When you watch what our dogs eat, from our human food, to dog food, whether dry or wet, to the carrion and feces of other animals, many dog owners will certainly ask themselves what the taste of our four-legged fur noses is is ordered. Do they taste different, do they taste better or maybe worse?
This is the question asked by Stanley Coren, an American behavioral psychologist and author of several books on dogs, in an article in April 2011. We know for sure that dogs have a far superior sense of smell and we also know that smell and taste are related. It is all the more surprising that the human sense of taste, at least in terms of the number of taste buds, is superior to that of dogs. In a comparison test for taste sensitivity, it was found that humans have a total of around 9,000 taste buds, while dogs only have around 1,700 such taste sensors.
But it’s not quite as simple as the comparison of numbers would suggest. The sense of taste is one of the oldest senses of all and has long been responsible for distinguishing suitable foods from unsuitable or even dangerous ones. Humans know four different flavors that respond to different chemical substances: sweet, sour, salty and bitter. The four different types of taste buds are distributed over different areas of the tongue. It is similar with dogs. Many mammals, like humans, have taste buds for salty, because in many grains and vegetables there is very little of it and so the body has to find a balance and therefore responds particularly to salty foods. This is different for dogs as predators, because meat always contains salt. Dogs are not pure carnivores, but in addition to taste buds for sweet, sour, bitter and salty, they have developed special taste buds for meat, fat and meat-related substances. As a result, dogs look for foods that taste like meat, or that contain flavors extracted from meat.
The taste buds for sweet in dogs react to a substance called furaneol. This occurs in fruits and tomatoes and is responsible, among other things, for the typical pineapple taste. On the contrary, cats are taste-blind to this substance. Dogs respond to this substance, presumably because they often supplemented their food with fruit in the days before modern dog feeding from small animals. Many dog owners observe that their dogs like to nibble on wild strawberries, raspberries or blackberries as soon as an opportunity arises on a walk. My dogs also love apples (note: grapes and raisins, even if dogs like to eat them, can lead to health problems and should therefore not be given to them The same applies to apples and pears.).
The taste buds for the different flavors are not evenly distributed over the tongue in both dogs and humans. Receptors for sweet are found around the front and on the sides of the tongue, the receptors for sour and salty are also found on the sides, but further back. The range for salty is rather small. The rearmost part of the tongue contains many receptors for bitter and the receptors for meaty are mainly found in the front two thirds. In principle, receptors for all flavors can be found everywhere on the tongue. However, they are more concentrated in the areas described. If a flavor is very strong, it is perceived on the entire tongue, but if it is only weak, the specialized areas come into play.
Since dogs do not like bitter taste, this peculiarity has been made use of and various sprays, gels and plasters have been developed to prevent dogs from chewing on certain things or licking wound dressings. However, since the taste receptors for bitter are quite far back on the tongue, a bitter taste does not protect if the dog only bites quickly into something, licks it briefly or swallows it quickly. A bitter taste is only recognized when it is licked or chewed for a long time and has a deterrent effect.
Unlike humans, dogs also have taste receptors for water, just like other carnivores such as cats. These receptors are located on the tip of the dog’s tongue, the part that rolls when the dog ingests water. These receptors are always active, but increase their activity if the dog has eaten meat or has eaten salty or sugary foods. This behavior is a mechanism with which the body’s water balance is to be kept in balance if more urine is given or more water is required for digestion after eating meat, salty or sugary food. Observations suggest that dogs then take water with greater pleasure than usual and also drink quite a lot.