How to Tell If Your Cat Is Sick: 10 Signs Alhambra Owners Often Miss

Cats are famously stoic. In the wild, showing vulnerability is dangerous — so cats evolved to mask pain and illness with impressive efficiency. For their owners, this means that by the time a cat seems “off,” something has often been wrong for longer than you’d think. Here are 10 signs worth knowing — including several that don’t look like illness at all. If you’re in the area, our Alhambra cat vet team is here to help.

1. Hiding More Than Usual

Cats are private animals, but a sudden increase in hiding — especially retreating to unusual spots like under the bed, in closets, or away from family interaction — is often a sign of pain or systemic illness. Know your cat’s normal behavior patterns. A cat that used to follow you around and now hides is telling you something.

2. Changes in Litter Box Habits

This covers a wide range: going outside the box (which can signal pain when getting in/out, a UTI, or kidney issues), straining to urinate or defecate, blood in urine or stool, very infrequent or very frequent urination. A male cat straining to urinate is an emergency — urethral obstruction can be fatal within hours. Don’t wait on that one.

3. Eating or Drinking Differently

Both extremes matter. Decreased appetite for more than 24–48 hours in a cat is a legitimate concern — cats that don’t eat can develop hepatic lipidosis (fatty liver disease) in as little as 2–3 days. But increased thirst and urination is equally important and is a classic sign of diabetes, kidney disease, or hyperthyroidism in older cats. Note changes and bring them up at your next visit — or sooner.

4. Weight Changes

Subtle weight changes are easy to miss because you see your cat every day. A cat losing 5–10% of body weight may not look dramatically different but is a significant finding. Weigh your cat monthly on a kitchen scale. Consistent losses — even small ones — in a middle-aged or senior cat almost always warrant a blood panel. This is one of the key reasons we recommend regular wellness exams for cats at every life stage.

5. Changes in Coat Quality or Grooming

Cats are fastidious groomers. A coat that’s suddenly unkempt, dull, or matted — especially in areas the cat can’t easily reach, like the back near the tail — suggests the cat is in pain, has mobility issues, or is systemically unwell. Conversely, over-grooming to the point of hair loss can indicate skin disease, allergies, or stress.

6. Bad Breath

A little cat breath is normal. A sudden change to unusually foul breath — especially a sweet or fruity odor (possible diabetes) or an ammonia-like odor (possible kidney disease) — is a sign worth following up on. The most common cause of bad breath in cats is dental disease, which is extremely common and often painful. Learn more about our veterinary dentistry services.

7. Changes in Vocalization

A quiet cat that suddenly becomes vocal (especially at night in older cats) may be experiencing cognitive dysfunction, hypertension, hyperthyroidism, or pain. A normally chatty cat that goes quiet may be withdrawn due to illness. Unusual vocalizations — yowling, howling, or crying — always merit attention.

8. Lethargy or Reduced Activity

This one’s tricky because cats sleep a lot normally — 12–16 hours daily. But there’s a difference between a cat that’s comfortable and resting versus one that’s dull, unresponsive, or not getting up to eat or greet you. A cat that isn’t doing its normal things — window watching, following you around, playing — for more than a day or two is worth calling about.

9. Third Eyelid Visible

The third eyelid (nictitating membrane) is the pale tissue visible in the inner corner of a cat’s eye. When it’s consistently visible at rest (called “haw syndrome”), it usually indicates systemic illness, dehydration, or a neurological issue. If you can see the third eyelid in both eyes when your cat is awake and alert, call your vet.

10. Reluctance to Jump or Move

Cats are athletic. A cat that hesitates before jumping to its usual spots, seems stiff after sleeping, or stops jumping onto the couch may have osteoarthritis — which is significantly underdiagnosed in cats because they hide pain so well. Studies suggest over 90% of cats over age 12 have radiographic evidence of arthritis, but most owners don’t know it because cats simply adapt their behavior rather than limping visibly.

What to Do If You Notice These Signs

Trust your gut. If something is off, it usually is — you know your cat better than anyone. A one-time oddity is often nothing; a pattern that persists for 24–48 hours, or anything from the “urgent” category (straining to urinate, labored breathing, collapse), warrants a call. When in doubt, it’s always better to check in.

Frequently Asked Questions

If your cat is due for a wellness exam or something has you concerned, the best next step is a conversation with your vet. Reach out to us at 3116 W Main St in Alhambra — established clients can book online, and we’re happy to answer questions over the phone before you decide what to do.