Common Cat Health Issues by Life Stage

Last updated May 18, 2026 · 8 min read

Different problems show up at different cat ages. Knowing what’s common at each life stage makes it easier to spot trouble early and easier to filter out the things that aren’t urgent. This isn’t a comprehensive list; it’s the issues a small-animal vet sees most often by age group, with the warning signs that warrant a call.

Kittens (0–6 months)

Intestinal parasites

Roundworms, hookworms, tapeworms, giardia, and coccidia are all common in kittens, often acquired from the mother. Signs include pot belly, soft stool, mucus or blood in stool, poor weight gain. Standard practice is to deworm at every kitten vaccine visit, even if you don’t see worms.

Upper respiratory infections (URI)

Feline herpesvirus and calicivirus are extremely common in shelter and rescue kittens. Sneezing, runny eyes, congestion, low-grade fever. Most resolve in 1–2 weeks with supportive care; severe cases need antibiotics for secondary bacterial infections.

Fleas and flea anemia

A heavy flea burden in a small kitten can cause life-threatening anemia. Pale gums in a young kitten are an emergency. Use kitten-safe flea prevention only. Some adult products are toxic to young kittens.

Panleukopenia

Feline distemper. Vaccine-preventable, often fatal in unvaccinated kittens. Sudden lethargy, severe vomiting and diarrhea, dehydration. Any unvaccinated kitten with these signs needs immediate vet care.

Young adult cats (1–6 years)

Urinary tract issues (FLUTD)

Feline lower urinary tract disease is one of the top reasons young adult cats see a vet. Symptoms: straining to urinate, blood-tinged urine, frequent small trips to the litter box, urinating outside the box. In male cats, a fully blocked urethra is a medical emergency. Without treatment it’s fatal within 24–48 hours. Any male cat straining unsuccessfully needs to be seen the same day.

Dental disease

By age 3, most cats have some dental tartar and may have early gingivitis. Bad breath, drooling, dropping food, or pawing at the mouth are signals. Untreated, dental disease progresses through middle age and contributes to chronic systemic inflammation.

Trauma

Young cats, especially outdoor or indoor/outdoor cats, are at highest risk for vehicle trauma, falls (“high-rise syndrome” from open windows), bite wounds, and other injuries. Most can be prevented by keeping cats indoors.

Stress-related illness

Idiopathic cystitis (FIC) is essentially urinary inflammation driven by stress. Multi-cat households without enough resources (litter boxes, water, vertical space) commonly produce stress cystitis in one or more cats. Often misread as a behavior issue.

Mature cats (7–10 years)

Obesity

The most common preventable health issue in mature cats. Indoor activity drops, but food usually doesn’t. The result: gradual weight gain, increased diabetes risk, joint stress, and shortened lifespan. A body condition score of 4–5 out of 9 (5 is ideal) is the target.

Early kidney disease (CKD)

Chronic kidney disease is the most common chronic condition in older cats. It begins quietly (mildly elevated kidney values on bloodwork, increased thirst, slight weight loss), sometimes years before clinical symptoms. Annual bloodwork from age 7 catches this stage, where dietary and management changes can extend kidney function meaningfully.

Hyperthyroidism

Caused by a usually-benign thyroid tumor that secretes excess hormone. Classic signs: weight loss despite a strong appetite, increased thirst, restlessness, sometimes vomiting or diarrhea. Routine senior bloodwork screens for it, and it’s very treatable with medication, diet, surgery, or radioactive iodine.

Dental disease (continued)

By age 7–8, many cats have moderate to severe dental disease and benefit from a professional cleaning under anesthesia. Untreated dental disease at this age contributes to kidney decline through chronic infection.

Senior cats (11–14 years)

Arthritis

Hugely under-diagnosed. Over 60% of cats past age 6 have arthritic changes on x-ray, and the share only climbs from there. Cats don’t limp like dogs; they reduce jumping, shift sleep spots downward, and stop grooming hard-to-reach areas. Modern treatment options including monoclonal antibody injections (frunevetmab) have changed senior cat comfort enormously.

Diabetes

Type 2 diabetes is common in overweight middle-aged and senior cats. Increased thirst, increased urination, weight loss despite a good appetite. Reversible in many cats if caught early and managed with diet and insulin.

Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common heart condition in cats. It’s often silent until a sudden event: respiratory distress, sudden hind-end paralysis from a clot, or sudden death. Routine listening can catch a murmur; echocardiography confirms it. Maine Coons and Ragdolls have known genetic predispositions.

Cancer

Lymphoma is the most common cat cancer, usually intestinal. Weight loss, intermittent vomiting, decreased appetite. Treatment outcomes vary widely; some forms respond well to chemotherapy.

Geriatric cats (15+ years)

Advanced CKD

Most cats at this age have some degree of kidney decline. Management involves prescription diet, subcutaneous fluids (often given at home), phosphate binders, and blood pressure monitoring. Many cats live years with managed CKD.

Cognitive dysfunction

Feline dementia. Nighttime yowling, disorientation, broken litter habits, withdrawal or new clinginess. Real medical condition, increasingly recognized and increasingly manageable with environmental support and nutritional intervention.

Hypertension

High blood pressure secondary to CKD or hyperthyroidism. Sudden vision loss is sometimes the first sign. An emergency. Routine blood pressure checks at senior visits catch it earlier.

Constipation

Common in geriatric cats from a combination of dehydration, reduced activity, and arthritis. Increased water intake, dietary fiber, and sometimes prescription laxatives help.

The universal warning signs

Regardless of age, these warrant a vet call:

• Not eating for more than 24 hours. Cats develop hepatic lipidosis (fatty liver) quickly with appetite loss; this is more urgent than it is in dogs.
• Vomiting that won’t stop, or vomiting blood.
• Straining to urinate without producing urine, especially in males. Same-day emergency.
• Difficulty breathing, open-mouth breathing, rapid breathing at rest.
• Sudden hind-leg weakness or paralysis. Possible aortic thromboembolism. Emergency.
• Yellow gums or skin (jaundice).
• Sudden blindness or pupils that don’t respond to light.

Knowing your cat’s life stage is the starting point for knowing what’s likely and what’s worth watching for. Use our cat age calculator to place your cat on the AAHA scale and get a quick read on what care that stage typically calls for.

The most useful habit

The shift to twice-yearly vet visits (encouraged from the mature stage at 7, standard from age 10), with senior bloodwork from age 10, catches more issues earlier than any other single move. Most age-related cat conditions are manageable when caught early and difficult when caught late. The visit cadence is the lever.

Written by the Cats Age Calculator editorial team · How we research & fact-check