Signs & Symptoms of Immune Disorders in Cats

Persian cats are prone to immune-related fungal infections.
i Jupiterimages/ Images

If your cat—let's call her Princess—is healthy, her immune system fights off germs. If Princess has an immune disorder, her system doesn't just fight nasty germs and other foreign invaders. It also attacks her own cells, leading to a host of health problems.


There are four basic types of immune-related reactions, numbered one through four. They range from simple allergies to tumors and life-threatening diseases such as feline immunodeficiency virus (FIV). To be safe, if you suspect there's a problem, consult an experienced veterinarian regarding the health and treatment of your pet.

Type I

Princess can develop localized Type I reactions, known as anaphylaxis, from bug bites, medications or food. She can also develop a systemic reaction. Watch for excessive scratching, vomiting, diarrhea, restlessness, pale or bluish-tinted gums, salivation and problems breathing. In extreme cases, your cat may suffer from convulsions or even death, so act swiftly to protect her.

Type II

Your veterinarian may not be able to determine the exact trigger for a Type II reaction. It could be a virus, medication or disease. Keep a close eye on your cat for intestinal issues such as diarrhea or vomiting. She may also develop a fever, swollen joints or joint pain. The Merck/Merial Manual for Pet Health lists thrombocytopenia and hemolytic anemia as the most common Type II reactions. These cause jaundice, pale gums, listlessness and excessive bleeding. If your favorite feline develops pimple-like bumps or crusts on her skin, she may be suffering from a Type II immune disorder, such as pemphigus.

Type III

Type III immune disorders commonly cause inflammation in vital organs—your cat's kidneys, brain, lungs or skin. The symptoms depend on which organs the disorder affects. General signs of ill health, such as fever, fatigue, muscle weakness, diarrhea and vomiting, can occur. You might also find that your cat is thirsty all the time. She may begin to walk funny, staggering around or running into furniture or random objects. Check her skin for rashes, and watch her litter box habits. If she has problems urinating—going too little or too much—she may have a disorder of the kidneys called glomerulonephritis.

Type IV

Have you heard of feline immunodeficiency virus or feline leukemia virus? If so, you already know something about Type IV immune disorders. Type IV disorders are caused by viruses, parasites, genetic inheritance and bacteria and can lead to some seriously scary health problems for your cat. Your cat's bones can become weak and diseased, leading to fractures. She may develop tumors or fungal skin infections, have problems breathing, lose weight and become easily fatigued. Skin lumps and rashes, diarrhea, excessive urination and loss of appetite are all indications your cat needs help.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

the nest