Try and change the substrate first before a vet trip.Allergies and irritation can happen with most substrates other than paper substrate,so it wouldn't be surprising if that was the cause.
Avoid Carefresh if you can since that could add more problems for you in terms of how dusty it is.Fitch as mentioned would be ideal,since it is completely safe unlike wood which can cause injury and allergic reactions and has virtually no dust whereas Carefresh is loaded with dust.Fitch also happens to be the safest economical substrate in the UK,and the value is far superior to Carefresh
