Quick answer
Cats often hide illness, so subtle changes can be significant. Key signs your cat is sick include loss of appetite, unusual lethargy, vomiting, diarrhea, and changes in litter box habits. Any difficulty breathing, straining to urinate, or suspected toxin exposure requires immediate veterinary attention.
Cats are masters of disguise, especially when it comes to illness. Their survival instincts drive them to hide weakness, which means by the time they show obvious signs your cat is sick, a condition may have progressed. As owners, learning to decode their subtle signals is one of the most important things we can do. This guide covers the common behavioral and physical changes that warrant attention and clarifies the urgent situations where you should contact your veterinarian without delay. For a broader look at maintaining your cat’s health, see our cat health and wellness guide.
Common Physical Signs Your Cat Is Sick
While behavior changes are often the first clue, specific physical symptoms are clear indicators that something is wrong. These signs should prompt a call to your vet, especially if they persist for more than a day or seem severe.
Changes in Eating and Drinking
A shift in appetite is a fundamental warning sign. This includes both a decrease and, less commonly, a significant increase.
- Not Eating: A cat refusing food for 24 hours or more is a serious concern. This can quickly lead to a dangerous liver condition called hepatic lipidosis, especially in overweight cats.
- Eating More: A sudden increase in appetite, especially if paired with weight loss, can indicate conditions like hyperthyroidism or diabetes.
- Changes in Drinking: Drinking noticeably more water can signal kidney disease, diabetes, or other metabolic issues. Drinking much less can lead to dehydration.
Changes in Elimination Habits
The litter box is a vital health monitor. Pay attention to frequency, appearance, and your cat’s posture.
| Sign | Potential Meaning |
|---|---|
| Straining to urinate, crying in the box, or frequent small trips | URGENT: Could indicate a urinary blockage (more common in males), which is fatal if untreated. |
| Diarrhea or constipation for more than a day | Digestive upset, dietary issue, or underlying illness. |
| Blood in urine or stool | Infection, inflammation, or other medical problem. |
| Going outside the litter box | May signal a urinary issue, arthritis pain, or stress from illness. |
Visible Physical Symptoms
- Vomiting: Occasional hairballs are normal, but repeated vomiting, vomiting with force, or vomiting with blood is not.
- Weight Change: Sudden weight loss or gain should be investigated.
- Coat Changes: A dull, greasy, or matted coat can indicate your cat isn’t grooming due to pain, obesity, or illness.
- Eye or Nose Discharge: Persistent discharge, especially if colored or accompanied by sneezing, can point to an upper respiratory infection.
Behavioral and Activity Warning Signs
Often, the earliest signs your cat is sick are not physical but reflected in how they act. A deviation from their normal personality is a red flag.
Energy Level and Hiding
Cats sleep a lot, but there’s a difference between rest and lethargy. A lethargic cat shows little interest in play, interaction, or things they usually enjoy. They may seem weak or listless. Conversely, a usually calm cat that becomes agitated or restless may also be in distress. Increased hiding or seeking unusual, secluded spots is a classic sign of feeling unwell or in pain.
Social Interaction Changes
A friendly cat that becomes irritable, withdrawn, or starts hiding may be ill. Conversely, a typically independent cat that becomes unusually clingy or vocal might also be signaling discomfort. Pay attention to changes in their usual communication patterns.
Posture and Movement
Watch for signs of pain or stiffness: reluctance to jump, limping, difficulty getting up or down, or a hunched posture. Excessive grooming of one area might indicate pain there, while a lack of grooming overall is also a concern.
Safety
Some situations constitute a veterinary emergency. If you observe any of the following, contact your veterinarian or an emergency animal hospital immediately:
- Difficulty breathing, open-mouth breathing, or pale/gray/bluish gums.
- Straining to urinate with little or no output (especially in male cats).
- Collapse, severe lethargy, or inability to stand.
- Suspected trauma (fall, hit by car).
- Seizures.
- Exposure to a known toxin (e.g., lilies, antifreeze, certain human medications). Contact the ASPCA Animal Poison Control Center on the way.
- Not eating for 24 hours or more.
- Profuse vomiting or diarrhea, especially with blood.
When to Contact Your Veterinarian
It’s always better to err on the side of caution. Use this general guide to decide when to make the call.
What to look for
- Call Immediately (Emergency): Any symptom from the Safety box above.
- Call Within 24 Hours: Subtle but persistent changes lasting more than a day—lethargy, appetite change, hiding, increased thirst, mild vomiting/diarrhea.
- Schedule a Check-up: Gradual changes over weeks, like slow weight change or reduced activity, which still require professional evaluation.
When you call, be prepared to describe the symptoms clearly: when they started, their frequency, and any changes you’ve noted in behavior or routine. This information is invaluable for your vet. Regular preventive care visits are the best way to catch issues before obvious signs appear, as your vet can detect subtle changes in weight, heart rate, or during a physical exam.
FAQ: Signs Your Cat Is Sick
How can I tell if my cat is in pain?
Cats rarely cry out in pain. Look for more subtle signs: hiding, decreased interaction, reluctance to move or jump, a hunched posture, changes in grooming (over-grooming one spot or not grooming at all), irritability when touched, or changes in eating and litter box habits.
My cat is eating but seems lethargic. Is this urgent?
Lethargy with a normal appetite is less urgent than lethargy with no appetite, but it still warrants attention. It could indicate a low-grade infection, pain, or the early stages of many illnesses. If the lethargy lasts more than 24-48 hours, a veterinary visit is recommended.
Why is my cat suddenly meowing more at night?
Increased vocalization, especially at night, can be a sign of cognitive changes in older cats, but it can also indicate pain, discomfort, hyperthyroidism, high blood pressure, or sensory decline (hearing or sight loss). A veterinary check-up can help determine the cause.
Are all houseplants toxic to cats?
No, but many common ones are. Lilies are especially dangerous—even a small amount of pollen can cause acute kidney failure. Other toxic plants include sago palm, tulips, azaleas, and dieffenbachia. It’s safest to research any plant before bringing it into a home with cats. The ASPCA maintains a comprehensive list.
How often should I take my healthy cat to the vet?
The American Association of Feline Practitioners recommends at least annual wellness exams for adult cats. For senior cats (age 10 and over), exams every six months are advised to monitor for age-related conditions. These visits are key for preventive health.
References
- American Association of Feline Practitioners (AAFP): Feline life stage guidelines and wellness care recommendations. https://catfriendly.com/
- American Veterinary Medical Association (AVMA): Resources for pet owners on pet health and emergencies. https://www.avma.org/resources-tools/pet-owners
- Cornell Feline Health Center: Educational materials on feline diseases and health monitoring. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center
- ASPCA Animal Poison Control Center: Toxin information and emergency hotline. https://www.aspca.org/pet-care/animal-poison-control
- Manufacturer manuals and specification sheets: For information on specific products and their safe use.
