It's a good reminder of why you should never rely on just one identification feature.
If you spot one of the features I mentioned in that video... always look to see if you can observe the others as well.
The golden rule that really does ALWAYS apply is that the more clues you have the more confident you can be about an animal's identity.
How To Know Domestic Dogs From Wild Canines
With a bit of practice it's also pretty easy to tell the difference between domestic dog tracks and wild canine tracks.
Dogs come in all shapes and sizes. Some are very small and others are very large. In these cases it's pretty easy to know that you're dealing with domestic animal by size alone.
But a lot of dog breeds do actually have a lot of size overlap with wild canines like coyotes, wolves or foxes.
In this case you need to rely on more subtle cues within the tracks. Here are some things to watch for:
How sharp are the nails? I already mentioned in the video that wild canines will tend to have much sharper nails. With a bit of comparison this is fairly easy to spot.
What is your location? Are you in a place that would even have wild canines in this size category? Coyotes and foxes can often live surprisingly close to people, but wolves are much more likely to be found out in remote wilderness areas. You can often rule animals out or in just by knowing what lives in your general area.
Are the tracks associated with people? Domestic dogs tend to be linked with the presence of human beings. Perhaps more importantly... Wild canines never travel with human beings. This doesn't mean you won't see coyote tracks on a walking trail used by people, but if you see a solitary canine trail with no human sign... it's much more likely to be a wild animal.
Is the trail neat or messy? Domestic and wild canines lead very different lifestyles. As a result they have very different behaviour that is even reflected in their movement patterns. A primary concern for wild animals is energy conservation. They don't waste energy, which makes their trail look very clean, consistent, and purpose oriented. Wild canines know where they're going before they go. They most commonly move in a direct register trot. Domestic dogs on the other hand are almost always wound up with energy and no outlet to spend it. Their trails then are much more variable. They trot for a bit... then run as fast as they can. Their trails zig zag and change speeds/direction frequently. These are all things that wild canines don't do except with direct purpose.
What About Wild Cat Tracks Vs House Cat Tracks?
In the cat family... Telling wild animals from domestic animals is usually much easier than dogs.
Since the size range of house cats is less variable than dogs, it's usually possible to tell wild vs domestic by size alone.
The only time it gets confusing is when you're dealing with a particularly large house cat or a small wild cat like an immature bobcat.
Some parts of the world have species of wild cats that are basically a feral ancestor of modern house cats.
In these cases, the best thing to do is get ULTRA familiar with the tracks of those animals through lots of practice. There ARE subtle differences in the shape of the heel-pad and toes that can be consistently detected with experience.
It's a tough thing to quantify but myself and many other trackers have learned to tell a small bobcat from a large house cat just by looking at the pad shapes.
As with all things in tracking - the most important thing is dirt time.
Just get out there and practice looking at the tracks of your area. Start with the basics and gradually move on to more and more complex challenges.