Remember to feed treats in moderation. Also keep in mind that fruit is actually quite high in sugar, which is converted into calories. If those calories are not burned off, they turn into fat. Excess sugar can also upset the delicate balance of good bacteria in your rabbit's gut and cause deadly gastrointestinal stasis. Be sure to wash all fruits and vegetables before feeding them to your rabbit. This helps remove chemicals, dirt, or other things that would be better if your rabbit did not eat.

Here is a list of treats to avoid, and why.
​Avocado: Poisonous
Broccoli: Can cause gastrointestinal distress
Brussels sprouts: Can cause gastrointestinal distress
Celery stalks: Can cause diarrhea and blockage
Iceberg lettuce: Can cause diarrhea
Kale: Can cause gastrointestinal distress

* Make sure to harvest these treats away from major streets where car pollution will settle on them. Also make sure to gather them from areas that are not treated with chemicals.

** High in calcium, limit to very small amounts.