Casper was born on my friend Tracy's farm and went into the brush herd when he was old enough. He retired from the working life when Tracy left the business. We have always jokingly called him the unfriendly goat because he is very skittish and always acts like we are there to eat him, not feed him. She called me the other day because Casper had been off his feed for a couple of days and was now down, and she had no idea what the problem was. I went over with some antibiotics, because he had gotten a pretty bad cut on his ear and Tracy was worried it had gotten infected and gone systemic. That didn't turn out to be the problem.
He was lying down by himself and doing a strange hiccuping thing that neither of us has ever seen a goat do before. His pupils were super contracted, which was another strange symptom. I have him the antibiotic injection and then went home, because we couldn't think of what else to do. Once I was home, I was reading about the ocular system in my goat medicine book and had a brainwave. I called Tracy, who said she was just texting me to tell me that Casper is blind. I was calling her to tell her the same thing. There are several reasons a goat can suddenly go blind, but I think he has developed polioencephalomalacia, otherwise known as goat polio. It is not viral like the human version, but basically results from a thiamine deficiency. Goats manufacture their own thiamine in their rumen, which is the first of their four stomachs. The bacteria in the rumen produces the vitamin, which is essential for proper nervous system function.
Goats can have a similar reaction if they eat bracken ferns, because the ferns contain a chemical called thiaminase, which mimics thiamine and prevents the brain from absorbing the real vitamin. This happened to another of the brush goats a few years ago, but Carl didn't go blind, he was paralyzed. The treatment for both bracken poisoning and polio is the same: massive doses of thiamine. We don't have just thiamine on its own, so we had to give Casper a B complex injection, and it was a big one. He has gotten a dose twice a day for three days and is back to eating, although he is still blind.
Of course, all this came about on a Saturday, and although our wonderful vet will answer texts on weekends, Tracy didn't want to bother her. She called on Monday morning, and the vet said we were doing everything right based on the symptoms. There is no way to definitively diagnose the polio without sending a poop sample to a lab, and since the treatment is relatively simple and not harmful, we decided we didn't need to bother. It's only to satisfy my own curiosity that I wish we were sending in the sample. I guess we'll never know. And we'll probably never know what upset his rumen bacteria so they stopped producing thiamine. The bracken ferns are all dead now so they can't be the culprits.
So that's the story of Casper and his medical mystery. I'm sorry for going full nerd there, but I found the whole situation really interesting and a great learning experience. His vision should gradually improve, and hopefully it will go back to normal, although some permanent blindness can occur. For now he's getting probiotics to jump start his rumen and probably a week with brewer's yeast in his food to deliver extra B vitamins. And we're keeping our fingers crossed.