White blood cell counts?

[Dancing David]

Hello,

Two days ago out kitty the intrepid Marshmallow got very sick. I took her to the emergency vet, she had a high fever (and was lethargic and in distress).

The question I have relates to the WBC, she has normal (low range normal) LEU (leukocytes) and MON (monocytes) and the only low level she has is NEU (neutrophils) and EOS (eosinophils), but her total WBC is like way way way low. A 2.25 (poor kitty).

So I take it there are other components to the WBC because I thought the leukocytes and monocytes comprised the bulk of the WBC. But I was very sleepy when I did all the reading.

Thanks in advance, she is hopefully going to the regular vet before work. (I know she likely has a bone marrow process or is septic. She might also have a viral infection FeLV, FIV, coronavirus or parvo). She also received an antibiotic and anti-inflammatory.

I was mainly wondering about the super low WBC when only one of the differentials is low.

[G O R T]

So I take it there are other components to the WBC because I thought the leukocytes and monocytes comprised the bulk of the WBC.


Actually, neutrophils comprise some half of the count.

Is it just a bad infection?

[Deetee]

In a human it would be consistent with an infection more likely viral (if it were bacterial the counts should be higher, unless we're also looking at one seriously ill moggie)

Vet help please??
Rolfe, BSM, Yurinalyssus, Dogdoctor??

[Badly Shaved Monkey]

G O R T has it right.

Personally, I don't find WBC counts very informative. I usually find myself justifying the result in terms of the other things I know about the patient rather than the other way round, i.e. their sensitivity, specificity and positive and negative predictive values can't be very high. We are all taught what narrative to give to accompany a given result but I just don't find it very useful.

We really need Rolfe, whose area this is.

[Badly Shaved Monkey]

In a human it would be consistent with an infection more likely viral (if it were bacterial the counts should be higher, unless we're also looking at one seriously ill moggie)

Vet help please??
Rolfe, BSM, Yurinalyssus, Dogdoctor??

Simultaneous posting!

Never mind the particulars, what do you think about the principles?

Mrs Monkey bought herself a laser flow-cytometer when her old haematology machine died, but cynical old me is rather of the view that you rarely make actual clinical decisions from a WBC count.

[BenBurch]

I messaged Rolfe with this thread URL.

[Badly Shaved Monkey]

I messaged Rolfe with this thread URL.

Thanks

[Deetee]

...I usually find myself justifying the result in terms of the other things I know about the patient rather than the other way round.....
Careful now BSM. Next you'll be telling us homeopathy works.

[Rolfe]

Thanks BenBurch.

If anyone is trying to do feline haematology on a point-of-care analyser, the first thing they need to do is quit and send the samples to someone who knows what they're doing. And these laser flow cytometers generally don't work on animal blood. If this is an amateur "vet trying to run his own haematology lab" thing, the best thing to do is simply ask for a sample to be sent to a lab who knows what it's doing. I have encountered far far too many spurious results from point-of-care haematology analysers even to begin to try to interpret them.

If on the other hand this was done by a reputable laboratory, it sounds as if there's a neutropenia present. The OP seems to have some misconceptions, because total white cells and leucocytes are one and the same thing. Maybe "leucocytes" has been typed in mistake for "lymphocytes"? The normal proportions of WBCs are, very very roughly:

Neutrophils 65%
Eosinophils 3%
Basophils 1%
Lymphocytes 30%
Monocytes 1%

You count the total number of cells, then multiply by these percentages to get the absolute counts of each cell type. If the total count is about 10, which is maybe a little above average but still normal, then you can easily see what the absolut differential figures would be.

So, WBC of 2.2 or 2.3 (I don't believe in a second significant figure after that decimal point, which again makes me suspect the methodology). With normal lymphocytes and monocytes. I don't really buy the "low" eosinophils, because quite a lot of normal samples don't have any eosinophils in an ordinary manual count. And if these results were from an automatic machine not backed up by a manual count of a blood film, they're not worth the paper they're printed on anyway.

But it's not really a super-low count. It's a concern, but it's not unusually scary. A lot depends on the age and the rest of the clinical history. This is NOT a usual presentation for FIP (coronavirus) so I'd forget that. Also, FeLV would not be anywhere near the top of my list of differentials, especially if the prevalance of FeLV was low in the area and/or the cat was vaccinated for FeLV. And especially if the cat isn't young.

