In general, viral organisms cannot live and reproduce except within the living cells of the cat (host). This one main and important characteristic separates viruses from bacteria. Viral infections can be picked up from the air, soil or other inanimate objects. Most viruses, however, cannot and do not survive very long outside of the cat. The major exception to this rule would be the feline distemper virus that can survive for many months in the environment. It is also important to note that viruses that infect cats do not infect people, and visa versa. Many cat owners erroneously think that their cat is safe in their house or backyard. FALSE! Although some diseases do require some degree of cat to cat contact, viruses cannot be kept out, and often owners or the wind carry deadly disease right to the cat on a regular basis. For this reason preventative vaccination is extremely important.

Feline calicivirus is a relatively common virus that can cause upper and lower respiratory disease in cats, especially in young kittens. Often, this virus combines with other agents to cause what is known as Feline Upper Respiratory Disease Complex. By itself, calicivirus can cause signs of sneezing, nasal discharge which may become thick, conjunctivitis, pneumonia and ulcers of the lips and gums (stomatitis). Arthritis occurs in a few rare cases. Most cats can recover with treatment but many become chronic carriers of the disease.  ((Oral Ulcers))

Diagnosis is based on the history and physical signs although blood counts and X-rays may be useful to evaluate the extent of the illness. It is generally impractical to identify the virus directly. Cats that recover and become chronic carriers either have no symptoms or will show signs including ulcerated gums, periodontitis, loss of teeth, chronic conjunctivitis and chronic rhinitis. What is worse is that these cats chronically produce and shed virus that can then infect other cats.

Most cats respond well to antibiotics, fluid therapy if dehydrated and nutritional support including tube feeding if needed. Keeping the cat's eyes and nose clean and using eye ointments may also be helpful in speeding recovery. A high percentage of these cats do recover but are not immune for life so regular vaccination is advised for all cats.

Feline distemper is actually caused by a parvovirus and produces disease similar to that seen in the dog. Like other parvoviruses, this one can remain in the environment for long periods of time, easily being moved about by other animals, birds, insects or on human clothing. Cats can become infected either by contact with the secretions of infected cats or via objects on which the virus might reside. While most cats affected are under 5 months old, cats can become ill at any age.

Once infected, the virus rapidly multiplies inside the cells of the intestines, lymph nodes and bone marrow. Clinical signs include a high fever, complete loss of appetite, depression, vomiting, diarrhea, dehydration and death if not treated properly. If a pregnant female becomes infected, infertility and abortions may occur. If the kittens do survive to term, brain damage may be present causing them to shake and stagger. This condition is known as Cerebellar Hypoplasia. Diagnosis is based on the history including vaccination status, symptoms present, blood counts and serum chemistries.

Most cats can be saved if rapid attention is given. IV fluids and electrolytes, antibiotics to control secondary infection, anti-vomiting medications and in some cases blood or serum transfusions are all useful. These cats do require intense nursing care but if they survive they can recover completely and lead an otherwise normal life. Vaccination can readily prevent this disease.

The feline immunodeficiency virus is a relative of the feline leukemia virus and causes a disease syndrome similar to AIDS in humans. Cats are most often infected by being bitten by another infected cat although other modes of transmission are possible. Mild symptoms may occur shortly after initial infection followed by a long phase where the virus remains dormant and few signs are present. Stress or other disease-causing agents become involved to later cause full and active illness.

Clinical signs are as follows: After first exposure a mild fever and enlargement of the lymph nodes may be present. During the latent phase no signs or only a mild lymph node enlargement could be all that occurs. With the active phase, stomatitis, gingivitis and moderate to severe periodontitis are most often seen. Other times, chronic diarrhea, generalized weight loss, fever, unusual behaviors, seizures and various repeated infections will be observed.

Diagnosis is based on history, clinical signs, FIV testing, FeLV testing, blood counts, serum chemistries, urinalysis and X-rays. There is no treatment or vaccination for this disease. AZT may slow the infection and antibiotics can be used for secondary infections. Good general care, high quality diets and prompt attention to any symptoms that arise can keep these cats living a relatively healthy life.

