In young pigs, infected by the milk of the dam, there are general
unthriftiness, stunted growth, emaciation and unhealthy skin, encrusted
with a dark unctuous matter or scurf, as in chronic hog cholera.
Temperature is variable on successive days, or times of the same day.
Digestive disorder is manifested by slight colics, diarrhœa, vomiting,
tympany and abdominal tenderness. The pig becomes pot bellied, with
hollowness of the flanks in front of the iliac bones, and manipulation
may detect the tuberculous bowels and mesentery in the form of a knotted
mass.
Roloff describes a caseous colitis with ulceration of the mucosa, which
is probably tuberculous.
Enlargement of the superficial lymph glands (pharyngeal, inguinal,
prescapular) may be present. Traumatic infection of the castration sore
and inguinal glands has been noted. As the disease becomes generalized,
implicating the lungs, there is a dry paroxysmal cough and hurried
breathing, becoming more oppressed on the slightest exertion. If quiet
and thin enough for auscultation and percussion the usual morbid lung
sounds can be heard. Unlike cattle, pigs are very subject to muscular
and intermuscular tubercles, and as there is a general tendency to
caseation, these are usually to be found as saccular cavities with soft,
sometimes liquid, caseated contents. The bones and joints may suffer, as
in cattle. The tonsils are usually enlarged and even caseous. The outer
auditory meatus and the interior of the eye have been found affected.
Cases affecting the brain were manifested by nervous disorder, rearing
up on the fence, turning in a circle, spasms, rolling of the eyes,
paresis and paralysis, often hemiplegic. When one or other of these
indications of local disease is found associated with the general
disorder of the lungs or bowels, in a herd fed on raw meat scraps, milk,
or the soiled food of tuberculous animals, the evidence is strongly in
favor of the local tubercle corresponding to the symptoms. It is
noticeable that diagnosis by microscopic examination is difficult and
uncertain because of the relatively very small number of the bacilli. In
the mature pig the disease may be difficult of diagnosis without
tuberculin, and a _post mortem_ examination may be necessary to identify
the disease in the herd.