Fig. 3.

Serology of vaccinated dogs challenged with Silveira arthroconidia. Serum from 30 dogs (n = 6/grp) was tested every two weeks from prior to vaccination until 42 days post-vaccination, and immediately prior to infectious challenge until euthanasia 8 weeks post-infection. (A) MVEIA values ≥ 8 EIA Units (EU) in dogs pre-infection until 8 weeks post-infection (termination). Dogs in the 100 K P and Control groups had IgG detected as early as 2 weeks post-infection and had more IgG positives over time, indicating greater disease activity. All dogs not represented on the graph had negative EIA results. (B) IgG by agar gel immunodiffusion was not detected in any dogs 28 days after primary vaccination (D28Vx), and one dog had a transient, low titer (1:4) 63 days after primary vaccination when tested prior to infection. There were no false positive results in unvaccinated Control dogs. Terminal IgG titers (range 1:4–1:64) were frequent in the 100 K P and Control groups but not in Prime/Boost groups. Only two Prime/Boost dogs had terminal IgG titers, and the dog with a titer pre-challenge had resolved by end of study.