Cats are really good at hiding pain. Because of this, many of the diseases that commonly affect felines can get pretty advanced before anyone realizes there is a problem. Your cat could be sick and still seem totally normal.
Most cats will not act obviously sick. They do not complain. They do not limp dramatically. Instead, you might notice small changes in behavior, like a skipped meal, more time spent alone, or drinking more water than usual.
Sometimes the signs are so subtle that you question yourself. But paying attention to the details matters, because with cats, the signs of illness are rarely obvious.
Which Diseases Affect Cats Most Often?
Over the course of their lives, cats can encounter a wide variety of diseases. Some illnesses spread through contact between infected animals. Others develop slowly as a cat’s body changes with age. Let’s go over some of the most common feline diseases.
Infectious Diseases and Their Symptoms
Cats can get infected by viruses, bacteria, or parasites. These diseases most often spread through close contact, bites and scratches, shared spaces, or contaminated environments. The good news is that the risk for many of these diseases can be reduced or prevented with vaccinations.
- Feline Upper Respiratory Infections (URI): Sneezing, nasal discharge, coughing, watery eyes.
- Feline Leukemia Virus (FeLV): Weakens the immune system and increases susceptibility to illness. Symptoms may include fever, weight loss, swollen mouth or lymph nodes.
- Feline Immunodeficiency Virus (FIV): Long-term immune suppression, often spread through bite wounds. Symptoms may include fever, lethargy, weight loss, swollen lymph nodes.
- Rabies: A fatal viral disease affecting the nervous system and preventable with vaccination. Cats may exhibit fever, behavior or temperament changes, excessive drooling, etc.
- Intestinal Parasites: Worms or protozoa that can cause diarrhea, weight loss, or poor coat quality.
Chronic Diseases and Their Symptoms
Chronic conditions are not contagious. They develop gradually and most often affect senior cats. But because chronic diseases progress so slowly, many people simply chalk it up to aging and adjust to the changes in their cat’s behavior without realizing anything is wrong.
- Chronic Kidney Disease (CKD) causes symptoms like increased thirst, weight loss, lower energy.
- Diabetes Mellitus can have symptoms like Increased thirst and urination, and weight loss, even with a strong appetite.
- Hyperthyroidism causes weight loss, restlessness, and rapid heart rate.
- Dental Disease shows up as inflamed gums, bad breath, or discomfort while eating.
- Arthritis in cats can look like stiff movements, hesitation to jump, or reduced mobility.
Signs Your Cat May Be Sick
Cats are quiet about discomfort, so it’s up to you to watch for clues. Behavior shifts can be telling. A cat that once jumped onto countertops might stop entirely. A social cat may retreat more often than usual. A habitual groomer might not take as many baths.
Changes in appetite, like eating less or drinking more, are often the first clue. Gradual weight loss can be easy to miss, so make sure to go to the vet for a weigh-in at least once a year.
Litter box changes also matter. Straining. Diarrhea. Urinating outside the box when that has never been an issue before.
Vomiting that happens repeatedly should not automatically be dismissed as hairballs. Always check your cat’s vomit before you clean it up to see if it contains anything strange. And if your cat is hacking and coughing but not vomiting, make a veterinary appointment right away.
Some symptoms should never wait. Difficulty breathing, persistent diarrhea, and sudden or extreme lethargy all require urgent care.
How to Prevent Common Feline Diseases
Routine Veterinary Care
Vaccinations and booster shots are the best way to protect your cat from contagious diseases. Wellness exams help our vets identify health problems before they advance too far. And occasional lab work can detect kidney problems or metabolic changes long before symptoms appear.
Nutrition and Weight Management
A balanced diet supports normal organ function and stronger immunities. Overfeeding increases the risk of weight gain and chronic diseases like diabetes and arthritis. Measuring portions may feel silly, but over the years, this precaution can really make a difference.
Parasite and Infection Prevention
Flea, tick and routine dewormings help reduce the risk of parasite-related disease. An indoor lifestyle will also reduce your cat’s exposure to potential infections.
Helping to Keep Cats Healthy in Harker Heights
Feline diseases can range from treatable infections to long-term chronic illnesses. But bringing your cat in for veterinary exams and acting quickly if something seems off can help them live a longer, healthier life.
We never want a pet to live in pain, so if you’re worried about your cat, please contact Aztec Pet Hospital to make an appointment. We are here to listen, evaluate the situation, and help you move forward with clarity.
Photo by Zheng Kai on Unsplash used with permission under the Creative Commons license for commercial use 03/18/2026