If you are looking for a guinea pig, Wheek Care has some for adoption and they need fosters, too. Humane Animal Rescue of Pittsburgh often has them, too. (They make lovely pets, I had thewhen I was younger).

Please contact them directly at wheekcare2017@gmail.com

they also accept monetary donations, which go towards vet care and supplies for the guinea pigs

This is from their FB post:

"Wheek Care is currently overwhelmed with pregnancy watch piggies & could use some foster families to take pairs of pregnancy watch piggies. If pregnancy watch isn’t your thing but you’re interested in fostering, we always have a need for foster families to help when we have piggies come in unexpectedly and/or in need of love & socialization and would love to add you to our foster family list. If you’re interested in fostering, email us at wheekcare2017@gmail.com."