Lung cancer symptoms. The early symptoms of lung cancer may be a slight cough or shortness of breath, depending on which part of the lung is affected. As the cancer develops, these symptoms may become more severe or intense. Like many other types of cancer, lung cancer may also cause systemic symptoms, like a loss of appetite or general fatigue.
Medium breeds (e.g. cocker spaniel size) begin swapping over at about 8 months, Large breeds (such as Golden retriever) must stay on puppy food for at least 12 months and Giant breeds (e.g. Great Danes) stay on puppy for for 18-24 months. When swapping the food ensure you do it over 7 days.
It is easier on their digestive system to start mixing the adult food with their puppy food to get them used to it. I transitioned my pup for about 7 -10 days then by the 10th day he was just eating the adult food. But I would check with your vet before changing his food-just to make sure.