This may come as a surprise to you, but rabbits do not sweat. Like pigs, they do not have sweat glands. They cannot keep themselves cool in hot weather by sweating like humans or even panting like dogs. That is a very big problem for a little animal with so much fluffy fur. If your bunny has been exposed to temps above eighty degrees and is acting funny, take him or her to a rabbit veterinarian (someone who specializes in rabbits, hares, and small animal care). Your bunny may be suffering from heat stroke and here is how the vet can tell and treat your bunny.
The first thing the vet will ask you about your bunny is how much water he/she has drank in the last day. Water is HUGE for rabbits, since it is the only thing that keeps them from overheating and dehydration. If your bunny did not get the equivalent of one very large drinking bottle of water every few hours during a heat wave, that definitely could be the problem. Since rabbits also move very rapidly, have very fast heart beats, and high metabolisms, a lack of water is an all-around bad thing for them because they need a lot of water to support their systems.
The next thing the vet will examine is your rabbit's, um, "pellets." His or her feces should be moist upon exiting, coated with a slime the rabbit produces in its anal sacs. When the "pellets" are extremely dry and lack that slime coating, your rabbit does not have enough water in his/her system. At the very least, he/she is suffering from dehydration, if not a full heat stroke.
Even if you have a "lazy" bunny, he or she should still be interested in running and darting about when out of his/her cage. A very slow rabbit that does not move or flops over to one side and does not get up, or hangs like a limp noodle, has heat stroke. Your bunny is now officially in danger of dying and needs emergency treatment.
How Your Rabbit Vet Will Treat Your Bunny
First and foremost, your rabbit needs fluids, and quite a lot. The vet will probably insert an IV in your bunny's paw, wrap it up in bandages so the bunny does not pull the needle out, and then force IV fluids until your furry friend begins to show signs of recovery. Your pet will also have to stay overnight in the vet clinic where there is plenty of air conditioning and quiet shadows in which to lie down. The vet will call you the next day to let you know if your bunny is ready to come home. Then you just have to make sure your pet is kept in a very cool place and fed plenty of water all day long.
For more information, contact companies like Pittsburgh Spay & Vaccination Clinic.