My horse developed over night a lump on the inside of his right jaw. Just one side, and it was very painful to the touch. Temp was completely normal, zero discharge from the lump or anywhere else, eating, drinking as normal and feeling REALLLYYYYY Fresh ( As in bucking and kicking around the place). Just this sore lump. LOL First noticed it on sunday, took a pick and sent it to my vet. She said keep an eye on it unless it gets worse or he feels worse. I can't feel any sort of a puncture wound, or anything. Its been completely dry, no crusty areas. I put some topical pain reliever ( Lame away) on it and by Monday it was 75% less sore. Didn't put any on yesterday and its back being sore again. Not getting any bigger, very localized. I'm beginning to think he got bit by something who knows what. Black widow who knows. How long would you give it before having the vet come take a look? I sent her another message this morning. THis one has me baffled since its extremely localized and no other side effects other than locally. I hate to have an expensive vet call for a spider bite. LOL Thanks! 

Peon developed one of those. Could not get it to drain, never crusted up, was irritating to him when I messed with it but didn't seem to bother him otherwise. We pulled a sample and sent it off and it came back negative for strangles. Our best guess was an encasulated tick. It never blew up and discharged like most of those do, tho. It took about 2 years to completely disappear. We also did a very thorough check in his mouth in case it was something draining from above. Negative. 

THanks! Yea its a mystery.. LOL My vet did call me back and wants me to put some icthamol on it and see if it will drain. We will see! She didn't suspect anything tooth related because he was eating and drinking fine. I will take a look in his mouth with my flashlight this afternoon! Good advice.