Guinea pigs are in general very robust animals, which are not very vulnerable to diseases. This good characteristic has to be supported by keeping the pets in a near-natural environment. If the guinea pig gets healthy food and enough room to move, it won’t get ill very often. In addition a clean cage will prevent most diseases.
Most of the diseases guinea pigs can get are not contagious for humans, but some fungal diseases and mites can be carried forward to humans.
The guinea pig owner should check his guinea pigs regularly for first indications of diseases. Though the guinea pig can’t tell if it is ill or not, the owner can recognize certain signs. Most minor problems may be solved on one’s own but if in doubt a visit to the vet is recommended. Guinea pigs will hide their diseases as long as possible in order to not be excluded from the pack. Thus when the owner recognizes a disease, a quick decision has to be made and in most cases the guinea pig should be taken to the vet.
A good indicator for a disease is that the guinea pig won’t eat anymore. This can have various reasons that can be solved by the owner like inappropriate food, a shortage of water or an inappropriate temperature in the cage. But it may be caused by other reasons like problems with the teeth, which will cause its death if not fixed by a vet, or the loss of a friend. In this case the guinea pig needs a new companion as soon as possible. If in addition the guinea pig has diarrhoea, seems emotionless or has a sticky nose, it has a disease for sure and needs to be taken to the vet.
Another good indicator is sneezing and coughing. This could be a common cold, caused by draught, the wrong bedding or an acrid cleaner. In this case, preventing the causes is enough, but if the guinea pig becomes disinterested or breathless, it should see a vet.
If the guinea pig has bald patches in its fur, this is most likely caused by mites and should get immediate treatment. Another possible explanation may be a lack of vitamins in the guinea pigs food, but the first is more common.