maggie is nothing if not a go-getter, and within hours, she was calling me back with the results of her research (and I will admit that it is wonderful having such a good friend and willing researcher, since I hadn’t even had time to bring up Google yet!). It turned out that Draxxin was developed for the cattle industry when they began to notice that there was bacteria in cattle that was developing resistance to the common antibiotics – those that we had used earlier this summer to try to treat our mystery illness and failed. Draxxin was developed because it was effective against pneumonias that had become resistant and E. coli that had mutated and also become resistant. It was at that point that everything suddenly fell into place.
Our acreage is the low spot and our pond is the drainage pool for about 60 acres around our farm. During most of the year, the water seeps down slowly through the ground to fill our pond, but in early spring, the run-off literally flows off our our neighbor’s farm and onto ours – and that neighbor has cattle. We had tried over the summer to find a common link between the many farms who had reported one or more lambs with this illness and had been unsuccessful. There were no common bloodlines, not always a common breed, no similar grazing – nothing we could think of, but we were still thinking. I suddenly realized that this was the common link between the farms – they all had cattle in their own fields or in neighboring fields that either provided nose-to-nose contact or spring run-off – or they got their sheep from those farms earlier in the season.
The more we thought about it, the more it all fit. This “new illness” we were seeing in sheep is most likely a mutated version of E. coli coming from the cattle industry, and it is resistant to our more typical antibiotics. Like most E. coli infections, it preys on younger animals – in our case, lambs. Once they have had it, they don’t seem to get it again, having developed some type of immunity. It seems to be the smallest and weakest of the flock that come down with it, and like the E. coli that is more commonly found in lambs, it produces scouring and fever – the difference being that it doesn’t kill nearly as quickly as the traditional version. This particular newer bacteria simply causes a dark green diarrhea and fever, causing the lamb to become more and more weak without treatment. Once treated, the lamb generally bounces back well and, in all of the cases I’ve followed this year, never gets it back again.
There is unfortunately no way to easily prove that we have solved the case of this mysterious illness, but my confidence level is high. The symptoms fit the diagnosis, and the source of infection is common among the impacted flocks – at least all of those that I know of or have checked with. All of the data we have collected, and all of what we know about this infection fits a diagnosis of E. coli. The documentation of mutated E. coli in the cattle industry and the use of Draxxin to treat it is available online. I think that I can now move on to other thing, knowing that I have checked this box. Thanks, Maggie! I couldn’t have done it without you!