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Pet Health

5 Most Common Terminal Cat Diseases

Although many feline diseases are preventable, a few can be terminal if left untreated or unnoticed. Here are five common terminal cat diseases.

Dr. Bethany Hsia

April 17, 2023

Watching our cats get sick is one of the most challenging parts of being a pet parent. However, knowing what they're going through and how you can help keep them comfortable and happy is one of the best ways of ensuring they're properly cared for.

Below are the five most common terminal cat diseases, including their clinical signs and care options.

1. End-Stage Kidney/Renal Failure

Kidney disease can occur at any stage of a cat's life, although it's most common in older cats. Chronic kidney disease typically develops later in life, while acute kidney disease can affect cats of any age, resulting from an injury, illness, or other triggering incident.

Chronic kidney disease is incurable but can be managed with the appropriate diet, medications, and fluids. However, the progression of kidney disease in cats may become terminal.

Clinical signs of end-stage cat renal failure may include:

  • Lethargy and unkempt coat
  • Loss of appetite and associated weight loss
  • Incontinence
  • Large volume of dilute urine leading to polydipsia (excessive thirst)
  • Dehydration
  • Halitosis
  • Anemia (observed as pale mucous membranes)
  • Behaviors that differ from their typical temperament, including hiding, pacing, or excessive vocalization

2. End-Stage Intestinal Lymphoma

Lymphoma is a cancer of the lymphatic system. While it can affect many parts of the body, it is most commonly found in cats' gastrointestinal (GI) tract.

Depending on the cell type of the cancer, it's possible to achieve remission with appropriate treatment. However, this cancer can be aggressive, and the best option for pet owners is to consult with a vet to determine the type and progression of the disease to assess what steps can be taken.

Consider the following clinical signs of end-stage cat intestinal lymphoma:

  • Vomiting
  • Diarrhea
  • Loss of appetite
  • Weight loss
  • Lethargy
Common Terminal Diseases in Cats

3. Feline Immunodeficiency

Feline immunodeficiency virus (FIV) is a viral disease most commonly transmitted from cat bites. FIV-infected cats have severely compromised immune systems, which makes them vulnerable to secondary infections.

To prevent the spread of this disease in cats, keeping FIV-positive cats indoors is recommended. This also ensures immunocompromised cats will not be unnecessarily exposed to viral infections and infectious diseases.

There is no cure for FIV. However, the disease itself is asymptomatic after the initial phase (lymph node enlargement, fever, inappetence). Pet parents often have many beautiful years with their FIV-positive with regular vet visits and a close eye kept on their health.

If you're a pet parent whose cat has FIV, monitor them for changes in their habits or demeanor. Doing so can help you quickly respond to anything that might indicate a worsening of their condition. In addition, regular vet visits are essential for monitoring any changes in their health.

Related content: How to decide what's right for my pet?

4. Feline Leukemia

Feline Leukemia Virus (FeLV) is a common and highly contagious disease that affects cats their entire lives. Like cats with FIV, FeLV-positive cats are at a higher risk of contracting secondary diseases like cancer and anemia and should be kept indoors.

While FeLV is untreatable, it can be managed. Pet parents should invest in regular vet visits and closely monitor their cat's health.

Common clinical signs of end-stage feline leukemia include:

  • Weight loss
  • Diarrhea
  • Secondary eye and skin conditions
  • Loss of appetite
  • Pale or inflamed gums
  • Inflamed lymph nodes

If your pet has been diagnosed with FeLV, speak with your veterinarian about the appropriate next steps to manage the virus.

5. Uncontrolled Diabetes

Diabetes is a disease that most commonly affects male, adult cats and can sometimes be challenging for pet parents to manage. Weight is another risk factor. Obese cats are four times more likely to suffer from diabetes.

Most cats require insulin treatment and will likely need a specialized diet. However, despite the diagnosis, many cats live long, healthy lives so long as their diabetes is managed. The issues arise when diabetes gets out of control, so pet parents should be aware of the signs and seek veterinary care quickly if they occur.

Clinical signs of uncontrolled diabetes include: (Speak to your vet about any of the diabetes signs below if you notice any.)

  • Polyuria (excessive urination)
  • Polydipsia (excessive thirst)
  • Weight loss despite appropriate appetite
  • Poor coat condition
  • Diarrhea
  • Vomiting
  • Increased appetite
  • Lethargy
  • Plantigrade stance (heels touching the ground when they stand or walk)
uncontrolled diabetes in cats

Making the Best Choice for Your Feline Friend

Gaining a better understanding of your pet's condition can help you navigate your options to keep them healthy and comfortable. The first step is always consulting a veterinarian for correct diagnosis and care.

When the quality of life is compromised, or a disease gets to a terminal stage, the most compassionate choice is often seeking out end-of-life services to relieve the suffering of a beloved companion.

CodaPet is here to help you navigate this challenging decision. When the time is right, you can book an appointment with one of our licensed and compassionate vets. 

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


Dr. Bethany graduated from the University of Illinois College of Veterinary Medicine in 2010. After graduation, she moved west. Dr. Bethany spent a year at a small animal exclusive practice in Washington state, where she was first introduced to in-home euthanasia.  Read More