SYMPTOMS 83 
only become typical when several appear conjointly. 
For instance, a mere watery eye, or an ordinary cough, 
or perhaps diarrhcea, without the addition of one or 
more of the accepted pathological conditions of dis- 
temper, could each conceivably have a separate existence 
of its own, arising from causes widely distinct from those 
of the malady under consideration. 
In a large number of cases the nose and eye symptoms - 
appear some days after the cough, and even may not 
' appear at all; in some other cases the dog dies of convul- 
sions within forty-eight hours, before any other serious 
‘secondary infection has had time to become manifest. 
Some authors are of opinion that broncho-pneumonia 
is largely responsible for the inception of nervous dis- _ 
orders; but it is also a fact, as just stated, that dogs may 
be affected with, or even succumb to, these conditions 
before pneumonia or any other phenomena have come 
into existence. We must therefore look for their cause 
in the formation of a toxin which attacks the central 
nervous system, or in a spread of infection by the 
causal organism of distemper from the pharynx to the 
brain and its coverings. 
Classification of Distemper into Four Divisions —Inasmuch 
as we know from clinical experience that distemper is 
peculiarly prone to manifest itself in some particular 
form in which many of the other well-known symptoms 
play no part, we can conveniently classify it for purposes 
of description into four main divisions, and place these 
in the order of their most usual preponderance and 
frequency : 
< 
1. Respiratory. 2. Intestinal. 
3. Nervous. 4. Exanthematous. 
goats, however, several organs are simultaneously 
affected, although the outstanding features may be those 
