Need more info; how many lumps? what size? pictures?
I recently had a pasture horse get a big lump (about 1 inch tall and about 2 inches long and 1 inch wide). The vet seemed to think it was trauma; maybe kicked by another horse. He drew some amber colored fluid out of it, and did a blood test to find out if there was any infection. There was no infection at all. He had me give her phenylbutazone bute twice a day for several days. The lump disappeared, but a little scar tissue can be felt under the skin. Who knows?
I had kind of thought they were from trauma as well. My first thought was our hay feeders. But that theory became questionable when I realized that some of the horses that have the lumps have different hay situations.
They are wormed regularly, though these did not pop up as a reaction to a specific worming incident. I don't think they could be from shots either because they are not painful, nor are they exactly where a shot would be administered -- either IV or IM.
I have spent many hours thinking of possible scenarios! Any other ideas?!
I suspect the question about worming was more along the lines of the bumps being caused by parasites and not the worming itself. If you do a search for neck thread worms you can find more information. I just read through it again last night.
Thanks everybody. I mentioned that idea to our vet. That is not something I'd considered. They are a bit bigger than the conventional neckworm lumps, and there is no itching or hair loss in conjunction with the lumps, but it still could be the answer.
If anyone thinks of any other ideas, please pass them along!