How DOG taste buds influence their choice in food.
Most journals investigate human taste buds because that is where the money is, but if you want to make your dog happy, surely you should be interested in what your dog likes to taste?
It’s also worth knowing how that compares to the wolf taste bud system and cats (our other great pet). And as expected one of the stronger dog taste bud senses, umami suggests that dogs still cling to their carnivore ancestry.
Medical analysis shows that taste-buds (Each taste bud contains about 50 taste-receptor cells) are typically associated sensitively wise to the NUMBER of them in on the tongue and in the mouth.
- Humans have 9000 taste buds
- Domestic dogs 1700
- Domestic cats 470
But what you perhaps should be interested in is the correlation between the HEALTH of your dog and what they can taste. In humans, we have read many times that we like many animals respond most to sweetness. And in humans that joy of sweetness has led to an obesity epidemic and diabetes and many other negative health outcomes. We are choosing the wrong (refined) sugars over natural types of carbohydrates. Sugars provide energy, but did you know that essentially the same energy values are available from protein? HENCE why meat-based treats provide the best nutrition AND energy your dog needs (as opposed to grain (carb) treats).
The major complication in understanding the value of their sense of smell with domestic dogs, is like their wolf ancestors, they have one of the best senses of SMELL in the animal kingdom, and as smell and taste are intimately connected AND Smell is a much more sensitive sense in dogs than taste, it is often the smell of a food that provides overpowering desire to eat something than taste or sight. We will draw conclusions about that later in this article.
Dogs also happen to have taste buds in the back of their throat so when they eat something without chewing, they can actually still taste it !,
DOG taste buds – The evolutionary imperative
Like wolves, tastebuds are found as the small bumps (papillae) on the top surface of the tongue. AND dogs also have taste buds on ‘roof of the mouth and at the back of the mouth where the throat begins (Yamamoto et al., 1997).’ Ref 1
For dogs in particular, ‘The ability to taste encourages animals to seek out and eat nutritionally beneficial and calorie dense food and helps them avoid eating anything that is spoiled or rotten that could make them sick.’ Ref 1
So, this might confuse some people where dogs seem to enjoy berries or carrots or why they eat rotten buried meat. You will find that texture, and foods like carrots that were not readily available to dogs in their natural environments add a bonus food source, a novelty that is sweet, hence they will often consume unnatural foods (non-animal products) – if they can.
The fact is that dogs evolved from wolves who primarily craved animals for their primary nutrition needs. When meat was not available, they would have a very minor supplement of berries but much of the vegetables in the form we buy from supermarkets were not readily available in wolf areas. So they ate what they evolved to eat, and most efficiently extract nutrition from (bio available food – animals).
Domestic dogs evolved from wolves around 20,000 years ago, and that evolution was mostly man-made. Humans coaxed dogs to live with us, to do work for us. We bred and changed their look but only accidently did this make slight changes to their digestion systems or type of food preferred.
The agriculture systems created by humans meant that they began large scale planned cropping and reduced their reliance on catching meat or having to herd animals. More humans and dogs began getting vegetable matter into their food. But humans began eating vegetables hundreds of thousands of years before dogs even existed. Our systems had a LONG time to evolve and switch from carnivore to true omnivore.
Domestic dogs didn’t ask to eat more vegetables, but if their owners were not rich enough to regular buy meat, or fit enough to hunt for meat daily, then their dogs would get whatever meat was left over after the human family was fed.
This meant that over the centuries dogs evolved to have amylase present in their mouth (the ability to digest plant matter better) – but they didn’t have anywhere near the amount of amylase in their stomach (like a true omnivore or herbivore will). Dogs today still have a very high acid environment in their stomach and short intestinal tract common to all carnivores. So you might expect dogs to have mostly a carnivore senses of smell and taste, and that is true.
So how does that part omnivore evolution affect what dogs can taste?
DOGS – Flavours they can Taste
Many EARLY texts suggested that dogs could only taste four basic flavours, but they taste the same amount as humans (FIVE) plus one extra taste sense: WATER!
