I am using these on two buck goats and they have worked wonderfully. I don't like flat collars and the rolled is comfortable when I have to take them by the collar without a lead. For the price, these are an excellent value and I am buying more for my dairy does.
Excellent value. Never noticed any fish oil smell; rivets lasted well over a year for an active dog tied out on an overhead zip line. DID notice shrinkage, but only after I allowed the collar to dry in the sun. Was utterly useless after that. If left to dry on the dog after a bath (with collar on during bath), I did not notice the shrinkage, probably because the leather was "worked" as the dog dried. Several of the collars had "Weaver" stamped on the leather. I bought the round ones and my dog stopped scratching around her neck; evidently the edges of flat collars drive her nuts.
I bought this collar becuase I wanted a cheap leather collar for my large breed puppy. I knew the pup was going to out grow anything in a month regardless, and I figured that I could stand to lose a few dollars if it was as bad as the reviews said. I was really pleasantly surprised. It does not have a smell nor does it rub off on her fur, so they must have corrected these problems. She is indoor/outdoor, very active and loves to swim in the pond, and the ONLY flaw with the collar thus far is that there are some "rubbed raw" spots in the leather that would probably not happen with better quality leather. Given the abuse my pup puts it through, it really is worth it and looks/feels so much better than nylon and it has plenty of holes for adgustment. I wouldn't necessarily recommend it for long term, but it has held up GREAT over the past 2 months on my very active puppy, though I will probably upgrade when she reaches her full size.