The clinical presentation and management of a naturally occuring Bluetongue virus infection in a pregnant Rottweiler dog

Abstract

Few reports of clinical Bluetongue virus (BTV) infections have been described in dogs. Most cases were linked to inoculation with a BTV-contaminated canine modified live vaccine. In dogs, cases have only been described in pregnant females with clinical signs of fever and abortion followed by severe dyspnoea and death. A pregnant Rottweiler dog was presented with a three-day history of progressive lethargy and anorexia. The patient was a guard dog living in an enclosure where sheep were kept at night. High mortalities had been experienced in the sheep but had not been investigated. On presentation, the major clinical findings were dyspnoea and hypoxia. Clinicopathological tests showed hypoxia and systemic inflammation. Radiological findings were consistent with non-cardiogenic pulmonary oedema. The patient was treated symptomatically and recovered but did not retain the pregnancy. BTV was identified in the patient’s blood using BTV RT-PCR (Ct value 24.7). At a follow-up farm visit, an ongoing BTV outbreak in the sheep was diagnosed with affected sheep testing positive for BTV on RT-PCR. This report describes the clinical presentation, diagnostic investigations and successful treatment of a dog with BTV infection. This is the first case report of a naturally occurring clinical BTV infection in a dog. Possible routes of infection were direct contact, midgeborne, or ingestion of infected afterbirth or abortus from sheep.