It is common and fairly harmless for sensitive dogs to go off their feed when something unusual is going on in the household: owner absence, guests, death of another dog, loud arguments, etc. Don't force-feed a dog unless it needs to take food with a medication. Given the state of the pet-food industry, dogs that stop eating a particular brand of commercial food may be the harbinger of a recall.

Barring obviously stressful circumstances, what if your dog is habitually disinterested or woeful about his daily ration?

Don't mix high-carb commercial treats with your dog's food or add salty, fatty or sugary "dressings" to tempt him. For a carnivore, these are the makings of gas, diabetes, gallstones and kidney stones.

Offer a high-quality diet. Raw diet is popular with most dogs. Or try out some of the high-protein dry foods that don't have a lot of corn and wheat fillers-- Dog Food Advisor has great resources for finding the best quality food for your budget. If you are using dry food, soak 1 cup of kibble in 1 cup warm water for 1/2 hr before giving it to your dog so that it smells tasty and is easier to digest. 

Increase exercise. This is always a good idea. It is virtually impossible to exercise a pet dog "too much", provided you increase the amount slowly, in an activity appropriate to the dog. For example, overweight or elderly dogs may be more comfortable swimming than running.

Put your dog on a feeding schedule so that his body begins to feel hungry at certain times of the day. I feed twice a day. If you have a deep-chested dog that is prone to bloat, three or four small meals are appropriate.

Develop a "warm up" routine like the following to get him engaged in eating:

  1. Call out, "Dinner time!" (your Pavlovian bell) 

  2. Ask him to fetch his dish, go to a mat, or perform some other task you only do at dinnertime

  3. Have dog wait while you fill up dish

  4. Dog follows you to the usual eating place

  5. Have him sit before you set it down

  6. Ignore the dog while he eats. Stay near enough he doesn't follow you off but far enough away that it is obvious you're not interested in what he does with the food.

Dogs love these rituals and it will give him a few minutes to get those saliva glands in gear, an involuntary reflex.

Pick up any food that the dog doesn't eat within 10 minutes, even if he has eaten nothing. I promise, he will not starve to death missing a meal or two. Reduce the amount you give him for the next meal until he is eating it all and looking for more each time.

Once you find a food the dog is enthusiastic about, let him work for it by hiding small portions around the house or stuffing a KONG or puzzle cube. This lets the dog exercise its latent hunt-dismember-devour instinct.

Avoid performing the following behaviors around your dog:
  • Hang over the dog worriedly, talking or staring, while he noses at his food

  • Badger or command him to eat, hold him at the dish or force his face into the food

  • Shut him in an un-liked place for feeding time (do preliminary crate training before you shut your dog in a crate with food)

  • Pet and cajole him when he walks away from the food