Eleven field piglets aged 3 weeks possessing maturnal hog cholera antibcdies were vaccinatd with bvine viral diarrhea ‘nnises (BVDV), Tobias stain. Seven weeks pc€tvathnation, the vaormnatoi pigs were challenged with AU] virulent hog cholera viruses. They showed no or morleratu reaction and all survived. Clinico-ethological studies were reformed to find out the reactions in these pigs.
Aft challenge, the BVDV vaccinarrl pigs showed thermal reaction for 2-3 days, some pigs anorexia aand depression but all recovered soon, The hog cholera viruses were detecti horn feceses and urine from the 3rd through the 6th day po€thallenge.
The leucopenia and the shift to the left of the neutrophils were noticed from the 2nd through the 4 th thy aft virulent hog cholera viruses challenge, simultaneously slight thrombccytoenia was observed. The activity of the serum glutamic oxalacetic u’ansaminase significantly increased akout two times the first week aft challenge and decreased rapidly in the sexnd week. Aft challenge, total proin concentrations in the serum were slightly increased, the albumin values decreased gradually, the rr-golb-u]in iunmary concentrations significantly increased and erticigeting with heerogotuin was evident
by the aprearance of two reak phase in the electrophoretic analysis, the n-and yglobulin concentrations were gradually but not significantly increased.
The level of neutrabng antibodies against hog cholera and DVI] viruses were rapidly increased in the pigs after challenge, and reacher] 2.41 and 2.54 (Log 10), respectively, 2 weeks aft challenge. The peripheral hemorrhage lesion was ccasionally observed in the stnal and mandibular lymph ncdes of the survival pigs. In one case the hia ion in parotid salivary gland in another case the spleen infarctions were noticed.
From the data obtained abDve, some survival pigs showed subolinical hog cholcirra, of particular importance was excretion hog cholera viruses and kecame carriers after infectionlc although the BVDV vathnation provided, the pigs some goetion against hog cholera infection. So that the use of BVDV for hog cholera control program shall Ire carefully evaluated.