Do Squirrels Have Fleas? And Can They Reach Your Pets?

Yes — fleas, lice, mites and ticks, routinely. But squirrel fleas do not settle on cats and dogs, and the case that actually causes trouble is a nest left in a roof.

What squirrels carry

Why your dog is probably fine

Host specificity is the whole answer. A squirrel flea can bite a dog or a person, but it cannot sustain a breeding population on one — it needs squirrels to complete its life cycle.

Cat fleas (Ctenocephalides felis), which cause essentially every household infestation, are the opposite: they use cats, dogs, foxes and rabbits interchangeably and breed happily in carpets and bedding.

The situation that does cause problems

A nest abandoned in an attic, soffit or wall void.

Fleas and their larvae stay in the nesting material after the squirrels have gone, and once there is no host, hungry adult fleas disperse looking for any warm body — which means down into the living space, usually within days. This is when most people notice.

Dealing with it properly:

1. Exclude the squirrels first — one-way doors, then seal. Never seal with young inside
2. Remove all nesting material. Gloves and a dust mask, bagged rather than swept
3. Treat the space — vacuum thoroughly, and use an appropriate insecticide in the void
4. Check pets are on effective prevention
5. Vacuum living areas daily for a week or two, emptying outside
6. Seal properly with half-inch hardware cloth or metal flashing

Rabies is the disease people ask about next, and the answer is reassuring for a different reason — see can squirrels get rabies.

Ticks are the bigger issue

Squirrels host ticks, including black-legged ticks, and are part of the local tick cycle in wooded and suburban gardens — though white-footed mice are the more important reservoir for the Lyme bacterium.

What actually helps is garden management, not squirrel management:

• Keep grass short at the woodland edge, where the tick density is highest
• Clear leaf litter and brush piles near paths and seating
• A three-foot gravel or wood chip strip between lawn and woodland is a recognised barrier
• Check yourself, children and pets after time outdoors
• Keep pets on tick prevention

The bald, scabby squirrel

Common, alarming to look at, and usually not something to act on.

• Mange — mites burrowing in the skin. Patchy hair loss, thickened grey skin, constant scratching. Not usually fatal in itself, but a squirrel without fur going into winter often does not survive it
• Squirrel pox — wart-like lumps around the face and feet. A virus, and often worse than mange
• Botfly warbles — lumps under the skin in late summer, with a breathing hole. Looks horrifying; the larva leaves and the squirrel is generally fine

Neither mange nor pox is normally treated in wild animals, and home remedies passed around for treating mange in wildlife — ivermectin in food, most commonly — risk dosing non-target animals. Keep your distance, keep pets away, and report a serious case to a wildlife rehabilitator rather than intervening.

Can you catch anything

Bites, mostly.

• Squirrel fleas and mites bite people opportunistically, leaving itchy welts usually around the ankles. They cannot establish on a human host
• Sarcoptic mange mites can cause a temporary itchy rash that resolves on its own, because they cannot complete their life cycle on people
• The genuine exception: in a few western US regions, ground squirrel fleas can carry plague. This is why dead ground squirrels should not be handled and why a die-off should be reported to the county health department

For tree squirrels in a garden, the honest summary is that they carry plenty and pass on very little — provided their nest is not inside your house.