Animal Welfare Professionals

Hello! Many of you had your questions answered in today's webinar, but for those questions that we ran out of time for we'll be posting here and Dr. Levy can chime in. Please feel free to add more! 

Is there any research on % that go from regressive to progressive?

Only in experimental laboratory infections. It often occurs after a very prolonged period of time.

First, here are the new guidelines and additional resources for you and your shelter: 

FeLV and FIV Client Brochure

https://catvets.com/public/PDFs/ClientBrochures/AAFP%20FeLV%20and%20FIV%20Broch_Final.pdf

AAFP Feline Retrovirus Management

https://catvets.com/guidelines/practice-guidelines/retrovirus-management-guidelines

2020 Feline Retrovirus Guidelines

https://journals.sagepub.com/doi/pdf/10.1177/1098612X19895940

Client Brochures for Cat Owners

https://catvets.com/guidelines/client-brochures

IDEXX Diagnostic Update
https://www.idexx.com/files/updates-diagnosis-management-felv.pdf

Are there any studies on stomatitis in FIV vs non-FIV cats? I've seen just as many Non-FIV cats (mostly community cats) with Stomatitis.

me too! And in my experience the FIV+ cats respond better to full mouth extractions than the FIV- cats do.The dentistry specials are studying this condition.

All the vets in our area have told us and other rescue organizations in our area to have FELV+ cats euthanized due to the painful ending they would meet.  What should we do with our FELV+ cats if we run a free roaming facility?

I believe that FeLV+ cats should be adopted into homes. We should think of them like we do other animals with an uncertain future like senior pets. In my experience they usually have a great quality of life until near the very end. it might help to identify and work with the FeLV-friendly vets in town initially while you work on spreading the word to the other vets. It's a process!  I wouldn't mix your FeLV+ cats in with your negative cats in your free-roam facility.

Will the ASV update their position statement on the testing of all cats prior to adoption, transfer, rescue, other?

I am sure they will review their position statements as they regularly do. The current statement does leave the option for testing post adoption, but this can probably be more strongly supported now.

Is PCR test IFA or, these are 2 different tests?

When are we IFA testing?   Is there any benefit to vaccinate for felv during a regressive period?

Two very different tests. PCR tests for viral DNA/RNA genetic material and IFA tests for protein antigens in circulating blood cells.

How can I share this information with my veterinarians and our local animal shelter?

In your experience, what may be the best way to communicate with a vet in a shelter setting who has been resistant to group housing FIV cats and adopting out FeLV + cats?

How much time is between the Ag + screening test and the second column in the staging chart.

No lag is needed. I would perform the FeLV lab testing panel right away since they are a different kind of test.

Would it be appropriate to re-test exposed cats at 2 weeks with the PCR instead of waiting 60 days for the ELISA?

I think it might be possible to miss some very recent infections by testing that early. I would wait at least 30 days to catch most of them. I once saw a litter that took >5 months to seroconvert to FeLV positive.

What is the risk of transmission for a progressive cat? Like in the second case discussed (cant remember kitty's name?).

progressive cats shed the most virus, so they are the riskiest for transmission. However the susceptibility of the cat they expose is also a factor - kittens are more susceptible than adults.

For the survival curve experiment - how were the abortive infected cats determined to have had the infection?

Great question. Gold star for noticing that mystery. All of the cats were screened for FeLV antigen with an IDEXX SNAP test before they were enrolled in the study for the extensive panel. Some of them were first tested as underaged neonates in the bottle baby program. In theory they could have been false-positives on that first screening tests, but we also have some antibody test results that I didn't share that indicate they had been infected.

Were all of the cats in the study adults over the full duration of the study? I'm curious if the overall findings would apply equally to cats who first test positive as kittens.

Not at all. The progressive cats can be any age and some kittens can be regressive or abortive.

Are most progressive cats kittens?

When do you send for IFA test?

The only lab I am fully comfortable with is National Veterinary Lab in New Jersey. https://www.natvetlab.com/

We usually do an IFA on Cats who test positive in the idexx snap test.  if we have a positive idexx test and negative IFA do I understand correctly that the cat may have an early exposure and it just has not reached the bone marrow yet?

Possibly, or it might just be a regressive cat.

With testing properly - must be in/from tube or heparinized, right? no direct samples?

Yes that's very important. Samples collected without anticoagulant can have micro clots than inhibit test performance.

Can you speak to the risk of contagion in repressively infected cats during the times they test positive?  Should we assume that these cats should not be housed with true negative/abortive cats and only be housed with other regressive cast or singly in the adoptive home?

I would not house regressive infected cats with uninfected cats. Their shedding level an contagion risk can change over time. If you have no choice, I would vaccinate the uninfected cats.

For cats you want to co-house do you recommend using both PCR and ELISA and how often?

From a practical point of view, performing the more expensive FeLV test panel with lab Ag+PCR seems excessive. However, I would consider it if the planned co-housing was prolonged, as in a sanctuary. It's important that we devote our limited resources to the best outcomes for the most cats possible, so don't overspend on testing when those funds could be used for more TNR, orphan kittens, adoption promotions, etc.

Purrfect Pals in Arlington WA, houses FIV and FeLV cats too. We have adopted out a lot of these cats. :)

Fantastic! They all deserve a loving home.

