Common Cat Health Issues and Early Warning Signs
The subtle symptoms owners miss that can save your cat years of pain (and you thousands in vet bills)
Cats are masters at hiding illness. By the time they “look sick,” they’ve often been suffering for weeks.
Learn your cat’s normal — then watch for these sneaky red flags.
1. Dental Disease – The #1 Silent Killer
80–90 % of cats over age 3 have some degree of dental disease
| Early (you can still reverse) | Advanced (vet needed now) |
|---|---|
| Mild bad breath, slight yellow on back teeth | Red/inflamed gums, drooling, dropping food, pawing at mouth |
| Occasional “chattering” when eating” | Loose teeth, pus along gums, weight loss |
Action: Start brushing 2–3× week + dental treats. Book anaesthesia cleaning the moment gums are red.
2. Chronic Kidney Disease (CKD) – The Silent Senior Thief
Affects 30–50 % of cats over 10, 80 % over 15
| Subtle early signs | Late-stage crisis signs |
|---|---|
| Drinking a little more than usual | Drinking/peeing massive amounts, vomiting, metallic breath |
| Slightly reduced appetite | Severe weight loss, ulcers in mouth, seizures |
Tip: Annual bloodwork from age 7 catches CKD at stage 1 (manageable) instead of stage 4 (terminal).
3. Hyperthyroidism – The “Skinny but Always Hungry” Disease
Most common in cats over 10
| Early clues | Obvious stage |
|---|---|
| Losing weight despite ravenous appetite | Vomiting, frantic behaviour, greasy coat, heart murmur |
| Slightly hyper, vocal at night | Muscle wasting, drinking from faucets |
One quick blood test (T4) diagnoses it. Treatable with medication, diet, or radio-iodine cure.
4. Hairballs vs. Serious Gut Issues
| Normal hairball (1–2× month max) | Red-flag vomiting |
|---|---|
| Occasional tube of hair + food | Vomiting >2× week, no hairball produced |
| Cat otherwise acts normal | Dry heaving, lethargy, constipation |
Frequent “hairballs” are usually IBD, food allergy, or cancer. Vet workup needed.
5. Skin Allergies & Overgrooming
| Mild | Serious |
|---|---|
| Occasional licking of belly or legs | Bald patches, scabs, red skin, constant licking |
| Small patch of thin fur | Symmetrical hair loss on back legs or belly |
Look for the “E” shape of hair loss on sides — classic flea allergy even if you never see fleas.
6. Urinary Tract Problems (FLUTD)
Life-threatening in males if blocked
| Early warning | Emergency (go NOW) |
|---|---|
| Straining in box, small pees | No urine in 12–24 h, crying, lethargy |
| Peeing outside box occasionally | Vomiting, hiding, bloated abdomen |
| Pink-tinged urine | Male cat repeatedly visiting box with nothing coming out |
A blocked cat can die in <48 h. Never wait.
7. Obesity → Diabetes → Expensive Regret
| Overweight
| Sneaky signs | Full-blown diabetes |
|---|---|
| Can’t feel ribs easily | Drinking/peeing excessively, plant-like walking (neuropathy) |
| Saggy belly pouch | Sudden weight loss despite huge appetite |
Most “chubby” cats are actually obese. Goal: you should feel (not see) ribs.
8. Arthritis – The Invisible Pain
Affects 90 % of cats over 12, but owners rarely notice
| Subtle signs | Obvious signs |
|---|---|
| Hesitates before jumping up | No longer jumps, cries when picked up |
| Sleeping more, less playful | Walking stiffly, litter-box accidents (can’t climb in) |
| Grooming less → greasy coat | Muscle loss along spine |
Start joint supplements (e.g., glucosamine, Adequan) at the moment you notice hesitation.
9. Lumps, Bumps & Cancer Red Flags
| Watch & wait (3-week rule) | Vet today |
|---|---|
| Small (<1 cm), movable, not growing | Rapidly growing, ulcerated, fixed to tissue |
| Soft fatty lipoma | Hard lump on belly (mammary), under jaw, or limbs |
Spay your female cat → 91 % reduction in mammary cancer.
10. The Big Three Behavioural Red Flags That Are Actually Medical
| Behaviour | Likely medical cause |
|---|---|
| Peeing/pooping outside box | UTI, kidney disease, arthritis, FLUTD |
| Hiding + not eating >24 h | Pain, nausea, dental disease, cancer |
| Sudden aggression or irritability | Pain (especially when touched), hyperthyroidism |
Never punish — investigate medically first.
Weekly 60-Second Home Health Check
| Area | Normal | Warning sign |
|---|---|---|
| Eyes | Clear, no squinting | Cloudiness, third eyelid showing |
| Mouth | Pink gums, minimal plaque | Red gums, bad breath, drooling |
| Weight | Ribs easily felt, waist visible from above | Can’t feel ribs, saggy belly |
| Coat | Shiny, grooms normally | Greasy, dandruff, bald spots |
| Litter box | 1–3 pees + 1–2 poops daily | Straining, blood, very strong odour |
| Energy | Greets you, jumps on usual spots | Hiding, low jumps, sleeping all day |
When to Call the Vet TODAY
- Not eating 24 h (kittens 12 h)
- Repeated vomiting or dry heaving
- Straining in litter box with no urine
- Laboured or open-mouth breathing
- Sudden inability to walk or extreme lethargy
- Seizure or collapse
Final Thought
Cats don’t “act sick” until they’re very sick.
But their bodies whisper warnings weeks or months earlier — in their litter box habits, appetite, grooming, and energy.
Catch those whispers and you turn emergencies into routine vet visits.
Ignore them and you’ll learn the hard way how fast a cat can crash.
Your superpower as an owner is knowing your cat’s normal and acting the moment something changes.
Do the weekly check. Trust your gut.
Your cat’s nine lives depend on the one person who watches closely enough to save them.
You’ve got this. They’re counting on you. ❤️