HELP!! Question aboutmy dogs butt

Question
I noticed today on my 7 year olds dog (terrier mix/ greyhound) has red around her butt hole.  The area looks irritated.  Please HELP!  It looks like the butt is swelling.

Answer
Aimee -

There is a possibility that your pup has a swollen or infected anal sac. Anal sacs are pockets in the anus that hold a fluid that expresses when the dog defecates.  If that area becomes infected,  one of the sacs may become swollen or irritated.  

Take your pet to the veterinarian as soon as possible.  

Best Regards,

Charlotte Sherrell, DVM