1 Like humans Dogs LOVE sweetness.
“(sugar-activated ion-transport pathway that is linked to sugar transduction (Mierson et al., 1988). Further studies have discovered that certain salts can actually enhance the responses to various sugars (Kumazawa and Kurihara, 1990a).
Ref 1
Unfortunately, that is why many unscrupulous dog treat manufactures use a lot of sugar and salt to disguise their bland grain-based treats with very low meat content.
All animals love sweetness, but dogs craving Animal products have other refined senses based on carnivore origins.
2 Sourness (dog taste buds)
= acidic stimuli. Dogs DO NOT typically like SOUR tastes. It is believed it is an evolution response to ‘discourage dogs from eating food that has been spoiled by acid producing bacteria (DeSimone et al., 2001).’ Ref 1
But a dog’s desire to bank food, Bury it and eat it later, means that their very powerful sense of smell for meat, even rotting meat, often overcomes their sense of dislike for bitter tasting spoiled meat.
3 Saltiness (dog taste buds).
This is the ability to discern salt in liquids or dried. The “amiloride-blockable sodium channels on the tongues of dogs (Avenet and Lindemann, 1988). “ Ref 1 Unlike humans and other animals, dogs do not have an affinity for salt. Most carnivores do not crave salt.
This is likely because their ancestors “diet consisted of roughly 80 percent meat in the wild, and meat is a very salty food. Making salt less palatable is nature’s way of prohibiting excess salt intake” REF 2
“Compared to people, dogs can’t taste salt very well. That’s because they evolved to eat meat, and meat naturally contains enough salt to satisfy their body’s need for it without them having to seek it out. But they can still taste it.” Ref 3
THIS is another good reason why you should be enjoying SINGLE INGREDIENT meat treats.
Dogs have a lessoned ability to detect salt, but salts are used by some dog food and dog treat makers to enhance other flavours and trigger the water taste bud (an enjoyable sensation) which might have them consume more salt than is healthy for them.
A significant amount of artificially added salt on dog treats or dog food can increase palatability (and make you think that the dogs are loving the food), but it is actually harming the dog – giving them an overload of what they should naturally getting, in natural form, in their animal products.
4 Bitterness dog taste.
‘It is believed that bitter taste perception is essential for animals in avoiding toxic and harmful substances (Go, 2006).’ Ref 1
So Bitterness taste in dogs round out the FOUR primary tastes that scientist believed were the only ones that humans could taste for years too. And like humans SOUR and BITTER are typically things that tell us that a food is not ideal or has spoiled. Though of course some recipes and foods rely exclusively on these taste sensations as their core marketing concept.
The big difference is that with a higher developed reasoning part of the brain, humans can make safer choices in what they eat – for instance many people enjoy the bitter flavours in coffee and chocolate, or sour lollies and know that these substances in moderation are not harmful.
For dogs, THESE Two flavours (bitter and sour) should mean for the dog NOT to eat the food. The only difference is that dogs don’t know where their next meal is coming from (evolutionary wise) and so they will bury and dig up food from their ‘larder’ that can taste spoilt and can harm them. But the smell of the rotting meat often overcomes their much more limited sense of taste that should have prohibited them from eating the spoiled meat. DOGS will often rather risk eating meat that is potentially harmful and throwing up, than going without food, knowing that if they are unable to hunt they might die.
5 Umami (dog savory taste )
– THIS was the surprise taste identified first for humans in 1907. But because it is so much more subtle than the other four flavours, its power was largely forgotten for many years. Also, it wasn’t until the year 2000 that the taste receptors specific to umami were properly identified by scientists.
This umami flavour is characteristic of broths and meats.
The reason that you should care about umami is that what is subtle for humans might actually be THE PRIMARY health taste sense for dogs.
“Chemical components associated with the pleasant taste of umami are amino acids and peptides. Boudreau et al. (1985) found that dogs have a sensitive taste to amino acids, which could be one reason they are so drawn to eating meat.’ Ref 1
This reference article gets many things right, however its highly likely that they got that last sentence backwards. Wolves evolved to become alpha predators. They hunted for a living; it wasn’t a lifestyle.