FIV is certainly one of my main concerns with an otherwise unexplained neutropenia, but this clinical presentation doesn't really suggest that to me. It sounds more like an acute infection by some other virus to me. Alternatively, some sorts of toxic insult (food toxicosis) can produce neutropenia, and if the cat is suspected of eating something she shouldn't, and/or has vomiting and/or diarrhoea, that is another consideration. And yet again, the very early stages of some bacterial infections show a temporary neutropenia.

Normally, I would advise strongly against giving pet owners copies of blood results, for exactly this reason. It enourages them to go on the internet and trawl for second, third and fourth opinions, and generally get in a lather about what might not be a very big deal. My normal course of action in this situation would be to treat the cat symptomatically (which seems to be being done) and resample in about a week. Only if there is still a significant neutropenia would I start to get concerned.

Mmmm, having just re-read the OP I realise that this was almost certainly results coming off a fully automated point-of-care analyser. Not worth paying any attention to. Their only use is as a quick emergency guesstimate, and even there they are vastly inferior to simply making a blood film and actually eyeballing these cells. I wouldn't give such an analyser bench space in any emergency clinic I controlled.

The main criteria are, how well does the cat respons to the symptomatic treatment, and is there still a significant abnormality in a haematology examination performed by a competent laboratory a week or so later. Right now, I'd be entirely concerned about how the cat is in herself and not at all concerned about a bunch of numbers that may or may not be right.

Rolfe.

[BenBurch]

Thank you, Rolfe.

[Rolfe]

Damn, I wish some of my tutorials and lectures were online.

Rolfe.

[Badly Shaved Monkey]

Careful now BSM. Next you'll be telling us homeopathy works.

I am well aware of the comparison and do try to "give good narrative" these days. The homs have taught me that, at least.

[Dancing David]

Thanks BenBurch.

If anyone is trying to do feline haematology on a point-of-care analyser, the first thing they need to do is quit and send the samples to someone who knows what they're doing. And these laser flow cytometers generally don't work on animal blood. If this is an amateur "vet trying to run his own haematology lab" thing, the best thing to do is simply ask for a sample to be sent to a lab who knows what it's doing. I have encountered far far too many spurious results from point-of-care haematology analysers even to begin to try to interpret them.

If on the other hand this was done by a reputable laboratory, it sounds as if there's a neutropenia present. The OP seems to have some misconceptions, because total white cells and leucocytes are one and the same thing. Maybe "leucocytes" has been typed in mistake for "lymphocytes"? The normal proportions of WBCs are, very very roughly:

Neutrophils 65%
Eosinophils 3%
Basophils 1%
Lymphocytes 30%
Monocytes 1%

You count the total number of cells, then multiply by these percentages to get the absolute counts of each cell type. If the total count is about 10, which is maybe a little above average but still normal, then you can easily see what the absolut differential figures would be.

So, WBC of 2.2 or 2.3 (I don't believe in a second significant figure after that decimal point, which again makes me suspect the methodology).

That was just off the paper, in the corner it said Lasercyte.

With normal lymphocytes and monocytes. I don't really buy the "low" eosinophils, because quite a lot of normal samples don't have any eosinophils in an ordinary manual count. And if these results were from an automatic machine not backed up by a manual count of a blood film, they're not worth the paper they're printed on anyway.

Well that would seem likely, they ran the test quickly as we were the last appointment at the end of the day.

her regular vet usually doesn't get a result so quickly.

But it's not really a super-low count. It's a concern, but it's not unusually scary. A lot depends on the age and the rest of the clinical history. This is NOT a usual presentation for FIP (coronavirus) so I'd forget that. Also, FeLV would not be anywhere near the top of my list of differentials, especially if the prevalance of FeLV was low in the area and/or the cat was vaccinated for FeLV. And especially if the cat isn't young.

Great.


FIV is certainly one of my main concerns with an otherwise unexplained neutropenia, but this clinical presentation doesn't really suggest that to me. It sounds more like an acute infection by some other virus to me. Alternatively, some sorts of toxic insult (food toxicosis) can produce neutropenia, and if the cat is suspected of eating something she shouldn't, and/or has vomiting and/or diarrhoea, that is another consideration. And yet again, the very early stages of some bacterial infections show a temporary neutropenia.

Could be, thanks. Not the food toxin, that we know of.


Normally, I would advise strongly against giving pet owners copies of blood results, for exactly this reason. It enourages them to go on the internet and trawl for second, third and fourth opinions, and generally get in a lather about what might not be a very big deal.
I wasn't doing that, we had already been told in February that cancer of some sort was a possibility. But not a confirmed idea, just one to consider. She could also just have a subchronic infection that flairs, was the other possibility in Feb.

