Re: Conditions for bloodwork

Trisha DePietro

Hi Lasell.  As far as the timing of the blood draw to the feeding....I give extra hay through the night and then get up at 5am and keep hay in front of the horses until the blood draw....usually we draw between 9am and 10am. I looked at your case history and I would draw the insulin, glucose and the ACTH all at the same time. I didn't see a glucose drawn on your last one, the Glucose:insulin ratio is a number to look at ...

Glucose:Insulin Ratio (G:I Ratio)

The upper limit of normal for glucose in a horse that has not been fed anything but hay prior to testing is around 100 mg/dL (5.6 mmol/L) by definition. It is important to also know that the horse could have an insulin result inside the lab's normal range and still have EMS. This is determined by the use of calculations called proxies and supported by abnormal leptin or adiponectin levels.

Based on human studies and data from our group members' horses, we have been using the G:I ratio proxy for many years now. It's very easy to do. Simply divide the glucose result in mg/dL by insulin in uIU/mL. (If your insulin is reported in pmol/L you have to convert it to uIU/mL by dividing by 6.0.) A normal value is 10:1 or higher. The lower the ratio, the higher the laminitis risk.

Air temperature is important in the sense that the results can be elevated from the cold. But if you live in a cold climate it is what it is, you can't really change your temperature, but you can make note of the temperature at the time of the draw and include that temp in your case history. This way, if there is anything unusual about your results, we have the temp for that day. for instance, insulin does go up from the cold weather, but its all relative. It is all factored into the big picture of Diagnosis, Diet, Trim and Exercise....Hope this helps.

If the blood is drawn at the beginning of the vets day...when will they get it back to the office to be spun? You might have already read this part but its a good review because not only do you want your horse non fasted and as calm as possible, you also need the blood sample to be handled appropriately....Here is the link to that detail if you haven't seen it yet.  --
Trisha DePietro
Aug 2018
Primary Responder
Dolly and Hope's Case Histories
Dolly's Photos 
Hope's Photos 

Join { to automatically receive all group messages.