Signs Your Pet May Be in Pain—and Why They Hide It

Why Animals Are Wired to Hide Pain

In the wild, showing vulnerability is dangerous. An injured animal that signals weakness becomes a target for predators — so evolution selected for animals that mask discomfort and carry on. That same survival instinct persists in the domestic pets sharing your home today.

This is not a quirk or stubbornness. It is deep biological programming. Even a pet experiencing genuine, significant pain may eat, greet you at the door, and appear outwardly healthy. The absence of obvious distress does not mean the absence of pain.

Understanding this instinct is the first step toward becoming a more observant, proactive pet owner. The cues your pet sends are there — they are simply quieter than a yelp or a whimper.

Behavioral Changes That Signal Discomfort

Pain most commonly reveals itself through changes in behavior rather than dramatic physical signs. Key patterns to watch for include:

• Withdrawal and hiding: A normally social pet retreating to isolated spots is a classic early indicator. Cats especially may disappear under beds or into closets when unwell.
• Altered activity levels: Reluctance to climb stairs, jump onto furniture, or go for walks — especially when this is a change from baseline — often points to musculoskeletal pain.
• Changes in appetite or water intake: Pain commonly suppresses appetite. Dental pain in particular can make eating uncomfortable; see our overview of dental disease in pets for more on that often-overlooked source of pain.
• Aggression or irritability: A pet that suddenly snaps, growls, or hisses when touched in a specific area is communicating something important. This is pain behavior, not disobedience.
• Excessive grooming or guarding a body part: Licking, chewing, or constantly attending to one area often signals localized discomfort.

For a deeper look at how body language communicates distress, the body language guide for dog owners is a useful companion resource.

Physical Signs You Can Observe at Home

Beyond behavior, some physical cues are visible to an attentive owner during routine interaction:

• Postural shifts: A hunched back, tucked abdomen, or weight shifted away from one limb are all compensatory postures that suggest pain.
• Facial tension: Research in veterinary pain science has identified consistent facial changes in animals experiencing discomfort — squinted eyes, tense brow muscles, and flattened ears.
• Changes in coat or skin: A pet that has stopped self-grooming may be too uncomfortable to maintain the behavior. Conversely, over-grooming a specific spot points to localized irritation or pain.
• Altered breathing: Shallow, rapid, or labored breathing at rest — not after exercise — can accompany internal pain or distress.

Senior pets are particularly worth monitoring. Arthritis is common and progressive, and its onset is gradual enough that owners often attribute slowing down to "just getting older." Our guide to senior pet care addresses how to adapt your observations as your pet ages.

When to Call the Vet — and What Not to Do

If you notice any of the above signs, especially in combination or persisting beyond 24 hours, a veterinary evaluation is warranted. Do not wait to see if the pet "walks it off." Pain that goes unaddressed can worsen underlying conditions and significantly affect quality of life.

Critically: never administer human pain medications to a pet. Common drugs like ibuprofen, aspirin, and acetaminophen are toxic to both cats and dogs, even in small doses. Only a licensed veterinarian should recommend or prescribe pain management for animals.

It is also worth considering that some behavioral signs overlap with stress or anxiety rather than physical pain. Our article on how cats and dogs show stress differently can help you think through what your pet's signals mean in context.

When in doubt, an examination is always the right call. Pets cannot advocate for themselves — that role belongs to their owners.

“Pain assessment in animals requires vigilance from owners because patients cannot self-report. Behavioral changes are often the earliest and most reliable clinical signal available.”

— American Animal Hospital Association, Veterinary accreditation and guidelines body for companion animal practice

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 regarding your pet's health.