Feline infectious peritonitis is an old term for the diseases caused by one variant of the feline coronavirus. The coronavirus that causes FIP is hard to distinguish from the one that is of little or no consequence. Most cats that become ill are under 2 years of age. As the virus does not survive well outside the cat, cat-to-cat transmission is probably the most common way for a cat to become infected although inanimate objects are suspected to spread the disease in some cases. Many cats with the disease are also positive for feline leukemia.

There are two common forms of the disease. The wet or effusive form where fluid builds up in the abdomen or chest cavities, and the dry or noneffusive form where damage to various organs will occur without fluid accumulation. The term feline infectious peritonitis came from the fact that some cats have fluid in the abdomen, but it needs to be clarified that this disease has no relation to true forms of peritonitis.

Clinical signs may develop months after the initial infection, unfortunately allowing the disease to become greatly advanced before a diagnosis is possible. Cats with the wet form of the disease will show signs of fever, weight loss, decreased appetite, a swelling of the abdomen and/or difficulty breathing. With the dry form the symptoms vary greatly depending upon which organs are being affected. Fever and weight loss is often present but other signs may include uveitis, blood within the eye, neurologic disease, kidney disease and liver dysfunction. ((FIP)) ((FIP2))

Diagnosis can be quite difficult. There are tests for FIP but they are not very specific and reliable in many cases. History, clinical signs, blood counts, serum chemistry, urinalysis, FeLV testing, fluid analysis if fluid is present and biopsy of affected organs are all useful to diagnose the condition.

TREATMENT OF FIP

There is no curative treatment for this disease. Cortisone type drugs may provide temporary relief of symptoms. Many cats are quite ill by the time a diagnosis is obtained and euthanasia is the only humane alternative. Cats exposed to infected cats should be tested for FeLV and FIV and if found negative, vaccinated for FIP. While there are questions about the true protective ability of the currently available FIP vaccine, it remains the only and best alternative at this time.

Feline leukemia virus certainly ranks as the number one agent of death and disease in pet cats. The virus is common and prevalent in the domestic cat population. The feline leukemia virus is unstable outside of the cat so transmission must occur directly between cats. Most cats are infected when young. Kittens can become infected before or shortly after birth.

Any cat exposed to the virus has the possibility of several different outcomes:

1. The cat may rid itself of the virus and develop natural immunity against infection.
2. The virus may cause some type of FeLV related disease.
3. The virus may become dormant causing no immediate problem but later surfacing to cause illness.
4. The cat may mount a partial immune response, not becoming ill but carrying and spreading the virus to other cats.

Cats that are tested and found not to harbor the virus should be vaccinated on a regular basis. Cats that are tested FeLV positive but are not ill should be kept inside and segregated from negative cats. These cats should never be allowed to roam free. If they test negative at a later time they may be vaccinated and associated with other felines. Positive cats should have vaccinations against all other contagious diseases.

There are "treatments" for cats with systemic illness but most cats with active disease syndromes will die or need euthanasia to prevent suffering.

Cats with FeLV that do become ill may develop a wide variety of diseases including:

Lymphoid leukemia, lymphosarcoma, myelogenous leukemia, nonregenerative anemia, myelofibrosis, erythemic myelosis, lymph node hyperplasia, apalastic anemia, enteritis, liver disease, infertility, fetal abortions, glomerulonephritis, neurologic disease, stomatitis, periodontitis, chronic rhinitis, and various skin infections.

Clinical signs can include fever, weight loss, loss of appetite, enlarged lymph nodes, oral inflammation, nasal discharge, dehydration, weakness, paralysis, open sores, diarrhea, trouble breathing and pale gums. In short, there are many possible combinations of symptoms that can be seen depending on which disease syndrome the virus causes. A good rule of thumb is that if the cat is ill and not vaccinated for FeLV, test it, and if the test is negative be thankful and move on.

Diagnosis is based on history, physical examination, feline leukemia testing, blood counts, serum chemistries, urinalysis and X-rays. A biopsy of nodes of affected organs may also be useful in some cases. If other cats reside in a household with a cat determined to have FeLV, these cats should be immediately tested and if negative, vaccinated before they can become ill. 

