When it comes to the sense of taste (or gustatory sense) in dogs, owners tend to fall into one of two categories—those who think that the dog has no sense of taste and therefore quite happily feed the dog with a bland and consistent diet; and those who think that dogs are like humans and want different food every day. Which type of owner are you? Today we’ll explore the sense of taste in dogs to find out the truth. Those dog owners who think that their pets have very poor taste in food may be justified in thinking this way, after all many dogs eat their poop. Dogs generally love to raid the garbage and we often observe our dogs eating grass. However, those who think that dogs prefer a varied diet are also justified in their manner of thinking because dog food commercials and advertisements often portray a sensitivity of taste in dogs. Taste is a very old sense in evolutionary terms because the general rule of thumb, at least for natural substances, is that bad tastes are a signal that the animal has encountered something that is harmful, indigestible, or poisonous; while good taste signals useful or digestible substances which are safe to eat. The sensations of pleasure or disgust therefore serve a survival function.
It is believed that, along with touch and smell, taste is a sense which is developed in dogs at birth. Vision comes at seven to ten days when the eyes open; and hearing comes at 14 to 21 days when the ear canals open. As in the case of humans, the dog’s sense of taste depends upon special receptors called “taste buds,” which are found in small bumps on the surface of the tongue called “papillae.” Taste buds are found in other places as well, such as the soft part of the roof of the mouth (the “palate”) and the back part of the mouth were the throat begins (the “epiglottis” and the “pharynx”). Taste buds are responsible for sampling concentrations of small molecules and relaying the information back to the brain via several nerves. An animal's taste sensitivity depends upon the number and type of taste buds that it has. Humans win the sensitivity contest for taste, with around 9,000 taste buds as compared with only 1,700 for the dog, but dogs have considerably more taste buds than cats, which average only about 470. Specific taste buds appear to be tuned to specific chemical groups and produce recognisable tastes. Four basic taste sensations have been identified for humans: sweet, salty, sour, and bitter. Scientific research shows that the taste receptors of dogs respond to the same kind of chemicals that trigger human taste sensations. Dogs therefore also have the same four taste sensations of sweet, salty, sour, and bitter; and two more which we will discuss later in this article. The main difference lies in the salt taste sensation. Humans have a strong taste response to salt: we seek it out, and like it on our food. We cook with salt, and snack on potato chips, pretzels and popcorn which are usually liberally dosed with salt.
Salt is needed to balance our diet because not a lot of salt is found in vegetables and grains. Other mammals, particularly herbivores, also have strong taste responses to salt because they need to find it to supplement a salt-deficient vegetarian diet. Dogs however, are primarily carnivores and in the wild, most of their food is meat. Because of the high sodium content in meat, the wild ancestors of dogs already had a sufficient amount of salt in their diet and did not develop our highly tuned salt receptors and the strong craving for salt. The most abundant taste buds in dogs are the sweet taste buds that respond to a chemical called furaneol, which is found in many fruits. Cats are virtually “taste blind” for this substance. A dog’s fondness for this flavour probably evolved because in a natural environment, dogs frequently supplement their diet of small animals with any fruits that happen to be available. More than 80 per cent of a canine’s diet in the wild will be meat, and for this reason dogs also have some specific taste receptors that are tuned for meats, fats and meat-related chemicals. Your dog clearly prefers the taste of things that contain meat or flavours extracted from meat. The taste buds for the basic flavours are not distributed equally across the tongue. Sweet is best tasted at the front and side portion of the tongue. The sour and salty taste buds are also on the sides but further back, with the salt responding area being rather small.
The rear portion of the tongue is most sensitive to bitter tastes. Sensitivity to meaty tastes is scattered over the top of the tongue, but mostly found in the front two thirds. However, all areas of the tongue can respond to all of the taste stimuli if they are strong enough. Dogs also have taste buds that are tuned for water, which is something they share with cats and other carnivores, but is not found in humans. This taste sense is found at the tip of the dog’s tongue, which is the part of the tongue that he curls to lap water. This area responds to water at all times but when the dog has eaten salty or sugary foods the sensitivity to the taste of water increases. This ability to taste water probably evolved as a way for the body to keep internal fluids in balance after the animal has eaten things that will either result in more urine being passed, or will require more water to adequately process. Whichever type of owner you are, remember that your dog can taste his food so if you wish to continue to feed an unchanging diet of dog chow, try offering fruits and vegetables as healthy snacks. Do not worry that this will make him stop eating his chow: you do not stop eating your meals because you snack in-between! For those owners who constantly change their dog’s diet, be careful of creating a finicky eater: if a dog knows he will get something better if he refuses to eat then you will simply end up spoiling your dog and creating an eating-disorder. It is best to feed your dog with either chow or a balanced cooked meal (sources of carbohydrate, protein and fat included) but to supplement with fresh fruits and vegetables; and you may use treats as part of obedience training.
This article is copyright to Best Pets Animal Behaviour Service.
For further information, contact Kristel-Marie Ramnath at 689-8113 or bestpetsbehave@ hotmail.com