Cat with PCV of 7%

RE: Cat with PCV of 7%

Sarah Keir — Tue, 14 Jan 2020 17:04:29 GMT

Good to know!

RE: Cat with PCV of 7%

Sarah Keir — Tue, 14 Jan 2020 17:04:14 GMT

Great that you are looking! Too many times I have seen reports with only automated machine counts of reticulocytes.

RE: Cat with PCV of 7%

Rob Loxley — Tue, 14 Jan 2020 13:51:35 GMT

[quote userid="9515" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/28761/cat-with-pcv-of-7/218778"]From what I remember, automated counts are pretty much useless in cats and you need special stains to see them on smears[/quote]

I seem to remember the IDEXX lasercyte having a tube of new methylene blue that it did the staining and counting itself; not sure how accurate that is?

RE: Cat with PCV of 7%

Beats — Tue, 14 Jan 2020 10:17:44 GMT

[quote userid="9515" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/28761/cat-with-pcv-of-7/218778"]How are you looking for reticulocytes?[/quote]

I mix one or 2 drops of the blood in a little urine sediment tube with 1 or 2 drops of NEW methylene blue (that is the stain "new methylene blue" as opposed to just a new bottle of the stain "methylene blue" which is a completely different stain). Leave for 20minutes and then put a drop on a slide and smear out as for blood smear, but with abrupt lifted end to smear before hit end of slide (is more watery due to mixing with stain and invariably are doing on watery anemic blood anyway). Then look at under microscope.

This is the stain I use https://www.clin-tech.co.uk/product/new-methylene-blue-1-in-0-9-saline-100ml/

Have had same bottle costing £13 for about 5 years now and still works as far as I know (but good point, perhaps time I got a new bottle!)

RE: Cat with PCV of 7%

Sarah Keir — Tue, 14 Jan 2020 09:19:57 GMT

How are you looking for reticulocytes? From what I remember, automated counts are pretty much useless in cats and you need special stains to see them on smears. Part of the reason I try to send haematology externally, making sure it includes manual smear checking (which is not automatically done at some of the labs now).

RE: Cat with PCV of 7%

Beats — Mon, 13 Jan 2020 20:09:55 GMT

[quote userid="7638" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/28761/cat-with-pcv-of-7/218641"]What did it turn out to be?[/quote]

To date (PCV=22% and still on decent doses of steroids - I'm not celebrating quite yet): severe anemia that appeared non-regenerative in a young cat and has most likely been steroid responsive (alternative explanations being doxycycline responsive, or steroid+doxycycline-responsive, or self-limiting).

I would speculate that NRIMHA is the most likely differential, followed by PRCA, perhaps followed by Mycoplasma?

Slide agglutination is now negative, reticulocyte numbers are still not very impressive to my eye, but I think I can at least see them now.

I thought I'd made a longer post in this thread with more detail, but perhaps I never actually posted it!

RE: Cat with PCV of 7%

Julie Turner — Mon, 13 Jan 2020 09:54:09 GMT

Totally agree Bob. The more That I learn, the less I realise I know.

RE: Cat with PCV of 7%

Mark Hedberg — Wed, 08 Jan 2020 05:30:06 GMT

Awesome! What did it turn out to be?

My former head nurse mentioned she had a cat with mycoplasma that had periodic recurrence of this severe anemia - anecdote, yes, but strangely similar.

RE: Cat with PCV of 7%

Beats — Tue, 07 Jan 2020 18:23:28 GMT

PCV = 21% now. yea!

RE: Cat with PCV of 7%

Bob Russell — Tue, 07 Jan 2020 14:55:49 GMT

We remain 'stupid' students all our working lives IMO.

Those that do not feel like this are either very bright or a danger to the public!

All too regularly I feel foolish when speaking to other vets. They seem to know so much more than I do!!

I have accepted my fate after all these years!!

RE: Cat with PCV of 7%

janine redman — Sun, 29 Dec 2019 01:13:35 GMT

Any value in using pradofloxacin as an alternative to doxycycline?

RE: Cat with PCV of 7%

Julie Turner — Sat, 28 Dec 2019 19:40:44 GMT

Aah Morag - I still react with fear of her questioning me, but she was actually a lovely person if one wasn’t a stupid student who hadn’t studied hard enough!

