RE: High blood pressure cause.

Claire Godfrey — Tue, 15 Nov 2022 22:15:51 GMT

Thank you both for your reply.

I saw the dog back on monday, and he was not doing well. Discussed with the owner either referral or PTS. Owner elected for PTS but wanted her equine vet to do it.

Equine vet said would be cushings, so has been for an ACTH stim test today. Will update with results.

Not sure if I have missed this, but ALKP and ALT completely normal. Not really seen a cushings case quite like this if it is. Will see what the results are.

Kathryn thank you very much for the tips on blood pressure. Will remember these for the future.

Have ultrasounded but my level is not finding adrenal glands.

RE: High blood pressure cause.

Andrew Kent — Tue, 15 Nov 2022 15:07:30 GMT

Hi Both,

Tough case - I agree with many of the comments above and would start by looking at whether the BP is repeatable. These breeds are often hypertensive in the hospital and so can be very difficult to know if its just a stressed unwell lurcher vs something else.

Glomerulonephropathies are common in sight hounds and that would, potentially, fit well with hypertension and proteinuria.

But I agree ruling out a pheo would be sensible.

I would likely start with abdominal ultrasound if you can?

Andy

RE: High blood pressure cause.

Kathryn Garven — Tue, 15 Nov 2022 09:50:03 GMT

Hi Claire, I’m not sure if you’ve had any responses so far, but I would likely start with basics with this one - it’s quite a complicated case and if the client doesn’t wish to refer or go into a massive investigation, then you can only do your best! I’ll preface by saying I’m a cardiology certificate holder so I’d be more than happy to defer to any additional comments that medics or endocrinologists can give.

For my tuppence worth though… and apologies if this all sounds quite basic and you’ve already thought of these things, but I often find checking the basics is the best way to start with weird cases…

First of all, I’d recheck the blood pressure - give consideration to your technique and circumstances of the high reading obtained the last time - right size cuff, position of dog, degree of anxiety etc. If he is a long-legged sight-hound type of lurcher, placing the cuff on the forelimb might put it well below the level of the heart in a standing or sitting position, which will artificially elevate the reading. If the patients choose to lie in lateral or sternal recumbency it’s ideal, but if a dog is quite stressy I’ll just let them sit up and elevate the limb so the cuff is level with the heart. If I get consistently high readings when the dog is chilled out, over a long period of time, then I’ll start to maybe believe it. Many times, if I keep going and repeating the measurements for 5 -10 minutes or more, the readings will fall as the patient gets used to it. Also, I would have a look at the retinas for any signs of hypertensive retinopathy.

Just to check - when you say he was flat - was he sedated - ‘poorly’ - or just a very quiet demeanour?

I’m thinking the thyroid is unlikely to be the cause of such reportedly significant pd/pu. I’d check there were/are no confounding medications in use at the time of the previous sampling, but given the very low initial T4 level you report, supplementation seems reasonable to me.

Endocrine problems can be broadly associated with hypertension, but I’d be cautious with any further increase in the thyroxine dose - if he is genuinely hypertensive, you don’t want to over-supplement. My feeling is I’d likely leave the thyroid meds as they are for now and put that on the back-burner while you think about the pd/pu, which is the main presenting complaint.

The urine and haematology is bugging me. Does he appear dehydrated clinically? He has relatively low SG and RBC parameters are increased. But SDMA and renal parameters are normal! Are there any other indicators of dehydration eg high end range albumin? Or could the RBC parameters be normal outliers; or a ‘true’ increase in red cells? (Did the sample get properly mixed before running…?) I’m sorry this is not really within my area of interest to comment with any authority. On a first opinion level, I’d be thinking about more simple pd/pu work up which might help shed light - getting the client to measure 24 hour water intake to put some objective numbers on it? Did you have electrolyte panel and bile acids in your profile (also thinking about pd/pu rule-outs? Is the dog entire, and could he have prostate or other lower urinary issues, regarding the recent increased urgency? I’d likely continue to keep an eye on basic urine analysis given the previous positive bacterial culture.

To come around to the phaeochromocytoma question - I have seen a few cases. You might have tachyarrhythmia, hypertension and/or other signs - which can be intermittent. It would certainly be a differential for unexplained hypertension. Or PC might be completely subclinical/incidental in some cases. They might have concurrent problems as they usually are older dogs. If you have ultrasound, you might find a mass beside a kidney. You can send urine for normetanephrine testing, which is certainly more convenient than histopathology! But I believe urine normetanephrine levels can also be intermittently normal with PC, so you can possibly get false negatives. If you’re thinking about testing, I would contact your lab - last time I requested (a while ago now) the sample was referred out to Europe and it may be quite pricey. I did get a positive diagnosis for that case though.

For PC cases with hypertension, beta blockers would usually be a logical choice… but I’d really recommend to confirm a diagnosis since beta blockers might be contraindicated in a patient with different medical issues. If he does have PC, it may be benign or malignant, and for a chance of cure he would need to go to surgery. For the few cases I’ve seen, outcome has varied, from euthanised ‘on the table’ at ex lap (a case many moons ago, before referrals had even been invented), to a decent couple of years on medical treatment (the latter case was 14 years old at diagnosis).

Otherwise, once you’re satisfied this dog is truly hypertensive, and you’ve double checked/gone as far as you can to diagnose the underlying cause of the pd/pu, for blood pressure readings which are that high I would likely consider amlodipine, as it’s unlikely that an ACE inhibitor alone would bring a 200mmHg systolic pressure down sufficiently.

I hope some of that is helpful - and I hope others might chip in with more from the medicine perspective. I’m interested to hear the outcome!

All the best,

Katy