What could be if my dog as a inflammation on his thraot?

I am not sure what you are trying to ask... Are you asking why yiur dog has an inflammation of the throat or what causes it?

Tonsils are lymphatic tissue and respond to infections like other lymph nodes. Sore throat/tonsillitis are synonymous and not at all unusual in dogs. For example, the first snow of the season usually would bring in a flood of 'sore throats', as the dogs are fascinated with the snow and 'eat' it to excess. Usual treatment is a week of antibiotics.

Another cause of sore throats are infected gums or other teeth/dental problems.