The double intradermic test in cattle / by T. Dalling, J.H. Mason and W.S. Gordon.

  • Dalling, Thomas.
Date:
1927?]
Catalogue details

Licence: In copyright

Credit: The double intradermic test in cattle / by T. Dalling, J.H. Mason and W.S. Gordon. Source: Wellcome Collection.

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    Table 1. Final Diagnosis on Three Injections. All 3 + All 3 — 2 ? 1 + 2 4- 1 ? All 3 ? Number of Cows. 8 4 3 • • •<* 1 4 = Positive Reaction. — = Negative Reaction. ? =Doubtful Reaction. Table IT. Observer. S.D. Character of Swelling. Tender¬ ness. -——--- I Diagnosis^ Sow 9 A 14 D — ?+ 13 D- — ? 1 11 D- — ? B 13 D — ? - 10 D — p _ 9 D- —- ? — Sow 10 A 12 D- + T 10 D + 4- 8 D~ : B 11 D + 4- | 10 D i i 4-4- 1 1 5 D + ?+ | Final conclusion Cow g, “ probably negative ” ; io “ positive.” Third injection in Cow io presumably too deep. S.D. ^increase in skin thickness between original and after secon injection (R.I.). D. == Diffuse swelling. D — =Indefinite, not clearly diffuse. Conclusions.—The error of the D.I.T. may occasionally be coi siderable in that the same injector may’obtain varying results wii1 the same tuberculin in the same cow. The reading of the results | also subject to variation, especially when “ doubtful” reactions a got. With reasonable care and experience these errors can, in practic: be minimised.