Page 1355 - Veterinary Immunology, 10th Edition

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FIG. 40.9 The importance of vitamin D in immunity. Note that
vitamin D is a potent stimulator of innate immunity by enhancing
production of antimicrobial peptides. It is, however, somewhat
suppressive of adaptive immune responses.

Taurine deficiencies in cats can result in a neutropenia, although

mononuclear cell numbers may rise. The neutrophils of taurine-
deficient cats show decreased respiratory burst activity and
phagocytosis. Although these cats may show a

hypergammaglobulinemia, germinal centers shrink, suggesting a
loss of B cell activity.
The effects of malnutrition may be reflected in altered resistance
to infectious diseases. Because bacteria can readily survive and
multiply in body tissues despite malnutrition of the host, starvation

commonly increases the severity of bacterial infections such as
pneumonia. Viruses, in contrast, require healthy host cells in which
to grow. Malnutrition, by rendering host cells unhealthy, may

therefore increase resistance to viruses. Over-nutrition can also
influence susceptibility to viruses. For example, overfed dogs show
an increased susceptibility to canine distemper and canine
adenovirus-1.

Exercise and Immunity

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