Feline Leukemia
Has several vaccinations but none of them are 100% effective

Feline leukemia is one of the leading causes of illness as well as deaths in cats worldwide, and it is also one of the most challenging.

It is estimated that over one third of the cats that are infected by this virus will eliminate it completely from their system within four to six weeks, and will not become ill.

The second third will not be able to eliminate it form their system but will not develop any related diseases, but for the final third, the outcome may be much more grime.

It is estimated that this last third will develop a related disease and as a result, will die with 12 to 24 months.


Feline leukemia is perhaps better known as feline leukemia virus, or FeLV, and is a viral disease that affects all breeds of domestic cats and attacks their immune system.

Once this system has become compromised, it not only can cause immunodeficiency as well as leukemia, it can and does cause other types of cancer.

There are several challenging aspects with this virus.

However, the largest is the fact that some cats may show absolutely no signs of infection for months or even years in some cases, after they have become infected.

It is considered to be one of the largest causes of both illness and deaths in cats, and the average age of the first signs of infection is about three years old or younger.

It is also believed that male cats for some reason are more prone to the virus, as well as cats that live in a multi-cat household.

However, if you regularly keep your cat in a cattery or live in an urban area such as New York City or London, your cat is also at a higher degree of risk of infection.


Feline leukemia or FeLV has yet another very challenging aspect to it; it is destroyed within minutes after reaching the environment.

However, it only takes a very brief encounter to infect your cat.

It is also very species specific, meaning it cannot be transmitted for cats to humans.

Once a cat becomes infected, they carry large amounts of the virus in their saliva, and this is by far and away the most common method of transmission.

However, even though bite wounds are one the various ways that it can be transmitted, it is not the most common.

Green eyes in catsFeline leukemia is extremely dangerous as it can trigger other diseases

The most common method is mutual grooming, and as any cat owner understands, this is extremely common in most cats.

If an infected cat touches noses with another cat, it may be passed.

If your cat shares a food or water dish with an infected cat, this is also one of the ways it is transmitted.

However, it can also be transmitted by your cat’s tears, their urine, or by their feces, but to a much lessor degree.

Once a cat becomes mature and their immune system is strong, it takes very large amounts of the virus for them to become infected.

Kittens will naturally become infected in two ways from an infected mother; the placenta and through their supply of milk.

If your cat is infected after any of these forms of exposure, it advances into the acute stage, where it can be found in large numbers in their bloodstream.

However, this is yet another of the challenges with this virus; if your cat blood is not tested you may never know they have it.

As indicated, the vast majority of cats, over sixty percent, will either naturally rid themselves of the virus or they will show no symptoms at all.

There are, however, several things that will happen to your cat.

The first is that absolutely nothing will happen, as their immune system naturally wards it off or the exposure was not strong enough to actually infect them.

However, some cats may develop latent infection.

A latent infection, or regressive infection, implies that your cats system was not able destroy the virus that is attacking them, but it can control it.

If your cat has this form of the infection, they will show no symptoms at all but something much more important happens; they cannot shed or transmit it.

If they develop what is referred to as a progression infection, the outlook is much more troubling.

When this occurs, your cats immune system is either not strong enough or is compromised, and as a result, they will permanently stay infected.

Once this stage is hit, two very troubling things occur; they saliva contains large amounts of the virus, and they will slowly start to develop the diseases that are associated with it.


Feline leukemia can cause several other diseases to develop as the result of the infection.

Unfortunately it is widely held that over one third of all progressive infected cats will develop cancer.

However, that is just the beginning of the list.

Immunodeficiency leads the list of other diseases, and this can place your cat in very high danger of developing other infections.

These include bacterial, and viral infections, as well as fungi infections.

One of the most common types of diseases to affect your cat with immunodeficiency is FIP, or Feline Infectious Peritonitis.

The next common disease is anemia, as leukemia naturally attacks your cat’s bone marrow. Reproductive problems are also a very large risk as it is often the underlying cause of infertility in cats.

It can also very easily result in a stillborn litter, abortions, as well as re-absorption of fetuses.

But there is still more, as it cans also cause gastrointestinal and neurological diseases.

Gastrointestinal diseases include cancer in your cat’s stomach or their intestines, as well as damaging their intestinal wall causing anorexia and severe weight loss.

Neurological diseases include blindness, paralysis, seizures, as well as ataxia, which is a condition where your cat will no longer be able to maintain their balance.

Feline leukemia can also lead to several different platelet disorders, including a dysfunction referred to as thrombocytopenia.

Your cat’s lymph nodes can also be attacked by this wicked virus and includes lymphadenopathy, which affects several of your cat lymph nodes.

It can also causes disease that affect your cats respiratory system as well as causing several oral diseases such as stomatitis and gingivitis.


Feline leukemia has become such a large threat, that AAFP, the American Association of Feline Practitioners, as well as similar groups in Europe, have completely revised there guidelines for FeLV testing.

They recommend that all cats be tested for this virus and some cats must be retested.

If you cat is sick at all, recently adopted, or is in a multi-cat household where another cat is infected, they must be retested.

However, there is yet another very challenging aspect to feline leukemia; not all of the testing is accurate.

Feline leukemia is a very challenging disease and you may never know that your cat has it, until it is too late.


There are several vaccinations for this virus, but there is still one more challenge.

None of them are 100 percent effective and some of them can cause vaccinated fibro sarcomas, which are tumors of your cat’s connective tissues.

The only real safe bet that you have with this very wicked virus, is to have your cat tested as it much better than not having them tested.

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