Respiratory Virus Complex are the three respiratory viruses that can also be inhaled by kittens cause varied symptoms from sneezing, runny eyes and nose, ulcers in the mouth, and pneumonia. Chlamydia, Rhinotracheitis, and Calici virus protection are all in the combination vaccine.

Herpes Virus is common in cats and kittens but a vaccine is not available. Sneezing and eye discharge are the most common symptom.

FELV: Feline Leukemia is the most common viral disease in cats. The virus is contracted either through the uterus in unborn kittens, through grooming, the bite of another cat, or contact from saliva and urine from an infected cat. The symptoms of this disease vary greatly from fever to forms of cancer. It is difficult to diagnose leukemia on the symptoms alone. Blood tests are valuable as an aid in diagnosing the disease but sometimes the virus can hide in the bone marrow of an infected cat for years with a negative leukemia test. Testing before vaccination is recommended. Cats with leukemia will have lowered immune systems and can remain carriers for life. Positive cats are susceptible to other infections due to a depressed immune system.

Feline Immunodeficiency Virus (FIV) attacks the cats body much like HIV (AIDS) does in humans. The symptoms vary depending on the cat but the immune system is always lowered. Positive cats never get rid of the virus and are susceptible to other conditions due to a depressed immune system. The virus is spread through the bite of another cat. Fortunately the incidence of FIV is not high for indoor cats.

Feline Infectious Peritonitis is a very serious disease that is almost always fatal. The virus that causes FIP is difficult to test for and the symptoms in cats are so varied the diagnoses is mostly an educated guess. Vaccinations to cats is controversial as many veterinarians feel there is not enough infection in the cat population to warrant the vaccination. This disease has a tendency to affect cats under 2 years of age and cats over 9 years of age.