I'm so happy the vet was able to give Milo something for the pain until the swelling goes down.
I'm not sure what the groomer could have done to cause an anal gland issue. Why do you think this? I think adding more fiber and even a little mineral oil everyday might help. My Mandie used to have constipation problems and this is what I did. She hasn't had problems in months now.
Praying the antibiotics get rid of any ole infection that Milo has and he's feeling better really soon!
