Canine insulinoma

RE: Canine insulinoma

janine redman — Mon, 21 Oct 2019 23:36:47 GMT

Just had one diagnosed at SCVS ct scan following bloods to look at glucose and insulin levels . will check the report . They have advised partial pancreatectomy although suspicious of metastatic spread already

had a few odd bouts of collapse . Glucose normal on pre referral bloods

RE: Canine insulinoma

Beats — Mon, 21 Oct 2019 19:48:01 GMT

[quote user="Nicola M"]Do you think these blood glucose levels are low enough?[/quote]

Not low enough to say has insulinoma (2.6 is suspicious though, especially if it was repeatable and done fresh in dog otherwise walking around merrily).

Neither do the readings suggest doesn't have insulinoma.

My approach:

If I get a patient with a low blood glucose reading that I think might have insulinoma, then I repeat the blood glucose there and then and also draw a yellow tube (fluoride oxalate) and brown tube (serum gel) and post them to idexx for AIGR (insulin and glucose) there and then. Not always convenient, but like with PTH testing for dog with low calcium or ECG for a dog with a pulse irregularity if you don't look while the problem is evident can be a pain to get it back another time only to find the problem is no longer evident or you need to resort to more expensive and complicated means to decide.

Even without the insulin test, there are few to no likely differentials if presented with a dog with persistently low blood glucose in spite of walking around wagging its tail in front of you, and with a history of episdes sounding like hypoglycemia that respond to feeding [see Whipples triad]. Like laryngeal paralysis, if you think a dog has insulinoma, then it probably does. I can't recall a case I ever tested that didn't have it. Based on information you've given though, I wouldn't be happy to call it yet on your case.

Once you decide a dog does have insulinoma, I personally prefer the mark-one eyeball to determine if there is a mass that can be resected without an excessively high risk of immediate serious morbidity [and then resect it if there is], in preference to diagnostic imaging. But I believe that triple-phase angiographic CT stands the best chance of answering that question in a non-invasive manner (if you can find anywhere local to do that either at all or indeed for a sensible price). If you can identify a problem on the pancreas with ultrasound then you are in a different league to me and I guess then that is a simpler way - if it's on the left limb I would generally chop it off [open the greater omentum to access the left limb of pancreas but WARNING: SOME CARE WITH ANESTHETIC AND RECOVERY NEEDED!].

RE: Canine insulinoma

Laurence Webb — Mon, 21 Oct 2019 19:42:05 GMT

I had a recent suspect case and was advised by IDEXX that it is best to check insulin:glucose ratio when the blood glucose is <2.5mmol/l. A single cortisol to screen for Adissons is probably worthwhile and you could consider fructosamine which won't account for temporary falls in glucose but could help to support or reduce your suspicion of an insulinoma.

RE: Canine insulinoma

Nicola Cole — Mon, 21 Oct 2019 15:01:47 GMT

Thanks for the reply

Bumping the post for any other opinions. Do you think these blood glucose levels are low enough?

RE: Canine insulinoma

Anthony Dennison — Mon, 30 Sep 2019 10:12:41 GMT

Don't have to worry about a glucose:insulin ratio but just check insulin levels - if BG is low and insulin is overtly high Idexx normally will call it from that.

Another possibility is atypical Addisons - we had a dog we were working up as an insulinoma, went for a second opinion elsewhere and was eventually diagnosed as Addisonian and complained to us that we had misdiagnosed