Dogs can sense by their scent whether or not there is a cancerous plaque in the human body.
Dogs cannot eat food that contains chocolate (cookies, a piece of cake, etc.). Chocolate is repulsive for them and may cause severe disruption.
Dogs have a remarkable sense of smell. For example, among the large number of apples packed in crates, the dog is able to find the rotten fruit. This is why these dogs are used by border and security services to search for prohibited goods.
You know, the dogs sniff the area under their tails one by one. They do this not for sexual reasons, but because there is a gland that gives off a distinctive smell unique to this animal. By sniffing the area under the tail, they seem to read the barcodes one by one.
The dog's nose has a unique pattern - as unique as the pattern of lines on a human finger.
It is interesting that Dalmatian cubs are born without characteristic beaches. They develop as they grow and mature.