The dermatological examinations that are useful in the guinea pig are the same as those carried out in the dog and cat.
- Direct observation. Cutaneous parasites, their eggs adhered to hairs and their faeces in the case of fleas are often directly visible with the help of a magnifying glass.
- Scotch test. This is a particularly useful test for detecting lice, surface mites and/or eggs attached to hairs. Material should be collected from all over the body of the animal in order to maximise the possibility of finding the parasites.
- Skin scrapes. This is a useful strategy for detecting mites, even though Trixacarus caviae are usually difficult to find. Hairs infected by dermatophytes can also be collected with skin scrapes.
- Trichogram (microscopic examination of hairs). Hairs infected by dermatophytes and parasite eggs attached to hairs can be observed and it can be determined whether the hairs are broken.
- Biopsies. Biopsies are indicated in the case of unusual lesions which do not heal as would be expected following therapy or to characterize neoplastic lesions after their excision.
- Cultures. Cultures and antibiograms are useful in cases of skin infections and abscesses (in these latter cases it may be more useful to examine a fragment of the abscess capsule than the pus, which may be sterile). Cultures for dermatophytes are useful if a fungal infection is suspected or to determine whether an animal is an asymptomatic carrier of an infection, a frequent condition in guinea pigs.