Sacha the desman is frequently referred to as a 'rat' or 'rodent' in the series. Desmans are actually a type of insectivore, related to moles.
Reg the mandrill often refers to the hyenas as his 'doggies'. Hyenas do not belong to the dog family, Canidae, but to a family of their own, Hyaenidae. They are actually more closely related to cats than to dogs.