Trying to zero in on a mystery illness

On July 26 of this year, I wrote about my attempt to determine the cause of a mysterious bacterial illness that struck two of our lambs this past spring. After seventeen years as a shepherdess, I’ve both experienced and heard from others about quite a few illnesses that appear in flocks of sheep, but this one was new. Not only had we never seen it before here at Peeper Hollow Farm, but as the year progressed, I heard about it being in other Midwest farms that had never seen it before. I found this particularly disturbing because the incidents were popping up before any sheep had started moving between flocks. Why was it suddenly appearing at so many different farms who had not brought in new sheep in months? I decided that if it came into our flock again, I would begin trying to figure it out. I didn’t want to do anything that might threaten the well-being of any of our sheep, but I also thought I might try some experiments to collect information. It was simply too puzzling to let it go.

Quiana had this mysterious illness for two weeks before the antibiotic finally killed it off.

I got a call from a good friend who had a lamb with the same symptoms, so I suggested they try a different antibiotic than the one I had used. The antibiotic I suggested is a common one for sheep, so using it to treat this illness would not be unusual. After 24 hours, their lamb still had the same symptoms, but the fever was a bit higher. At that point we decided they needed to treat with the original antibiotic I had used, which could be used in conjunction with the one they had previously given. Within 24 hours after the second treatment, the lamb was symptom-free. We now knew that the bacteria did not respond to all antibiotics. Huh.

A few weeks ago, I noticed that Romeldale lamb Quiana seemed to have the same scouring that was so typical of this mystery illness. Before I treated, I decided to see whether she could get rid of this problem on her own, so I gave her some time. Her fever was elevated, but not so much that it was a crisis, so I just monitored her closely. After a week with no improvement, I decided to deworm her to see whether that might help her fight the illness — but that brought no improvement. About two weeks after her first symptoms, I got a call from a friend at whose farm two of my breeding groups are located. One of my Romeldale lambs, Quenby, had just begun showing evidence of dark green scouring and fever in their field — what did I want to do? At that point I decided to collect fecal samples from both Quenby and Quiana and then treat them with the drug of choice for this illness. Each of the girls dried up and was fever-free within 24 hours after treatment — the right antibiotic worked surprisingly fast. What the heck was going on? I took the fecal samples to my vet and he sent them off to Iowa State’s College of Veterinary Medicine.

Quenby came down with it even though she was eight miles or so from Quiana.

Romney Quella is the most recent lamb to come down with the mystery illness.

Only a week later, Romney lamb Quella developed the same symptoms in another field here at our farm — and that field has no common fenceline with Quiana’s group. I treated her with the same antibiotic, and she was symptom-free the next day. I have seen no more of this illness since then.

I have no idea what this is or how it is transmitted. The only symptoms we see are the dark olive-green scouring and a fever usually between 103.5 and 105. The lambs do not seem ill (except for the dirty back end), nor do they seem lethargic. They behave normally except that they drip when they walk, leaving a dark green trail in their wake. Once treated, they don’t seem to get it again (do they develop immunity, or will they get it again in future years?) nor do other lambs in the same field come down with it. It seems to be limited to lambs, since — at this point — we have never seen it in a sheep over a year old.

The vet school will culture the stool samples to try to determine what bacterium is causing the illness. This may not be a particularly helpful idea since fecal matter is full of various bacteria, so isolating the problematic one will be a challenge. Regardless, I hope we can continue to work to identify the source of this infection. New illnesses don’t come along often — and this one preys on the youngest and most susceptible members of the flock. I only hope we can figure this out.

Shearing update: We sheared our market lambs last week, and I am in the process of skirting their fleeces. On Thursday, November 2 (most likely in the late afternoon), we will email our customers a list of the ram fleeces from our June shearing and the recent market lamb fleeces.

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