I agree with Gippy.

Iron injections should only be used on vet's advice after a blood test, as you don't know whether a dog needs it or not, and if you give it to a dog that doesn't need it, it can make the dog very sick.
So...... Iron injections should only be used AFTER a blood test has shown it is needed.

If you need to pick up a dog, you can give Folic a few days before a race (I find Foliphos the best but only to be used sparingly, not all the time otherwise it will just stop working for the dog.) and B12 about 4-6 hours before a race.

However all injections should really only be done by a confident experienced person as damage can be easily done by a novice.

cheers