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  • Writer's picturePet Waggin' Pet Care Team

Signs Your Cat Might Be Sick

Disclaimer: Nothing contained in articles and/or content is or should be considered, or used as a substitute for, veterinary medical advice, diagnosis or treatment. Please refer to your veterinarian.

We know our cats are independent and pretty secretive. That’s part of what we love about them. Unfortunately, it means that sometimes we don’t know our cats are sick until they’ve developed severe symptoms. 

cat veterinary check up

Even when they do their best to hide it, some signs can tell you if your cat might be sick. We want to make it easier for you to tell if your cat is hiding an illness… or just hiding. We’ve put together a list of illnesses that are common in cats and some of the “tells” they display. If your cat is showing any of these signs, or even if you just have a feeling something is “off”, it’s time to put in a call to their vet. 

Common Cat Illnesses and Their Symptoms

Respiratory Infections- There are too many causes of respiratory infections to count. Fungi, bacteria, viruses, and protozoa make themselves at home in the warm, moist regions of the respiratory tract and then they multiply. Feline calicivirus (FCV), Feline Herpes virus, feline viral rhinotracheitis (FVR), and feline Chlamydophila felis are just a few of the respiratory infections that cats are prone to. 

Respiratory tract infections don’t always stay in the nose and lungs. They can cause inflammation in the mouth and even discharge and ulceration in the eyes. Fortunately, if your cat is otherwise healthy, these illnesses are usually treatable and will resolve with rest and medication. 

sick cat signs of a sick cat

Signs your cat might have a respiratory infection include:

  • Swollen crusty eyes

  • Lack of appetite

  • Wheezing or snorting

  • Swollen mouth

  • Lethargy

Feline Urinary Tract Disease (FLUTD)- This isn’t one disease. It encompasses most of the diseases that affect a cat’s urinary tract. It includes urinary tract infections, feline idiopathic cystitis, blockages, and uroliths. These diseases all have similar symptoms and require immediate attention from a veterinarian. Untreated uroliths can quickly turn into blockages, especially in male cats.

Symptoms to look out for include:

  • Urinating outside the box

  • Straining to urinate

  • Licking 

  • Blood in the urine

  • Yowling while urinating

Hyperthyroidism- As your cat ages, they are more likely to develop hyperthyroidism. This is a disease in which the thyroid gland produces too much of the hormones T3 and T4. Hyperthyroidism can cause secondary diseases in your cat since thyroid hormones serve a purpose in most organ systems. It is very important to take your cat to the vet if you suspect they may have hyperthyroidism. Hyperthyroidism can be managed with medication, radioactive iodine therapy, and in extreme cases surgery. 

Symptoms you should be aware of include:

  • Weight loss

  • Increased appetite

  • Increased thirst

  • Increased urination

  • Vomiting

  • Greasy unkempt fur

Diabetes- Older cats are at higher risk for developing diabetes, and just like with people, incidents are on the rise because of increasing rates of obesity. Cats are much more likely to develop Type II diabetes than to suffer from Type I. Diabetes can be managed, usually with a combination of dietary therapy and insulin injections. Diabetes can have serious complications if left untreated, so if your cat is showing symptoms, get them to the vet ASAP. 

cat injection

Common symptoms of feline diabetes include:

  • Increased thirst

  • Weight loss

  • Increased appetite

  • Increased urination

  • Sweet or fruity-smelling urine

Feline Leukemia Virus (FeLV)- Despite a reduction in rates of infection, FeLV remains the most common infectious disease in cats. It is easily passed through saliva and is transmitted from mother cats to her kittens. There is a vaccine, but it is not 100% effective at preventing infection. FeLV is a serious disease but is not a death sentence. It can’t yet be cured, but it can be treated. FeLV-positive cats should be either only cats or in a FeLV cat-only household. 

Symptoms of FeLV can take weeks or years to develop. Once they begin to develop these are the most common:

  • Loss of appetite

  • Gradual weight loss

  • Fever

  • Enlarged lymph nodes

  • Diarrhea

  • Pale gums

Dental Disease- Somewhere between 50-90% of older cats suffer from some form of dental disease. Gingivitis, periodontitis, and tooth resorption are the most common dental issues seen in cats. Dental issues affect more than just the mouth. The bacteria that thrive in diseased teeth and gums can move into the bloodstream and infect the heart and other organs. The earlier you get dental problems under control the better. Dental disease is usually managed by tooth cleaning, antibiotics, and extractions when necessary. 

cat dental check for dental disease

Some symptoms you might notice in your cat are:

  • Bad breath

  • Decreased appetite

  • Drooling

  • General smelliness (from grooming with an infected mouth)

  • Turning head to the side while eating.

Chronic Kidney Disease- Cats have delicate kidneys that start out with fewer nephrons (the part of the kidney that filters blood). This makes them much more prone to conditions like Chronic Kidney Disease. Repeated kidney infections, kidney stones, and conditions like FeLV can all contribute to your cat developing Chronic Kidney Disease. Fortunately, it can be treated if caught early enough. Your veterinarian will determine which stage of CKD your cat is in and prescribe a course of treatment. Once your cat develops CKD, they will need to maintain treatment for the rest of their life since the disease process is irreversible. 

Symptoms to watch for include:

  • Weight loss

  • Poor coat and skin

  • Bad breath

  • Increased drinking

  • Diarrhea

  • Mouth ulcers (which can cause drooling)

General Signs Your Cat Might Be Sick

Sometimes it can be hard to tell if your cat is in the early stages of an illness or just being weird. You know your cat best, so if your cat seems like they just ADR (veterinary speak for “ain’t doing right”), don’t be afraid to call your veterinarian. 

There are some general symptoms that can alert you if your cat may be getting sick. 

  • Changes in food and water consumption

  • Increased vocalizing

  • Pacing

  • Changes in litter box habits

  • Increased hiding behavior

  • Changes in skin and coat like dandruff and increased shedding

  • Licking in one area

As always, your veterinarian is your best resource if you have any questions about your cat’s health. They know your cat best and can help you come up with the best course of action.


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