The present study describes the clinical, serological and bacteriolological findingsin calves from two beef herds experiencing outbreaks of pneumonia. The clinical signs were nasal discharge, cough, pyrexia and increased respiratory rates. The morbidity and mortality rates over a month period were 40.72% and 15.63% respectively. Laboratory investigations revealed that bovine viral diarrhea virus (BVDV) was involved in and probably initiated both outbreaks as indicated by a significant increase in antibody titers against BVDV in sera of convalescent calves (paired serum samples). No antibodies bovine herpesvirus-1 (BHV-1), bovine respiratory syncytial virus (BRSV) and parainfluenza-3 (BPIV-3) viruses were detected in both acute and convalescent sera. Mycoplasma bovis was concurrently demonstrated in lungs of affected calves as it was isolated from 13 (81.25%) of examined lungs suggesting that there may be a synergism between bovine viral diarrhea virus and Mycoplasma bovis in the pathogenesis of pneumonia. A total of 15 (68.18%) isolates of Mannheimia haemolytica, 5 (22.73%) Pasteurella multocida, 1 (4.54%) Pseudomonase aerugenosa, 3 (13.64%) Staphylococcus aureus, 3 (13.64%) Actinomycis pyogenes, 1 (4.54%) Klebsiella pneumonae, 1 (4.54%) Streptococcus pneumonae, 2 (9.09%) E. coli and 2 (9.09%) Aspergellus fumigatus were recovered from lungs of calves suffering from pneumonia.

Lymph nodes (Ln) are the preferred samples for virus isolation and detection. Inthe present study, carcass and visceral Ln of apparently healthy cattle were screened for the presence of bovine herpes virus type 1 (BHV-1) and bovine ephemeral fever virus (BEFV) antigens. A total of 198 Ln (114 carcasses Ln and 84 visceral Ln) were collected. Lymph node homogenates were assayed by agar gel precipitation test (AGPT), rapid Staphyloccocal protein A (SPA) agglutination test and Dot-ELISA. The overall results revealed that BHV-1 antigens were detected in 43.9%, 56.1% and in 68.4% of carcass Ln, and in 29.8%, 47.6% and 57.1% of visceral Ln collected from slaughtered cattle by AGPT, SPA agglutination test and Dot-ELISA respectively. On the other hand, BEFV antigens were detected in 5.3%, 38.6% and 52.6% of carcass Ln, and in 6%, 41.7% and 54.8 % of visceral Ln collected from slaughtered animals by AGPT, rapid SPA agglutination test and Dot-ELISA respectively. The results showed high percentage of positive samples with SPA agglutination test and Dot- ELISA in comparison to AGPT for both BHV-1 and BEF.

During summer 2004, an outbreak of bovine ephemeral fever (BEF) had beenspread among cattle as well as buffaloes in Egypt. The most striking clinical signs incattle were fever of short duration, depression, stiffness, lameness and sometimerecumbency. Young calves, unfattened bulls and dry, lean non-pregnant cows showed only mild signs while fattened calves, mature heavy bulls and high-producing dairy cows and cows at the late stages of pregnancy were severely affected and signs persisted longer. Deaths and other complications accompanied the disease such as subcutaneous emphysema was not recorded in these outbreaks. In buffaloes, the clinical signs were mild and less severe compared with that of cattle. Serological examination of paired serum samples collected from the diseased animals using serum neutralization test revealed rising of the neutralizing antibody titers for BEF virus after 3 weeks from the onset of clinical signs. Blood picture and biochemical analysis of sera of 6 diseased animals, showed anemia represented by significant decrease in RBCS, PCV% and Hb content. The leukogram showed neutrophihia and lymphopenia with normal leukocytic count. There was rise in plasma fibrinogen with drop in calcium and phosphorus values. All of these parameters were more or less improved three weeks post-recovery. Good nursing care with early treatment with non-steroid anti-inflammatory drug (Phenylbutazone) or administration of calcium borogluconate of lame or recumbent animals lead to rapid and prompt recovery.

Forty-eight pathogen free New Zealand rabbits were divided into two groups, the first group contained eighteen rabbits served as normal control and the second group of thirty rabbits were received 1 ml bovine herpesvirus-1 (BHV-1) virus suspension (107 TCID 50) by intraperitoneal route. Rabbits both groups were subjected to hematological, serum biochemical, different serological and histopathological examination 3,7,10,14,21 and 28 days post infection. Clinical observation of infected rabbits showed febrile response and mild conjunctivitis after 24 and 48h. of inoculation, respectively. The hemogram revealed no significant alteration in the erythrogram while leucogram showed leucocytosis accompanied with heterophilia, lymphopenia and monocytopenia at the 3rd and 7th days post infection. Serum biochemical analysis showed significant elevation in the activity of AST, ALT and AP and in blood urea nitrogen and creatinine concentration along the experimental period. Serum total proteins, albumin, :, ; and < globulin significantly increased at different periods of the experiment. BHV-1 antibodies were detected in the sera of infected rabbits by Dot ELISA and ELISA from the first week until the forth week post infection. Histopathological examination revealed that the most affected organs were the trachea, lungs and liver while adrenals, kidneys, and spleen showed mild pathological alterations.

The effect of a novel bovine mastitis trivalent vaccine, containing Staphylococcus aureus capsular polysaccharide type 5 (T5), 8 (T8), and 336 (T336), on lymphocyte subpopulations, antibody production, and neutrophil phagocytosis was evaluated. Twenty pregnant heifers were immunized with either the trivalent alone, trivalent emulsified in Freund's incomplete adjuvant (FICA), trivalent in aluminum hydroxide, or adjuvant only (FICA). Immunization was done 30 d before the expected calving date followed by 2 boosts in a 2-week interval. Compared to FICA, serum antigen-specific immunoglobulin (Ig)G1 and IgG2 were significantly increased in all the vaccinated groups before parturition and sustained until 3 wk postpartum. In comparison with the trivalent alone, formulation with either adjuvant enhanced production of IgG2, but not IgG1. Immune sera, which contained the highest amount of antibodies, slightly increased neutrophil phagocytosis to the 3 serotypes of killed S. aureus, but most of the differences were not significant due to large variation between the cows. The percentage of CD4+ lymphocyte was significantly higher in vaccinated groups than that of FICA 4 wk after the primary immunization. In comparison with FICA, cows inoculated with trivalent vaccine and adjuvants had an increased percentage of CD8+ lymphocytes at 2 time points, 2 wk before and after calving. Our results indicated that the whole cell trivalent vaccine, with or without adjuvants, is able to elicit antibody responses specific to the 3 capsular polysaccharide antigens. The increase of T8-specific IgG2 was more noticeable when the vaccine was emulsified with adjuvants.