I have a 3 year old bitch who has developed a mass on her lower ribcage, in the region of a mammary gland. I first noticed subconsciously a few days ago but didn't think anything of it, maybe because I was expecting some mammary swelling as she is nearing the end of her heat cycle. Anyway, yesterday I really 'noticed' it and had a moment of panic, took her into the vet asap thinking of all sorts of horrid possibilities. Vet's first thought was mammary tumor or broken rib. She palpated it, aspirated it, and x-rayed it from 2 angles. Palpation suggested that it is not involved with the mammary gland and the gland is not active. Aspiration revealed a kind of gooey fluid (she said it reminded her of what you'd find in a salivary gland) - red blood cells and neutrophils but no white blood cells, no tumor cells. X ray showed ribs are in good condition, all visible organs looked normal, lump did not show up that well but did not see any evidence of calcification or foreign bodies. Her conclusion was that it might be a dry abcess or more likely a hematoma, but she didn't seem very confident on that and I'm not entirely convinced either. She sent us home with cephalexin in case there was some undetected infection, and said to provide hot compresses to the area twice a day in hopes of softening it up for drainage. The mass is about 4x4 inches in area and rises about 1/2 -3/4 of an inch outwards from her ribcage, sprang up pretty suddenly and hasn't noticeably changed since I first saw it. The vet remarked that it felt 'crunchy' when she aspirated, but it is smooth and hard, not lumpy feeling. It is painful to the touch although this dog is pretty stoic and isn't being overly dramatic with her reaction, she is wincing a little. There is nothing on the exterior that is suspicious- hair is all healthy, skin in good condition, no wounds, etc.
In addition to the obvious mass, a 'symptom' which may or may not be related is that Shelby has been restricting her movement for about the last month. Not limping, but choosing not to run most of the time and hesitating on jumps/stairs. She is a VERY high drive dog and her favorite activity is blasting around at warp speed so it is pretty unusual that she isn't wanting to run. The reduced mobility started at an agility trial where she wasn't jumping correctly and seemed to be unable to extend her left front (lump is also on the left side but wasn't visible at that time). I pulled her from the trial and she was rested for about 2.5 weeks, started training again for a few days, then I was away, and when I came home she is sore again and with this mass.
So.... any thoughts on what this could be (does hematoma even seem like a likely hypothesis?) If a hematoma could result from her smashing into something, that seems possible as she is a 'full body contact' kind of dog, although if it related to her intial soreness it seems to have taken a long time to appear! However, I am worried that it is something more serious and don't want to wait too long before taking action if that's the case .... The plan is to continue with the compresses/antibiotic and if there is no change by next week, to go for an ultrasound to try to get a better look at it and for possible drainage. If there are any suggestions as to what things we should be ruling out at the u/s appointment, or if there are any suspicious alternate diagnosis based on what I have described, please share. I'll post a picture of it tomorrow if that helps.