How to Spot Pain in Your Pet: 10 Signs You Shouldn't Ignore

Why Pets Hide Pain

The single most important fact about pet pain is that dogs and cats evolved to hide it. In the wild, an animal that limps, vocalizes, or shows weakness becomes a target. That instinct is still wired into your dog or cat today, and it means a pet who is uncomfortable will often look completely normal — until the pain is too severe to mask.

The Merck Veterinary Manual notes that recognizing pain in animals is one of the hardest assessments in veterinary medicine, and recent research suggests dog owners miss the early signs in roughly half of all cases. Cats are even more subtle — most owners do not notice chronic feline pain until a routine vet exam catches it.

This guide walks through the 10 most reliable behavioral and physical signs of pain in pets, the validated pain scales vets actually use, and the situations that should send you to the vet today rather than tomorrow.

1. Changes in Posture or Gait

One of the earliest signs of orthopedic pain — arthritis, disc disease, soft-tissue injury — is a change in how your pet stands or moves. Watch for:

• Shifting weight between limbs while standing.
• Stiffness or slow rising after rest, especially first thing in the morning.
• Reluctance to climb stairs, jump on furniture, or get into the car.
• An arched or hunched back, especially in cats.
• Walking with a stiff, splinted gait — moving the whole spine as one piece.

These signs often start mild. A dog who used to jump on the couch and now hesitates is telling you something even if they never limp.

2. Decreased Activity or Reluctance to Play

A pet who stops doing things they used to enjoy — fetch, chasing toys, greeting you at the door, climbing the cat tree — is communicating discomfort. This is one of the most missed signs because owners often write it off as the pet getting older or calmer.

Aging alone does not make a pet unwilling to play. Pain often does. If your 8-year-old Lab was happily fetching last spring and is uninterested this year, schedule a vet visit before assuming it is just age.

3. Hiding or Withdrawing

Cats in particular hide when they are in pain. A normally social cat who starts spending entire days under the bed, in a closet, or behind the couch is often communicating illness or pain. Dogs may do a milder version — staying in another room, avoiding eye contact, withdrawing from family activities.

This is the opposite of what most owners expect. A pet in pain rarely whimpers or asks for help; they retreat.

4. Changes in Grooming

Cats normally groom several hours a day. A painful cat often grooms less, leading to a coat that becomes greasy, clumpy, or unkempt — especially over the back and hindquarters where they cannot easily reach. The opposite pattern is also a sign: over-grooming a specific area, sometimes to the point of bald patches or sores, often indicates pain or itch in that location.

Dogs may chew, lick, or scratch one specific spot repeatedly. Joint pain often shows up as obsessive licking of a wrist, elbow, or hip.

5. Changes in Appetite or Drinking

A dog or cat who suddenly eats less or refuses food is often in pain — dental pain, abdominal pain, nausea, or systemic illness. The reverse can also signal trouble: increased thirst and water consumption is a hallmark of kidney disease, diabetes, and several painful conditions.

Cats are especially sensitive here. A cat who skips more than two meals in a row needs veterinary attention. Cats can develop hepatic lipidosis (a serious liver condition) within days of stopping eating.

6. Vocalizing Differently

Pain vocalization is not always dramatic. Subtle changes count:

• Whimpering when getting up or being touched.
• Excessive panting in a dog who is not hot or excited.
• Growling or hissing when you go near a specific area of the body.
• Cats: increased meowing, especially at night, or new-onset yowling.
• The opposite — a chatty cat who suddenly goes quiet — also matters.

7. Facial Expression Changes

Both dogs and cats have validated facial pain scales used in veterinary medicine. The Glasgow Composite Measure Pain Scale for dogs and the Feline Grimace Scale for cats both score specific facial features.

For cats, signs include:

• Ears rotated outward or flattened.
• Eyes squinted or partially closed.
• Whiskers pulled forward and bunched, or pushed flat against the cheeks.
• Muzzle tense rather than relaxed.

For dogs, signs include lip-licking outside of meals, frequent yawning when not tired, looking away rather than making eye contact, and increased blinking. These signs can be subtle on a single occasion but become reliable when they appear repeatedly.

8. Changes in Sleep Patterns

A pet in pain often sleeps differently. They may rest constantly during the day but pace, change position frequently, or seem unable to settle at night. Cats with arthritis often abandon high resting spots they used to favor in exchange for floor-level beds.

Restless sleep, frequent position changes, and a pet who cannot find a comfortable position to lie down all suggest discomfort.

9. Avoiding Touch or Aggressive Reactions

A normally affectionate pet who pulls away when you reach for a specific area, growls when you handle their hindquarters, or snaps when picked up is often telling you something hurts. Owners often interpret this as a behavioral problem when it is actually a medical one.

If a previously easygoing dog or cat develops sudden defensive behavior — especially when touched — pain should be the first explanation considered, not the last.

10. Changes in Bathroom Habits

Pain can manifest as elimination changes:

• A dog with hip or back pain may strain to defecate, hesitate to squat, or have accidents in the house.
• A cat with arthritis may stop using a litter box because the high sides hurt to step over.
• Straining to urinate (especially in male cats) is a medical emergency — a urinary blockage can be fatal within 24-48 hours.
• Blood in urine or stool is always worth a same-day phone call.

How Vets Actually Measure Pain

Veterinarians use validated scoring systems to track pain. The Glasgow Composite Measure Pain Scale - Short Form is the most common for dogs in clinical practice, scoring posture, comfort, mobility, vocalization, and response to handling. The Feline Grimace Scale, validated in 2019 and now standard in many U.S. clinics, scores facial features alone and is reliable enough that even untrained observers can use it after a few minutes of training.

If you suspect pain, you can do a simple home version: rate each of the 10 areas above on a 0-2 scale (no change, mild change, significant change). A total score of 5 or higher is worth a vet visit.

When to Call Today vs. When to Wait

Same-day or emergency call:

• Sudden onset of severe pain — yelping, screaming, or hiding immediately after an event.
• Straining to urinate, especially in male cats.
• Pain combined with vomiting, diarrhea, or refusing food for more than 24 hours.
• Sudden inability to bear weight on a limb.
• Trauma — being hit, falling, or being attacked by another animal.
• Pain with pale, blue, or grey gums.

Schedule a routine visit within a week:

• Gradual stiffness or reduced activity.
• Changes in grooming habits without other signs of illness.
• Subtle behavioral or sleep changes.
• Mild appetite reduction without other symptoms.

Pain Is Treatable — But Only If Caught

Veterinary pain management has advanced significantly over the last decade. There are now safe long-term anti-inflammatory medications for both dogs and cats, joint-protective supplements with strong evidence, monthly injectable arthritis treatments approved in 2023-2024 (Librela for dogs, Solensia for cats), and physical therapy options that have moved from luxury to mainstream.

The bottleneck is recognition. A pet whose pain is identified gets treated; a pet whose pain is missed loses years of comfort. Treat any of the 10 signs above as worth at least a phone call to your vet — your pet cannot ask for help, but you can ask for them.

This article is for informational purposes and is not veterinary advice. Always consult a licensed veterinarian about your pet's specific health concerns. In an emergency, call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435.