_Synonyms._ Contagious catarrhal fever; Dog ill; Bronchial Catarrh; Intestinal Catarrh; _Fr._ Maladie des Chiens, Maladie du jeune age, Typhoïde, Typhus des chenils, Variole du chien; _Ger._ Staupe; _It._ Cimurro. _Animals susceptible._ Dogs, especially puppies and young dogs, and other members of the canine race, fox, jackal, hyena, wolf. Cats suffer from inoculation (Laosson), also apes (Cadeac). Old cats and dogs are often immune, also all animals that have passed through one attack of the disease. _History._ The older English veterinarians quote the epizoötics in dogs described by Virgil, Aristotle and even Homer as probably distemper. Laosson attributes to it a canine epizoötic which prevailed in Bohemia in 1028. It appears to have been unknown in Europe in the earlier third of the 18th century though prevailing in Peru. According to Ulloa, it was introduced from Peru into Spain in 1735, whence, it spread into France (1740), Germany (1748), Ionian Isles, Greece (1759), England (1760), Italy (1764) and Russia (1770), Sweden and Norway (1815), Siberia (1821). Since that time it has prevailed in Europe and many dependencies of European nations. _Causes._ Its advent in Europe as a new disease in the second third of the 18th century, its steady spread, its continued prevalence, and extension, concur with the infection of kennels and districts by the introduction of a sick dog, in demonstrating its purely contagious nature, and this implies a living microbe transferred from animal to animal. If any doubt remained it must be dispelled by the inoculations which have been constantly successful when made on young puppies, or dogs that have not previously suffered, and on cats. A first attack confers immunity. Among _accessory causes_ may be especially named _contact with the sick dog_, its _clothing_ or _bedding_, and above all its _kennel_. A kennel may retain infection indefinitely, especially if there is a constant accession of puppies or susceptible dogs. On the contrary it is not readily carried on the clothes of attendants, and the inmates of a kennel often remain sound, though only separated by a yard from the infected one, and though cared for by the same attendant. Yet so universally diffused is the contagion that few dogs escape it until they are a year old. The habit of letting dogs run at large, to meet in roads and fields is a most prolific cause, which might easily be done away with where distemper is prevalent. A _chill_ is a common condition, hence injudicious washing, swimming in cold water, exposure of house dogs to cold storms, or outdoors at night, sleeping in cold, damp cellars, on cold stones or metal plates, or in passages in a current of cold air are frequent factors. Yet it often spreads rapidly in the summer, the heat favoring the preservation and diffusion of the germ.