Per se, there is no specific treatment for the feline leukemia virus and thusly, FeLV related diseases. With that said, there is a plan of action when faced with an ill cat that is FeLV positive. First, test and vaccinate or segregate any other cats in the household based on their FeLV status. Bacterial infections secondary to FeLV can be treated with antibiotics. (Skin, nasal infections) Assist or stimulate bone marrow function if needed with supplements, anabolic steroids or erythropoietin. Chemotherapy can be used to treat the various types of cancer.

There are a number of experimental therapies that have been used to "treat" ill cats or to try to prevent illness in well but positive animals. These are listed here for informational purposes only as none are considered reliable cures. These include acemannen, interferon, serum (antibody) transfusions, blood transfusions, bone marrow transplants, hyperthermia, diethycarbamazine, cytokines, AZT, immunoreglan, suramin, ImuVert, BCG, foscarnet, dextran sulfate and several other drugs too experimental to include herein. If a person wishes to treat a FeLV positive cat, careful and thoughtful consultation with a qualified veterinarian is essential. Vaccination of positive cats is not effective or ever advised although positive cats should have vaccinations against all other contagious diseases.

Rabies is a viral illness that attacks the nervous system of the cat and other warm-blooded animals. An animal or man gets rabies by being bitten by an infected animal, and on rare occasion through contact with infected bodily fluids. When the cat is bitten, the virus replicates in peripheral nerves, travels to the brain and spinal cord where further damage is inflicted, and lastly spreads to other tissues allowing it to infect another animal. In the wild, bats, foxes, raccoons and skunks all carry and promulgate the illness. Because vaccination of dogs is common while cats are often neglected, there tend to be more cases of rabies in cats than in dogs.

An infected cat will have clinical signs that are divided into three phases. The first 2-3 days post exposure there will be mild behavioral changes that may go unnoticed. A mild fever, dilation of the eyes, and extreme pain around the bite wound will usually be present. The next phase is known as the "furious phase". For 2-5 days cats will be excitable, aggressive and may attack without any provocation. Staggering, salivation and muscle tremors may also be present during this phase. The last phase is known as the paralytic phase and lasts only a few days until the cat dies. For the final 2-4 days of the infection, the cat may seizure, a general paralysis will overtake the feline and death will occur after the patient falls into a coma.

Diagnosis is based on clinical signs and a special IFA test performed on brain tissue from the dead animal. If a cat bites a human, it will be quarantined for about 10 days for observation. If no signs are present, all involved can rest easily. Cats showing clinical symptoms or animals otherwise killed after a bite will (MUST) have their brain examined by this IFA test for rabies. Since this is such a serious human health hazard, all cats older than 4 months of age should receive regular rabies vaccination. There is no treatment for feline rabies. ANY cat suspected of having rabies should be handled with extreme caution.

Feline rhinotracheitis, caused by the feline herpesvirus, is a relatively common cause of upper and lower respiratory disease in cats, especially in young kittens. Often, this virus combines with other agents to cause what is known as Feline Upper Respiratory Disease Complex. By itself, herpesvirus can cause signs of sneezing, coughing, a nasal discharge, salivation, conjunctivitis, ulcerative keratitis and pneumonia. Most cats can recover with treatment but kittens may suffer a relatively high death rate. Recovered cats can become chronic carriers of the virus. 

Diagnosis is based on the history and physical signs although blood counts and X-rays may be useful to evaluate the extent of the illness. It is generally impractical to diagnose the virus directly. Cats that recover and later become chronic carriers may have no symptoms or show occasional signs of conjunctivitis, keratitis and sinusitis.

Most cats respond well to antibiotics, fluid therapy if dehydrated, and nutritional support including tube feeding if needed. Keeping the cat's eyes and nose clean and using eye ointments may also be helpful in speeding recovery. A high percentage of these cats do recover but are not immune for life so regular vaccination is advised for all cats.

Pseudorabies is an uncommon disease affecting the nervous system, caused by the porcine (pig) herpes virus, Herpesvirus suis. Most cases are seen in farm cats kept near swine, most acquiring the disease from eating infected material. Most cases occur suddenly and progress very quickly to death of the cat. Clinical signs include sluggishness, intense itching, self-mutilation, seizures, coma and death, all usually within 24 hours. There is no treatment or prevention for cats so affected. Diagnosis is usually based on clinical signs and autopsy results.

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