my 16 year old hack russle X chiwawa dog is blind , 3 days ago i notices his left side of his face was swollen , swelling has gone down now its just under his eye socket he is eating n drinking as normal his eye looks wet to can u help
Has you/his vet ever mentioned "dry eye"? That is a common problem and can be treated with an ointment. I'll guess dry eye is worse with age and perhaps with blindness.
That's all that occurs to me. Hope you get more time with you Terrier, but 16 is old even for a small terrier. Be ready for what will come.