Ever see a squirrel that just doesn’t look right and wonder what’s going on? Squirrels get sick from viruses, parasites, bad food, and injuries. If you know the signs, you can act quickly.
Most of the time, squirrels run into trouble from mites (mange), fungal infections, or viruses like squirrel pox. Sometimes, it’s just spoiled food or dirty water.
You’ll find out how these issues start, what changes in a squirrel’s behavior or appearance, and what you can actually do to help—without risking yourself. Spotting problems early matters, so you’ll know when to call a wildlife rehabilitator or just keep pets and family safe.
Common Causes of Illness in Squirrels
Several things can make squirrels sick, affecting their skin, breathing, or even organs. Some issues show up in ways you can see from a distance. Others? You’ll need a wildlife expert to figure them out.
Squirrel Pox and Squirrel Fibroma
Squirrel fibroma—people usually call it squirrel pox—is a virus that causes firm, bald bumps on the skin. You’ll notice these from tiny bumps to big lumps, usually on the head, feet, or body.
If these growths end up around the mouth or feet, eating and moving gets tough for the squirrel.
Biting insects and direct contact spread the virus. Gray and fox squirrels get it the most.
Some squirrels manage to fight off mild cases, but bad infections can cause weight loss and even death.
Humans, cats, and dogs don’t catch this virus, but pet rabbits rarely can.
If you spot several squirrels with these bumps near your feeders, take the food away for a while and call local wildlife officials.
If you want more details on how it spreads or what to watch for, check out squirrel diseases.
Mange in Squirrels
Tiny mites cause mange by burrowing into a squirrel’s skin. This leads to intense itching, hair loss, and thick scabby patches.
You might see bald spots, flaky fur, and thin bodies. Squirrels with mange often move slowly, clearly exhausted from all the scratching.
Mange passes from squirrel to squirrel through close contact or shared nests.
Young, old, or stressed squirrels usually suffer the most.
Scratching can cause wounds that get infected and become dangerous.
Wildlife rehabbers use medicated dips or shots to treat mange; you shouldn’t try to treat wild squirrels on your own.
Keep your pets away from any squirrel that looks mangy and report what you see to animal control or wildlife officials.
Parasitic Infections: Cuterebra, Warbles, and Others
Cuterebra larvae cause warbles—those weird lumps under the skin with small breathing holes.
You’ll notice hairless swellings, especially in late summer and fall.
Each one has a tiny hole where the larva breathes before it drops out and pupates in the soil.
Warbles rarely kill squirrels, but lots of them—or infections—can weaken the animal.
Other parasites like fleas, ticks, and worms can cause anemia, weight loss, and a scruffy coat.
If you find a nest full of infested babies, call a licensed rehabber.
Don’t try to remove larvae yourself; you could hurt the squirrel or spread infection.
Bacterial Diseases: Francisella tularensis and Beyond
Francisella tularensis brings on tularemia, a nasty bacterial disease that hits squirrels and other mammals.
Squirrels with tularemia act tired, show swollen lymph nodes, and sometimes die suddenly.
People can get tularemia from handling sick squirrels or from bites, so always use gloves and call public health if you find one that looks seriously ill or dead.
Other bacterial problems include abscesses from bites and lung infections that cause snotty noses or labored breathing.
These usually happen after wounds or when a squirrel’s immune system is run down.
If you see one with open wounds, pus, or struggling to breathe, keep your distance and let the pros handle it.
How Squirrel Health Is Impacted and What to Do
Sick squirrels usually look off—you can often tell from a ways away.
If you act quickly by cleaning feeders or calling a wildlife rehabber, you might stop things from getting worse.
Recognizing Symptoms of Sickness
Watch how a squirrel moves.
Dragging a limb, sitting hunched, or bobbing its head? Not normal.
A tilted head or wobbly walk often means something’s seriously wrong, maybe a parasite or a nerve issue.
Check the fur and skin.
Bald patches, scabs, or constant scratching suggest mange or a fungal problem.
Swollen eyes, runny noses, or drooling point to infection.
Pay attention to appetite and behavior.
If a squirrel stops eating, seems weak, or barely moves for hours, it probably needs help.
Seizures, bleeding, or big wounds mean you should call a professional right away.
When to Contact a Wildlife Rehabilitator
Call a licensed wildlife rehabber if the squirrel is a baby, badly hurt, or acting strangely.
Rehabbers can treat dehydration, mange, and serious infections—stuff you just can’t handle at home.
Give them clear info about where the squirrel is and what shape it’s in.
Let them know if it’s a baby, if a pet bit it, or if it’s been on the ground for a long time.
Don’t handle the squirrel unless they tell you to; stress can make things worse fast.
If the squirrel just looks a little rough—thin or with minor fur loss—ask the rehabber if you should just keep an eye on it.
They might suggest putting out fresh water and removing hazards until someone can help.
Environmental and Stress-Related Factors
Your own yard can make squirrels sick, especially if there’s spoiled food or standing water around.
Old birdseed and moldy feed grow bacteria that cause diarrhea and weakness.
Clean your feeders every week and pick up spilled seed.
Predators and loud humans can stress squirrels out.
Constant stress lowers their immunity, making mange and parasites worse.
Keep dogs and cats away from nests, and try not to make sudden changes in the yard.
Extreme weather matters too.
Young or weak squirrels can die from cold or heat.
Offer safe, sheltered spots like brush piles, but don’t hand-feed or try to keep wild squirrels as pets.
Squirrel Care and Prevention Tips
Stick to simple, safe steps: keep those feeders clean, offer fresh water, and toss out any moldy food as soon as you spot it. Doing this cuts down on bacteria and parasites, plus it keeps your pets safer.
If you like feeding wildlife, pick squirrel-proof feeders and hang them high up. That way, squirrels and other critters have less contact with droppings, which helps stop diseases from spreading.
Try switching up where you feed them now and then. Clean any surfaces with a mild bleach mix (just 1 part bleach to 9 parts water) when things get messy.
Spot a sick squirrel? Put on gloves and avoid touching it more than you have to. Snap a photo of the symptoms and reach out to a licensed wildlife rehabilitator.
Skip the home remedies—guessing with treatment could make things worse for the animal.
