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The stuff about evolving the digestive tract to get more out of food is super interesting and never thought about it.

The whole thing about human buttocks as well I recently learned about after getting a dog of my own (ya ya, covid puppy acquirer here). I was always weirded out by my childhood dog's butt and read up on it while I was researching dog ownership before I got my current little buddy. I figured I was going to have to wipe his butt to ease my slight-yet-ever-present faecal phobia. I then learned that dogs (and most mammals) actually prolapse pretty extremely when pooping, making it so that poop rarely touches their butts (at least on short haired dogs). As it turns out, my pup's butt is generally the least smelly part of him!

Anyway, a bit of a ramble about a dog's butt that many probably already know, but(t) I found it fascinating.




> my pup's butt is generally the least smelly part of him

The mind boggles at how you've determined this...

But indeed the digestive tract is what makes us tori and not spheres.


Not too much of a mystery here... my dog's tail is constantly up with his butt on full display, so it's easy to establish a safe proximity to give it a quick sniff to alleviate my fears that his butt will smell terrible (I haven't actually done this in months). To get a little more specific from my prior claims, his butt actually smells like literally nothing, and yes, I do mean "literally". Every other part of him has some kind of smell, especially his paws and face. Well, I've never put my face anywhere near his reproductive bits so I have no info there. I do, however, always give that area a quick wipe whenever we get in from a walk (he's a small dog).

Hopefully this isn't TMI and in the spirit of this article!


This really turns up the curiosity related to questioning what exactly dogs are smelling when they do this to each other.


They're smelling anal gland secretions, which are too subtle for humans to detect.


That might be what they're sniffing, but anal gland secretions are not subtle. They're the opposite of subtle.

I have a lot of dogs. Every once in a while, it seems that one of them gets a plugged up anal gland, or it doesn't get fully expressed when they poop. An earlier commenter said to look for liquid dropping out when they poop; I see this all the time. But sometimes that doesn't work for whatever reason, and then later on the gland "pops" and all the stuff comes out. The dog is usually sitting on my lap when this happens. It happens with both girl and boy dogs. My wife calls it getting butt-juiced.

The smell causes me to immediately change my clothes. It's not a fecal smell. I can't begin to describe it, but once you smell it you'll never forget.

Years ago we fostered a girl dachshund who loved my wife but hated me and feared me like the devil himself. Often when I would approach her in any but the slowest and most non-threatening way, she would tense violently and squirt anal gland juice like a skunk. Sometimes she'd leave a trail of the stuff on the floor as she ran for her life. One whiff would tell you it wasn't urine.

(BTW, that poor girl dog was eventually adopted by a sweet single woman and they are now inseperable companions)


This is true. I meant that they are subtle in the amount available when dogs butt-sniff each other. Dogs can detect the tiniest amount, way before a human even notices it's there. The concentrated stuff is, as you say, very intense.


Ah right, of course, that makes sense.


> The smell causes me to immediately change my clothes. It's not a fecal smell. I can't begin to describe it, but once you smell it you'll never forget.

I'm sorry to put this in your head but... fish sauce.


With really old dogs the gland sometimes won't unblock itself and becomes infected. The cure is to milk it. This is a vet's least favourite job, and they have some pretty grim tasks.

Source: I heard it from a vet.


> The mind boggles at how you've determined this...

Depending on pup, you can easily get a bunch of body parts shoved into smelling distance without any effort other than continuing to be alive. Then it's just a matter of recall and forming an opinion.


Dogs tend to be pretty physically close to humans. If your dog had stank-ass, you'd know it.


How much is humans needing to wipe their behind after pooping not simply modern dietary habits?

There are a great many such things, such as that skeletal remains of old civilizations showing very good teeth for civilizations wherein the brushing thereof was nonexistent, but the diet contained no added sugars.


It's also because most of us poop in a sitting position.

Squatting, as you would do outdoors if you didn't have a toilet, spreads the buttocks and there is much less cleaning needed. It also promotes more complete emptying so you don't have fecal matter left "pinched" in the anus that needs to be wiped up. If you use a typical western toilet, get something like a Squatty Potty to prop up your feet and you'll find you need to do much less wiping.


I don't use a Squatty Potty, I just spread my cheeks as I go to sit down. I barely have to wipe if at all, and I don't have that great of a diet. This method works on any toilet seat (work, school, friend's house, etc) - no feet prop required.


Absolutely! While we do have these fatty buttocks and... er, well, we're in polite company here, but... stuff will rub up against them if pooping in any other position than a squat... but ya, in past dietary experiments I've done, I didn't actually need to wipe. I still did, of course, but it was truly unnecessary.


I spread my cheeks as I go to sit down on the toilet seat. Thus I only have to wipe very little if at all, and I don't have the best of diets. Do other people not do that?


I only do this when I shit from the window of an automobile.


Is that a joke/reference? It doesn't make sense. There must be a more efficient/reasonable way to defecate.



