[Your letterhead, if desired; if not, your return address]

[Date of letter-month, day, and year]

[Recipient's first and last names]
[Company name]
[Street or P.O. box address]
[City, State ZIP code]

Dear [recipient's name]:

We are writing to let you know that your dog's barking has been disrupting our ability to have peace and quiet inside our home and in our back yard. Your dog is often outside in your yard for several hours at a time, and he barks for long periods of time when he is outside. We are thus unable to quietly enjoy our own yard.

Please make the appropriate changes immediately so that your dog does not bark like this anymore. Thank you in advance for adhering to this request and for thus preventing us from having to contact the city animal agencies to address this barking situation.

Sincerely,

[Signature]

[Sender's first and last names]