Top 5 Signs Your Cat May Be Hiding an Illness

Top 5 Signs Your Cat May Be Hiding an Illness

Cats are remarkably skilled at masking pain and sickness — often until an illness has progressed significantly. This instinct traces back to survival behavior in the wild, where showing vulnerability could make a cat a target. The result: by the time many pet parents notice something is off, their cat may have been unwell for days or even weeks.

Knowing what to look for can make all the difference. Here are the five key warning signs to watch for, followed by what each one means and when to act.

The 5 signs at a glance:

1. Increased vocalization
2. Hiding behavior
3. Changes in movement or posture
4. Personality changes
5. Changes in litter box habits

If your cat is showing any of these signs — or simply isn't acting like himself — schedule a check-up with your veterinarian without delay. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information

1. Increased Vocalization

One of the earliest signs many pet parents notice is a change in how much their cat is "talking." A cat who suddenly meows more than usual, yowls, growls, or cries — especially at odd hours — may be trying to communicate that something isn't right.

Cats tend to increase vocalizations when they are in pain or experiencing discomfort. This is especially notable in cats who are typically quiet. Conversely, a cat who is usually vocal and suddenly goes silent can be equally concerning. Both shifts in communication pattern are worth paying attention to and mentioning to your veterinarian. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information

What to watch for:

• Sudden increase in meowing, yowling, or crying
• Vocalizing when touched in a specific area (a sign of localized pain)
• Unusual nighttime crying
• A normally chatty cat who becomes quiet and withdrawn

2. Hiding Behavior

Hiding is one of the most commonly overlooked signs of illness in cats — precisely because it can seem like normal, quirky cat behavior. But there's an important distinction between a cat who occasionally retreats to a cozy spot and one who suddenly starts avoiding people, staying under the bed for hours, or disappearing into closets.

Cats may hide to reduce stress from household activity, to avoid alerting others to a visible injury, or because they are experiencing pain, fever, or stomach upset. If your cat's hiding behavior is new or has intensified, take it seriously. It's worth noting that hiding can also be linked to stress or anxiety unrelated to physical illness — but either way, a sudden behavioral shift warrants a veterinary conversation. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information

What to watch for:

• Retreating to unusual or hard-to-reach spots
• Avoiding family members he normally seeks out
• Staying hidden for unusually long stretches
• Reluctance to come out even for meals or treats

3. Changes in Movement or Posture

A cat in pain will often adjust the way he moves or holds his body in an effort to minimize discomfort. These changes can be subtle at first — a slight hesitation before jumping, a stiffness in the hind legs, or an unusual hunched posture while sitting or walking.

Watch for a cat who suddenly stops jumping onto furniture he used to frequent, who moves more slowly than usual, or who flinches or pulls away when touched in a particular spot. Changes in gait — such as limping, favoring one side, or an unsteady walk — are also red flags. Any new or worsening change in the way your cat carries himself should be evaluated by a veterinarian. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information

What to watch for:

• Reluctance or refusal to jump up or down from surfaces
• Limping, favoring a limb, or an unsteady gait
• Hunched posture or a tucked abdomen
• Flinching, growling, or pulling away when touched
• Moving more slowly or stiffly than usual

4. Personality Changes

Cats are creatures of habit, and a sudden, unexplained shift in personality is one of the clearest signals that something may be physically wrong. These changes can swing in either direction.

A cat who was previously gentle may suddenly become aggressive — striking out, biting, or scratching during activities he once tolerated or enjoyed, like being petted or picked up. This is often a pain response; he's not misbehaving, he's hurting. On the other end of the spectrum, a typically independent cat may become unusually clingy or affectionate, seeking more contact than normal as a way of communicating that something feels wrong.

Neither shift should be dismissed as "just a mood." When personality changes appear suddenly and without an obvious cause — like a new pet in the home or a recent disruption to routine — a veterinary evaluation is the right next step. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information

What to watch for:

• Sudden aggression toward people or other pets
• Biting or scratching during previously enjoyed interactions
• Unusual clinginess or neediness
• Withdrawal from social interaction he normally seeks
• Uncharacteristic irritability or fearfulness

5. Changes in Litter Box Habits

Changes in bathroom behavior are among the most telling — and actionable — signs that something is wrong with your cat's health. A cat who was previously consistent about using his litter box and suddenly begins having accidents, avoiding it altogether, or straining inside it deserves prompt veterinary attention.

Cats experiencing pain from arthritis or other illness may find it physically difficult to step into or crouch inside the litter box. Cats with digestive issues, urinary tract infections, kidney disease, or internal discomfort may urinate more or less frequently than usual, produce stool with a different consistency, or cry out while using the box. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information

Important: If your cat is straining to urinate and producing little or no urine, this can indicate a urinary blockage — a medical emergency. Contact your veterinarian or an emergency animal clinic immediately. https://www.aspca.org/pet-care/animal-poison-control

If accidents are occurring, bring a fresh urine or stool sample to your veterinary appointment. These samples can provide critical clues about what's causing your cat's discomfort and help your veterinarian reach a diagnosis more quickly.

What to watch for:

• Missing the litter box or eliminating outside of it
• Straining, crying, or spending excessive time in the box
• Urinating more or less frequently than usual
• Changes in stool consistency, color, or frequency
• Blood in urine or stool

A Quick-Reference Guide to the 5 Signs

Cats are masters of concealment, and that instinct can work against their wellbeing. Staying attuned to these five signs — and trusting your gut when something feels "off" — is one of the most important things you can do as a pet parent. When in doubt, call your veterinarian. Early detection almost always leads to better outcomes.

The 5 Signs at a Glance: What to Watch and When to Act

Tip for your vet visit: If you notice litter box accidents, collect a fresh urine or stool sample in a clean container before your appointment. That sample can give your veterinarian valuable clues and may speed up diagnosis.

This article was created with assistance from AI tools and reviewed for accuracy by Petco's content team.