Quick Summary: Cats often hide health issues until they worsen, so owners should watch for subtle signs like not eating, vomiting, or litter box changes. Key problems include dental disease, urinary issues, kidney disease, obesity, and respiratory infections, which require prompt vet attention when symptoms appear. Regular wellness exams and daily monitoring help catch problems early, improving outcomes and quality of life for cats.
Your cat may act normal while a real problem is building. A day of cat not eating, a bout of cat vomiting, or new litter box habits can look minor. Sometimes those are early cat illness symptoms. Cats hide pain well, so common cat health issues often stay hidden until they get worse.
That is why many owners miss early cat health problems. Cat dental disease, cat urinary problems, cat kidney disease, and cat obesity health risks can all start with small changes at home. You might notice cat not eating, cat vomiting, coat changes, weight loss, or subtle cat arthritis signs before anything else. Questions about when to call vet for cat often start there.
This guide covers common cat health issues and the cat illness symptoms owners actually see. It explains when to call vet for cat for cat health problems like cat diabetes symptoms, hyperthyroidism in cats, cat upper respiratory infection, fleas ticks worms cats, hairball remedies cats, FELV symptoms, and FIV in cats. The list focuses on common, easy-to-miss, or urgent cat health problems, using signs owners can spot at home, plus cat preventative care and wellness exams for cats.
Quick Comparison
| Issue | Best for | Common signs | When to call the vet |
| Dental disease | Recognizing mouth pain, bad breath, and food refusal early | Bad breath, drooling, head turning while eating, soft-food preference | Best for spotting a very common hidden cause of bad breath, drooling, and eating problems. |
| Urinary problems | Spotting emergencies and early bladder trouble | Straining, frequent trips, blood in urine, outside-box accidents | Best for recognizing litter box red flags and emergency warning signs. |
| Vomiting and digestive upset | Telling the difference between a one-off upset stomach and a real problem | Vomiting, reduced appetite, diarrhea, lethargy, dehydration | Best for understanding when a hairball is harmless and when vomiting is not. |
| Kidney disease | Understanding senior-cat thirst, weight loss, and appetite changes | More drinking, more urination, vomiting, weight loss, reduced appetite | Best for catching increased thirst, appetite loss, and weight loss early. |
| Not eating | Recognizing one of the most important early illness signs | Skipping meals, eating less, hiding food, sudden picky eating | Best for identifying one of the most important early illness signals in cats. |
| Obesity | Understanding weight-related health risks before they become chronic | Difficulty grooming, reduced jumping, low stamina, visible weight gain | Best for owners who need to understand long-term health risks from excess weight. |
| Upper respiratory infection | Recognizing cat colds and when congestion becomes serious | Sneezing, eye discharge, runny nose, lethargy, poor appetite | Best for sniffles, eye discharge, and appetite changes tied to cat colds. |
| Fleas, ticks, and worms | Understanding parasite-related skin and digestive symptoms | Itching, hair loss, vomiting, diarrhea, weight loss, skin irritation | Best for parasite-related itching, anemia risk, and overall prevention. |
| Arthritis | Spotting pain and mobility changes in older cats | Stiffness, less jumping, difficulty grooming, litter box avoidance | Best for senior cats with stiffness, jumping changes, or litter box avoidance. |
| Diabetes and hyperthyroidism | Recognizing classic endocrine disease warning signs | Weight loss, drinking more, urinating more, appetite changes, vomiting | Best for spotting classic hormonal disease signs like weight loss with drinking and urinating more. |
What to know about common cat health issues
Cats hide pain well. That is why many cat illness symptoms show up as small behavior changes first. You may notice cat not eating, less grooming, hiding, or litter box changes before you see clear signs of illness. A problem like cat vomiting, cat urinary problems, or cat dental disease can look minor at first, then get worse fast.
Early action matters. Many issues, including cat kidney disease and weight gain linked to cat obesity health risks, are easier to manage when caught soon. Routine vet visits help, but daily habits at home matter just as much.
If you are unsure when to call vet for cat, trust sudden changes in appetite, energy, breathing, water intake, or bathroom habits. Small shifts can be the first clue.
1. Dental disease
Cat dental disease is a major hidden cause of pain, bad breath, and eating trouble. Many cats keep eating even when their mouth hurts, so the signs of dental disease in cats are easy to miss.
Wary tabby cat avoiding kibble near owner
Highlights
- Bad breath in cats is a common clue, but mouth pain can also show up as drooling, dropping food, or chewing on one side. The AVMA lists these warning signs clearly.
