“It can’t possibly be fleas!” Unfortunately, they are the most likely culprit.
Fleas are kind of the worst. A pet’s constant scratching, licking, biting and chewing as a result of these itchy little bugs can drive a concerned and exasperated pet owner to the brink, and one skipped dose of preventative can quickly trigger a metamorphosis as eggs and larvae that had been dormant gleefully emerge as blood-sucking adults to begin the cycle of terror anew.
An important fact to note is that, truly, it only takes one flea. An adult flea can lay 40-50 eggs within just 1-2 days of her first blood meal, and these microscopic eggs (which hatch into microscopic larvae) are designed to shed from a pet’s fur and hide in carpet fibers and bedding, where they can wait months (even a year, under the right circumstances) for viable conditions to hatch. In fact, short of adult fleas themselves, the only sign of their presence may be tiny, black specks of digested blood (known as flea dirt). This is why applying flea medication is often not enough to stop an outbreak - equally important is washing and drying fibrous material or bedding to make sure fleas at all lifestages are completely eliminated.
Most of the time, a pet will scratch after a flea bite (and occasionally lick or chew), but some pets experience a more severe allergic reaction to proteins in flea saliva. This can lead to redness, irritation, hairloss and self-inflicted sores from biting or scratching as pets seek to quell the itch. These sores can fester with secondary bacterial infections and require stronger medical intervention. This reaction is known as flea allergy dermatitis (FAD) and often requires a three-pronged treatment approach. This may involve a flea preventative to kill live fleas/pupae/eggs, an anti-itch injection to calm the immune system and antibiotics to address any bacterial infection. It’s best if all interventions are administered simultaneously.
It’s also best to get a prescription-strength flea preventative from a veterinarian rather than an over-the-counter product. Many OTC products have been on the market for many years, giving flea populations plenty of time to build up an immunity. A veterinarian can also direct owners to the safest product for their pet based on medical history and other drugs that they may take.
What you can do at home
Keep your pet on prescription flea meds, even if they have minimal outdoor exposure. Once a flea gets into your home, eradication can be difficult, even costly. Thoroughly vacuum carpeted surfaces and big furniture like sofas and chairs. Wash ALL linen that your pet may have snuggled on - did they jump in the dresser drawer when you removed your socks? Did you leave a pile of canvas tote bags on the floor, and did your pet find them to be quite a comfortable bed? Make sure you then dry all items to actually kill the fleas - roasting them to a crisp in the dryer is one of the only ways to guarantee that they’ve actually perished. If things get really dire, you may need to consider contacting an exterminator to flea bomb your home.
TL;DR
Fleas are designed to latch onto your pet’s fur, infiltrate their environment and reproduce quickly
Fleas have strong exoskeletons and flat bodies that make them extremely difficult to pinch, smash or squish. Flea preventative and thorough washing and drying are the most effective and least harmful ways to eliminate fleas from an environment
Some pets experience a severe allergic reaction to flea saliva that requires more intensive treatment to resolve
Prescription-strength medications are far more effective at killing and preventing fleas than those sold over the counter