The soft lump on your dogs leg may be a fatty tumor, referred to as a Lipoma.
Canine lipomas are a harmless, benign overgrowth of fat cells which are easily diagnosed by your vet with a simple aspiration cytology. This procedure generally requires less than 5 minutes to perform and diagnose.
Dr Carol Osborne, DVM
Thanks so much for your advice I appreciate it. I was thinking the same thing but just wanted to get a vet's opinion to feel better. Have a good day:)