NH homesteader
Herd Master
Thanks for the update. Sounds like your friend the vet tech might be a good bet. Good luck at the vet! And glad to hear the others are doing great.
Yes, you can have a failure to thrive animal but it doesn't necessarily mean this animal is one.I don't own goats yet so am NOT speaking from experience... just from what I've read/learned, not personal experience. It seems you've covered the bases for internal parasites and the antibiotics should have taken care of any potential infections. The only other thing that comes to mind and I believe it's been discussed is mineral deficiency... selenium, copper, cobalt, and the other trace minerals that goats need... The only way to be 100% sure would be a blood mineral analysis. If the minerals are being provided and the goat is eating them, then that shouldn't be the issue either.
I don't want to sound mean or uncaring, & I'm not accusing or pointing fingers at the breeder (or you), but you may have been "stuck" with a goat that just wasn't "meant to be here"... Referred to as "failure to thrive" or other terms. There may be something physically wrong with the animal that just can't be "fixed". I am not sure if this only happens in very young/newborn animals, as I recall yours was born in July. I say this because parasites, internal or external, and viral or bacterial infections,would generally affect any other goats and the others aren't having any problems/issues. If I'm off base, I'm sure the pros will correct me here... Just something to consider...
Since your friend the vet tech has offered to help and try to get him better, I'd say why not? Hoping for the best.