I use to give Rex:
Aspirin, when his leg aches;
Immodium, for diahrhea;
Johanniskraut, to help his aggressions issues;
Iodine, for cuts;
Lanolin and Vaseline, on his paws;
Bakers yeast, agains doggie odor and fleas;
Apple Cider Vinegar, in his water bowl and some in the water to rinse him, same as above;
Garlic (raw), against worms and fleas.

In Sommer he shedded a lot and his coat was really uggly, I gave him Becozyn Forte (Vitamin B Complex), now he has a wonderful, shinny coat.