Wolves ability to kill dangerous animals larger than themselves by hunting in packs meant that they evolved a NATURAL LUST for meat and all animal products. IT would only make evolutionary sense that the primary thing that they existed for, also gave them the most joy when eating. So it’s highly likely that umami, or the meat taste, is still high on a dogs taste agenda. Gives them considerable pleasure to continue the risk of hunting potentially dangerous animals.
6 Water (dog taste buds).
UNLIKE HUMANS, dogs have a taste reception JUST for water.
“ It is believed that it is integrated in the systemic feedback loops of ionic and osmotic regulation along with salty and sour tastes (Lindemann, 1996). In other words, desiring the taste of water helps ensure dogs drink enough water to maintain a healthy functioning body.” REF 1
The water taste buds in dogs “ are found at the tip of the tongue where it curls as the animal laps water, and although it reacts to water at all times, it’s more sensitive after eating salty and sugary foods.” REF 2 This means that after eating salty meat, dogs will usually drink water to flush the salt through their body.
NOTE that in people, the tip of the tongue is most sensitive to sweet tastes – so perhaps true omnivores are geared more towards sweetness and carbs, and dogs to umami and water and meat. Because they literally live to eat meat.
In summary, Domestic dogs ‘showed a strong rejection to the bitter tasting solution, a mild rejection to the salty solution, and a strong preference for the sweet solution.’. REF 1
That SWEET addiction is likely to have been created with man feeding and rewarding dogs throughout the last 20,000 years with much cheaper, and readily available vegetable scraps rather than species appropriate meat.
Not everyone was a farmer or rich, so until meat become regular available (think supermarkets), meat wasn’t always readily available for urban human masses, or their dogs. But by the time mass production lowered the price of meat, dog food manufacturers started marketing and advertising to owners that their dogs didn’t need meat. They needed a brand full of grain instead.
Hence why many owners, and many dogs, still don’t get the 80% plus animal products that they evolved to efficiently healthfully run on.
Dogs also happen to LOVE the smell of meat, Love the taste of meat, the UNAMI taste sense, and when they eat it (and all of its natural salt), their WATER taste bud is triggered to drink water to keep their systems running well.
WHY dogs don’t always seem to make wise eating choices.
“Food Smell and taste are very closely related, and dogs can actually taste foods through their sense of smell with a special organ along the dog’s palate. Note that while dogs can differentiate between meat-based and non-meat-based foods without smell, they cannot differentiate between chicken, beef, fish, or pork without smell. “ Ref 2
Humans don’t have the ability to taste through their sense of smell like dogs, but it certainly proves the point that if something smells good, it’s going to taste good (enough to eat) to a dog. “This is also why dogs are more interested in foods that smell stronger, such as canned foods versus dry kibbles. Canned foods are often much more aromatic, and therefore, more enticing. “ Ref 2
So here in lies the issue with commercial dog food manufacturers uses very little quality meat in their product (to maximise profits) and covering that fact with adding sugar, salt and oil or even disguising SOY as meat (the TVP mimic).
Commercial dog food companies are billion-dollar enterprises that spend millions each year in order to make food more palatable (desirable to eat). Rather than adding more meat, a natural ingredient for a species that is mainly carnivore, all they have to do is make grain or any vegetable smell stronger with a smell associated with one of the major senses like sweetness or umami.
Just because a dog food manufacturer has learnt over the last seven decades to fool your dog better, doesn’t mean that owners should fall for this too.
Most owners will not go ‘cold turkey’ off their favourite brands kibble, but that doesn’t mean that you can’t supplement their diet with single ingredient healthy dog treats made of meat, the GREAT umami taste. With just the right amount of salt.
REFERENCE
Ref 1 Do Dogs Have Taste Buds? By Dr. Kaitlin Wurtz July 10, 2020
Ref 2 Can Dogs Taste? By Katie Finlay Mar 17, 2017
Ref 3 Accounting for Taste: What Do Dogs Find Most Delicious? By Caroline Coile, PhD