Key Takeaways
- Pets instinctively mask pain, so subtle behavioral and physical changes are often the earliest clues.
- Changes in posture, appetite, grooming, and vocalization can all signal that a pet is hurting.
- Some pain signs — such as labored breathing or collapse — require immediate emergency veterinary care.
- A veterinarian is the only qualified professional to diagnose pain and recommend appropriate treatment.
- Knowing your pet's normal behavior makes it much easier to spot when something is wrong.
Why Pets Hide Pain — and Why That Makes Your Job Harder
Dogs and cats are descended from animals that survived by concealing vulnerability. In the wild, showing weakness invites predators. That instinct hasn't disappeared in our domestic companions, which means a pet in significant discomfort may still greet you at the door, eat most of its meals, and appear broadly normal — until the problem becomes severe.
This guide outlines the most telling signs that your dog or cat may be in pain, ranging from obvious to easy to miss. Understanding these signals is the first step toward getting your pet the help it needs. For a deeper look at how animals communicate distress through body language, see our plain-language guide to pet body language.
This article is for general informational purposes only and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a licensed veterinarian if you have concerns about your pet's health.
Changes in posture or movement
A pet in pain often holds its body differently. Dogs may hunch their back, carry their head low, or shift weight away from a painful limb. Cats frequently adopt a hunched, tucked posture with elbows turned out — a classic sign of abdominal discomfort. Reluctance to jump, climb stairs, or rise from lying down can all point to musculoskeletal pain.
Watch for any new asymmetry in how your pet stands or walks. A subtle limp that appears only after rest, or only after exercise, is still worth reporting to your veterinarian.
A new limp — even a subtle one — is always worth reporting to a vet.
Unusual vocalization
Whimpering, whining, growling when touched, or crying out during routine movements can be direct expressions of pain. Cats may vocalize more than usual, produce a low continuous purr (which can accompany distress as well as contentment), or become unusually silent. A pet that yelps when you touch a specific area is giving you a fairly direct signal — take note of exactly where and when it happens.
Growling when touched or yelping unexpectedly can be a pet's clearest pain signal.
Withdrawal and changes in social behavior
Animals in pain often isolate themselves. A dog that normally follows you from room to room may retreat and refuse engagement. A usually social cat may hide under furniture or in closets for hours at a time. Conversely, some pets become clingy and seek more contact than usual when they feel unwell.
Sudden behavioral shifts — particularly alongside other physical signs — frequently indicate a medical cause. Our article on how behavior can signal a medical problem explores this connection in detail.
Sudden withdrawal or unusual clinginess can both signal that a pet is hurting.
Changes in appetite, thirst, or elimination
Pain frequently suppresses appetite. A pet that skips more than one or two meals, or shows markedly reduced enthusiasm for food it previously enjoyed, deserves attention. Increased water consumption alongside reduced eating can indicate systemic illness causing discomfort. Changes in litter box use — a cat suddenly eliminating outside the box, or a dog with previously reliable house training having accidents — can also indicate pain during normal posturing.
Skipping meals repeatedly or eliminating outside normal areas may reflect pain, not just bad habits.
Altered grooming habits
Both over-grooming and under-grooming can signal pain. A cat obsessively licking, biting, or chewing at one spot is often responding to localized discomfort — skin irritation, nerve pain, or an internal ache felt at the surface. Dogs do the same, particularly with paws. Conversely, a cat that was previously meticulous about its coat but now looks unkempt may be in too much discomfort to groom normally, which is particularly common with arthritis or dental pain. For more on reading feline signals, see our field guide to cat body language.
Excessive licking of one area, or a suddenly unkempt coat, can both indicate localized pain.
Facial expression and eye changes
Veterinary researchers have developed pain-assessment scales for both dogs and cats that rely partly on facial cues — including squinting eyes, a fixed forward gaze, whisker position, and tension around the muzzle. A pet with squinted, partially closed eyes in a non-sleepy context may be experiencing discomfort. Dilated pupils in cats, outside of a dark environment, can also signal fear or pain.
Squinting or tension around the muzzle are recognized veterinary indicators of pain in both cats and dogs.
Aggression or resistance to handling
A pet that was previously tolerant of being touched but now snaps, hisses, or pulls away when you handle a specific area is communicating important information. Pain-induced aggression is one of the most common reasons previously gentle animals bite. Never punish this response — instead, note exactly which area provokes it and share that information with your veterinarian. It is a symptom, not a behavioral problem.
Pain-induced aggression is a symptom — note the trigger location and report it to your vet.
When to Act — and How Urgently
Not every pain signal demands a midnight emergency visit, but none should be ignored indefinitely. As a general principle: if your pet's discomfort appears sudden, severe, or is accompanied by difficulty breathing, collapse, pale gums, or uncontrolled bleeding, treat it as an emergency and contact a veterinary clinic immediately.
For milder or gradual signs — a slight change in gait, reduced appetite over a day or two, unusual quietness — schedule a veterinary appointment as soon as reasonably possible rather than waiting weeks. Pain that goes unaddressed can worsen underlying conditions and diminish your pet's quality of life. Older animals may be especially susceptible; our article on caring for a senior pet covers how age-related health changes can complicate pain recognition.
Keep a brief log before your vet visit
Before your appointment, jot down when you first noticed each sign, whether it's constant or intermittent, and any recent changes in diet, environment, or activity. Even a simple note on your phone helps your veterinarian build a more complete picture and speeds up diagnosis. Videos of unusual gait or posture — shot on your phone at home — can be especially valuable.
It can also be worth considering whether what you're seeing is pain or stress — two states that share overlapping signals. Our piece on stress signals owners tend to miss can help you distinguish between the two before your vet appointment.