canine/ broken tail

Question
1.5 yr old, tall version, yellow lab. Noticed last pm that he wasn't holding it up and wagging as over-zealously as usual.  today very noticeable.  Gave him a dose of canine anti-inflammatory med.

Answer
First of all, what is your question?
Second, anything broken the vet needs to see. It might not be his tail at all but the sacral area of his spine. That is the most common place dogs hurt themselves (in the back area) and when it is hurt they cannot or will not wag their tails.
Time for a visit to see the doctor!