- If your cat not eating starts suddenly, call your vet promptly. Reduced appetite or refusal to eat can get serious fast.
- Cat dental disease may also matter beyond the mouth. One large JAVMA study on periodontal disease and cat kidney disease found an association with higher CKD risk.
Specs
- Best for: Recognizing mouth pain, bad breath, and food refusal early
- Common signs: Bad breath, drooling, head turning while eating, soft-food preference
- Vet urgency: Call promptly if your cat stops eating, drools, or seems painful while chewing
- Prevention focus: Dental checks, brushing, and regular wellness exams
Pros
- Very common and partly preventable with routine care
- You can often spot subtle signs at home before a crisis
Cons
- Cats hide pain well
- Advanced disease may need anesthesia and extractions
It ranks first because it is common, often missed, and can affect appetite faster than cat urinary problems, cat obesity health risks, or even cat kidney disease.
2. Urinary problems
Urinary problems are common in cats and can turn serious fast. They range from bladder inflammation and infection to crystals, stones, and full blockage, often grouped under FLUTD.
Highlights
- Frequent litter box trips with little or no urine are a red flag.
- Pain, crying, or blood in the urine need prompt vet care.
- A cat that cannot urinate is an emergency, especially a male cat, according to Cornell Feline Health Center.
Specs
- Best for: Spotting emergencies and early bladder trouble
- Common signs: Straining, frequent trips, blood in urine, outside-box accidents
- Vet urgency: Immediate for inability to urinate; prompt care for pain or blood
- Prevention focus: More water, clean boxes, healthy weight, reduced stress
Pros
- Clear warning signs if you know what to watch for
Cons
- Blockage can be fatal without rapid treatment
It ranks high because owners often mistake it for behavior trouble, but it can become life-threatening within hours.
3. Vomiting and digestive upset
One vomit episode may be a small stomach upset. Repeated vomiting is different. Cats may throw up from hairballs, diet changes, parasites, toxins, or deeper disease, and Cornell notes frequent vomiting needs veterinary attention.
Highlights
- Hairballs happen, but frequent vomiting is not normal.
- Vomiting with low appetite, diarrhea, or lethargy is more serious.
- Ongoing vomiting can cause dehydration, and Cornell lists lethargy, poor appetite, and dry gums as warning signs.
Specs
- Best for: Telling a one-off upset stomach from a real problem
- Common signs: Vomiting, reduced appetite, diarrhea, lethargy, dehydration
- Vet urgency: Call if it repeats, lasts over a day, or comes with other illness signs
- Prevention focus: Slow diet changes, hairball control, safe home setup
Pros
- Easy to spot
- Can flag internal disease early
Cons
- Owners often downplay repeat vomiting
- Hairballs can hide a bigger issue
It ranks high because cat vomiting is common, but the pattern tells you how urgent it is.
4. Kidney disease
Kidney disease is a big concern in older cats, and it often starts quietly. You may first notice your cat drinking more, peeing more, losing weight, or eating less, which is why Cornell Feline Health Center stresses regular senior-cat checks.
Highlights
- Increased thirst and urination are classic early clues.
- Weight loss, vomiting, and poor appetite often show up later.
- Cats can seem “just older” while feline CKD screening guidance says early disease is developing.
- Prompt vet evaluation matters if thirst, appetite, or weight changes appear.
Specs
- Best for: Understanding senior-cat thirst, weight loss, and appetite changes
- Common signs: More drinking, more urination, vomiting, weight loss, reduced appetite
- Vet urgency: Prompt evaluation if thirst, appetite, or weight changes appear
- Prevention focus: Annual or semiannual wellness exams and lab screening
Pros
- Early detection can improve comfort and slow progression
- Often manageable with diet and medical support
Cons
- Signs are easy to miss until disease is advanced
- Usually chronic rather than curable
It ranks here because kidney disease is one of the most common chronic problems in cats and one of the easiest to mistake for normal aging.
5. Not eating
A cat not eating is one of the clearest signs that something is wrong. Loss of appetite can point to nausea, dental pain, fever, congestion, kidney disease, constipation, or a urinary problem, and Cornell notes that even 24 hours without food can hit a cat hard.
Highlights
- A sudden drop in appetite is often an early illness sign.
- Dental pain and nasal congestion can make eating painful or hard.
- Cats that do not eat for too long can face serious risks like hepatic lipidosis.
- Track food, water, and litter box changes together.
