Antibiotic issues for airway pathogens in sheep

Healthy animals are a cornerstone for a sustainable and profitable sheep production. Respiratory tract infections are a frequent problem in Swedish sheep farms and the second most common cause warranting antibiotic treatment. Identification of the causative agent facilitates the choice of correct treatment and promotes improved animal health.

The knowledge about respiratory tract infections caused by viruses and to what extent secondary bacterial infections occur in Swedish sheep is very limited. Furthermore, data regarding the distribution of respiratory pathogens in sheep is lacking. Expanding the knowledge about respiratory tract infections in sheep could help guide treatment options, such as when to use antibiotics and what substances to use.

The aim of this project is to investigate the causes of respiratory tract infections in sheep in Sweden. A similar study was conducted in Sweden in 2008, however, due to the lack of relevant diagnostic tools, the issue of etiology behind respiratory infections could not be addressed adequately. This project will be using molecular diagnostics to assess viral and bacterial causes of respiratory tract infections in sheep. SVA has set up a respiratory tract diagnostic package, using PCR to screen for Mycoplasma ovipneumoniae, Bibersteinia trehalosi, Histophilus somni and Mannheimia haemolytica. Stored swab samples from sheep lungs will be subjected to analysis using this PCR as well as conventional bacterial culturing. Relevant bacterial findings will be tested for antimicrobial susceptibility. In addition to this, selected samples will be screened for the following viruses: lentivirus, adenovirus, respiratory syncytial virus and parainfluenza virus. New samples fromsheep authopsies collected during the year will also be analysed accordingly.