Urine marking in female dogs

Spayed females commonly mark their territory with urine, but Frankie (AKA Francesca) is a little different to most. Her marking is possessively personal and never ceases to make us smile on our walks. While Freya saunters along with prolonged sniffing, randomly leaving messages and marking territory, Frankie waits patiently behind her, has a good sniff, and then squirts a little of her urine over the top.

Frankie looking sheepish over-marking Freya’s urine

This led to my usual online investigation to discover whether this was normal behaviour. However, I couldn’t find any articles which related specifically to female dogs over marking another female’s urine. I’m sure this can’t be unique, but I’ve never encountered it when chatting with other dog owners.

Frankie the cockapoo cocking her leg to urinate like a male dog.
Frankie also cocks her leg like a male dog, but this can be more common in females

So what’s happening when a dog marks with urine?

Essentially, they’re sharing their social profile with personal messages. Sniffing other dogs’ urine plays an important role in their daily walks as it helps with mental stimulation and enrichment. 

Comparison of olfactory receptor size: the number varies in humans between 5 and 6 million

Compared to the mere five to six million olfactory receptors in humans, a dog has 300 million. The vomeronasal, or Jacobson’s organ as it’s more commonly known, is situated above the roof of their mouth. This is a separate sensory smell area humans don’t have and helps with the trapping of scents.

As a dog’s urine contains pheromones (hormone-like substances), this means a good sniff reveals a dog’s background: gender, age, health, stress level, neutered or spayed and their diet type. And if a female, whether she is in the estrus cycle, pregnant or has recently given birth.

A fun video explaining how and why your dog reacts to smell and how amazing this makes them

Is urine marking a sign of dominance?

This was the initial conclusion I came too. And as many research articles cite urine is used for establishing dominance, surely the higher rank means the eldest of the twosome should be the dominant one. But this didn’t make sense. Frankie’s two and a half years younger, and in all else, she’s not the dominant dog of the pair, while Freya – now aged six – is!

I did find a comment in one article stating that female dogs may occasionally urinate next to another dog’s but not on top of it. And so being the sad person I am, I then monitored Frankie’s behaviour and, as evidenced in the first video, she’s definitely overlaying Freya’s urine!

So, it’s still a mystery, but one that amuses us on walks each time Freya picks up and posts her social media along the way.