Jawline lump?

[FirstLight]

Hi, Just wondering if you have any idea what this could be.
2 weeks ago my 5 year old welsh cob came in with a slight swelling on his jawline on the curve where the throat lash would sit, his skin wrinkled a bit. I thought it was a horse fly bite as he had one last summer on his neck which looked similar and took about 3 weeks to go completely. Anyway I was just washing it with antibac and it was starting to go down although with a bite you can usually feel where the actual biting happened, I couldn't feel this. It continued to go down although the skin and coat was still slightly wrinkled. Yesterday morning I go to him and it has swollen up again bigger than when I initially saw it, he isn't in pain with it i can feel it and so on it feels like a fleshy lump attached to the bone? Any ideas on what it is? It seems too high for teeth? I'm thinking of taking him to the vets tomorrow...
Thankyou

 

[Fides]

Google Grass Mumps. It could be this?

 

[_HP_]

Sounds like swollen glands but best to check it out with your vet as my mare presented with swollen glands as the first visible sign of cancer

 

[FirstLight]

Had a look up grass glands/mumps and these seem to be in the hollow under the jaw? His is more on the side of the jaw/ cheek on the curve.

 

[windand rain]

You get grass mumps where ever there is a salivary gland so cheeks, under the jaw and in front of the ears. It could still be those or a tooth problem. Best bet is a vet as a tooth problem can be difficult to sort out and if it is grass mumps it will reassure you. Of course there are other much rarer things it could be but please don't panic as serious problems are very very rare