PSA: Marking this post as NSFW, as it does show some minor open wounds, but I personally would not describe it as extremely graphic. I wanted to shed some insight in case anyone is okay with typical wounds but was hesitant to look at the images.

I need some help/advice identifying what might be going on with my horse. All it might be is some kind of self-inflicted accidental injury, maybe a gnarly bug attacked her, or even dermatitis.But my mind can’t help but stress it could be something else (and please only provide educated guesses if you can rather than extreme speculation. I’ve already had some horse-knowledgeable people I know jump to serious conclusions that I don’t believe align with what my horse is experiencing, which has caused me some paranoia).

Yesterday morning, I just so happened to notice that part of my horse’s skin around her mandible/jaw area had an odd, wet look to it. When I felt it, it had a slightly thicker and sticky texture to it than what water or sweat would have. As I looked closer, I noticed she had what i’ll refer to as lesions on a patch of her skin. They appeared to be fleshy, but I couldn’t see too much more than that. 

When I checked it later in the evening, it appeared about the same. This morning, the lesions appeared to be a bit more red/inflamed than before, and I noticed quite a bit of yellow discharge. It’s hard for me to precisely describe the appearance, as I know discharge being yellow doesn’t always mean just one thing, but there is a picture included for reference.

At this point, I called the emergency line for my vet (since it’s Saturday) and described what was going on. She recommended clipping the fur down so that the discharge wouldn’t continue to clump and to apply a standard ointment that treats cuts, scrapes, burns, etc. that would protect the area until at least Monday, so I did. When I clipped the hair/applied the ointment, it was about 4 hours since I last looked at it, and to be honest, I was nervous to clip her hair down and anticipate what I might see more clearly underneath. Once I did, it was surprisingly not as bad as I expected and it looked like scabs might have already started to form. I put Man or Beast (antiseptic) salve on it, as my family has always sworn by this for decades.

Tonight when I went over, what had appeared as scabbing was no longer present and was instead all open flesh again.

Below is some relevant information that hopefully provides context/clarity in narrowing down thoughts as to what this might be:

She is a 21-year old American Quarter Pony mare. I live in Ohio and she is only ever exposed to a standard indoor barn and grass field in terms of environment/weather conditions. The only other farm animal she lives with/is ever in close proximity to is a donkey (the last time they were exposed to another horse was almost 3 years ago). There have been no recent changes to her environment, routine, diet, etc. She has not shown changes regarding her eating, drinking, or typical habits/behaviors. Her breathing sounds like it usually does and she has a respiratory rate ranging around 14 breathes per minute. I did not physically take her temperature, but when feeling different areas of her body, she never appears overheated or colder than usual. She does not have a runny nose or any gunk coming from it or her eyes. When feeling the lesions, they do not appear to run above/below the surface, meaning, I don’t think they are filled with liquid like an abscess would be. She does not appear to be experiencing severe pain from them. She starts to become fidgety when i’m feeling the area for an extended amount of time, but I would anticipate that with any level of wound. I have tried to keep what I apply to the area at a minimum, but I have continued to wipe the area down with water and pat it dry with clean paper towels. I can’t currently think of any other things, but I’m sure there might be some I missed and will include an ETA if I add anything. Feel free to ask any questions regarding anything I may not have covered.

Attached are pictures in order of the progression since I noticed it yesterday morning until this evening. Any indications as to what this might be/what caused it?

Random lesions around jaw area