PDA

View Full Version : Cat positive to Felis Leukemia test


Ronin
October 1st 05, 01:26 AM
Hello everybody

I'm from Italy, I already posted a message on the italian cat newsgroup, but
I'd really like to submit the same problem also to you.

I live with my family in a flat. My building is surrounded by small garden.
At the beginning of August I've found there a cat, aged 2-3 years (no more),
male, already neutered. It was definitively family-owned and then most
probably abandoned. But he's charming, kind, cute! He's a very, very good
fellow with a fantastic behaviour! ...I cannot really understand why
abandoning such a lovely cat. I asked around, but nobody came to seek him
during the last month... In the meanwhile he decided to stop permanently
into the garden.

I was almost convinced to keep it and bring it at home. There I already have
a cat (male, neutered, 4 years), who lives inside my house and never leaves
it. So, I first brought the "new" one to the vet. He initially said it was
ok... No intestinal parasites, no flu, etc. Then he suggested to test him
for FIV/FeLV. He ran the ELISA test and found the cat positive to Leukemia.
That was really sad news. My cat at home is negative to both feline aids and
leukemia so I asked about vaccination, but the vet warned me that it is not
100% sure and there's about 1-2/10.000 possibilities that the vaccine may
give health problems (may also develop a tumor). I do not really want to
take those risks.

Nevertheless the vet suggested me to wait about 6 months and repeat the test
or take a more accurate one. There's a slim chance that the cat might result
negative, as the ELISA test can only determine if there's a presence of
antibodies in one cat organism, but tells nothing about his effective
illness or status of virus spreading (if any). If the cat will result
negative, said the doc, then I could bring him into home safely.

In the meanwhile, I'm giving hospitality to the "newcomer" inside my
garage... I don't keep my car inside it, it is large enough (about >20mq),
with a safe and almost humidity-free enviroenment. We feed the cat regularly
and he can rest with doors closed overnight so he can sleep well,
undisturbed by other animals. He seems to enjoy the situation: during the
day he's very playful and at a first glance he always appears to have a very
good health!

What worries me are the two following perspectives, on which the doctor was
a little unclear:

1) I know that there's no definitive cure for FeLV, although some cats may
survive and develop a self-immunity. While in other cats, who still don't
die, the illness goes in a latent state and then it may not be detected by
the ELISA test. A more accurate and expensive test in laboratory perhaps
could? I believe yes... but is there actually a chance that this cat could
definitively and permanently result negative one day and forever? During
these 6 months, can I give him something to strenghten its immunitary
system? I was thinking about Aloe Vera... Does anyone know which kind and
dilution to use? The vet on the other hand didn't propose anything...

2) Assuming the lucky chance that the cat will result fully negative at the
end of the 6 months... Will it be really safe to bring it at home where he
will meet the other (healthy) cat? Or there will be still a chance to
contaminate him somehow?


Any help with this matter will be sincerely appreciated.

Phil P.
October 1st 05, 11:05 AM
"Ronin" <(debris)@(email).(it)> wrote in message
...
>
> Hello everybody
>
> I'm from Italy, I already posted a message on the italian cat newsgroup,
but
> I'd really like to submit the same problem also to you.
>
> I live with my family in a flat. My building is surrounded by small
garden.
> At the beginning of August I've found there a cat, aged 2-3 years (no
more),
> male, already neutered. It was definitively family-owned and then most
> probably abandoned. But he's charming, kind, cute! He's a very, very good
> fellow with a fantastic behaviour! ...I cannot really understand why
> abandoning such a lovely cat. I asked around, but nobody came to seek him
> during the last month... In the meanwhile he decided to stop permanently
> into the garden.
>
> I was almost convinced to keep it and bring it at home. There I already
have
> a cat (male, neutered, 4 years), who lives inside my house and never
leaves
> it. So, I first brought the "new" one to the vet. He initially said it was
> ok... No intestinal parasites, no flu, etc. Then he suggested to test him
> for FIV/FeLV. He ran the ELISA test and found the cat positive to
Leukemia.
> That was really sad news. My cat at home is negative to both feline aids
and
> leukemia so I asked about vaccination, but the vet warned me that it is
not
> 100% sure and there's about 1-2/10.000 possibilities that the vaccine may
> give health problems (may also develop a tumor). I do not really want to
> take those risks.
>
> Nevertheless the vet suggested me to wait about 6 months and repeat the
test
> or take a more accurate one. There's a slim chance that the cat might
result
> negative, as the ELISA test can only determine if there's a presence of
> antibodies in one cat organism, but tells nothing about his effective
> illness or status of virus spreading (if any). If the cat will result
> negative, said the doc, then I could bring him into home safely.



Your vet is half right- ELISA positives should be confirmed by an IFA
because an ELISA+ doesn't necessarily indicate a marrow-origin infection.
An ELISA+ could mean either he's in the process of clearing the virus or
developing a persistent infection or he's harboring the virus is some
*nonmyloid* compartment (not infectious to other cats)-- or the test wan't
run properly (most common). Most cats clear their intial infection and
become immune.