RE: Cat with PCV of 7%

Mark Hedberg — Sat, 28 Dec 2019 12:25:35 GMT

[quote userid="12930" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/28761/cat-with-pcv-of-7/218441"]And I gave a stronghold plus for the fleas[/quote]

Definitely, as you rightly say, avoid any unnecessary blood loss!

How bad were the fleas? I've heard of mild anemia from high flea burden but at 6-7% there's probably other things going on...

RE: Cat with PCV of 7%

Beats — Fri, 27 Dec 2019 19:34:17 GMT

Oh. And I gave a stronghold plus for the fleas.

RE: Cat with PCV of 7%

Beats — Fri, 27 Dec 2019 19:30:55 GMT

Thanks Ian!

I'll assume this cat is not FeLV based on SNAP result at this point - seems a safe enough assumption. Thanks for detailed info.

RE: Cat with PCV of 7%

Beats — Fri, 27 Dec 2019 19:28:36 GMT

Thanks Lucy.

I found a good summary of the differentials at https://journals.sagepub.com/doi/full/10.1177/1098612X19856178 and as you say I reckon "non-regenerative immune-mediated haemolytic anemia [NRIMHA as they call it] looks to be number one contender given the negative Idexx FIV/FeLV SNAP result.

We see occasional FeLV positive case [last one with anemia this bad was few years ago now] only. Probably a bit more FIV.

RE: Cat with PCV of 7%

Beats — Fri, 27 Dec 2019 19:23:49 GMT

Hi Neil.

Why aren't you advocating preds as a starting medication? I can't think of a better plan?

The level of diagnostic refinement needed is essentially "steroid-responsive" or "not steroid responsive", rather than pathological level of diagnostic refinement?

Over Xmas and Boxing day it didn't do so amazingly - PCV approximately 6% I make it today, but notably cat is much worse - I gave 30ml of untyped [only 1 donor available, but i guess an argument could be made for using a dog in preference to an untyped cat?] cat blood and is much better again and eating and able to sit up etc. I used to like oxyglobin for these, but I think that's still unavailable - right? Aim was to but a few more days to see if any signs of steroid treatment leading to increased circulating rbcs.

RE: Cat with PCV of 7%

Beats — Fri, 27 Dec 2019 19:16:06 GMT

Thanks KMurphy.

PRCA or "non-regenerative immune-mediated haemolytic anemia" [NRIMHA] both would seem to fit and only be differentiated on bone marrow as you say.

As I treat them both the same though I'm not sure if it matters?

I'm relucatnt to do bone marrow as:

1) I don't look at enough to get much info from and usually takes a week from Idexx [whom I trust to do this] at best of times, let alone holidays.

2) I'm not sure it is likely to alter case management presently.

3) I wish to avoid any blood loss presently.

If I WAS doing Bone marrow though, which would be more helpful - an aspirate or a biopsy - i'm thinking aspirate? My experience with doing both is that either I get bad slides because I continue on to do the biopsy and leave someone else to do the slides before clots, or it bleeds quite a lot while I do the slides and put some new gloves on before doing the biopsy.

RE: Cat with PCV of 7%

Beats — Fri, 27 Dec 2019 19:10:27 GMT

Thanks Richard.

I thought FPV (panleukopenia / parvo) affected myeloid cell line rather than erythroid cell line - have you seen a case that had normal wbcs and very few circulating rbcs before or do you have a link / reference to info on this?

Getting 0.7ml colvasone q24hrs currently (I got weight wrong in first post - is about 3kg). Have started doxy also, but actually I like your idea or marbocyl maybe as I have injectable powdered bottle on shelf and that would be easy while the cat is here - I don't normally use Fluoroquinolones, but it is Christmas.

I still don't have any B12. This is a sore point.

RE: Cat with PCV of 7%

Beats — Fri, 27 Dec 2019 19:01:28 GMT

Thanks Jenny. According to https://www.ncbi.nlm.nih.gov/pubmed/25736447 up to 50% might have non-regenerative anemias (although I'm a little unclear from the abstract as to whether some of those cats could have been cats that were anemic for another reason and incidentally also PCR positive for Mycoplasmas - I haven't read the full text yet).

