My 7 year old mutt has a lump...

My animal has a lump too, but not as big as yours. My animals lump was caused by a BB that hit it and the skin grew over it. Just in case get it checked

From your description it sounds like what my former employer Dr. Richard Mabie, called a Fatty Tumor. But you should never put your pets health into question. Take your pet in and have this lump checked.

You should get your dog checked out just in case. It could be nothing but in case it is at least you caught in time.I had a cat that developed a lump under his left ear. It turned out to be cancer.

I would definitely have a vet check that out. One of my cats had lumps that turned out to be nothing while I've met many pets whose lumps turned out to be something. It's not something that can be judge by anyone else than a professional.

Petsmart's Banfield runs clinic hours every week where they waive the doctor visit fee. They are very reasonable in their prices on stuff, so if money is a problem they might be a solution over your regular vet.

We have a 15 1/2 year old yellow lab, he started having lumps about 2-3 years ago. They are actually common in labs, so says my vet. They are usually nothing to worry about. Often they are soft, moveable and don't bother the pet. I have friends that have had them removed but, lots of times they come back. Max has his on tummy and belly. They have never bothered him. I check them daily to make sure they aren't open or haven't changed.

It could be a follicular cyst. I would watch it and if it keeps growing get the vet to check it out ASAP. It also could be a fatty tumor. Not knowing how often your dog sees the Vet, it is hard to say how long I'd wait to get it checked. My dogs see the vet at least twice a tear, sometimes more often if needed.