Figure 7. The degree of tonsil colonization was associated with development of colonization of Eustachian tubes.

Relationship between the number of M. bovis recovered from pharyngeal tonsils and the number recovered from the left and right Eustachian tubes in calves inoculated with M. bovis by either the oral (N = 8) or transtracheal (N = 5) routes. When only the undiluted broth was positive, results were assigned a log₁₀ value of 0.5. No mycoplasmas were recovered from carrier inoculated control calves (N = 8, data not shown).