Ever spot a squirrel with bare patches and wonder what’s going on? Usually, it’s something common and treatable—parasites like mange mites, skin infections such as ringworm, or even just natural behaviors. Sometimes, females pull fur to line their nests.
Most of the time, missing fur doesn’t mean the whole squirrel population is sick. It usually means that individual needs warmth or could have a treatable skin issue.
Keep an eye on the squirrel’s behavior and body condition. If it looks thin, sluggish, or you see thick, crusty skin, that’s more serious than just seasonal thinning.
The rest of this article covers the main causes, how to spot the differences, and when it’s time to call wildlife professionals.
Primary Reasons Squirrels Lose Fur
Maybe you’ve seen a squirrel with patchy or missing fur and wondered why. The usual culprits are parasites, fungal infections, genetics, or a poor diet.
Each of these problems needs a different approach.
Mange and Mange Mites
Mange is one of the top reasons squirrels lose fur. Tiny mites like Notoedres burrow into the skin, causing itching, scabbing, and big bald spots around the ears, face, and tail base.
You’ll probably notice a squirrel scratching, rubbing, or moving slowly because of all the irritation.
Mange spreads between squirrels and through nests. Even after treatment, a squirrel might get reinfested if it returns to an infected nest.
Wildlife rehabilitators or vets use prescribed anti-parasitic drugs, but you shouldn’t try to treat wild animals yourself. Over-the-counter pet products can actually harm them.
If you see a squirrel with mange, don’t handle it. Instead, contact a local wildlife group.
Fungal Infections Like Dermatophytosis
Fungal infections—especially ringworm—cause round, flaky patches of hair loss. These spots might not itch much at first, but they can spread and lead to crusty skin or even bacterial infections.
Ringworm passes through direct contact or by touching contaminated nests. If you feed squirrels or clean their areas, disinfect feeders and nest boxes to help prevent spread.
Don’t try using antifungal creams on wild squirrels. Trained rehabbers use specific treatments and keep infected animals isolated to avoid spreading it to pets or people.
Genetic and Hereditary Factors
Some squirrels just inherit fur problems. Conditions like hypotrichosis cause steady, non-itchy hair thinning, but you won’t see the inflammation you’d get with mites or fungus.
These inherited issues pop up more in small, isolated populations where inbreeding happens. Usually, the squirrel acts completely normal and eats well, even if its fur looks thin.
There’s not much you can do in these cases. Wildlife biologists keep an eye on population health, but they don’t treat individual animals for this.
Nutritional Deficiencies and Diet
A bad diet can mess with fur quality and cause gradual thinning. Squirrels need protein, fats, vitamins (like E), and minerals (like zinc) for a healthy coat.
Too many human foods—bread, chips, salty snacks—make their fur dull and patchy.
If you feed squirrels, stick to unsalted nuts and seeds. Rehabbers recommend balanced, high-protein feeds or special formulas for baby squirrels.
Better food often helps fur grow back, as long as parasites or disease aren’t involved.
Other Contributing Causes of Fur Loss in Squirrels
Lots of things besides disease can make a squirrel lose fur. Stress, injuries, little parasites, normal shedding, and even mother squirrels pulling out their own fur all play a role.
Stress, Environmental Factors, and Overgrooming
When squirrels deal with heat, crowded feeders, or too much human activity, stress changes their behavior and bodies. Stressed squirrels might groom more than usual.
All that grooming wears away fur, leaving thin or bald spots—especially along the flanks or tail base.
Bad weather and poor nesting materials can make things worse. Wet or dirty nests irritate their skin and encourage even more grooming.
If you notice squirrels crowding around feeders, that stress can spread skin problems. Try cleaning or taking down feeders for a bit. Less crowding gives squirrels a chance to relax and groom normally.
Injuries, Parasites, and Bacterial Infections
Bites, thorns, or falls break the skin and cause local hair loss while healing. Open wounds attract bacteria and tiny parasites like fleas or mites.
These infections lead to scabs, swelling, and even more fur loss around the injured spot.
Fleas and lice irritate the skin and make squirrels scratch off fur. Bacterial infections show up as red, moist patches or crusts and often need a vet’s help in captivity.
Wild squirrels sometimes recover on their own, but severe infections can really weaken them.
If you find an injured squirrel, reach out to a wildlife rehabilitator. They know how to clean wounds, treat infections, and check for parasites safely.
Natural Shedding and Seasonal Changes
Squirrels molt at certain times, usually spring and fall. During these molts, you’ll see thin fur or uneven patches as old hair falls out and new hair grows in.
This is totally normal if the skin looks healthy and the squirrel stays active.
Young squirrels go through rapid coat changes as they grow. In late spring or summer, you might spot juveniles with patchy coats, but their hair fills in as they mature.
Keep an eye out for other warning signs—lethargy, sores, visible mites—to tell normal shedding apart from illness.
Letting squirrels follow their natural routines and keeping outdoor spaces clean helps them get through molts with less stress.
Maternal Fur Pulling and Baby Squirrels
Mother squirrels sometimes pull fur from their bellies when they’re making a nest. They grab this fur and use it to line the nest, which helps keep their babies warm.
You might spot an adult female with a bald belly and a soft, fluffy patch. Honestly, that’s pretty normal during breeding season.
Nest lining often leaves temporary bald spots, but the fur usually grows back after the babies are gone. But if you notice the mother has sores, scratches a lot, or looks thin and weak, something else is probably going on—maybe a disease, not just nest-building.
In situations like that, it’s best to reach out to wildlife professionals who know how to care for baby squirrels and their moms.
If you stumble upon a nest or some baby squirrels, resist the urge to handle them. Call your local rehabilitator for advice.
