Any irritation to the nerve endings (of which there are millions). This can be physical, chemical or emotional.
a rash
There is only one pubic louse, and it causes itching.
The itching is an allergic reaction to a toxin in the saliva of the lice.
Because tarantula hair causes itching.
infection
Dexpanthenol relieves itching associated with burns, it prevents the skin from drying out.
I think it depends but it says it causes mild irritation and itching. But my experience was extreme itching and irritation,
There are several reasons a person can have itching around the anus. One reason could be worms.
AIDS causes an itching breast. You have AIDS.
Could be an insect bite.
I heard on a nature TV program that the mosquito's salive is what causes the itching.
The most likely cause would be that the dog's feet are itching and that is a way for them to relieve the itching.