Clinical and pathological investigations were conducted on outbreaks of infectious bursal disease (IBD) in pullets under brooding using the battery cage system in a commercial poultry farm in Kaduna, Nigeria. Two consecutive outbreaks of IBD on the same farm were studied. The onset of the disease and morbidity and mortality rates were recorded. Postmortem examinations were conducted and gross lesions recorded. Tissues were collected and fixed in 10% buffered formalin and processed for histopathological examinations. In the first outbreak, 80 to 100% of the chicks were affected at the age of 4 to 5 weeks and mortality rate was 95.8% and lasted for 9 days. In the second outbreak, the mortality rate was 43.3% and it also lasted for 9 days. At the onset of the disease, the birds were also 4-week-old like in case 1. The disease was diagnosed based on clinical signs, pathology, and agar gel immunodiffusion test (AGID). Clinical signs, gross lesions, and histopathological findings were characteristic of virulent infectious bursal disease. After the first outbreak (case 1) the house was disinfected using polidine® (iodophor compound), V-ox® (inorganic peroxygen compounds), CID20® (quaternary ammonium chloride, aldehydes, and alcohol), terminator III® (phenols), and glutasan® (aldehyde and quaternary ammonium chloride). But they failed to eliminate the IBD virus from the poultry pen.

In this study, the authors determined whether vvIBDV could be transmitted from chickens to pigeons and vice versa, and the relative severity of the lesions in the two species. Thirty 3-to 6-week-old pigeons and thirty 3-week-old chickens were grouped as follows: A (10 uninoculated pigeons), B (10 inoculated pigeons+10 sentinel chickens), C (10 inoculated chickens+10 sentinel pigeons) and D (10 uninoculated chickens). Inoculated birds were administered 0.20 mL of vvIBDV (titre of 109.76 CID/mL) followed by introduction of their respective sentinels post-inoculation. Post-inoculation/exposure (pi/ pe), dead birds were necropsied, organs grossly examined, weighed, and sections processed for histopathology. Results revealed mild, gross and histopathological lesions in pigeons at 7 and 14 dpi/dpe. In chickens, gross and histopathological lesions were severe at 3 and 4 dpi/dpe, moderate at 7 dpi/dpe and mild at 14 dpi/dpe. Carcass weight showed no statistical difference (P > 0.05) in all pigeons, but was statistically higher in uninoculated compared to inoculated and sentinel chickens. Relative weight (RW) of the liver was significantly lower at 14 dpi/ dpe in pigeons. In chickens, RW of the bursa of Fabricius (BF) was significantly higher in inoculated and sentinel at 3 and 4 dpi/dpe. In conclusion, there was transmission of vvIBDV from pigeons to chickens and pathological changes due to vvIBDV infection were less severe in pigeons than in chickens.

The study investigated the mitigating effects of two probiotics on blood parameters of ISA Brown chicks inoculated with a very virulent infectious bursal disease virus (vvIBDV). Two hundred chicks were assigned into four groups of 50 birds each. Groups A and B were administered Antox® in water and Bactofort® in feed daily from 1 to 42 days of age and inoculated with a vvIBDV at 28 days and C and D served as positive and negative controls, respectively. Blood samples were examined for changes in packed cell volume (PCV), haemoglobin concentration (Hb), red blood cell (RBC), total white blood cell (TWBC), heterophil and lymphocyte counts seven days post inoculation. The PCV between groups A and C differed (P < 0.05) and in group B it was higher (P < 0.05) than that of group C. The Hb concentration between groups A, B and C differed (P < 0.05). There was a difference (P < 0.05) in RBC counts between groups A, B, C. Differences in TWBC between group A and C were significant (P < 0.05) and TWBC in group B was higher (P < 0.05) than that of group C. There was a significant difference in heterophil (P < 0.05) and lymphocyte (P < 0.05) count between group A and C, and B and C. Heterophil/lymphocyte ratio was significantly higher in positive control compared to groups A, B, C. Antox® and Bactofort® mitigated the deleterious effects of vvIBDV on blood parameters and can assist in the control of IBD.

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