For any meat-eating humans out there, there is nothing better than the smell of cooking bacon.
Yes, cooked bacon is delicious. However, us humans have to cook our meat. Otherwise, we run the risk of getting seriously sick.
Meat-eating animals, or carnivores, rely on raw meat in their diet. Yet, they rarely get sick.
But why? How can so many animals tolerate raw meat in their diet?
Certain animal species are better at eating raw meat than others. However, almost all species of carnivores are more adapted to consuming raw meat than humans. Freshness of the kill, sense of smell, and strong digestive enzymes are all contributable factors as to why wild animals do not get sick from raw meat.
Read on to discover the carnivorous world of meat-eating animals, and the theories put forward to suggest just why on earth animals don’t get sick from eating raw meat.
Humans Can Eat Raw Meat
Before we continue, we need a clarification. A disclaimer, if you will.
Humans can eat raw meat. In fact, many cultures across the globe feature raw meat as a staple in their diet.
Take the Inuits of the Arctic, for example. Some indigenous communities rely on seal meat and blood in their diet.
However, eating raw meat is like playing a game of Russian Roulette. One bite could be fine, while the next bite could yield a parasite or two, causing detrimental health problems.
It is our nature of storing and processing meat products that increases this risk. The longer raw meat is left untreated, the higher the likelihood of it becoming more dangerous.
The same can be applied for carnivorous animals.
The longer a kill has been festering in the sun, the higher the chances of harmful pathogens developing. These pathogens can cause harm to animals.
However, on the whole, animals can tolerate raw meat in their diets far better than us humans ever could.
So, let’s explore some of the reasons why animals get sick less frequently when eating raw meat.
Reason 1: Freshness Of The Kill
Humans have developed many ways to store food. Many different methods exist to prolong the shelf life of certain meat-based products.
Freezing, salting and canning are all ways in which humans store meat for longer periods of time.
Carnivores do not have this luxury.
After a kill, most carnivores will need to feed immediately.
There are many reasons as to why most carnivores consume their prey as soon as they kill it.
Of course, carnivores need to swiftly replenish the energy they lost from the costly process of hunting.
Another reason could be to avoid kleptoparasites, or animals that steal food from other animals.
However, one of the most important reasons as to why carnivores eat their prey almost immediately, is to prevent their kill from rotting and going bad.
This is especially true in hot or humid conditions, such as savannahs or tropical rainforests.
By consuming their kill as quickly as possible, carnivores reduce the time for bacteria and parasites to become established on a carcass.
Some carnivores, such as the African hunting dog, take things one step further. After chasing their prey to exhaustion, the canids tear chunks of flesh out of their victim, effectively eating it alive- and they’re not the only species that do this.
Hunting dogs, however, are by no means the only animal that consumes their prey alive. Chimpanzees have also been known to hunt, catch and tear their targets apart. All while they’re still alive.
The below clip shows the hunting behaviors of a community of chimps on the hunt. This clip may be distressing to some.
Reason 2: Strong Sense Of Smell
Many predatory species of reptiles, amphibians and mammals have evolved a specialized olfactory organ that can be found on the roof of their mouth, just behind the upper incisors. This is known as the Jacobson’s organ.
The Jacobson’s organ connects the mouth and the nose, and is capable of analyzing different smells.
I know, I know. This sounds way too sciency. However, there is one huge evolutionary advantage of this olfactory organ: the ability for carnivores to distinguish between fresh kills and older kills.
Species of wild felines, such as lions and tigers, possess a rather sophisticated Jacobson’s organ.
If you have a pet cat, you may notice they often open their mouths when they sniff something out. Well, wild cats do exactly the same thing.
If you thought they were just pulling funny faces for the fun of it, you would, unfortunately, be wrong.
Instead, they’re carrying out a specific behavior, known as the Flehmen response. Somewhat like a grimace, the cat opens its mouth slightly, exposing their front teeth. As they breathe in, air floods the Jacobson’s organ, revealing a world of hidden sensory information.
As with humans, many predators have a preference to avoid older, rotting carcasses, as these pose a potential breeding ground for a plethora of harmful pathogens that could cause disease, and serious sickness.
And again, if you own a pet cat, you’ll know that they can be very fussy eaters. Apparently, they are just being over-cautious, worried that you may be contaminating their food with harmful bacteria or parasites.