I started some doxycycline today - I was put off as only have 100mg capsules and splitting them then squirting into mouth is pain for all involved, but at this point I think more likely to help than harm, even if I've never knowingly diagnosed a cat with M. hemofelis in this area before.

No signs in blood smear of this. Decided against doing PCR test as results would be too long away to have effect on decision making in short term and it seems counter-productive to remove more blood from this cat than is absolutely strictly necessary to guide therapy currently.

RE: Cat with PCV of 7%

Ian Ramsey — Fri, 27 Dec 2019 10:00:52 GMT

Hi Neil,

Just to add some detail to your comments on FeLV testing being 80-90% accurate -

I agree that caution is important in interpreting FeLV tests (as any other test) but the point that Morag Kerr was mainly making was the importance of checking positive results using an external laboratory technique like immunoflouresence or virus isolation (or nowadays PCR). Nothing has really changed in the nearly 30 years since she wrote that letter to the Vet Rec.

For example, the most recent reference is from Australia* (a country with a historically low prevelance of FeLV) and showed that false positive results were common in the cats that tested positive but the chance of getting a false negative was very low indeed (as most casts are negative anyway). There are a couple of other recent studies looking at experimentally infected cats or selected populations of 50% prevelance and the conclusions are very similar when adjusted for more realistic populations. The figures (depending on study) for the most commonly used in-house tests are that about 60-80% of positive cats are truly positive (positive predictive value) whereas 94-100% of negatives are truly negative (negative predictive value).

So I would always recheck a positive result but would trust a negative result unless I had considerable evidence to doubt it (such as a combination of a young cat (less than 4y) with a history of exposure (i.e. multi-cat, unvaccinated and untested household), and compatible clinical evidence ( lymphoma, overt leukaemia, non-regenerative anaemia etc). I should also say that during the 12 weeks after initial infection cats are likely to be negative but they are unlikely to show clinical signs so soon. So retesting this particular cat is not unreasonable if there was a history of exposure but otherwise it is a very long shot indeed.

Totally agree with your other comments.

Best wishes of the season

Ian

*Reference

Comparison of Three Feline Leukaemia Virus (FeLV) Point-Of-Care Antigen Test Kits Using Blood and Saliva
Mark E Westman 1, Richard Malik 2, Evelyn Hall 3, Paul A Sheehy 3, Jacqueline M Norris 4

DOI: 10.1016/j.cimid.2016.11.014

Abstract
Feline leukaemia virus (FeLV) can be a challenging infection to diagnose due to a complex feline host-pathogen relationship and occasionally unreliable test results. This study compared the accuracy of three point-of-care (PoC) FeLV p27 antigen test kits commonly used in Australia and available commercially worldwide (SNAP FIV/FeLV Combo, Witness FeLV/FIV and Anigen Rapid FIV/FeLV), using detection of FeLV provirus by an in-house real-time polymerase chain reaction (qPCR) assay as the diagnostic gold standard. Blood (n=563) and saliva (n=419) specimens were collected from a population of cats determined to include 491 FeLV-uninfected and 72 FeLV-infected individuals (45 progressive infections [p27 and qPCR positive], 27 regressive infections [p27 negative, qPCR positive]). Sensitivity and specificity using whole blood was 63% and 94% for SNAP Combo, 57% and 98% for Witness, and 57% and 98% for Anigen Rapid, respectively. SNAP Combo had a significantly lower specificity using blood compared to the other two kits (P=0.004 compared to Witness, P=0.007 compared to Anigen Rapid). False-positive test results occurred with all three kits using blood, and although using any two kits in parallel increased specificity, no combination of kits completely eliminated the occurrence of false-positive results. We therefore recommend FeLV proviral PCR testing for any cat that tests positive with a PoC FeLV antigen kit, as well as for any cat that has been potentially exposed to FeLV but tests negative with a FeLV antigen kit, before final assignment of FeLV status can be made with confidence. For saliva testing, sensitivity and specificity was 54% and 100%, respectively, for all three test kits. The reduced sensitivity of saliva testing compared to blood testing, although not statistically significant, suggests saliva testing with the current generation of PoC FeLV antigen kits is unsuitable for screening large populations of cats, such as in shelters.

