Esther, Lake Oswego, OR
Some dogs and cats, like some people, simply develop an excessive love of food during their lifetimes. This could be the case with your dog.
Although changes in the weather rarely affect appetite to the extent you describe, there are a number of health matters and diseases that can cause increased appetite.
Are you feeding your pet a high-quality diet? Dogs and cats whose nutritional needs are not met may become excessively hungry. I recommend feeding a premium dog or cat food. There are several available that are nutritionally replete and will ensure that your pet’s dietary needs are fully met.
Is your dog taking any medications? Some medicines, especially prednisone (which is a type of cortisone, frequently prescribed for allergies and other problems), can cause increased hunger. Do not discontinue any medicines without consulting your vet.
Intestinal parasites can cause increased hunger, but usually not to the degree you describe. Nonetheless, your pet’s stool should be microscopically examined (by your vet, of course) to test for parasite eggs and larvae.
As any person who has eaten pickles and ice cream in the middle of the night can attest, pregnancy can lead to unusual appetites and increased hunger. Is your dog spayed?
Finally, a number of medical conditions can cause increased appetite. These include diabetes, problems with the pancreas or intestines, hormone imbalances related to the adrenal glands, and cancer. In cats, a hyperactive thyroid gland can cause increased hunger. Many of these diseases will cause increased thirst, diarrhea, or other symptoms as well. However, three year old dogs are at low risk for most serious medical disorders.
I recommend you take your dog to the vet for a checkup. He or she should be able to sort out whether there is a medical condition, or whether you need to enforce more willpower on your pet.