I was just looking. FeLV and FIV seem low but FIV was mentioned by the weekend vet at the clinic.

My normal course of action in this situation would be to treat the cat symptomatically (which seems to be being done) and resample in about a week. Only if there is still a significant neutropenia would I start to get concerned.

Mmmm, having just re-read the OP I realise that this was almost certainly results coming off a fully automated point-of-care analyser. Not worth paying any attention to. Their only use is as a quick emergency guesstimate, and even there they are vastly inferior to simply making a blood film and actually eyeballing these cells. I wouldn't give such an analyser bench space in any emergency clinic I controlled.

Okay.

The main criteria are, how well does the cat respons to the symptomatic treatment, and is there still a significant abnormality in a haematology examination performed by a competent laboratory a week or so later. Right now, I'd be entirely concerned about how the cat is in herself and not at all concerned about a bunch of numbers that may or may not be right.

Rolfe.

Thanks Rolfe, it was the weekend vet at a clinic, and they gave me the results to give to our regular vet today. I may have misread it as LEU when it was LYM. I don't know, the papers are with the regular vet. I was asking because I was curious, I have no concerns that The doctor will not answer. She had a similar incident in February and she is an 11 year old cat. So his concern at that time was some process that was not known at the time. Then she had the same symptoms but was not as lethargic, and her 'response to bacteria' WHC was high. She was treated and recovered.

So my question was answered, NEU are a large part of the WBC!

Thanks.

PS I have had some old cat issues before, so I am not overly concerned. She responded last time, it is what keeps causing her to have this that will be a concern. She is 11.5 years old and obese, otherwise she is healthy.

[Rolfe]

Doesn't sound too scary at the moment, if she's responding clinically. I do understand about giving the owner the results to pass on to the regular vet, it's a good way of ensuring they get there, indeed. I don't entirely blame emergency vets who use these damn machines, because there is a lot of pressure to do so. It's just a shame that more reliable emergency results can be obtained more cheaply with just a little bit of thought and practice and no expensive instruments.

An FIV test might be advisable, if only so that she can be given special mollycoddling if the result is positive. I will mention that Rolfe was FIV positive and lived to be 17 with no serious health issues. However, if she had a neutrophilia in February, my suspicion is that the present neutropenia is strictly temporary and that a repeat haematology in a few days will show a recovery of that cell type.

Rolfe.

[BenBurch]

I learned to do a WBC count with a microscope and some stain long ago. Don't they do that any more?

[Rolfe]

No. They've been got at by slick salesmen on commission who are pushing automated counting machines, and who tell them that this is much less laborious. The problem is that while you can easily tell if what you're doing with a microscope is unreliable, when a spiffy machine prints out a number it tends to be regarded as gospel by clinicians who have no technical training or experience. Reputable laboratories first, don't use methodologies ported from human haematology that don't work on animals (salesmen on commission have no such scruples, and clinicians are poorly edicated in this field), and second, they understand their machines and methodologies well enough to produce reliable results.

Sometimes I feel like doing a dea - look, I won't try to do complicated orthopaedic surgery (which I was trained for 35 years ago but which I have not attempted since), if you won't try to run a pathology lab (which you aren't even trained for at all).

Sigh.

None of this is intended as specific criticism of Dancing David's vet, who has done nothing untoward, and whose results might even be right. It's just a general, frustrated rant.

Rolfe.

[Dancing David]

Doesn't sound too scary at the moment, if she's responding clinically. I do understand about giving the owner the results to pass on to the regular vet, it's a good way of ensuring they get there, indeed. I don't entirely blame emergency vets who use these damn machines, because there is a lot of pressure to do so. It's just a shame that more reliable emergency results can be obtained more cheaply with just a little bit of thought and practice and no expensive instruments.

An FIV test might be advisable, if only so that she can be given special mollycoddling if the result is positive. I will mention that Rolfe was FIV positive and lived to be 17 with no serious health issues. However, if she had a neutrophilia in February, my suspicion is that the present neutropenia is strictly temporary and that a repeat haematology in a few days will show a recovery of that cell type.

Rolfe.


She actually did not have a low count in february. the vet says she is negative for FIV, and if she improves that it was an infection, if she has lymphosarco she will probably not get better. She is much more alert and seems to be resting. She is also bulging from the sub-cutaneous water. (She threw up the water yesterday.)

he actually used the term 'diagnosis by treatment'.

thanks again for the information.

[Dancing David]

Sure, he was not her regular vet. And I understand.