When I set up my classroom in August, I don't bring any of my pets to school for two reasons. One, the heat is too much for them (and me)! Two, I don't yet know if anyone coming into my class has allergies.
So, the first week of school, I send home a packet for parents which includes information on school and class procedures, expectations, schedules, etc. Included in the packet is a parent information form that parents fill out and return to me. I gather a lot of information about my students from this form including, "Does your child have any allergies (including animals)?"
After I get these forms returned, I go from there.
My tarantula comes to school first. No one is ever allergic to it and the kids don't really handle it! And being a desert animal, the heat doesn't bother it, like it does the kids and me.
If a parent lists a pet allergy (other than guinea pig or rabbit) on the information form, I contact them to discuss the severity of the allergy, symptoms, etc. Together we decide which furry animal to introduce into the classroom first. Then we touch base everyday for a couple weeks to see how things go before bringing in the other animal. And the process repeats.
My experience has been that the most common allergies are to dogs or cats. I've only had one child allergic to rabbits, and he was okay as long as he washed after petting the rabbit. His allergy wasn't too severe and his parents were fine with the pets in the class.
I've never had any problems with guinea pigs, hedgehogs, hamsters, walking sticks, snakes, or lizards. Some kids don't want to handle the animals and some know they can't because they sometimes get itchy.
No matter what, kids should always wash after handling any animals! Non-furry pets carry different risks such as salmonella, so washing is a must.
Birds have a different kind of dander (is that what it is called?) that can be difficult for kids with respiratory ailments. I've seen some people sensitive to rat dander, too.
The health and well-being of my students is my top priority, so if a student has a reaction to any of my pets the pet will go home to live. I make sure the parents and kids know that. Yes, the kids would be saddened, but caring for our friends in class is more important.
I've only had one pet go home and it was because one of our specialist that used my room had a reaction.
The worst that can happen is your pet comes home for a while. And after all, they are your pets first and foremost!