This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
The sarcoptic itch of the dog, as well as that of the cat, is transmissible to man.
The Tinea tonsurans, the so-called barbers' itch, due to a trychophyton, and affecting both the dog and cat, is highly contagious to man. Favus, Tinea favos, caused by achorion schoenleini, of both animals, is readily transmissible to human beings. The dog carries in his intestines many kinds of tœnia (tapeworm), among them Tœnia echinococcus, the eggs of which cause hydatic cysts. Hydatic cysts occur in persons who are always surrounded with dogs, or in constant contact with them.
Aviar diphtheria (i. e., the diphtheria of birds), caused by at least two microbes (bacillus of Klebs-Loeffler and bacillus coli), may easily be transmitted to man and cause in him symptoms analogous to those of true diphtheritic angina.
Parrots are subject to an infectious enteritis which may be communicated to human beings, giving rise to the so-called psittacosis (from the Greek, psitta, a parrot), of which there have been a number of epidemics in France. It is determined by the bacillus of No-card.
Human tuberculosis is certainly transmitted to dogs, cats, and birds. Cadiot, Gibert, Roger, Benjamin, Petit, and Basset, as well as other observers, cite cases where dogs, cats, and parrots, presenting all the lesions of tuberculosis, were shown to have contracted it from contact with human beings; while there are no recorded cases, there can scarcely be a natural doubt that man may, in a similar manner, become attainted through them, and that their tuberculosis constitutes an actual danger to man.
Need we recall here the extraordinary facility with which hydrophobia is communicated to man through the dog, cat, etc.?
We may, therefore, conclude that we should not permit these animals to take up so much space in our apartments, nor should they be petted and caressed either by adults or children in the reckless manner common in many households. The disgusting habit of teaching animals to take bits of food, lumps of sugar, etc., from between the lips of members of the family is also to be shunned.
Finally, any or all of them should be banished from the house the moment that they display certain morbid symptoms. Besides, in certain cases, there should be a rigid prophylaxis against certain diseases—as echinococcus, for instance.