Effect of intranasal recombinant Mannheimia haemolytica vaccination on some haematological indices of goats infected with peste des petits ruminants virus

Abstract

There is dearth of information on the haematological changes associated with Mannheimia haemolytica vaccination in goats, hence this report which describes some haematological changes observed following vaccination with intranasal Recombinant Mannheimia haemolytica vaccine in goats naturally infected with peste des petits ruminants (PPR) virus. Twenty one (male, n=11; and female, n=10) goats were assigned to three vaccinated groups (A, B and D) with five goats per group (male: 3, female: 2), while the control group had 6 goats. Group A was vaccinated once intranasally, group B was vaccinated intranasally twice at one week interval and group D was vaccinated intranasally twice at two weeks interval . The control group (C) was not vaccinated. The vaccinated and control groups were challenged by comingling with pneumonic goats to simulate the field experience. PPR virus infection was later diagnosed in all the groups post vaccination. An average of four animals per treatment group in post-vaccination days were bled once weekly for six weeks (every week) to evaluate some haematological changes. The PCV values were within the normal range, while there was a decline in lymphocyte count at week 5, and a steady increase in neutrophil count in group A. In Group B, there was similar decline in lymphocyte count from the sixth week, while in groups C (Control) and D, the lymphocyte count declined at the 7th week, as the neutrophil counts increased. There were no significant changes in monocyte and eosinophil counts. The degree of changes in lymphocyte and neutrophil counts was mild in group B and marked in group D. This study revealed that intranasal vaccination of recombinant Mannheimia  haemolytica vaccine in the presence of PPR virus outbreak results in mild hematological derangement when the goats were vaccinated with  Mannheimia haemolytica bacterin at a week interval.

Keywords: Goats, Haematology, Intranasal Recombinant Mannheimia haemolytica, Peste des Petits Ruminants, Vaccination