This is a rehabber document
Sarah Howard, MS Animal Nutrition — Rehabilitator, Out of the Woods Wildlife Rescue & Rehab
Cottontails are among the most fragile animals in rehabilitation, and it is illegal to keep one in Tennessee without a TWRA permit. If you have found a baby rabbit, go to our rabbit page or text 901-340-6534 — most of the ones we get calls about were never orphaned to begin with. This guide is for permitted and training rehabbers.
Found a baby rabbit?
On intake
Always warm the baby first, slowly. Rabbit body temperature is around 101 to 103°F. Never feed a cold animal.
Weigh the baby and give 5 to 8 percent of its body weight in grams, in mL of warmed electrolytes, for the first one to two feedings. Do this even if the baby is hydrated and has a milk line. It clears the gut and prevents tummy upset.
Example: a 50g baby. Five percent is 2.5 and eight percent is 4, so give 2.5 to 4 mL of electrolytes.
Electrolytes
Electro Stat by Fox Valley is the most recommended electrolyte for bunnies. Mix per the bag directions.
Pedialyte, clear only, warmed, diluted 1:1 with water.
Homemade, refrigerated and discarded after 24 hours: 2 cups warm water, 1/4 tsp table salt, 1 tbsp table sugar.
Lactated ringers, last choice.
Formula
Goat's Milk Esbilac
Highly digestible on their ultra-sensitive stomachs. Mix 1 part GME with 1 part Fox Valley Ultraboost and 1/8 to 1/4 part Lacto Bac 200 by Fox Valley. Probiotics matter for bunnies — in the wild they get these from eating the mother's cecotropes.
If you cannot get the Fox Valley products, leave them out. They are online-only, so in a genuine emergency, skip them. GME is usually available in pet stores, Tractor Supply and some veterinary offices.
Overall, mix 1 part powder to 2 parts warm water. Stir gently. It will be clumpy and a fork gets some of that out. Let it sit in the fridge for a few hours after mixing so the bubbles dissipate — bubbles cause gas buildup, and gas can kill a bunny. Discard unused formula after about 24 hours.
To warm for feeding, put hot water in a mug, draw the formula into the syringe, and stand the syringe in the mug. It should be very warm on your wrist but not hot enough to burn you. A bunny that stops eating well has often just been handed formula that went cool — pause, re-warm, continue.
If GME is unavailable, regular Esbilac puppy formula or KMR may be substituted, PetAg brand only, mixed the same 1:2. Do not use liquid or pre-mixed.
We do not use Wombaroo on wild cottontails
This is where we differ from a lot of published advice, and we want to be specific about why. Wombaroo works well with domestic rabbits. In our hands it produced major GI distress in wild bunnies. We ran it for a full season, including with fresh bags to rule out a bad lot, and did not have a single newborn survive in 2023. We stopped.
Feeding mechanics
Weigh daily. Bunnies should gain at least 2 to 4 grams per day.
Feed approximately 10 percent of body weight in grams, in mL, per feeding. Do not exceed 12 percent — that causes GI upset. A 50g bunny gets about 5 mL.
For the first feeding or two, dilute further: half mixed formula, half plain warm water. If there is no diarrhea, go to full strength after two feedings.
If you see diarrhea, stop formula and give electrolytes.
Luer-lock syringe and a Miracle Nipple or similar. Syringes only — never puppy or kitten bottles. If you have no Miracle Nipple, borrow one from a rehabber or use an oral syringe very carefully.
Bunnies aspirate easily. Feed slowly and wipe formula away from the nose so they do not inhale it.
Feed upright or slightly tilted prone. Never on their backs. In the wild the mother hovers over the nest so she can bolt if threatened, and the babies reach up to nurse. Mimic that.
Week by week
Up to one week, until eyes open
Fully furred at 5 days, eyes usually open at 7 to 10 days. Generally under 65g.
Bedding: fleece, receiving blankets or old T-shirts. Avoid anything that catches nails, which rules out most towels. They cannot thermoregulate yet — heating pad on low under half the enclosure so they can move off it, or a rice sock.
Feed 3x daily, 8 to 10 percent per feeding.
You will need to stimulate them to eliminate. A warm wet paper towel works well; brush gently across the genitals at about the speed you would use with a pencil eraser. They may not poop on cue but should urinate — you will often find tiny black specks on the bedding where they went on their own. The first urine may look dark and muddy. That is normal for a wild rabbit and clears as they transition to formula.
Week two, once eyes open
Typically 65 to 80g. If they are eating and gaining, drop to 2 feedings a day, morning and evening.
Start offering greens. Spring mix and kale are favourites; romaine, turnip greens, mustard greens, arugula, cilantro and dandelion greens are all fine. No iceberg. If you have a spot you are certain is pesticide-free, they love clover and wildflowers — serve immediately, they wilt fast.
Switch bedding to timothy or alfalfa hay, over pine pellets or paper bedding since hay is absorbent and needs something under it. Hay doubles as something to nibble.
Give them somewhere to hide. Opaque, not clear — these are not domestic rabbits and they want to feel hidden. A small cardboard box or a planter on its side works.
Three weeks
Typically 80 to 95g. Eyes wide open, ears standing, coordinated hopping, able to lap from a shallow dish.
One formula feeding a day. Sometime this week they will start refusing the syringe. Offer formula in a jar lid instead. As long as weight holds, let the syringe go.
A pinch of dry oatmeal in the dish cuts the splashing, and a little sprinkled in the hay gives them something to forage.
Offer water in a shallow dish or dripper bottle. Most of their hydration comes from greens, so do not be alarmed if they barely drink.
Four weeks
Typically 100 to 125g. Once they are eating greens and hay well, stop formula altogether. Watch weight closely. They may plateau for a day or two and then resume gaining. If they lose, supplement with formula in a dish for a couple of days and try again.
Five weeks — release
Release once they have been off formula for at least 5 days while maintaining or gaining. Average release weight is 125 to 150g.
Do not hold them longer than you have to. The older they get, the more they register you as a predator, and the more likely they are to develop capture myopathy.
A hard truth
Cottontails are extremely fragile, and based on recent national data only about 10 to 15 percent survive captivity. If you lose them, it is usually the nature of the animal rather than something you did. Thank you for giving them a chance and a safe place to land.
Questions
Email sarah.ootw@gmail.com or text 901-340-6534.