Last updated: October 3, 2026
Cat Health Guides
Plain-language guides to common cat symptoms and illnesses. Understand what a symptom might mean, what you can do at home, and the red flags that mean it is time to call your vet. Start with Sick Cat Symptoms for the overview, or pick a symptom below.
These guides are general information, not veterinary advice. They cannot diagnose or treat your cat. If your cat is unwell or you are worried, contact your veterinarian. For emergency signs such as open-mouth breathing, collapse, or straining to urinate with nothing produced, seek emergency care immediately.
Not sure how urgent it is?
Try the Cat Symptom Checker. Pick what you are seeing and get likely causes, a general urgency level, the emergency red flags, and the guide that covers it. It is educational triage, not a diagnosis.
Open the Cat Symptom CheckerRespiratory
Digestive and appetite
Cat Throwing Up
Vomiting causes, what the color means, and when it is serious.
Cat Diarrhea
Common causes, home care, and the red flags to watch for.
Cat Constipation
Signs of constipation, home steps, and when to see a vet.
Cat Hairballs
Why they happen, prevention, and when hairballs are a problem.
Cat Hairball Remedy
The remedies that work, from gels and diets to grooming, and how to use them safely.
Cat Not Eating
Why a cat stops eating and why it becomes urgent quickly.
Kidney, urinary and thirst
Cat Kidney Disease
Signs, IRIS stages, and management of this common senior-cat condition.
Cat UTI Symptoms
Straining, blood, and the male-cat blockage that is a true emergency.
Cat Drinking a Lot of Water
Increased thirst can be an early sign of kidney disease, diabetes, or thyroid trouble.
Cat Dehydration
How to spot dehydration and what to do about it.
Skin, coat and parasites
Cat Fleas
How to tell if your cat has fleas, the health risks, and how to get rid of them.
Ear Mites in Cats
Dark ear discharge and head shaking, and how ear mites are treated.
Ringworm in Cats
A contagious fungal skin infection, not a worm. Signs, treatment, and stopping the spread.
Worms in Cats
Types of worms, how cats get them, and safe deworming.
Cat Tapeworm Medicine
Which dewormer actually works, praziquantel, and why fleas must be treated too.
Capstar for Cats
The fast flea knockdown tablet: what it does, dosage, and where it fits a flea plan.
Flea Comb for Cats
How to use a flea comb, what to look for, and where combing fits a full flea plan.
Metabolic and hormonal
Whole-body signs
Sick Cat Symptoms
The overview of signs your cat is unwell, and when it is an emergency.
Cat Lethargic or Weak
Why lethargy matters, and why lethargy plus not eating is urgent.
Cat Fever
Normal cat temperature, signs of fever, and the human-med warning.
Cat Limping
Injury, arthritis, or something more, and when limping needs a vet.
Cat Losing Weight
Unexplained weight loss is a top early warning sign in cats.
Vaccines and prevention
How to Use These Guides
Reading your cat's symptoms without guessing
Watch for change
The most useful signal is a change from your cat's normal. A cat that suddenly eats less, drinks more, hides, or loses weight is telling you something. Note when it started and what else changed.
Symptoms cluster
Symptoms rarely appear alone. Increased thirst with weight loss points somewhere different than vomiting with diarrhea. Each guide links to the related symptoms so you can see the bigger picture.
Know the red flags
Every guide lists the emergency signs for that symptom. Breathing trouble, collapse, and a male cat straining in the litter box with nothing produced are always emergencies.
Then call your vet
These pages help you decide how urgent something is and what to tell your vet. They do not replace an exam. When in doubt, a phone call to your clinic is the safest next step.
Frequently Asked Questions About Cat Health
Common questions about spotting illness in cats
How do I know if my cat is sick?
Cats hide illness well, so watch for changes from their normal: eating or drinking more or less, weight loss, vomiting or diarrhea, hiding, low energy, changes in litter box habits, or any change in breathing. Any sudden or lasting change is a reason to call your vet. Our Sick Cat Symptoms guide walks through the signs in detail.
What are the most common cat health problems?
Some of the most common issues cat owners search for are hairballs and vomiting, coughing and sneezing, diarrhea and constipation, dental disease, and the big senior-cat conditions: chronic kidney disease, hyperthyroidism, and diabetes. Each has its own guide here.
When should a cat symptom be treated as an emergency?
Seek emergency veterinary care right away for open-mouth or labored breathing, blue, grey, or very pale gums, collapse, repeated vomiting with inability to keep water down, straining to urinate with nothing produced (especially in male cats), seizures, or a cat that has not eaten for more than a day. These cannot wait for a routine appointment.
Can I use this site to diagnose my cat?
No. These guides are general information to help you understand symptoms and decide when to seek care. They are not a substitute for a veterinary exam. Only your vet can diagnose and treat your cat.
Check Your Cat's Weight and Body Condition
Many health issues show up first as weight change. Our free tools help you track it.
Free cat printables
Keep these cat care guides handy
A rotating selection of practical cat guides chosen from our free printable library.Kitten Growth Chart
Week-by-week weight and development milestones.
Kitten Calorie Guide
Calorie targets by kitten age and weight.
Cat Feeding Guide
Portions by weight, age, and life stage.