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Formula for Squirrels

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Squirrel Refuge recommends using Fox Valley Day One formula for squirrels.  For squirrels up to four weeks of age, the best formula is Fox Valley Day One 32/40 (appropriate for baby squirrels under four weeks, eastern cottontail, or baby opossum under 45 grams).  For squirrels over four weeks (or with eyes opened), Fox Valley Day One 20/50 is recommended.  


Both products can be readily ordered directly from Fox Valley Animal Nutrition Inc. (800) 679-4666 or from any of the squirrel rehabilitation supply online retailers listed. Alternatively, some rehabilitators feed their squirrels Zoologic Milk Matrix 33/40 By PetAg.

Preparing Formula

Combine 2 parts very hot water with one part Fox Valley formula and mix well.  After mixing, let formula rest for at least 20 minutes to cool and allow air bubbles to settle.  Refrigerate mixed formula for up to 48 hours.


Milk replacers for babies transitioning to formula or those with stool or digestive problems should be supplemented with a small amount of acidophilus (1/8 tsp) per ¼ cup mixed formula or plain yogurt.


If this is the first time you are offering formula to the baby, the baby must be fully hydrated and slowly transitioned onto full strength formula.    Reference transition instructions below.

Temporary Formula Substitutes

Depending on the degree of dehydration, the squirrel should initially be provided an infant rehydration formula such as Pedialyte® for at least the first twelve hours (more for severely dehydrated or emaciated babies!.)  


Once fully hydrated, you may start to transition the baby over to an appropriate milk replacer. When transitioning from a hydration fluid to any formula, follow the same transition method as described in the Transitioning Formulas section below.

Since squirrel formula is generally not available in your local pet store and it will take a few days for the formula to arrive, the Squirrel Board ( recommends a temporary formula that may be fed in the interim.  


Please note: this is not a nutritionally complete milk replacement formulation that can sustain an infant long term but is intended to be used as a temporary measure until the Fox Valley Formula arrives.


Three parts fresh goat’s milk (made for human consumption and available at most health food stores that sell groceries) to one part plain or vanilla yogurt (full fat with no artificial sweeteners).  Once the baby is eliminating (defecating normally) gradually start adding 1 part heavy whipping cream.  

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Chris' Squirrels & More

Our favorite place to shop for supplies

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The Squirrel Store

Another great place for rehab supplies

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Henry's Healthy Pet Foods

One more great option for supplies

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Fox Valley Animal Nutrition

Buy baby squirrel formula online.

Homemade Formula

for interim use only

  • ¾  cup Fresh Goat’s Milk

  • ¼ cup  plain or Vanilla Yogurt or a pinch of acidophilus powder

  • 1/8 to 1/4 cup Heavy Whipping Cream

Important!   Whipping cream is harder to digest but is necessary to increase the fat content in the formula.  Start by adding in a very small amount and slowly increasing with each feeding.

Transitioning Formula

Once the Fox Valley formula arrives, gently transition from the temporary formula to the full strength Fox Valley formula over six feedings.  This schedule helps the baby to slowly transition to the new formula without overly stressing its delicate digestive system.

  • First two feedings: Combine two parts Goat’s Milk Mixture to one Part Fox Valley Formula (2:1)

  • Second two feedings: Combine one part Goat’s Milk Mixture to one part Fox Valley Formula (1:1)

  • Last two feedings: Combine one part Goat’s Milk Mixture to two parts Fox Valley Formula (1:2)

  • Subsequent feedings: Feed full strength Fox Valley Formula

Using Emergency Formulas

for People, Puppies, and Kittens

Because of manufacturing issues, Esbilac puppy milk replacer is no longer being recommended for squirrels or other wildlife.  


Nonetheless, if nothing else is available, squirrels have survived on a commercial puppy milk replacement formula just fine.


Puppy milk replacer is generally better than one made for kittens since their protein needs are much higher. Never use a milk replacer for human infants or cow’s milk.   See image to right.


The advantage of using a puppy formula is that it can be readily purchased at most pet stores; however, please note that there are disadvantages:

  • Many squirrels (especially very young ones) cannot tolerate a puppy formula and will succumb to diarrhea. This may be alleviated by adding a small amount of acidophilus powder or yogurt to the formula.

  • These formulation do not contain enough fat for proper weight gain. Adding supplemental heavy cream can help.  

  • Puppy formulas are much more expensive than purchasing the Fox Valley formula online which is usually available for under $12 per pound, which is typically enough to feed an orphan through weaning.

More Resources

Feeding Techniques

Learn how to properly and safely prepare food for and then feed your baby squirrel.

Feeding Schedule

Learn how often to feed your baby and exactly how much based on their age and weight.



Get recommendations on the best possible implements for feeding baby squirrels.

Feeding Complications

Make yourself of what could go wrong during feeding, what signs to look for, and how to prevent it.

Warming Baby Squirrels

Before you feed, make sure your baby squirrel is safely warmed using our gentle and simple methods.

Treating Dehydration

Learn the signs of dehydration in baby squirrels and how to treat them.



Learn how to safely stimulate your baby squirrel until they are able to potty themselves.



Have more questions? Ask the Squirrel Board, a forum managed by rehabbers and experts.

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