View Full Version : Why don't wild animals get sick?

09-22-2003, 12:47 PM
Specifically from drinking water/eating older (or possibly fresh) kills.

On the Survivor show for instance,as well as in Boy Scout manuals I suppose,we're taught to boil/disinfect water before drinking.And mayo laced food sitting in a warm environment is supposed to be consumed within a prescribed period of time.Cook meat to x temp.to kill anything in it.

Why don't animals get sick,or get the runs or something?Gives a new meaning to the turkey trot :)

Or do they?I can't picture a lion taking a Bromo for some bad antelope he's eaten.

My WAG is there's something specifically for killing toxins in their digestive tract,but if so,what is it,and why don't humans have it?

09-22-2003, 01:13 PM
They do get sick. Wild animals can be presumed to be infested with parasites and diseases to some level or another. This is yet another reason to leave them alone.

Diseases are not caused by "toxins", by the way.

09-22-2003, 01:18 PM
Some predators have a shorter digestive tract. This, presumably, prevents certain microbes from being able to reproduce to levels that would create disease as they are expelled quickly.

Dogface, I was under the impression that the waste products of various micro-organisms, (toxins), are what the body had a reaction to in some cases. Maybe I'm wrong. Hopefully, (dopefully), someone will be along to give a more authoritative answer.

09-22-2003, 01:25 PM
Wild animals do get sick, but it's probably safe to assume that those who survive long enough to reproduce have some pretty hardy immune systems. That would be essential for an animal that survives solely through scavenging, like a vulture.

Wild meat-eating mammals like wolves have shorter digestive tracts than humans, so stuff doesn't sit around inside them for as long. This helps them if they eat something bad. I've also been told that wolves and dogs have a higher acid content in their stomachs which help kill bacteria, but I don't know if that is a scientific fact or not.

09-22-2003, 01:34 PM
Originally posted by SimonX
Dogface, I was under the impression that the waste products of various micro-organisms, (toxins), are what the body had a reaction to in some cases.

Yes, this is true. Botulism is a classic example - it is not the bacteria that makes you sick with botulism poisoning, it is the toxin those bacteria produce. Antibiotics can kill the bacteria, but there is no cure for the toxin - you just have to hope the bacteria are killed before they've produced enough toxin to kill you.

There are other bacteria in the Clostridium family that can cause severe gastrointestinal problems via the toxins they produce as well.

09-22-2003, 01:34 PM
It's also possible that being exposed to various diseases throughout your life gives a higher tolerance to those who survive.

I have to confess I've never checked a cite to see how often wild animals get sick, but just assumed it was obvious that they would, and indeed would often die of it. (I'm not being stupid here, right?)

Seriously, I'm curious - why would people assume they didn't?

09-22-2003, 01:39 PM
They do indeed get sick, and sometimes die of whatever disease they got exposed to.

For instance, anthrax spores survive in the soil where the last animal died of anthrax, and that's where the next animal catches it.

One of their defenses is better sense of smell than ours, but it doesn't protect them from everything.

09-22-2003, 02:03 PM
I can tell you as an erstwhile pet buyer that ALL wild-caught animals have parasites; we used to say, "All God's chilluns got worms." Which was why, whenever possible, I bought from breeders. The only wild-caught animals we bought were those that could not be bred in captivity.

09-22-2003, 02:08 PM
The Op seems to refer to th eability of wild animals to drink from streams, ponds etc w/o any apparent harm whereas a human would get giardia or some such from drinking the same water. What's different about their systems? Didn't humans have to drink from the same sorts of water sources not that long ago?

09-22-2003, 02:21 PM
OK, well spotted Simon. In that case my guesses are just:

Your immune system gets used to it.
They do, but one human catching something is a lot more noticable than one squirrel.

09-22-2003, 02:42 PM
When you arrive on this planet, you're susceptible to all kinds of little nasties. Gradually, as you survive this little infection or that, or you collect vaccinations, you add to the list of ickies to which you have resistance. The "list" of things each individual is resistant to is kind of a life history of the things that individual has been exposed to. Living in the wild and drinking "dirty" water and eating uncooked dead things, you'd have quite a long lifelist of exposures and, assuming you're still alive and healthy, a correspondingly long list of resistances. If you've spent your life watching TV and eating Lean Cuisine, you'd have a relatively shorter list, therefore a longer list of susceptibilities. So do the math, and you'll understand why Mitzie from Park Avenue is more likely to get sick from stream drinking and road kill eating than Bambi.

