Why is it that humans are constantly exhorted to maintain a far high level of hygiene with dire warnings of the consequences of failure, while animals routinely live out their lives with virtually no concerns about these matters? (I’m not sure if hygiene is the proper word here - I’m thinking of things like food intake (cleanliness, cooking) care of wounds, as well as general cleanliness and concern about germs and bacteria etc.)
I can think of four (non-exclusive) possibilities:
[ul]
[li]Animals are somehow different than humans[/li][li]Animals do in fact suffer for their “contaminated” lifestyles, but no one pays all that much attention - we just don’t tolerate that level of risk for humans[/li][li]Poor hygiene is overrated even for people[/li][li]Something about the modern human lifestyle increases susceptibility to germs[/li][/ul]
I imagine it’s some combination of the above (esp. the first three), but I’m wondering if there’s something I’ve missed.
[Also, I’m aware that it varies by species, and that some creatures are specifically designed to be resistant to germs, e.g. vultures. Still there does seem to be a divide between humans and animals as a whole.]
Wild animals do walk around with a infections both chronic and acute and a load of parasites all the time. This is one reason wild animals tend not to live so long as animals kept by humans.
The current standards of hygiene as practiced by many Americans are overkill - normal healthy people do not require daily shower, antibacterial soap, and can safely tolerate a certain level of dirt and germs.
We also have some people who are kept alive by modern medicine who are unusually vulnerable to infections and such, for whom stricter hygiene is very necessary. 100 years ago these folks probably would not remain alive long.
Of course, some animals are adapted to, for instance, eating rotten meat. And as far as raw meat in general goes, strict carnivores have much shorter guts - less time to grow nasties.
I think there’s also an element of humans wanting that level of hygiene rather than needing it; if you only showered once every few days, it probably wouldn’t increase your chances of getting ill by that much, but you’d smell bad. If you don’t clean your kitchen that often it might not be as risky as it’s made out to be in terms of health, but it’d be cluttered, the counters would be sticky, it’d stink and it’d generally be pretty nasty to live in, and so on…
Carnivores are also less susceptible to certain bacterial diseases because of their relatoively short digestive tracts. Cats that eat salmonella-infected meat, for instance, are usually fine afterwards because the salmonella passes out the other end before it has a chance to do anything. I know, salmonella doesn’t have much to do with cleanliness, but I’m assuming this is true for other infectious agents.
For that matter, cats in specific are very hygenic animals. They groom themselves, bury their waste, and have anti-bacterial agents in their saliva.
All four of your explanations come into play to some degree. Water quality is a good case where it’s partly cultural and partly based on modern people having not built up defenses.
Many people in many parts of the world drink water that just isn’t safe by any definition - it’s a major cause of illness and death in third world countries. The water in Mexico is mostly treated and healthy, but it isn’t sanitized to the standards Americans are used to. If we drink it, we get sick for a couple of weeks, but then we could continue drinking it without any ill effects. But, despite the America’s water-quality standards, there are people who drink only bottled water because they think those standards aren’t high enough.
So I think you have a continuum that goes from:
Clearly Bad: sewage in your water
Improved: Mexico’s level of treatment
Good: America’s level of treatment
Paranoia: drinking only bottled, distilled water
You can draw a similar continuum for bathing, hand-washing, food treatment, medicine, etc. The key thing to remember is that even in terrible conditions, most people/animals manage to survive; not at their peak health or for as long as they might otherwise, but they do get by.
You might want to consider what percentage of humans live to what percentage of their maximum natural lifespan as compared to animals in the wild. Sure, hygiene isn’t the only factor, but it’s a big one. The other big one is predators. And if you’re at high risk for predators, it’s understandable why hygiene isn’t your top concern.
I thought the primary reason was that as the animal aged past prime health, it was more vulnerable to predators, and also less able to find enough food (which itself made it even weaker and more vulnerable to predators).
…
[li]Something about the modern human lifestyle increases susceptibility to germs…[/li][/QUOTE]
Your fourth point might carry more weight than you thought:
Also consider the effects of population density. Humans are living in huge, dense concentrations, unlike anything in our evolutionary history. That makes sanitation a much more pressing matter, since without some sort of sewer system it’s pretty much guaranteed that your drinking water will contain lots of nasty pathogens. Now, this isn’t an issue in any big industrialized city these days, but there are still major cholera and dysentery epidemics in places without proper sanitation.
In the wild, an epidemic would quickly wipe out any population, or lead to evolution of traits that confer resistance to epidemics.
Now, current obsessions in the US are certainly overkill, and as other posters have mentioned, possibly even counterproductive. Still, it’s a great idea to keep your waste water separate from your drinking water, and washing your hands regularly can’t hurt.
Antibacterial soap is silly, useless, and is starting to lead to evolution of bacteria resistant to common antibacterial agents.