Specs
- Best for: Recognizing one of the most important early illness signs
- Common signs: Skipping meals, eating less, hiding food, sudden picky eating
- Vet urgency: Call promptly if your cat stops eating for a day or seems weak or painful
- Prevention focus: Monitor daily intake and book a checkup if changes last
Pros
- Easy to spot early
- Often shows up in many diseases
Cons
- Many different causes
- Cats may hide how sick they are until later
It ranks this high because appetite change is one of the most dependable early warning signs.
6. Obesity
Obesity in cats is not just about looks. Extra weight raises the risk of diabetes, joint pain, urinary problems, and a lower quality of life, and Cornell notes that many owners miss slow weight gain until daily movement changes.
Highlights
- A heavy cat may stop grooming well, jump less, and tire faster.
- Obesity puts more strain on joints and can worsen arthritis.
- It is strongly tied to diabetes risk. Cornell’s feline diabetes guide says obese cats are up to four times more likely to develop diabetes.
- Measured meals, body condition scoring, and daily play help prevent it.
Specs
- Best for: Understanding weight-related health risks before they turn chronic
- Common signs: Difficulty grooming, reduced jumping, low stamina, visible weight gain
- Vet urgency: Schedule a wellness exam if weight gain or mobility changes appear
- Prevention focus: Portion control, activity, and body condition scoring
Pros
- Often preventable with steady habits
- Weight loss can improve comfort and mobility
Cons
- Weight gain is easy to miss
- Overfeeding and inactivity can reinforce it
It ranks here because it is extremely common, often under-recognized, and affects many body systems over time.
7. Upper respiratory infection
Cat colds often start small, with a few sneezes and watery eyes. But a cat upper respiratory infection can quickly affect smell, appetite, and breathing, so mild signs should not be ignored.
Highlights
- Sneezing plus eye or nose discharge are classic cat illness symptoms.
- Congestion can make a cat not eating problem worse because smell drives appetite.
- In shelter studies, upper respiratory disease is a common problem in multi-cat settings, and stress can worsen spread and illness according to JAVMA research.
- Mouth ulcers, fever, and lethargy can show up too, especially with some viral causes reported in feline herpesvirus cases.
Specs
- Best for: Recognizing cat colds and when congestion becomes serious
- Common signs: Sneezing, eye discharge, runny nose, lethargy, poor appetite
- Vet urgency: Call if breathing is difficult or appetite drops
- Prevention focus: Vaccination, hygiene, and reducing stress
Pros
- Symptoms are easy for owners to spot
- Many cats recover with supportive care
Cons
- Can turn serious if breathing or eating is affected
- Spreads fast in multi-cat homes
It ranks here because it is common, contagious, and often first shows up in daily signs you can catch early.
8. Fleas, ticks, and worms
Parasites can make a cat miserable fast. Fleas, ticks, and worms may cause itching, hair loss, vomiting, diarrhea, weight loss, and even anemia, so this is a key part of cat preventative care. According to PetMD, cats need year-round flea and tick prevention, even indoors.
Highlights
- Itching, overgrooming, and skin irritation can point to fleas or mites.
- Worms may show up as tummy upset, weight loss, or a dull coat.
- Outdoor cats and multi-pet homes face higher risk.
- The CDC notes that fleas can also spread tapeworms, which adds to the problem.
Specs
- Best for: Understanding parasite-related skin and digestive symptoms
- Common signs: Itching, hair loss, vomiting, diarrhea, weight loss, skin irritation
- Vet urgency: Prompt care if signs last or your cat seems weak or pale
Pros
- Strong prevention options exist
- Fits routine wellness care
Cons
- Signs can look like allergies
- Reinfestation is common
It ranks here because parasites are common, preventable, and often behind mixed cat illness symptoms owners spot at home.
9. Arthritis
Arthritis is a big senior-cat problem, and it often looks like a cat who is “just slowing down.” Cats hide pain well, so small movement changes matter. Cornell notes that trouble with stairs, grooming, and litter box use can all point to joint pain.
Highlights
- Jumping less often is a common clue.
- Less grooming can mean pain or stiffness.
- Litter box avoidance may happen if entry hurts.
- FDA guidance says home changes like ramps, lower-sided boxes, and raised bowls can help.
Specs
- Best for: Spotting pain and mobility changes in older cats
- Common signs: Stiffness, less jumping, difficulty grooming, litter box avoidance
- Vet urgency: Schedule evaluation when movement or grooming changes appear
- Prevention focus: Weight management and senior wellness exams
Pros
- Often improves with pain care and home changes
Cons
- Owners often mistake it for normal aging
It ranks here because arthritis is common, subtle, and often treatable once you catch it.
