Nodules on rear leg

Last Saturday, I took both Odo and Zek to the vet; Odo's eye was watering and Zek needed one more recheck on his bloodwork (he previously had a high white cell count, which we treated with antibiotics (see his history here)--and we wanted to confirm that it had stayed low after waiting another month). While we were there, the wonderful vet tech took Zek's temperature and noticed a small nodule on Zek's left rear leg. The nodule was smaller than a pea, and I hadn't noticed it before (though I don't often feel around at that end of the cat).

The vet took a small sample (needle biopsy) and examined it under the microscope. She said that the sample was full of cellular debris, and it was probably just a cyst but to keep an eye on it. True to form, I've been keeping close tabs on the bump. After the vet had taken a sample, the nodule seemed to elongate (originally it felt spherical, but now the first nodule is more oval in shape).

Almost 24 hours ago, I noticed a second nodule, small and spherical, next to the first. It also feels like a third one may be forming though I could be imagining that--it just feels like there is some thickening under the skin next to the second nodule. They don't appear to itch, but he doesn't like it when I mess with them. The fur and skin are still intact in that area, and there isn't any sign of oozing.

We have an appointment first thing on Saturday morning (my vet is not in the office tomorrow) and I'm trying not to panic in the meantime. Zek's only about 2 years old (I adopted him from the shelter in October 2007). I don't know if he's had a rabies vaccine (the shelter apparently didn't give him one nor has my vet) but they did give him a FeLV vaccine on 9/27/07 (I won't be continuing with that as he isn't at risk of exposure). He certainly doesn't act sick (he's currently running all over the place) but he didn't seem sick when he WBC count was double high normal either.

Does anyone have ideas about what this might be so that I can do lots of research before the vet appointment? I'm terrified it could be a vaccine-associated sarcoma, but I don't know his symptoms fit the profile. Are there other possible causes of nodules popping up practically overnight?

It doesn't sound like an injection-site sarcoma, so try not to worry about that.

Years ago one of my cats had the same thing you're describing about Zek. It was on the back of one of her rear legs, in the "thigh" area. My vet said it was a skin granuloma and didn't think it was serious. She did recommend that I monitor it in case it worsened. It didn't and resolved on its own.

I can't remember the specific cause of this, but I believe it was a type of allergic reaction.

Hope it clears up for Zek too!

PS - Your babies are very lucky to have a mom who takes such good care of them!

Thank you for suggesting that possibility. Did the granuloma change or multiply at all? Originally we just thought it was a cyst, but after the extraction of some of the material, it changed shape and and another one or two (one is definitely round is present, like a tiny metal ball, and the other just feels thickened but less distinguishable). The rapid change is what is making me nervous.

By the time I found it, there was about a 2 inch "line" of bumps along the back of the leg.
I don't remember it getting worse or changing at that point, but I also don't know what it may have looked like when it started because I didn't catch it early enough. Once we found it, though, I believe it had gotten as bad as it was going to be and fortunately, from that time on it healed.

I can understand your concern about the rapid change. If it is some type of allergic reaction, that can happen.

BTW, handsome Zek looks like a tux - is he? My girl who had the granuloma is a tuxedo kitty.

Yep, he's a tuxedo with a white chin as well.

Oh my goodness, is he ever adorable!!! The only white part of my girl's face is her chin too!

We just got back from the vet. She shaved the area, tried to aspirate the nodules and took a skin scraping. The results indicate eosinophilic granuloma. The vet suggested a Depo-medrol shot but she knows how much I like to research things and could see I was concerned about giving steroids. I'm off to look up other options and the side effects of those, and to see if there could be a specific cause/allergy that could be eliminated.

I'm glad you have a definitive diagnosis; you must be relieved! At least now you know what you're dealing with and you can make some decisions.

I'd be wary of steroids too, especially Depo since it's particularly strong. Hopefully, you'll find alternatives to this as you do your research. Maybe I was just lucky that my cat's granuloma resolved untreated. Unless your vet advises otherwise, perhaps you could wait a week or so and see how Zek's leg does on its own.

Please keep us posted on how he's doing.

I figure since I waited a week between finding the first lump and bringing him back in, and the number of lumps increased, I'm probably not going to be able to just wait this one out. I did find a really great article on the topic though, which includes possible treatment options:

http://www.vin.com/proceedings/Proce...6694&O=Generic

I figured I would start with the easiest--adding fatty acids. My vet's office had 3V HP caps, so I squirted some on Zek's food yesterday--bad idea. He ran around the house like crazy. When I finally caught up to him, he was covered in drool. I guess they don't taste very good. I felt really bad for Zek--he had a rotten day yesterday, with the needle aspirate, skin scraping, and then bitter medication. I'm going to keep trying to use them, but I'll pill him instead of risking more icky tastes.

If the fatty acid supplement doesn't help, I'll look into food trials. The boys currently get Orijen dry and a variety of canned (mostly chicken and turkey flavors). Orijen is great for Odo, who tends to gain weight on grainy foods, but it may have too many possible allergens for Zek. I'll probably switch back to California Natural, since I still have most of a bag of the Chicken and Rice.

My Cat has had the Depo Midrol Shot before. It can not be used often my Vet said. I hope your Cat feels better. Her last one was in Aug when it gave her a lump that took 2 months to go away. She has Allergies too.

Hi my little man paco has this going on too its on his left leg on the back feels like alot of knots bu5 in a vein like pattern going up his leg i shaved the area some and the bumps have a white patch on top not likeva pimple though. I dont see any irritation really and he dont seem in pain. I hope hes ok i tried getting pictures . Any ideas