The inspection of meats for animal parasites / prepared under the direction of D.E. Salmon.

Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: The inspection of meats for animal parasites / prepared under the direction of D.E. Salmon. Source: Wellcome Collection.

    87/172 (page 81)
    Disposition of measly beef.—Measly beef should be condemned to the tank as unfit for food when the infection is general, or when the inva sion by the parasites has caused a watery and “tiabby” condition of the meat. In case of light infection the meat can be used for food aftei the cysticerci have been rendered harmless, but even in these cases it is well to cut away the most heavily iufested portions. Oases of so-called “single infection” should be treated the same as cases of light infection, for although it may unquestionably happen that an animal is infected with but one bladder worm, still the finding of only one parasite is no proof that other parasites are not present; further- more, iu a number of cases of alleged u single infection,” later and more thorough examination has revealed further worms. In case of infection with only very young parasites, in which the suckers are not fully developed, the meat may safely be passed and allowed to go on the market without restriction. In case of infection with fully developed live bladder worms, the meat should be subjected , to some safeguarding method before being placed on the block, or it should be sold under declaration of its exact character. Opinion differs as to the method which should be followed in case of infection with degenerated bladder worms. It is maintained by some that this meat should be allowed on the market without restrictions. The finding of degenerated cysts, or bladders, however, is no proof that all the parasites are dead, for not only are cases more or less frequently found in which both live and degenerated bladders are present, but even if the cyst, or bladder, is degenerated the head may, in some cases, still retain its vitality. It is accordingly safer to treat carcasses with degenerated cysts in the same manner as carcasses with live cysts; and should any exception to this be made, such exception should be limited to cases in which the degenerated parasites are found in the muscles of the jaws. The cysticerci may be killed by cooking, by salting or corning, or by cold storage. Cooking.—This is the surest method of killing the parasites, but it is open to the serious practical objection that, according to estimates, cooking in a steam sterilizing apparatus results in a shrinkage of from 33 to 50 per cent, and this heavy loss will undoubtedly be a drawback to its general use. Perroncito found that below 30° G. the movements of the worms are very slight, or practically nil; from 36° to 38° C. the movements are livelier; at higher temperature they diminish, ceasing at 44° 0.; they 5257—No. 19 6 Fig. 74.—Egg of Beef-measle Tapeworm (Taenia saginata), with thick eggshell (embryophore), containing the six-hookecl embryo (oncosphere), enlarged. (After Leuckart.)