10. Diabetes and hyperthyroidism
These are common hormone diseases, mostly in middle-aged and older cats. Watch for a pattern: weight loss, thirst, peeing more, and appetite changes. According to Cornell’s feline health center, hyperthyroidism often causes weight loss despite a strong appetite.
Highlights
- Weight loss despite eating well is a big clue.
- Both diseases can cause cat drinking more water and larger urine clumps.
- Hyperthyroidism in cats may look like restlessness or extra energy, not sickness.
- Diabetes is more common in overweight cats, and AAHA notes obesity is a key risk factor.
Specs
- Best for: Recognizing classic endocrine disease warning signs
- Common signs: Weight loss, drinking more, urinating more, appetite changes, vomiting
- Vet urgency: Prompt evaluation if weight or thirst changes persist
- Prevention focus: Routine screening and body-weight management
Pros
- Often responds well when caught early
Cons
- Easy to mistake for aging or normal appetite shifts
It ranks here because owners may miss the pattern until the disease is already advanced.
How to Choose the Right Vet Visit Timing for Cat Health Issues
Use a simple triage rule: emergency, same-day call, or routine booking. That keeps guesswork out of the moment.
- Go to emergency care now if your cat cannot urinate, struggles to breathe, collapses, or has repeated severe vomiting. These can turn critical fast.
- Call your vet the same day if your cat has not eaten for about 24 hours. Cats can go downhill quickly, especially if they already seem tired or nauseous.
- Book a regular visit soon for slower changes like weight loss, drinking more, a rough coat, bad breath, less jumping, litter box accidents, or sleeping much more than usual.
- Track the last 24 to 48 hours before you call. Write down appetite, water intake, litter box output, energy, grooming, and any vomiting or diarrhea. Clear notes help the vet judge urgency.
- Do not write things off as “just age” or “just behavior.” Cats hide pain well. Small shifts often matter.
If you are unsure, treat sudden change plus poor appetite as a reason to call.
Spotting cat health problems early can save stress, money, and sometimes your cat’s life. If you want more plain-English pet care advice you can actually use, visit Your House Pet. You’ll find trusted guides that help you track warning signs, make smarter care choices, and know when home care is enough – and when it’s time to call your vet fast.
Frequently Asked Questions
Q1: What are the most common health problems in cats?
Common issues include dental disease, vomiting, diarrhea, fleas, worms, obesity, urinary trouble, kidney disease, diabetes, skin problems, and arthritis. Many start with small changes in eating, litter box use, energy, coat, or behavior.
Q2: How do I know if my cat is sick?
Watch for hiding, less appetite, vomiting, diarrhea, weight loss, bad breath, limping, coughing, sneezing, drinking more, or litter box changes. Cats hide pain well, so even subtle shifts that last more than a day matter.
Q3: When should I take my cat to the vet?
Go fast for trouble breathing, straining to pee, collapse, seizures, severe pain, repeated vomiting, blood loss, or toxin exposure. Book a visit soon for appetite loss over 24 hours, weight loss, ongoing diarrhea, or behavior changes.
Q4: What are the signs of dental disease in cats?
Bad breath, drooling, pawing at the mouth, chewing on one side, dropping food, red gums, and less interest in dry food are common clues. Dental pain can also show up as irritability, hiding, or poor grooming.
Q5: Why is my cat vomiting?
Cats may vomit from hairballs, diet changes, eating too fast, parasites, food intolerance, toxins, kidney disease, or gut problems. One mild episode may pass. Repeated vomiting, blood, lethargy, or appetite loss needs a vet check.
Q6: What are the symptoms of kidney disease in cats?
Early signs often include drinking more, peeing more, weight loss, poor appetite, and dull coat. Later, you may see vomiting, weakness, bad breath, dehydration, and mouth ulcers. Older cats need prompt checks for these changes.
Q7: How can I prevent urinary problems in my cat?
Feed moisture-rich food when suitable, keep fresh water in several spots, clean litter boxes daily, reduce stress, and help your cat stay lean. Male cats that strain, cry, or pass little urine need urgent care right away.
Q8: Is my cat overweight?
You should feel the ribs with light pressure, and your cat should have a waist from above. If the belly hangs low and movement slows, extra weight is likely. Your vet can confirm body condition and safe targets.
Q9: What causes diabetes in cats?
Extra weight is a major risk. Age, low activity, some medicines, and other hormone problems can add to it. Common signs are more thirst, more urine, weight loss despite eating, and weakness in the back legs.
Q10: How can I keep my cat healthy as they age?
Schedule regular vet visits, track weight, support dental care, keep exercise gentle and daily, and watch for pain, thirst, or litter box changes. Senior cats do best with early testing because small signs can point to big problems.
