Widely Believed Pet Health Myths—and What the Evidence Actually Shows

A study published in the journal Applied Animal Behaviour Science found that fewer than 25% of dogs vomited regularly after eating grass, and only around 10% appeared sick before doing so. Grass-eating appears to be a normal, opportunistic behavior — possibly related to instinct, fiber intake, boredom, or simply enjoying the taste and texture. While occasional grass consumption is generally harmless, a sudden increase, especially if paired with vomiting, lethargy, or appetite loss, is worth discussing with a veterinarian.

Cats do have a well-documented righting reflex that helps them orient feet-downward during a fall. However, landing feet-first doesn't eliminate injury. Falls from windows or balconies — commonly called "high-rise syndrome" — frequently result in broken legs, jaw fractures, and internal injuries requiring emergency veterinary care. Interestingly, some research suggests cats falling from very high floors may reach terminal velocity and spread their bodies, which can reduce impact forces — but this doesn't make any fall safe. Keeping cats away from open, unscreened windows remains important preventive care.

A dog's nose can be warm after sleeping, dry from sun exposure, or slightly moist after a drink — none of which reliably signals illness. Veterinarians use a thermometer, not a nose touch, to assess fever. A normal dog body temperature generally falls between 101°F and 102.5°F. If you're concerned about fever, the only accurate approach is a proper temperature reading. Focus instead on behavioral cues: unusual lethargy, loss of appetite, vomiting, or nasal discharge alongside other symptoms are more meaningful signs worth flagging to a vet.

Fleas can hitch rides on clothing, other pets, or enter through window screens. Mosquitoes — which transmit heartworm disease — routinely enter homes. Even a cat that never goes outdoors can be at risk. The American Heartworm Society and many veterinary guidelines recommend year-round heartworm prevention for both cats and dogs regardless of lifestyle. Your veterinarian is the right resource for determining the appropriate parasite prevention plan based on your pet's specific situation and your geographic region.

Purring is often associated with contentment, but it's more accurately understood as a self-soothing and communication behavior. Cats have been observed purring during veterinary examinations, when injured, and in the final stages of illness. Some researchers suggest the vibration frequency of a purr (roughly 25–150 Hz) may have physiological self-calming effects. Rather than relying on purring alone to assess a cat's wellbeing, observe the full picture: body posture, ear position, appetite, and willingness to interact. A pet training and behavior resource can help owners read feline body language more accurately.

This myth likely stems from the observation that animals lick their own wounds — a behavior that may provide minimal short-term benefit in some contexts, but carries real risk for people. Dogs' mouths harbor bacteria including Pasteurella, Capnocytophaga, and others that are harmless to the dog but potentially harmful to humans, particularly those who are immunocompromised. Medical guidance consistently advises against allowing pets to lick open wounds or broken skin. Standard wound care — cleaning, covering, and consulting a healthcare provider when needed — remains the appropriate approach.