Cats will hide when they don't feel well, making it challenging to recognize when they are sick. In today's post, our Lakewood vets share some common cat illnesses, their symptoms, and diagnosis procedures.

Your Cat's Health

As a pet parent, it is critical to track your pet's health and take him or her to the vet if he or she begins to feel ill. The following are some of the most common illnesses seen in both indoor and outdoor cats.

Common Cat Illnesses

Some illnesses are more common than others, and the illnesses most seen in indoor cats aren't always the same as those in outdoor cats. Nonetheless, there are a few common feline illnesses that all pet owners should be aware of. Here are some of the most common illnesses seen in cats by our vets.

Upper Respiratory Infections (Cat Colds)

Viruses and bacteria can make your cat develop upper respiratory tract infections. These affect their sinuses, nose, and throat. They are also quite contagious.

This illness transmits between cats living in multi-cat households, shelters, or who spend time outside. Cats infected with the virus can spread the disease to other cats in the household or in the neighborhood. Upper respiratory illness in cats has the following symptoms:

  • Coughing
  • Congestion
  • Drooling
  • Sneezing
  • Gagging
  • Fever
  • Loss of appetite
  • Nasal discharge

Feline Immunodeficiency Virus (FIV)

Feline Immunodeficiency Virus, or FIV, manifests in male outdoor cats with a tendency to fight. This serious illness spreads through bites sustained during fights, although in rare cases a female cat can pass it to her kittens.

FIV is a slow-acting virus, and symptoms may appear until years after the initial infection. FIV can weaken your cat's immune system, making your cat susceptible to many serious secondary infections.

With appropriate treatment, infected cats kept in an indoor, stress-free environment can live comfortable lives for many months or years.

If your cat has any of the following symptoms, they may be suffering from Feline immunodeficiency virus (FIV). You should seek veterinary care as soon as possible to help prevent symptoms from worsening.

Common symptoms of FIV include:

  • Enlarged lymph nodes
  • Fever
  • Anemia
  • Unexplained weight loss
  • Poor grooming
  • Disheveled coat
  • Lack of appetite
  • Diarrhea
  • Abnormal appearance
  • Inflammation of the eye
  • Inflammation of the gums and mouth 
  • Skin redness or hair loss
  • Wounds that don’t heal
  • Sneezing
  • Discharge from eyes
  • Runny nose
  • Frequent urination
  • Straining to urinate
  • Urinating outside of the litter box
  • Behavior change


If your cat cannot produce enough insulin to balance glucose levels or blood sugar, they will develop diabetes. Left untreated, diabetes can shorten a cat's life and lead to nerve disorders, health issues, and emergency situations. Treatment for diabetes in cats focuses on managing the disease and may include insulin injections. Signs of diabetes in cats include:

  • Increased urination
  • Dehydration
  • Loss of appetite
  • Coma
  • Increased thirst
  • Increased appetite
  • Vomiting
  • Motor function problems


Our veterinarians frequently see a variety of cancers in cats. Cancer begins in a cell, then attaches to the tissue beneath the skin and potentially spreads to other areas. Cancer in cats may be treatable if detected early. Cancer symptoms in cats can include:

  • Marked increase or
  • Decrease in appetite
  • Lumps that change in size or shape
  • Difficulty urinating 
  • Bad breath
  • Sores that do not heal
  • Chronic weight loss
  • Straining during bowel movements
  • Unexplained bleeding
  • Unexplained discharge

Early detection is essential for good outcomes when it comes to treating cancer in cats. Some other factors which influence the success of cancer treatment include the type of cancer, the extent of its spread, and the location of the tumor. Recommended treatments for cats diagnosed with cancer include surgery, chemotherapy, and radiation.

Can cat illnesses affect humans?

While most cat illnesses are not transmissible to humans, there are some exceptions. One example is toxoplasmosis, a parasitic infection that can be transmitted from cats to humans through contact with contaminated feces. Another example is ringworm, a fungal infection that can be passed from cats to humans through direct contact with infected skin or fur. It is important for cat owners to practice good hygiene and take precautions to prevent the spread of these illnesses.

What To Do If Your Cat Is Sick

If your cat is showing signs of any of the illnesses listed above, it's important to seek veterinary care as soon as possible. Many cat illnesses progress quickly and can become very serious quickly.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

Do you think that your cat may be sick? Contact our Lakewood vets at Red Rocks Animal Center today to book an examination for your kitty.