i think its a liquid filled swelling, something to do with fluid retention. I get them in my knees and have to have them drained off - part of my arthritis!
Related to this... heres a quick query for some of you who sound like you may know more about this than me
(warning - its long)
Going back last year, I made the stupid mistake (on someone's advice mind!) of adding a squirt of washing up liquid to warm water and using it on a very heavy stable stain on my boys tummy and just round the bottom of his sides (girth area). The following day he had lumps that looked like reactions on either side, a few inches behind his shoulders and where the girth would lie. My trainer went crazy about them saying they were oedemas but that they couldnt be related to what i washed him with. I called my vet who didnt class it as an emergency and made an appointment for 3 days later. The following morning, these had moved downward and under his tummy... so they looked like liquidy swellings hung under his tummy area. The next day they'd gone (before the vet got out)
Summer of this year I was going somewhere and washed him in a horse shampoo id not used before and again had to scrub his tummy area and lower sides. When we arrived at our destination, he had the same lumps on either side where the girth would lie. Again, the following day they had moved down under his stomach and then went. On both occasions when I parted the fur, I could see skin irritation present but the lumps created were soft... not hard like i expected with a reaction?
Final occurance... This summer he had an accident in the field where he fell on his head. I have no clue how he did it but he came in with a shredded l/w turnout and a huuuuuge grass stain right down his face. He also had swelling round his nose and head and was very much "out of it". Spoke to the vets and they said there was little they could do and just to keep an eye on him. At the front of his chest where his rug buckle was.. he had a very very raw graze. Obviously whatever knot he had gotten himself into had resulted in the rug really digging into him with some force. It was just like the kind of graze you got as a kid when you fell on concrete but it didnt actually bleed.
I used cold compresses on this and put cream on (it was really really sore). The next day he had, what I assumed to be an oedema there. The area localised to the graze had swollen quite dramatically. Again, i cold compressed it and left it alone. Next day the whole thing had moved downwards between his front legs and was quite easily the size of an egg hung down. The YO freaked out and managed to convince me that it was a blood clot and, being close to his heart area, that it was really serious. My vet thought otherwise because when I described the swelling, he said it couldnt have been INside any kind of artery because it was hung down like that just due to gravity. He again arranged to come out a day or so later. Once again, the thing shrunk and vanished completly.
So! Question! Do you think the first instances were allergic reactions? But would you expect those to create a liquid type swelling under the skin? Im assuming it must have been liquid because it moved! Do you think they are the same things that occured the second time when he had the trauma to his chest? My vet has been unconcerned each time although has promised me that if he gets another, he'll come out straight away just to see what they are. But since then ive stuck to the same brand of shampoo and had no issues at all. In all instances he hasnt seemed in any pain and has let me have a good old prod. At worse Id say they may have been very slightly tender but he never exhibited any behaviour that said "get off".
Anyone have any ideas at all? None of them have left any kind of marks or tenderness - they just moved down underneath him (gravity??) then vanished!
I would say the first two are reactions to the soaps you used. Is your horse grey or have pink skin in those areas? Pink skin tend to be more sensitive. You also may not have washed off all the soap which could have casused sensitivity.
The last one that was a trauma, I think is unrealted to the the first.
With fluid collection under the skin; it can travel. For example a horse that has odema in the knee or hock can have fluid in the fetlock the next day. Gravity and cirulation move the fluid downwards. As long it is soft not hard I wouldnt be surprised if you saw it gravitate downwards. However it would be interesting to have the vet take a gander at it.
I honestly thought they were harmless too but my YO did scare the living daylights out of me, saying that she had never seen skin reactions like the first two and then that the second could have been something major! (My boy has a heart murmour - the harmless type that he was born with and she seemed to be implying something was connected to that)
Good old greys...I have one myself. My suggestion is to use the soaps you know he doesnt have a problem with and rinse really well. Also be carefull what you use to wash blankets, rugs and pads...he may be skin sensitive to that as well.
You treated the trauma on his cheast well with the cold compresses. Its always scary when bad things happen...especially to your own boy.
id say reactions
the last one trauma.when you dmage cells the fluid will leak out.
gravity will indead cause it to move to the lowest point once it gets heavy enough.horses that have sore knees can have the swelling move down the leg.