Dog with possible polycythaemia Vera

Re: Dog with possible polycythaemia Vera

ruths — Thu, 21 May 2015 17:10:14 GMT

yes- that was my thinking too.

Thanks -))

Interesting case. I'm dredging up memories of a big stripy cat I used to see who had polycythaemia.

maybe you could leech the dog -))

Re: Dog with possible polycythaemia Vera

Rory Bell — Thu, 21 May 2015 16:23:09 GMT

I apologise for my inner geek!

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Thu, 21 May 2015 15:22:55 GMT

[quote user="Rory Bell"]I agree with Martin - seizures in hyper viscosity are usually due to ineffective perfusion leading to cerebral hypoxia. [/quote]Only you put it much more esoterically!

Re: Dog with possible polycythaemia Vera

Rory Bell — Thu, 21 May 2015 14:57:06 GMT

Sorry, meant to write 'sludging' rather than 'slugging' of blood in the retinal vessels, though I suppose if red cells were to slug the vessel walls, that might cause some bleeding too....

Re: Dog with possible polycythaemia Vera

Rory Bell — Thu, 21 May 2015 14:54:51 GMT

I agree with Martin - seizures in hyper viscosity are usually due to ineffective perfusion leading to cerebral hypoxia. Patients with polycythemia do not usually have a systemic coagulopathy; the retinal haemorrhages are thought to occur due to slugging of blood in the retinal vessels leading to a marked segmental dilation and associated diapedesis of red cells. I don't know if that could occur in other vessels (specifically cerebral blood vessels), and if it did, whether the loss of red cells would be sufficiently severe to cause hemorrhagic stroke. As far as I am aware in people, hemorrhagic stroke is not a recognised complication of polycythemia. Spontaneous haemorrhage has been reported in people with polycythemia, but is apparently very rare.

Patients with hyperviscosity due to hyperglobulinemia can have systemic coagulopathies, usually because the immunoglobulins bind onto platelets causing platelet dysfunction.

cheers

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Thu, 21 May 2015 14:05:58 GMT

[quote user="ruths"]

do you think the seizures were due to hyperviscosity?

And does hyperviscosity due to increased red cell mass cause sponanteous bleeding or is it just the hyperviscosity due to increased proteins that cause bleeding?

[/quote]It was my deduction that the hyperviscocity was causing a stroke like syndrome by reducing blood flow through small vessels in the brain. However given that one symptom of polycythaemia is retinal haemorrhages (not seen in this patient) it could equally be the latter.

Re: Dog with possible polycythaemia Vera

ruths — Thu, 21 May 2015 12:39:22 GMT

[quote user="Rory Bell"]

Hi Martin

From the tone of your last post I guess you're not too worried about a PCV of 60%.....I would not be either. I seem to recall some very old studies which showed that a PCV >66% was associated with an increase in red cell mass to the point where clinical signs of hyper-viscosity became likely.

cheers

[/quote]

do you think the seizures were due to hyperviscosity?

And does hyperviscosity due to increased red cell mass cause sponanteous bleeding or is it just the hyperviscosity due to increased proteins that cause bleeding?

Re: Dog with possible polycythaemia Vera

ruths — Thu, 21 May 2015 12:35:15 GMT

[quote user="Andrew Henfrey"]

It was a 2.5yo JRT. It had been having some weak episodes on back legs for couple weeks which lasted a few seconds then back to normal. We hadn't seen it since puppy vaccines. At 9 weeks old it was noted there was a "faint" murmur but this was not noted at the 10 or 13 week vaccines. The puppy was described as quite small for breed. There were no signs of CHF 2 weeks ago and HR120 with synchronous pulses.

I didn't see it so I don't know if the hindpaws were cyanotic.

[/quote]

I once had some beautiful xrays of a cat with a shunt like that. There was an obvious iinterstitial pattern in the lungs with no other obvious changes. it was really interesting.

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Thu, 21 May 2015 09:02:36 GMT

[quote user="Rory Bell"]From the tone of your last post I guess you're not too worried about a PCV of 60%[/quote]I'm not worried about it because there is a downward trend and if there are no more neurological issues it wouldn't over concern me after all a racing cyclist would die (probably literally) for a natural PCV that high! We'll see what happens when it comes out of kennels in a couple of weeks.

Re: Dog with possible polycythaemia Vera

Rory Bell — Wed, 20 May 2015 19:22:52 GMT

Hi Martin

cheers

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Wed, 20 May 2015 19:04:07 GMT

Update: saw dog tonight had one more minor seizure Monday evening after I saw it but been fine since. PCV down to 60% today, I did a more comprehensive evaluation of the cardiovascular system and all seems normal, and can't feel any renal enlargement. Owners are away on holiday next week so anything else put on hold for now. Will repeat PCV when they return.