A strong sense of smell allows many species to be able to eat raw meat without getting sick as they can differentiate fresh meat from rotten meat.
Reason 3: Powerful Stomach Acid
Carrion-feeders, or scavengers, feed off dead bodies and carcasses; fresh or rotten.
As we’ve discussed, rotten flesh is likely to be contaminated with a wide range of harmful pathogens, from bacteria to parasites.
Many carnivores would get sick from eating highly contaminated flesh. However, scavengers have incredibly potent stomach acid.
Many carnivore species have a stomach acid of around 1 – 2 pH. This can be compared to industrial strength hydrochloric acid.
The evolutionary adaptation has enabled them to exploit a biological niche. In other words, these animals can eat to their heart’s content, with limited risk of something else stealing their meal.
Take the humble vulture, for example.
Often seen as pests, they play an incredibly important role in the ecosystem. Without them, festering carcasses would pile up and diseases would run rampant.
Not only is the stomach acid of vultures extremely potent, capable of destroying DNA, recent research has unraveled a co-evolutionary relationship between vultures and flesh-eating bacteria.
Besides giving vultures an exceptional tolerance to deadly bacteria on rotting flesh, it is also thought that this ancient bird lineage puts the bacteria to good use. So much so, the vultures use the decaying properties of the bacteria to absorb more nutrients from the food they’re eating!
C’mon. Nature is cool, right?!
Vultures are amazing animals. Check out the video below of vultures swarming on a carcass:
Reason 4: Digestive Enzymes
Besides powerful stomach acid, the digestive system of carnivores is also full of digestive enzymes.
Enzymes are complex proteins. Their primary function is to break down animal protein and convert it into an energy source, which can be used for homeostasis.
Some of the most common enzymes present in the digestive system of carnivores are pepsin, trypsin and chymotrypsin. These are known as proteolytic enzymes and help convert raw animal protein into the building blocks of life: amino acids.
Without these enzymes, nutrients would not be able to be absorbed into the body.
Autolysis is a biological process whereby enzymes break down the tissues within their own body.
It is thought that by consuming raw meat, the digestive enzymes of both the predator and prey work in conjunction with one another.
In other words, the tissues of the prey begin breaking themselves down and the digestive enzymes of the predators digest the raw meat further. The combination of digestive enzymes and the process of autolysis contributes to wild animals not getting sick when eating raw meat.
Cooked meat, on the other hand, may cause health problems for carnivores. The cooking process of meat changes the protein structure and destroys heat-sensitive vitamins, such as vitamin C.
Reason 5: Strong Immune Systems
Not only do enzymes digest animal protein, they also help strengthen the immune system of carnivores.
Raw meat is also high in iron and zinc, which have been linked to an improved immune system.
As a result, carnivores can tolerate consuming raw meat frequently, and fight off any nasty pathogens that come with it.
Now, I’m not saying that carnivores have a better immune system than humans. However, their immune system has coevolved with the type of environment, and potential immune threats, that they live in.
For example, certain carnivorous mammals of the African savannah, such as hyenas, have a higher manageable parasite load. This means they can tolerate a higher density of internal parasites, such as roundworms or tapeworms – common parasites that can be found in raw meat.
Despite having a potentially high density of parasites in their intestinal system, their overall fitness is not compromised, thanks to their immune system.
However, parasite load increases in decaying or rotting meat. This is where all the other reasons touched upon above, come into effect.
There really is no single reason as to why carnivores can eat raw meat without getting sick. Rather, it is a collection of different measures working together.
Eating Meat Isn’t A Choice For Many Animals
Obligate carnivores, or animals that only eat meat, do not choose whether or not they want to run the risk of consuming raw meat.
Their bodies have evolved to digest meat. This is evident in the shortness of their digestive systems and presence of specific enzymes.
Even if carnivores were starving, they simply would not be able to survive on grass or berries alone. This is because they lack a carbohydrate-digesting enzyme: amylase.
Carnivores, and their bodies, have adapted over millions of years to be able to process, digest and derive energy from raw meat without getting sick, regardless of the appearance of the meat.
There’s nothing worse than food poisoning.
Unspeakable substances passing through orifices, uncontrollably. Stomach cramps that have you doubling over. Yup, food poisoning is not fun.
However, carnivorous animals have evolved to eat raw meat without getting sick.
On the most part, at least.