I don't think any reputable adoption process is free here in Vancouver, BC. I have visited homes and people who were desperately trying to rehome their animals due to whatever situation and usually these adoptions are free as the owners are just looking for a loving family to take over and are more than grateful to meet with you and hand over the animals once they trust you. I have a lot of sympathy for these situations.
Whatever or however you adopt, please make sure to check each animal carefully so you know exactly what you are signing up for. Look carefully at the ears including behind the years to check for flaking or redness that can indicate mites or fungal infections. Ask the owner or breeder if you may (with clean hands) look at their eyes and gently open them to make sure that the whites are not red with conjunctivitis or pink eye. Lastly, always check the feet and watch carefully between the toes and fingers to see any redness, skin peeling or sores. Don't be shy to look up the ankles as well as hairy guinea pigs can hide big sores on their ankles under the hair. Observe the behaviour of the guinea pig to see if they kick back with your gentle touch as this can mean that there are sores and they are sensitive before you even see the sores. Don't distress the animal longer than a minute or so. Guinea pigs like to keep their feet on something solid so having them all four up or held up is distressful for them. When you put them back on their feet in the crux of one arm, for example, don't be afraid to part their hair and look carefully at the skin as well for any redness, flaking or any small particles or mites that could be near the roots. Just be sure to check them over.
I should also really emphasize that all guinea pig guardians should be checking their pigs over at least a minimum of once a week. Check them also if you're introducing new mates to the area when you're cleaning the enclosure after a day or so. Just be watchful of any changes. It is unfortunate sometimes that guardians don't handle their animals or check them as often as time goes by. The diligence should continue throughout the animal's life in a way that least causes any distress or discomfort. Once a week is sufficient.
