So we adopted a mastiff that 3in a kill shelter, we usually have small dogs but this is our first mastiff. So he is under weight. We are feeding him 4 cups of purina pro plan and to fatten him up also giving him 2 cans of wet pro plan. He has been neglecting his dry food . He is 2 to 3 years old and weighs 105. We took him to the vet and got all his shots up to date and his heartworm treatment is in process. So hes good. Trying to be responsible parents. But cant understand why he is not eating his dry food. And looking for ways to help him get his weight back to normal. Any suggestions? We really love him and are doing everything we know of but we are hoping someone here can advise us. Thank you in advance.