You'll probably notice that your pup turns his nose up at some foods but happily chows down on others, like yummy doggie treats. While this preference is based somewhat on his sense of taste, it's actually primarily based on his sense of smell because dogs have very sensitive noses. This is why pups typically prefer canned food to dry: because of its more potent aroma.
A dog's sense of smell is much more acute than that of a human and the one that he relies on the most. Each dog has more than 220 million olfactory receptors in his nose, compared to only 5 million in people, according to the Alabama Cooperative Extension System. Not only that, but your pooch has a special organ in his nose called the Jacobson's organ, located at the base of his nasal passage. This organ allows him to smell pheromones, making his sniffer even more sensitive than a human's, according to the Public Broadcasting Service Online. It's this sensitive nose that your pup follows to the food he enjoys.
Limited Taste Buds
Unlike his sense of smell, a pup's sense of taste is far less sensitive than a person's. On average, a dog has only around 1,700 taste buds on his tongue, compared to around 9,000 on a human's, according to Psychology Today. Our canine companions can taste the same flavors that we can, namely sour, sweet, bitter, salty and umami, a meat-like flavor, but to a lesser degree. All pups also have more specialized taste receptors than we do for the flavors related to meats and fats; pups even have taste buds that are water-specific. For this reason, your pooch will seek out and generally prefer moist foods that contain meat and fats.
A Combination of Senses
The senses of taste and smell are closely linked and actually work together to determine your pup's food preferences. Initially your pup relies on his sense of smell to determine if the food item in front of him seems yummy; then he relies on his sense of taste, when he actually eats the food, to confirm this. As an example, while dogs don't like bitter or sour flavors, if something smells good and it's slightly bitter, your pooch may eat it so quickly that he won't notice the bitterness, according to psychologist Dr. Stanley Coren. It usually takes prolonged chewing of something for your pup to realize that it doesn't taste as good as it smells.
Enhance Dog Food Scents
As a dog ages, his sense of smell decreases, sometimes by up to 40 percent, according to "Train Your Dog Positively" by trainer Victoria Stilwell. For this reason, an older dog or one with a stuffed-up nose due to a canine cold isn't as apt to eat as one with a fully-functional sniffer. To encourage Fido to eat, pour some low-sodium chicken or beef broth over his food to moisten it and increase its aroma for him. You can also heat some canned dog food in the microwave for a few seconds to warm it before serving, which also enhances the food's scent, recommends PetEducation.com.