The cord should be on the outside of the cage where Harvey can't reach it. I have 6 assorted water heaters and three kennel mats, all outdoors.
No rabbits, but I've never had any electrical problems with them. Unless you count the GFCI switch flipping, and I believe that was my extension cord.
NYboy, It might be OK if you have only the brass tube in the cage everything else should be kept far away from a rabbit ... the cord and housing has to be made for OUTDOOR use and plugged into an OUTDOOR / WEATHERPROOF OUTLET . Does it have UL label on it ? ... It is made in China so ??? By the way, fried rabbit is DELISH !!! Try ordering some at a fine restaurant to see for yourself.
If you look at the photo in the ad you'll notice a wire shield is wrapped around the elect cord, which should not be in the cage with the animal.
Looks safe to me.
Seriously? Do you know how many rabbits are living outdoors in this world? They have these wonderful fur coats that are designed for outdoor life and would most likely be completely miserable indoors in a winter heating system unless they were already conditioned for indoor living.
The electric heated water bowl my rabbits use has a cord that is wrapped similarly, and a smaller metal bowl like what you'd have for a dog in winter. My sister's rabbit uses one like yours. She's had it forever, no problems. The wire wrapping on the cord is more to protect the cord from crushing or abrasion, not stop chewing. Just make sure it is on the outside of the cage. I don't have a GFCI outlet in the barn, but bought a GFCI power strip to plug into instead. They're pretty cheap, like $20.
Rabbits do much better handling cold than they do heat, as long as they have a box or cubbie hole to get out of the wind. That soft, thick fur is made for weather like this and ventilation is better outside. Breathing the ammonia in their urine can really make them sick.