I don't know what type of fly I'm dealing with out there, but the removal of the standing water certainly helped get rid of them. Unfortunately, their damage was already done with Old Red.
In my post the other day I said that Red was bobbing his head, so I went out to look and there were little flies in his ears. I could tell that there was scabbing and crusting going on in there, but he wouldn't let me get my fingers in. I had to do the best I could to doctor it up and put some repellent around the area, and then I put a fly mask with ears on him.
The next day he'd itched off the fly mask, but the flies were gone. In their place, there was a lot of scabbing and irritation and the hair on the inner ear was largely removed.
Today he'd itched off his mask again. There was a large scab he'd itched off in one ear that showed exposed skin. The other ear looks like it's healing pretty well--scabby, but no blood. He will not let me apply ointments to them. I could barely get his mask back on. I decided to lock him in and feed him in the dark stall, which seemed to make him pretty happy.
The removal of the standing water seems to have ridded us of the pesty small flies that were biting on the horses. Were they black flies? Here is a description.
•Black flies (Simuliidae) are small in size (approximately 2mm-5mm) and breed in rapidly moving water. High-risk times are dawn and dusk during spring and early summer, when stabling may be helpful.
These flies commonly feed around the face – particularly inside the ears, where they trigger allergic skin reactions to their saliva, and distract the horse – but also on the horse's neck and underside. Bites form as painful lumps, often with pin-prick areas of bleeding and crusting.
Synthetic pyrethroid fly sprays can act as a deterrent, although physical barriers such as ear nets and oil-based products – oil of citronella, for example – will discourage these flies from landing on the horse. Petroleum jelly (Vaseline) applied inside the ears may prevent the insects biting.
Cowboy's itching has stopped, as far as I can tell. He had some flies in his ears the other day, too, but no scabbing. So, whatever these were, they were definitely attacking the ears.
Cowboy has also stopped his head bobbing and dragging. He's been in constant turn-out since I released him four or five days ago. Is it possible that the flies got into his nasal passage? Could that even happen? That would confirm what some of you said about having a "bug up his nose."
In any case, he's doing very well, but I'm going to keep a close watch on Red's ears. I'll try to get a picture of it when I go to check on him again.
This is all new for me. I've NEVER had this problem before. We've never had an issue with biting flies until now. Red is over 30...does that make him more susceptible?