We’ve already talked about other senses of our pets, like their vision and their ability to see colors. So, we thought, why not talk about another one of the senses that our pets use whenever they can: taste.
The sense of taste is what we perceive when a substance in our mouth chemically interacts with our taste receptors. Yes, it sounds a bit redundant.
Taste receptors are structures located in specific cells in the mouth (which are often grouped in the so-called taste buds).
When something enters the mouth, some of its molecules dissolve in the saliva and come into contact with the taste receptors. These receptors are of different types, and each one recognizes and reacts to specific molecules. When the receptors are activated, the cell sends signals to the brain. The interpretation of these signals in the brain gives us the flavors.
Humans recognize the five basic tastes:
- Sweet. Recognized by G-protein-coupled receptors (GPCRs) that interact with sugars or molecules that mimic them.
- Sour. Recognized by cells called type III cells. When an acidic food releases hydrogen ions (H+), the electrical charge triggers a cellular response. These are not really taste receptors but pH receptors, but the message interpreted is that of a sour taste.
- Salty. Basic recognition is done by cells through sodium channels. Similar to sour, the response is triggered when the molecule Na+ is detected in the mouth. However, other cations (positively charged ions) like potassium also trigger this response.
- Bitter. Recognized by GPCRs, this taste evolved to warn the organism of toxic substances in food. It is considered the most sensitive of all, but due to cooking techniques and modernization, humans have lost this sense.
- Umami. Recognized by GPCRs, it primarily detects glutamate and amino acids.
In addition to the taste receptors, this sense is closely related to other sensations. The sensation of taste doesn’t solely come from the taste buds.
Other elements involved in taste are smell, texture, temperature, and other chemical modifications, like the spiciness or the cold sensation from menthols.
Do dogs and cats have taste buds?
This means that dogs and cats do have a sense of taste. Although we have more taste buds than they do.
Humans have about 10,000, while dogs have around 2,000 and cats have 1,000 or fewer. We have the advantage of a larger tongue.
In exchange, they have an advantage in enjoying flavors better than us.
We can assume that, in dogs and cats, the influence of the sense of smell on taste is greater than in us.
After all, they have a stronger sense of smell. A human has between 5 and 10 million olfactory receptors. A dog has between 50 and 200 million, depending on the breed. Bloodhounds can have up to 300 million!
Cats are believed to have between 50 and 200 million receptors, less than dogs, but far superior to humans.
Your dog likes water more than you do
Dogs distinguish flavors in a similar way to us. They taste food and are capable of distinguishing the five basic tastes.
It’s normal, as they’ve been sharing our leftovers for thousands of years, adapting to our diets. Dogs reflect human history.
That’s why dogs are omnivores, while wolves, their wild cousins, remain carnivores.
Compared to wolves, dogs have developed a taste for sweetness, due to changes in their diet.
That doesn’t stop them from still being attracted to animal protein and fat.
One difference with humans is the threshold for salt. For dogs, salty flavors are less pleasant than for humans. It is believed this is because their ancient meat-based diet was very salty, so adding more salt from external sources could jeopardize their health.
Additionally, they perceive water differently. They have a set of taste buds at the tip of their tongue that are specialized for water. These taste buds are more sensitive after coming into contact with salty and/or sugary products.
The theory is that these encourage the animal to drink water after eating, to avoid dehydration issues.
In dogs, the smell of food is particularly important. In an animal that can sniff five times per second, that sense is the priority for deciding whether to eat something.
Once food passes the smell test, it’s rare for them to reject it when they put it in their mouth.
That’s why food with strong smells attracts them more. This is a trick used in canned dog food, which has a potent smell to make it more appealing.
Yes, your cat eats grass
Cats distinguish flavors, but not the same way as dogs and humans.
Cats have a highly developed sense of taste for detecting amino acids in food. We could say they taste the amino acids in food more strongly than humans.
That’s why they prefer the flavor of umami above the others.
It makes sense: cats are much more carnivorous compared to dogs. They have a strong preference for meat, foods rich in proteins and fats.
Additionally, they can’t detect sweet flavors. It’s the flavor they don’t perceive. Sweet foods hold no charm or appeal for them.
Being strict carnivores, sweetness was never part of their diet. Their tongue had no interest in convincing them to suck on sugar cane.
Perhaps some, with the strict carnivore part, wonder why they’ve seen their cat eating grass.
Dogs also do it, but here we could justify that they are omnivores. And dogs. Dogs have this habit of putting almost anything they find on the ground into their mouths at least once in their lives.
When young, both pets do it out of exploration. They’re learning from their environment.
Other reasons, in both dogs and cats, could be boredom, combating intestinal parasites, a trait preserved throughout evolution, or nutritional deficiencies, maybe in fiber.
In the case of dogs, it’s believed they also do it to induce vomiting. Cats are too elegant to fall into that behavior.
Another thing they have in common with dogs is the water receptors on the tip of their tongue. In this, we humans are the odd ones out, as we lack them.
Another detail: cats chew less than dogs and humans. Some experts believe this makes them give more importance to the texture of food inside their mouth.
As an additional test, they decide whether to swallow or not based on the texture of what they’ve put in their mouth.
Dogs and cats are much more complex than they seem. And more than we think. To understand that complexity, you can help yourself with the Koko Genetics DNA test, where we will explain the secrets hidden in their genetics. Discover your pets’ genes!