The part your vet was wrong about is antibodies. The ELISA and IFA for FeLV
both test for viral *antigen* not antibodies. The ELISA and Western Blot
for *FIV* both test for antibodies because the amount of antigen necessary
to cause infection is much to small to be detected by either test.





>
> In the meanwhile, I'm giving hospitality to the "newcomer" inside my
> garage... I don't keep my car inside it, it is large enough (about >20mq),
> with a safe and almost humidity-free enviroenment. We feed the cat
regularly
> and he can rest with doors closed overnight so he can sleep well,
> undisturbed by other animals. He seems to enjoy the situation: during the
> day he's very playful and at a first glance he always appears to have a
very
> good health!
>
> What worries me are the two following perspectives, on which the doctor
was
> a little unclear:
>
> 1) I know that there's no definitive cure for FeLV, although some cats may
> survive and develop a self-immunity.

The vast majority of cats clear the virus and become immune. Because of his
age, I'd say he has an excellent chance of clearing the virus. Resistance
develops with age. Cats over 16 weeks are not easily infected. Of course
age-related resistance isn't absolute. A large viral load injected directly
into the bloodstream from a bite wound or stress or steroid therapy could
overcome the cat's resistance.


While in other cats, who still don't
> die,

The outcome after infection is probably influenced by the cat's
cell-mediated immune response- but probably more by the virus subgroup. All
FeLV-infected cats are infected with FeLV-A- which causes immunosupression
and is very slow to cause disease by itself. Cats infected with only FeLV-A
can and do live many healthy years after infection and are the most likey to
clear
or extinguish the virus. FeLV-B causes neoplastic diseases (i.e., tumors and
other abnormal tissue growths), and FeLV-C causes severe anemia. Only
FeLV-A is transmitted contagiously between cats. The other two subgroups
are generated within the cat by recombination with FeLV-A and the cat's own
FeLV sequences (all cats have them). So, FeLV is not necessary an immediate
death sentence.


the illness goes in a latent state and then it may not be detected by
> the ELISA test. A more accurate and expensive test in laboratory perhaps
> could?

PCR of bone marrow cells or bone marrow reactivation test. But these tests
aren't really necessary unless you have a large population.

Latent infections can't be detected by *either* the ELISA or the IFA because
viral antigen isn't produced or released during latency. For this reason,
cats with latent infections *are not* infectious to other cats. Most cats-
in fact the overwhelming vast majority of cats with latent infections
eventually clear the virus. They mount a strong cell-mediated immune
response against the virus that drives the virus into latency instead of
infection. This strong CMI just gets stronger and eventually extinguishes
the virus. However, stress or steroid therapy can reactivate a latent
infection before the virus is extinguished.




I believe yes... but is there actually a chance that this cat could
> definitively and permanently result negative one day and forever?


Absolutely! Most cats *do* clear the virus. Otherwise FeLV would rapidly
deplete the general feline population of the world! Actually, the infection
rate has been declining over the past 20 years. The FeLV vaccine is *not*
responsible for the decline because it began before the first FeLV vaccine
was introduced in 1985.


During
> these 6 months, can I give him something to strenghten its immunitary
> system? I was thinking about Aloe Vera... Does anyone know which kind and
> dilution to use? The vet on the other hand didn't propose anything...


Forget the Aloe Vera- if you give him anything give him recombinant human
interon-alpha (interferon-IFN-a) at about 30 IU a day, 7 days on/7 days off.
If you
mix it up the dilution yourself its very inexpensive. Just get a script
from your vet for a the 3 million IU vial and buy the interferon at any
human pharmacy-- its about 1/5 the cost. If you go this route I'll explain
how to dilute it down to 30 IU/ml-- its easy. Early treatment with
rh-IFN-a might stimulate some early events in the immune cascade-- which
might lead to a systemic response that could extinguish the virus before it
reaches
the bone marrow. There's a new Feline Interferon available in Europe that
might be even more effective.



>
> 2) Assuming the lucky chance that the cat will result fully negative at
the
> end of the 6 months... Will it be really safe to bring it at home where he
> will meet the other (healthy) cat? Or there will be still a chance to
> contaminate him somehow?


You don't have to wait 6 months to retest him with the IFA. The virus takes
about a month to infect the bone marrow- although it could take 12 weeks in
some cats. You can have him retested with the IFA in about a month. Run
another ELISA on the same day your vet draws blood to send out for the IFA--
he might clear the virus by then. If the IFA comes back + there's still a
chance that he's in the process of clearing the virus and becoming immune-
retest him again in another 3 months. I've seen cats take as long as 6-12
months to finally test negative on the IFA-- so a + IFA doesn't always mean
the cat is infected for life. Many cats test ELISA+/IFA- These cat's are
usually not infectious to other cats.

Negative ELISAs are highly reliably because they're incredibly sensitive-
but that same incredible sensitivity is what makes ELISA+ unreliable. If he
retests negative on the ELISA-- its highly probable that he is indeed
negative.




> Any help with this matter will be sincerely appreciated.


I think it may be a good idea to find a vet who knows a little more about
FeLV than your present vet.


Keep the faith.

Best of luck,

Ciao,

Phil.

PS: Do you live anywhere near the Torre Argentina ruins in Rome? I *gotta*
adopt one of those cats!!! ;-)