[Black Sheep]

I am going to use the rest at a Slightly higher dose rate within a few weeks and if there is any left I will bin it.

I would suggest caution. Doing this makes an assumption that some of the activity of the drug has been lost due to the period after expiry and uses a "bodge factor" to try and compensate. The obvious issue is whether the "bodge factor" is anywhere close to achieving what it aims to and whether you then under or overdose the animal. Both could have consequences. "Bodge factors" of "slightly higher" and "double" have already been suggested in this thread - they can't both be right. Ask yourself whether you would do the same with human medication for you or your children.

But as with other previous discussions on people making judgements on how/when to use medicines there are other major factors to consider that aren't immediately obvious and can lead to failures to recognise the risks involved.

So for example, how do you know that the product does not degrade into toxic substances and that by giving a higher dose of the out of date product you'd inadvertently end up administering an even greater amount of something toxic?

A practical example of this are tetracyclines (and perhaps quite relevant given their widespread use in livestock - e.g. Alamycin). Tetracyclines degrade into substances that can cause liver damage - certainly in humans and I would thus anticipate (although don't know for sure) similarly in other mammals. So you wouldn't want to use out of date Alamycin etc.

Do you know the same issue doesn't apply to this product?

No-one here, I don't think, is qualified to tell you something is still as effective or safe, three months of date.

Quite.