Final answer:
Upon receipt, animals in poor health should undergo isolation to prevent disease transmission to healthy animals and to monitor their health closely for recovery.
Step-by-step explanation:
When newly received animals are in poor health, the correct process they should undergo upon receipt is isolation. Isolation is critical to prevent any possible transmission of diseases to healthy animals in the existing colony. This also allows for close monitoring of the new animals' health and provides an opportunity for them to recover without the added stress of competition or interaction with other animals.
Pairing them with healthy animals or immediate introduction to the colony could exacerbate their condition and pose a risk to other animals. Experimental testing should not be considered until the health of the animals is fully assessed and they have recovered.