1. Wounds and sore that won’t heal 

So, you have observed that your dog has a new wound. You examine it and think that maybe they just scratched themselves too hard. It has happened before; there is nothing new.

A week has passed, and the wound is still there. The good part is that it is looking better. It will probably go away in another week or so. There’s nothing to worry about.

One sign of skin cancer in dogs is sores and wounds that appear to heal, scab over, and then come back again. If you observe any wounds like this, take your dog to the vet because it needs further investigation.

But a slow-healing wound can also mean that your dog suffers from an infection or that their immune system is very weak.