This no doubt was a common vaudeville turn but I know of no 1895 film by Edison on the subject. Its origin in films would very definitely seem to be French. La Charcuterie mécanique was one of the earliest comic films shot by the Lumières, in fact by Louis Lumière himself, early in 1896 (so just after the first public projection in December 1895). The first known showing of the film took place at Lyon on 18 April. It showed a whole pig being fed into one end of the machine and various ready=made charcuterie products coming out the other end. The gag is a mild satire of mass production and would later often be associated particularly with the US (the Belgian graphic artist Hergé uses it this way in his 1932 Tintin en Amérique)but the original Lumière film associated it with specifically with Marseille. It was advetised in the US later that same years as "The Famous Mechanical Sausage Factory at Marseilles". It has also been described (rather fancifully) as "the first science fiction film".
The second known version (which I have not found) was called The Sausage Machine and was made in the US in January-February 1897 and was the first film to show dogs and cats being fed into the machine and was supposedly also the first to link it specifically to conveyor-belt mass-production, The film was almost immediately remade made by the Brighton film-maker G. A. Smith as Making Sausages or The End of All Things (available on youtube). In Smith's more artisanal version the cooks again put a whole range of different animals (dogs, cats and even an old boot) into the hopper that produces sausages at the other end.
This Gaumont version directed either by Alice Guy or by another Gaumont employee, Henri Vallouy (who acts in it), followed in 1900.The scene is still relatively artisanal but the innovation here is to de-link the final product from the original, with hats rather an sausages coming out the other end, suggesting that anything can be made out of anything It seems to have taken Edison's a surprisingly long time to have to round to remaking the gag but they made up for it by remaking it twice, as Fun in a Butcher Shop (1903) and Dog Factory (1904), the latter, and perhaps both, filmed by Edwin Porter. The first (available on youtube in a Huntley Archives compilation (44141) was one of a whole series of rather racist comedies made by Edison's at this time, generally portraying the nasty habits of the Germans or (in this case) the Dutch Both films feature pet dogs being turned into sausages and the earlier one is is otherwise almost identical to (but less good than) Smith's 1897 version.
Dog Factory differs from the others only in that the process has seemingly become reversible so that a string of sausages can also be turned back into the dog of choice. Mass-production has seemingly changed from being a form of exploitation into the epitome of customer choice! The gag is also reprised, now in its definitive form of a conveyor-belt process, in the 1926 Mutt and Jeff cartoon, Dog Gone.