Comp Immunol Microbiol Infect Dis, 50, 88-96 Feb 2017

RE: Cat with PCV of 7%

Ian Ramsey — Fri, 27 Dec 2019 09:55:39 GMT

Hi Neil,

Just to add some detail to your comments on FeLV testing being 80-90% accurate -

Totally agree with your other comments.

Best wishes of the season

Ian

*Reference

Comparison of Three Feline Leukaemia Virus (FeLV) Point-Of-Care Antigen Test Kits Using Blood and Saliva

Mark E Westman¹, Richard Malik², Evelyn Hall³, Paul A Sheehy³, Jacqueline M Norris⁴

DOI: 10.1016/j.cimid.2016.11.014

Abstract

Feline leukaemia virus (FeLV) can be a challenging infection to diagnose due to a complex feline host-pathogen relationship and occasionally unreliable test results. This study compared the accuracy of three point-of-care (PoC) FeLV p27 antigen test kits commonly used in Australia and available commercially worldwide (SNAP FIV/FeLV Combo, Witness FeLV/FIV and Anigen Rapid FIV/FeLV), using detection of FeLV provirus by an in-house real-time polymerase chain reaction (qPCR) assay as the diagnostic gold standard. Blood (n=563) and saliva (n=419) specimens were collected from a population of cats determined to include 491 FeLV-uninfected and 72 FeLV-infected individuals (45 progressive infections [p27 and qPCR positive], 27 regressive infections [p27 negative, qPCR positive]). Sensitivity and specificity using whole blood was 63% and 94% for SNAP Combo, 57% and 98% for Witness, and 57% and 98% for Anigen Rapid, respectively. SNAP Combo had a significantly lower specificity using blood compared to the other two kits (P=0.004 compared to Witness, P=0.007 compared to Anigen Rapid). False-positive test results occurred with all three kits using blood, and although using any two kits in parallel increased specificity, no combination of kits completely eliminated the occurrence of false-positive results. We therefore recommend FeLV proviral PCR testing for any cat that tests positive with a PoC FeLV antigen kit, as well as for any cat that has been potentially exposed to FeLV but tests negative with a FeLV antigen kit, before final assignment of FeLV status can be made with confidence. For saliva testing, sensitivity and specificity was 54% and 100%, respectively, for all three test kits. The reduced sensitivity of saliva testing compared to blood testing, although not statistically significant, suggests saliva testing with the current generation of PoC FeLV antigen kits is unsuitable for screening large populations of cats, such as in shelters.

RE: Cat with PCV of 7%

Lucy Fleming — Thu, 26 Dec 2019 10:11:56 GMT

The answer to your question 2 is yes, they can, and this case would be pretty suspicious of this. As others have mentioned, mycoplasma possible, but possibly less common?

The accuracy of the snap tests is probably impacted by the low prevalence of FeLV in the general population (out with the odd high-density pocket), so I think your local incidence would probably have to inform your decision making on that one.

RE: Cat with PCV of 7%

Neil Wheadon — Tue, 24 Dec 2019 19:17:07 GMT

3 anecdotes

1) Someone in our year did an elective on FeLV in-house test kits where they looked at how accurate they were. This was in the days of Morag Kerr running vet lab who said that an external lab was the only way of getting close to 100% (and FeLV was rife) The kits varied from 80-90% accurate, in my opinion not that great, have things improved?

2) Cats can get away with an amazingly low PCV - 7% isn't surprising - Chronic?

3) The last 3 cases of cat anaemia I saw deeply investigated all yielded no diagnosis but all responded to preds. I'm not advocating preds as a starting medication but it's interesting

Merry Christmas

Neil

RE: Cat with PCV of 7%

KMurphy — Tue, 24 Dec 2019 17:45:54 GMT

It might be pure red cell aplasia - signalment fits. If possible, a bone marrow aspirate would help confirm and PCR testing for FeLV can reveal latent or regressive infection.

Treatment is as for IMHA but prognosis can be good if FeLV negative.