4 min read


Can Dogs See Pee Marks?



4 min read


Can Dogs See Pee Marks?


You can likely smell when a dog has marked a spot if it's recent, right? The scent reaches your nostrils and you realize that a pup has marked their territory. Imagine, now, being a dog and being able to not only smell marked spots, but being able to see spots where dogs have marked as well, even if they're weeks or months old. 

Dogs have the uncanny ability to sniff out marked urine spots, but they can also see these spots, too. How can you tell if your dog is able to see the spots where another pooch marked? How can you know where spots are so you can get them out? How can you teach your dog to not mark over other dog's pee marked spots? 

We've got all that and more in our ultimate guide below. Read on to understand better how dogs are able to sense marked spots both inside and outside of their homes.


Signs Your Dog is Sniffing Another Marked Spot

If your dog has detected another dog's marked spot, chances are, you're going to know about it soon. Unlike dogs, we're not able to see spots that have been marked - either by your dog or another - if they've soaked into the area. Your dog, though, can both see and smell these spots weeks, months, and sometimes years after they've been marked. 

So, how can you tell if your dog is seeing or smelling another dog's marked spot? The dead giveaway is repetitive and excessive behavior. If your dog keeps returning to a spot to lick, sniff, bite, or scratch, then it's possible they've encountered a spot marked by another dog's urine.

Another terribly annoying sign your dog might give you when they detect a marked spot? Urination. That's right, your dog is a sweet pup, but he or she is also territorial, so they'll often try to re-mark the spot another dog has claimed - even if it's inside your home. 

Your dog, unlike you, can see the residue that another dog's pee leaves when it hasn't been fully cleaned from something. This is because urine stains are on the UV wave length, a spectrum humans don't see in, but dogs do. Expect your dog to pay extra attention to those spots, return to them frequently, and probably mark them a bunch, too.

Body Language

Here are a few body language cues your dog might be giving you if he or she is sniffing out another dog's marked spot:

  • Alert
  • Barking
  • Howling
  • Wag Tail
  • Sniffing
  • Lip Licking
  • Tail Up
  • Licking

Other Signs

A few more signs your dog has detected another dog's marked spot include:

  • Obsession With A Specific Area Outside
  • Obsession With A Specific Area In The Home
  • Urinating Or Re-Marking A Spot
  • Excessive Licking

The History of Dogs Marking


Think about the human world for a second. When we want to mark our territory, we put up a house, a fence, a gate - anything to determine that the area we want to claim is protected. Now, consider the dog world. If dogs want to claim something as their own, they can't put up houses or fences to make sure other people take note. 

Instead, they have their own signal for making sure others know what belongs to them - marking. Dogs descend from wild animals (specifically, wolves). These pack animals claim property to survive, a characteristic that's been passed down to your dog, too. Because dogs use their noses as their primary sense, they use their urine, a distinctive, smelly substance, to mark which territory belongs to them.

The Science Behind Dogs Seeing Pee Spots


There are a few scientific explanations for why dogs can see pee markings from other animals while humans cannot. Obviously, people can see when dogs leave a puddle of urine on the floor, but dogs can see marks weeks, months, and years after those puddles have been cleaned up. Why? 

For starters, dogs are seeing the residue that's left behind from a puddle of pee on the floor. If something isn't fully cleaned up, the residue will be left there and absorb into the floor, but your dog can still see it. The bigger reason is that your dog can see in UV wavelengths while we cannot. Urine stains are on the UV wavelength. 

Have you ever cleaned a bathroom with a blacklight? It's gross, but you can see the urine marks that are left in the bathroom. Your dog basically has a blacklight sensor installed in his or her head that helps them see this all of the time.

Training Your Dog to Stop Marking Other Dog's Spots


Because dogs are able to see and smell where other dogs have marked, and because dogs can be notoriously territorial, it's possible that they'll pick up on marking behavior in order to maintain their territory. This can be both annoying for you and destructive for your home, so it's important that you make sure you don't let your dog do this in areas that are indoors. So, how can you train your pup to stop his or her marking behavior? 

First, consider all of the areas in your home that might already be marked - by your dog or by other dogs. The best way to train your dog not to mark is to remove all the marking scents from your home. Consider using something without ammonia in it as that can confuse your dog into thinking they're smelling urine from another dog. 

To guarantee that you're rid of the marked spots, try to see like your dog does and get out a blacklight. With this kind of vision, you'll be able to see that all the odors are neutralized and all spots are gone. 

Consider spaying or neutering your dog to help with this behavior as well. Changes in marking behavior are often seen weeks after surgery as the production of reproductive hormones disappears. 

Next, make sure that you're not allowing your dog to mark while you're out on walks. This kind of behavior will not make sense to your dog and they will try to mark the areas in your home as well. Make sure you're being consistent with your pup. Punish your dog appropriately when they mark in areas they're not supposed to and reward your dog when they don't mark.

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By a Great Dane lover Hanna Marcus

Published: 04/13/2018, edited: 04/06/2020

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