An update for you Sam - and anyone else interested!
The Homeopet Nose Relief was delayed in arriving, Vet UK were out of stock until last week so it was 22 December before it turned up!
I am treating two piggies with the drops. Gwen tends to suffer the grumbly breathing, but she's also quite lethargic and has mild nasal discharge most days. Frankie has consistently crusty/watery eyes, a red tinge to the whites of his eyes, and mild nasal discharge.
They're each on 5 drops three times a day for the next week, then it will be reduced to twice a day, then once daily as the symptoms ease.
Ever after just 5 days on the drops, there is an impressive improvement. Gwenivere has been a lot more active and seems a lot brighter in herself. She's very difficult to dose as she clamps her mouth shut, but what is going in is obviously doing her a world of good.
Frankie's improvement has been a bit less dramatic but still notable. He still has crusty and watery eyes, but the redness in the whites of the eyes has definitely eased.
It is still early days and they may need to be on the maximum 3x daily dose for a little while, but so far so good - I am very impressed and would recommend it to other guineas suffering chronic allergy/hayfever symptoms.