Actually it is the same, but lime sulphur sold as dog/cat dip is heavily diluted about 1:16 to 1:32. Like rockm said the non diluted stuff would dissolve your dog or cat since it is corrosive to the skin.
If you are buying a 4 oz bottle it is likely a repackage. Since the product is no longer to be imported from Japan to the US it is likely subject to price gouging and black market approaches.
It is still available to me rather cheaply so if I seem a little fickle about your shipping I apoligize. Right now I collect Roman coins from the Roman Empire and have been paying as much as 10.00 in shipping for a single coin, so 4.00 or 5.00 dollars for a 4 poz bottle which will probably last a number of years seems rather inexpensive to me.
A four ounce bottle will likely last you five years, or longer, unless you have large collected california junipers with deadwood areas the size of barn walls...
Attempting to make this stuff from other sources or from scratch can end in disaster, a nasty, smelly disaster.
Additionally, there are products sold in nurseries that CONTAIN lime sulphur, but they are NOT the stuff you want for bonsai. Usually the nursery stuff has an oil additive that will make a mess of your deadwood. The prepared bonsai solution really has no correllary, as it is technically illegal in the US to use it as a wood preservative. The personnel at the National Arboretum can't use lime sulphur on the national bonsai collection for that reason. They have tried to come up with a substitute, but haven't been real successful.
My local nursery sells it for 9 bucks a quart. Be sure to add some ink or your deadwood will come out looking like a good old boy from down south on Sat. night wearing a sheet wth two eye holes cut out. The only sheet they wash by the way. That would be bright white for you Yankees.......