Hello I am Dr. Joey. Thanks for trusting me to help you and your pet today. I am a licensed veterinarian with over 15 years of experience. I look forward to working with you.
This poor guy. He's been through so much. What a survivor.
I cannot link the eye swelling with the sores on his hind end. I think this may be a different problem. There are many possible causes for swelling in this area ranging from a insect/spider bite/sting to acute allergic reaction to trauma. If the swelling has been slowly worsening, then acute allergic reaction or bite/sting is more likely. In that case you could safely try administering Benadryl (diphenhydramine) at 1 mg per pound every 12 hours. IT may cause some drowsiness but no anticipated other issue.
With regard to other issues to look for, you should look at his pupil and make sure it is the same size as the other eye. This is best checked by shining a small light into his eyes (a penlight or small flashlight). If you notice the pupils are not the same, then this is an indication he really needs to have an exam today. That may mean he had some trauma in which case treatment now would be indicated.
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