It is very common for dogs to develop these (usually benign) fatty tumors on their body. The tumors may appear anywhere and often grow in size slowly. The number of tumors and the size is not related to the question of whether it is cancerous or not. Most dogs will get a lipoma and it will grow. As long as it does not interfere with movement they are not worrisome.
However, a lipoma is a sign that your dog has a digestive, metabolic or diet challenge. Commercial foods are likely the culprit for this problem. When the body cannot use or expel certain indigestible fats it stores them in these unglamorous tumors. The solution for stopping the growth and the appearance of new lipomas is to switch to a homemade diet that uses only high quality fats and stresses whole grains and finely minced green veggies (parsley, cilantro, basil, spinach, broccoli, kale etc).
If you cannot identify the food your dog is eating (such as potato, rice, meat, yogurt etc) then the diet you're using is over processed and probably high in bad fats.
Yogurt is an excellent digestive aid and I give it to my dogs daily. Sometimes I will substitute a probiotic supplement.
For tumors that already exist, there is a slight chance that they may reduce or disappear. Don't bother having them removed unless they interfere with movement. You may try a yellow light on the dog for 15-30 minutes at a time for several days or even weeks. Some holistic vets have experienced success with this kind of light therapy.
Exercise, good diet and digestive aids are your priorities when it comes to lipomas.