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Wed, 20 May 2015 15:27:23 GMT

[quote user="Rory Bell"]I usually use EPO to determine whether a renal mass is responsible for the polycythemia (producing EPO) or not.[/quote]That was my rational especially as we don't have ultrasound to look for a renal mass. Still won't run before I can walk and will retest PCV this evening.

Re: Dog with possible polycythaemia Vera

Rory Bell — Wed, 20 May 2015 14:40:04 GMT

I'd probably not worry about EPO just now. A low/normal EPO would be consistent with haemoconcentration secondary to dehydration, of primary erythrocytosis / polycythemia vera, whereas a high EPO could occur secondary to EPO producing neoplasia or physiologically appropriate erythrocytosis (secondary to R-L cardiac shunts or pulmonary disease). It doesn't narrow down the differentials too much and it will take a little while to get a result back.I usually use EPO to determine whether a renal mass is responsible for the polycythemia (producing EPO) or not.

cheers

rory

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Wed, 20 May 2015 14:08:29 GMT

The dog is coming in tonight for a repeat PCV. I was just wondering about the value of measuring endogenous EPO as a diagnostic aid. Any thoughts on this anyone?

Re: Dog with possible polycythaemia Vera

Joyce Whitehead — Tue, 19 May 2015 19:51:21 GMT

We have also had a lab with a reverse PDA with polycythemia. Although she presented with hind limb weakness/collapse at 4-5 months. No murmur, but hind end cyanosis. Sadly pts at about a year of age due to worsening of pulmonary hypertension and clinical signs. We took blood every other week for the last 8 weeks to reduce her red cell count. Which made her feel much better for 10 days or so. As always, a really nice dog with lovely owners.

Re: Dog with possible polycythaemia Vera

Andrew Henfrey — Tue, 19 May 2015 19:08:53 GMT

I didn't see it so I don't know if the hindpaws were cyanotic.

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Tue, 19 May 2015 10:35:33 GMT

[quote user="Andrew Henfrey"]

We had a very similar presentation 2 weeks ago:- seizures, PCV 79%. Turned out to have a right-to-left shunting PDA. Just a thought!

[/quote]How old was it though and were there any symptoms of heart failure?

Re: Dog with possible polycythaemia Vera

Andrew Henfrey — Mon, 18 May 2015 22:28:40 GMT

We had a very similar presentation 2 weeks ago:- seizures, PCV 79%. Turned out to have a right-to-left shunting PDA. Just a thought!

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Mon, 18 May 2015 19:06:06 GMT

[quote user="Gerry Polton"]In practice, I don't always get a marrow sample. There are always limitations on what we think is a reasonable test to do. [/quote]Thanks Gerry I knew you would be along soon with a sensible answer.

Having spoken again to the owners I've opted to follow Michael's suggestion as they said she was out in the sun all day yesterday and was drinking more but have thrown bone marrow biopsy and imaging for tumours into the ring to think about. Polycythaemia is a better bet than a brain tumour anyway, at least we have a chance of treating it successfully!

Re: Dog with possible polycythaemia Vera

Gerry Polton — Mon, 18 May 2015 18:21:55 GMT

Hi Martin

If I could have the marrow aspirate, once other simpler things have been excluded, I would be happier. Polycythaemia is one of those difficult diagnoses like chronic granulocytic leukaemia. There is nothing about the peripheral blood cells that tells you there is a neoplastic cell line and there are countless aetiopathogeneses for a high red cell count which are non-neoplastic. I worry in cases like these: just because I can't think of a possible further pathogenesis doesn't mean there can't be one.

In practice, I don't always get a marrow sample. There are always limitations on what we think is a reasonable test to do. For example, if the cost of the test puts the treatment out of reach, I will try to make the best clinical judgement I can without that test. I know most would do/think the same.

Gerry

Re: Dog with possible polycythaemia Vera

Michael Woodhouse — Mon, 18 May 2015 17:58:53 GMT

[quote user="Martin Atkinson"]so not indicating dehydration id that's where you're going![/quote]

It was. I'd still not rush into anything until checking a PCV tomorrow.

Re: Dog with possible polycythaemia Vera

Martin Atkinson — Mon, 18 May 2015 17:52:57 GMT

[quote user="Michael Woodhouse"]

I would like to confirm the raised PCV tomorrow.

What are albumin, globulin and total protein like?

[/quote]FFS doesn't anyone read properly before they answer? TP normal!

OK TP 72g.l (54-82) Alb 42g/dl (25-44), Glob 30 (23-52) so not indicating dehydration id that's where you're going!

Re: Dog with possible polycythaemia Vera

Michael Woodhouse — Mon, 18 May 2015 17:43:27 GMT

Don't call me Vera!

I would like to confirm the raised PCV tomorrow.

What are albumin, globulin and total protein like?