My favorite theme, dogs

I´m so glad that dogs´ rights are finally changing in Mexicobecause for many years dogs have been terribly mistreated maltreated. Now things are changing, and many shelters and foundations have been created and or established.

My favorite theme is also dogs! I could go on and on about them. When you are writing a sentence with the word "and", you need a comma before the "and" if the words before and after the "and" can stand alone as separate sentences (independent clauses). For example:  I am tall, and I like to eat chocolate. I am tall. I like to eat chocolate.