The Bleeding Dog

So we were presented with Jess, a 5yo FN labrador. She has a 24 hr history of marked lethargy and melena.

What questions would you like to ask the owner?

We got some history back: Previously well, no past history of GI signs, vaccinations are current, no previous bleeding, not on any drugs, comes from a rural environment, has access to outside and is a scavenger.

What are your differentials for melena?

And just in case anybody was confused as to what melena looked like, Nick added this lovely picture…Poor Liz got another dose of gross!

So it's time to take a quick clinical exam….

So we've got a lethargic dog with melena and mm pallor, which is either caused by anaemia or poor peripheral perfusion (due to heart failure or shock). Now it's time to think about the tests we might want to perform to differentiate between these.

Most people started to describe the anaemia- great! There was a little confusion over whether the anaemia regenerative or not…. It's important to remember that although in this case the MCV and MCHC values suggest that the anaemia isn't regenerative, these are average values. In addition, it takes around 3 days for the bone marrow to respond to an acute anaemia with a regenerative response.

So we've confirmed she's anaemic…. now we need to think about what causes anaemia! Again, there were lots of excellent answers- Nick clarified the main ones he was looking for:

There was a little confusion over whether the platelets were low enough to be causing spontaneous bleeds on their own- Nick kindly clarified.

Good point Amanda!

This question caused a 50/50 split between the answers- a tricky one! Nick gave us a big hint

…. which got us all agreeing at last- yay!

So a quick think-back to 1st and 2nd year with a look at what happens in both primary and seconary haemostasis. More useful revision slides from Nick!

So we've decided on secondary haemostasis in Jess… how do we go about testing for problems in secondary haemostasis?

Nice one Amanda and everybody else who got the right answer! Some results then…

So we can be sure this dog has a problem with secondary haemostasis… what can cause this?

Ratbait toxicity is the most common cause of problems with secondary haemostasis… what's common is common!
Emily had a good question….

Back to the case then…. how are we going to treat poor Jess?

And a few extra tips to wrap up:

And a final question from Abi before we go home…

So a big thank you to Nick for running such an interesting case discussion for us…. once again it was a lovely evening and very useful revision!