eodemolay

Supplements of this nature can sometimes be efective, but they are
awfully expensive. Most of the time feeding a decent food will provide
a greater level of critical N-3 fatty acids than the supplements by
far.

As kind of an example, Derm Caps ES and Tri-V caps are fairly common
fatty acid supplements sold for this purpose. I don't know what
exactly is in the Shed Stop product but assume it is a fatty acid
supplement product of some kind. If you stop and examine the amount of
actual Omega 3's they provide compared to foods you may be surprised.
By looking at the levels in the food provided per day for a 10kg (22
pound) dog:

Brand X Canine Adult provides as much Omega 3 fatty acids as:
14.7 Derm Caps Regular per day or 3.6 Tri-V caps per day.

Brand X Sensitive Skin Canine Adult
51.6 Derm Caps Regular per day or 12.7 Tri-V caps per day.

As you can see you could spend a bunch of money on supplements only to
find out that buying a better food was a great deal less expensive
(than supplement and food combined) or provides much more fatty acids
to begin with.