Spavined Gelding
09-22-2003, 03:08 PM
The easy answer is that wild animals to get sick all the time. Being in the wild, however, few people are in a position to notice. For instance, mange pretty well wiped out the fox population around my part of the country some years ago. Coyotes moved into the void the fox die off created until the coyotes in successions got mange. Now the surviving foxes are starting to come back.

There has been an out break of a ďwasting diseaseĒ among white tail deer in Southwestern Wisconsin.

The West Nile Virus first appeared in birds, especially crows. The crow population has decreased but the survivors, who are presumably resistant, are reproducing and the population is increasing toward the old levels.

Unless you are dealing with a top end predator, like a mountain lion or a bear, a sick animal is likely to end up as lunch before they can die of their ailment. Even wolves will attack and kill the weak members of the pack. Remember the buffalo wolves that hung along the fringes of the heard to take down the old, the weak, the sick and the unprotected young. Because of the wolves there were not very many sick buffalo. Sick wild animals donít stick around very long.

09-22-2003, 04:24 PM
Just got back to the thread,thanks for the responses.As I mentioned in the OP (not the header-A DELIBERATE TRICK TO GET MORE hits :),and hopefully a wider range of animal mavens.

I'm particularly interested in the ability? to not get sick as in Lissener and Simon's responses.

I realize they contract diseases ranging from rabies, to possibly cancer.

So it's a safe guess to assume it's an inherited abilty thru eons of eating/drinking less than A code food/drink?

Or could something like the appendix,which we were taught had no known use those long years ago when I attended PS, in animals have a use, where our corresponding organ/gland's functions have just been frittered away by the many years of civilization?

I'm thinking some biologists or somebody might have done a study of this

09-22-2003, 04:34 PM
Wild animals are no more unlikely to get sick than are domestic animals who somehow grow up in the same environment. Presume that any wild animal you meet is infected or infested, and you will usually be right.

Disease in wild animals has been studied. The results. They get sick a great deal. They get giardia. They die from mange. Elk Wasting Disease is a problem for some species of deer. They have worms.

There is absolutely nothing innately special about wild animals' resistance to disease.

And toxins do not cause disease. Some pathogens produce toxins, but it is the pathogens that are regarded as the cause of the diseases, not the toxins.

09-22-2003, 05:49 PM
Wild meat-eating mammals like wolves have shorter digestive tracts than humans

Except for the numerous wild meat eating animals like bears, pigs and chimps that have noticably longer digestive tracts than people.

As for the OP, what you have to remember is that the life expectancy of a wild animal is incredibly short. Many of them never live to sexual maturity, which in most specie sis less than one year old. The exact numbers vary from species to species, but on average I imaging the lifespan for a medium sized wild animal would be in the range of 6 months. I suspect that very few of them die of disease directly. Instead the disease weakens them and they die of exposure, predation or starvation/thirst. Not all animals die of course, and not all people get sick from drinking cholera contaminated water. Itís pot luck in the truest sense of the term, but on the whole itís risky. Thatís why the warnings to boil water, not eat warm mayo and so forth.

Exposure to contaminated water does produce a resistance to low level pathogens. People in Mexico obviously drink the Mexican water with no or little ill effect. On the other hand a Mexican moving from one area of Mexico to another will often get ill when drinking the water although often less so than someone form the US.

09-22-2003, 06:09 PM
What this thread needs is a cite (http://www.sciam.com/article.cfm?colID=1&articleID=00028CB6-F60A-1EBB-BDC0809EC588EEDF).


09-23-2003, 02:45 AM
i wanted to add that well cared for domesticated animals live a much longer life than their wild counterparts. however, that thought reminds me of those 100 year old turtles, giant squids, fishes and such; don't they get sick and die? will they live twice as long domesticated?

09-23-2003, 06:11 AM
Domestic animals do have a much improved life expectancy, but their life spans are not that much higher.

Sick animals die in the wild for the reasons I gave above: predation, exposure, stavation etc. Domesticated animals have longer life expectancies in large part because they don't suffer those things. They can lie down for three days without being eaten, food is always plentiful and water is always nearby.

The other factor is the amount of general stress. Working dogs live slightly longer than wolves, but not as long as pets of the same breed.

If we were to domesticate a tortoise or squid we could prevent disease etc which would increase life expectancy. We could also endure that when the slowed down they with age the wouldn't die (although this may be less critical for a totoise). But the actual increase in lifespan would probablly not be great.