With the heat wave continuing, please remember any outdoor rabbits. Here is some advice from Richard Saunders BSc(Hons) BVSc MSB CBiol DZooMed (Mammalian) MRCVS
RCVS Specialist in Zoo And Wild Animal Medicine
Offer a water bowl so that they can get a better drink; they will drink more efficiently and faster this way, and that’s important in the heat. Cool water will help to cool them down a bit. Don’t chill the water, but make sure it’s not boiling in the sun
Do not give your rabbits to ice cubes as they can cause problems with their digestion system.
Sun tan lotion is a no. They are likely to lick it off, and we have yet to see a rabbit with ear skin cancer. Instead, make sure you offer them plenty of shade, but if you are draping something over a run, make sure the air can circulate. Use of a battery operated fan on runs or enclosures can help.
Frozen water bottles or cool pods are helpful. ,
No need to change diet at all just, to stick to usual diet and make sure they drink lots by following the tips above.
Access to a safe shady exercise area 24/7 is even more important in this heat as they will want to exercise when it cools down am and pm.