Contains ivermectin, collies do not tolerate ivermectin.

I have heard the same warnings applied to Advocate re. Collies though so doublecheck. It's to do with the MDR1 - you can actually have the dog tested to check if this is normal or the harmful mutation which could be useful as it may open up your options in terms of flea and worm treatments if your dog is clear.
http://www.awca.net/drug.htm (just found this on Google quickly, not sure if it's the best page of info or not)

What are the main symptoms of lungworm?

www.lungworm.co.uk

Why can't collies use it? Wot about collie x?
ATD

Some Collies have a different gene that affects the way these medicines are absorbed and can cause health problems. I believe Collie crossbreeds can inherit this gene, but you can have your dog tested to see whether they've got a normal gene or this "bad" one, to determine if it's safe to use the flea/worming treatments that can have adverse effects.

Learn something new everyday, we used milbrimax a couple of times with michael but use drontal now
ATD x