How to keep guinea pigs warm & prevent URI? Do snuggle bags help?

The best ways to prevent URIs is to make sure to use a dust free bedding, change the cage at regular and appropriate intervals, feed a high quality diet and supplement with high quality vitamin C. Keep the cage well ventilated and away from drafty windows or other conditions which may cause extremes in temperature. Providing lots of healthy fresh fruits and vegetables will also help improve the immune system. I hope this helps and please feel free to post any additional questions.

Guinea pigs do not get URI from cold weather, they get it from bacterias in most cases. this could be from other guinea pigs and sometimes can be present in the environment. the treatment for URI is antibiotic treatment only.

heat pads and snuggle sacks cannot prevent respiratory infections. They can only keep your guinea pig warm when it is cold. The only thing that can keep your guinea pig from contracting upper respiratory disease is to make sure his cage is always clean,. she gets fed good quality dust free hay, some fruit and veggies in addition and always fresh clean water. Here is very good information on how to keep a guinea pig properly: https://vet.purdue.edu/vth/sacp/documents/CareofGuineaPigs_001.pdf

Unfortunately if Carby has a URI, and it does sound like it from your description, then he will need antibiotic treatment in order to get better. it's important for him to be stress free and eat a good quality food as it can improve his immune reaction to the infection, but this does not replace antibiotics, which you can only get from the vet.

There is no specific incubation period. URIs in guinea pigs (and other mammals) can be caused by more than one organism. Yes, if left untreated a URI may progress to more severe illness such as pneumonia.

I am sorry to hear about Biscuit. I would be concerned about an upper respiratory infection with this noise you describe. Sometimes we can have mild symptoms at first which then progress as infection worsens. I would recommend having her examined by a vet. In the meantime, you can give her a steam treatment by putting her in the bathroom while you run a steam shower for 10 minutes a few times a day or placing a humidifier in her room. You can also place her on paper bedding or fleece bedding to decrease respiratory irritants/dust and ensure the cage is staying very clean to decrease ammonia exposure which can irritate the respiratory tract.

Do not introduce any new guinea pigs to your current pigs without them being quarantined first for at least 2 weeks. That way no new infections will be introduced. Feed them a high quality diet like Oxbow. Remember, the majority of the diet should be hay (preferably Timothy). ( https://www.viovet.co.uk/advanced_search_result.php?keywords=oxbow ) Make sure all the husbandry is 100% correct - housing, diet, supplements, bedding, etc. Regular vet checks - about once per year - to check their teeth and overall health. ( https://www.petcoach.co/article/the-best-way-to-care-for-and-feed-your-guinea-pig/ )