Not that many because most of the world uses water and flush which is far cleaner. But it seems Westerners think their society is so superior, that they haven't figured this out this one simple trick yet.

In the West I have to go through meetings knowing how unclean everyone's bottoms are /s


This doesn't make me want to own a dog, but it does answer some questions I had about its hygiene. Especially the hairier dogs, I know their butt is hairless but with all that nearby hair things cannot end well.


Yes, I very specifically chose a shorthaired (fur) dog and this was one of the reasons. He is going to shed a hell of a lot when he's older but it is one con out of many pros. But yes, with very hairy dogs, the poop will touch it--they do keep it clean themselves but still...

I'm not trying to convince you to get a dog or anything, but I never wanted one and it completely changed my life in so many positive ways. I'm getting outside regularly, I've made new friends, I've developed acquaintanceships with several awesome people in my neighbour, I talk to strangers, and my weekends now have structure which has made me incredibly productive in my personal projects--I now view the downtime I have between walks and general caretaking of my pup as very precious and not to be wasted whereas before I could spend an entire Saturday in bed if I felt like it.


Poodle and Maltese owner here. Yes, long haired dogs have dingleberry issues. We often have to shave the but area between groomings. Baby wipes are useful when said dogs have loose stools.


Maybe not a HN worthy comment here, but poodles are such amazing dogs. No offence if you have chosen to give yours the classic poodle haircut, but it's funny how said cut causes people to think of poodles as these fragile, precious, chichi dogs. They are so friendly, intelligent, hilarious--and I can only assume loveable--and a huge personality. Anyway, just another thing I learned after embarking into fulltime care of a canine.

(ya, I said embarking... I know what I did)


I just want to echo your endorsement of poodles.

I and my family have had lots of dogs over the decades, and, looking back, the poodles have been my favorites. My present dog is a standard poodle who exemplifies what I like about the breed. She's smart, polite, curious, friendly, playful, and compliant. Smart and compliant in particular don't always go together in dogs, and it's a real bonus when they do.

Molly loves everyone, and is always happy to meet new people and other animals. She is nevertheless a good watchdog, who feels it's her duty to inform us if anyone (human or otherwise) approaches the property. On the other hand, as soon as we acknowledge her alerts, she stops them, which means they don't become tedious.

Poodles are retrievers, which may account for her tendency to bring me small animals, always completely unharmed, and to come and get me when she finds injured or dead animals near our house. Some birds and squirrels owe their continued lives to Molly.


Gotta keep it clean down there is all. Make sure the hair isn't too long.


That prolapse is also important for your pup's health, and also not evenly distributed. If you think your pup's butthole doesn't smell, and your pup doesn't squeeze a bunch of butthole out with a poop, get ready to learn about anal glands.


How do you mean in regards to "evenly distributed" in regards to health? Actually, what do you mean overall? I have a pug and know full well that he will be emitting fish smells when he gets older that will sometime appear in solid form. I'm just not there yet. But am eager to hear more (I will of course google otherwise).

Obviously my pug's butt has some kind of smell because all the other dogs keep smelling it :D My complacence is more with that if he sits his butt down on my pillow, I'm not going to freak out about it. Should I be concerned about this?


What I mean is that dogs have anal glands that need to release really awful smelling fluids, probably what you and your other dogs are noticing. When it happens naturally you will see a drip if you watch your dog do the deuce.

The uneven distribution is that not all dogs do it naturally, some need occasional assistance (you can do it but I’d recommend a quick/cheap vet visit, it’s gross and a bit of finesse). Some dogs just don’t get it done naturally and need that assistance on a regular cadence.

The health implication besides being a natural bodily process is that if it backs up, the whole solid waste system backs up.

Edit: don’t be overly worried, but do be attentive. If you see butt scooting this is probably what’s going on. (If it’s not it might be something more serious like a tapeworm. But I doubt that from what you described.)

And dogs are very attuned to the scent. If you smell it too it’s probably a good idea to go let a vet nurse squeeze out your pup’s anal glands. It’ll be a relief for pup and not at all traumatic.


If needed, dogs will perform their own anal gland expression by sitting, pulling their hind legs up, and wiping their butt across your carpet. My dogs like to look at me when they do this like it's a fucking joke.

I've seen videos on youtube of people expressing a dog's anal glands, but I myself have never once been able to do it. There must be a special technique that I just can't get.


Our dog had an ingrown corkscrew tail (English Bulldog) which was amputated (laser surgery!) and anyway, I'm telling you this because our groomer does anal expression and said at first, it wasn't working for her because there was no tail to grab onto.

There is definitely a technique, but for $5 or $10 extra at the grooming appointment I think I can afford to go a while longer yet before I try to figure it out for myself - I mean, I know you can go on YouTube and learn pretty much anything but I just can't see myself...


I wish my anus was more like a dog.




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