Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE Dogs (age INTEGER, dog_id VARCHAR)
TABLE: CREATE TABLE Treatments (age INTEGER, dog_id VARCHAR)

### Question ###
What is the average age of the dogs who have gone through any treatments?

### Accurate SQL ###

SELECT AVG(age) FROM Dogs WHERE dog_id IN (SELECT dog_id FROM Treatments)