What about false positives in healthy cats? (ie. where prevalence is low, ai is generally is in out populations)

False-positives in low-risk cats are definitely a problem, more with some brands that others That's why following up with a different type of test like PCR is helpful. However if the results are discordant, it's hard to know which result to Believe.

Hello- I adopted a FELV+ and FIV+ cat.  Wondering if there were any findings for cats that test positive for both.  Thanks for all the information.

There is not a lot of life-long information about dual-infected cats since it is not very common. From the little but I've seen the cats have a pattern more life the progressive FeLV infections. Thank you for rescuing that poor kitty.

During kitten season we have a lot of kittens that are being treated for URI.  What symptoms would you look for to determine when testing is indicated?

testing should be considered for cats that are not responding to treatment as expected. However if you are seeing a lot of shelter-acquired URI in your shelter, it is more likely to be related to crowding, stress, prolonged length of stay, and inadequate housing than to FeLV/FIV. Check out www.millioncatchallenge for ideas on how to save more cats by intake diversion and controlling LOS and stress.

How well does the FeLV vaccination work?  I understand it is 70% effective.  Please comment.  Thank you.

70% is a reasonable protection rate, although it's different for different brands and different ages. I would not knowingly co-mingle FeLV positive and negative cats hoping that the vaccine would protect them.

Can an FELV patient test low on the quantitiave PCR but later test high? Or there is no need to ever retest the quantitative PCR?

Yes that can definitely happen and it did with a few of the cats in our long-term study. In general cats will hover mostly around progressive levels or around regressive/abortive levels, but sometimes they cross over. That's why we now understand that it's impossible to put cats into a stage from testing at a single point in time and expect it will be that way for the cat's lifetime.

And do we know if a cat that was exposed and fought it off (abortive), is that cat immune/ protected from re-infection?

Immunity to reinfection is believed to be the case, although I don't know if that protection is lifelong. In Europe they can perform FeLV antibody tests that can help document that a cat was previously infected and is still immune to reinfection. We do not have those tests available in North America.

Do we know if/which FeLV regressive cats can transmit the virus  to other cats?

There hasn't been enough research to fully answer this question. In addition, a cat may have little virus shedding at one point and then have a higher level at another time if its immune system is suppressed even transiently.

What are the protocols for vaccinating against feLv WITHOUT screening test.  is it ok to still vaccinate?

We recommend testing cats for FeLV before vaccinating. The vaccine wont help cats that are already infected.

Suggestions for co-housing regressive and progressive cats? Are the regressive cats at risk of being re-infected with more virus therefore challenging their immune system. Their immune system is currently doing a great job but could exposing them to more virus be too stressful for them?

That's a great question and I haven't seen any research that can answer the question about superinfections. On a practical basis, I think putting all the positive cats together makes good sense. However getting them into homes would be even better for them.

If they have abortive infection, are they then immune to future infection?

That is believed to be the case, although I don't know if that protection is lifelong. In Europe they can perform FeLV antibody tests that can help document that a cat was previously infected and is still immune to reinfection. We do not have those tests available in North America.

What’s the risk of housing FeLV+ cats in group housing together, if we aren’t doing such extensive testing to understand regressive vs progressive status

That's a great question and I haven't seen any research that can answer the question about superinfections. On a practical basis, I think putting all the positive cats together makes good sense. However getting them into homes would be even better for them.

With the uncertainty behind the FeLV testing protocol—can you ever feel confident that a cat who was initially snap positive is TRULY abortive?

You can never be 100% certain about anything in medicine. Once we let go of the idea that we can be certain, it's much easier to move ahead with protocols that cover the situation most of the time. Personally, I think it's very hard to ever prove a cat is uninfected once it's had a positive test. Remember that we are only testing one compartment - the blood - and not all of the other tissues than harbor virus.

Concerns about putting fiv + cats, or felv + cats,  who are not suited to be indoor back outside?

Once they are spayed/neutered they are unlikely to be a large threat to other cats in the neighborhood. About 3-5% of outdoor cats are infected already (via reproduction and fighting primarily), so removing one of them isn't likely to make a significant change in the overall transmission risk. Keeping them inside or confined to a catio might be the top choice, but if that's too stressful, going back outside might be the best option.

When is it better not to put an FELV cat back outside? Ie - What if they test high positive on a quantitative PCR test and positive on a POC test?

I wouldn't use the PCR quant as the most important factor. I think how the cat is adjusting to indoor life is more important. If the cat is spayed/neutered it won't be reproducing and is unlikely to have the kind of direct contact with other cats that is needed to spread infection. Catios are a great option too.

Should we be doing the initial Elisa snap tests on whole blood or serum? After watching the webinar from Austin Pets Alive we started testing on serum for FeLV+ cats on whole blood and found that many of them were negative on serum. Does that mean they were false positives or regressives with a lower viral load? If they are positive on whole blood should we just go straight to PCR for confirmation if our budget allows us to??

I recommend testing with the IDEXX SNAP test with whole blood. If it is positive, submit a panel for testing at IDEXX (Test Code 26355), where they will run a special plate text and quantitative PCR. https://www.idexx.com/files/updates-diagnosis-management-felv.pdf