Glad he's on the mend now! I was going to say it sounded like an allergy...

My dog is allergic to NZ Christmas Trees (the ones that blossum) We were renting a house off our parents and there was about 5 or 6 of them, quite big too, and we ended up chopping them all down because they were just giving him so much troubles...

Although, a week later someone from the council came to see us about them... and apparently they are quite expensive and they were willing to buy them off us to relocate for $100 bucks each