Clinical presentation and management of African horse sickness in two dogs

Abstract

A 10-month-old, spayed, female beagle (case 1) and an unrelated two-year-old, intact, female labrador retriever (case 2), both living in Pretoria, South Africa, presented individually on separate occasions with acute onset dyspnoea and severe hypoxia. Thoracic radiographs demonstrated severe, diffuse interstitial to alveolar lung patterns with mild pleural and mediastinal effusion. Mixed airway inflammation was seen on transtracheal aspirate cytology in case 1. Both cases received supportive therapy, but only one dog survived (case 2). African horse sickness (AHS) was diagnosed at necropsy based on histopathology and immunohistochemistry in case 1 and was diagnosed antemortally using reverse transcriptase-PCR on whole blood in case 2. To the authors’ knowledge, this is the first report to detail the haematological, biochemical, thoracic radiological, arterial blood gas and transtracheal aspirate cytology findings of AHS in dogs. This report also describes the treatment of a dog surviving clinical AHS infection.

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

“…The AHSV belongs to the same genus of Orbivirus as BTV and clinical canine cases have been recently diagnosed at the same institution (O'Dell et al 2018;Whitehead et al 2018). The treating clinicians had strongly suspected AHS, which has a remarkably similar presentation, but was excluded with a negative RT-PCR in this case (Whitehead et al 2018).…”

The seroprevalence of African horse sickness virus, and risk factors to exposure, in domestic dogs in Tshwane, South Africa

“…Recent dog mortalities without access to horse meat (van Sittert et al, 2013;O"Dell et al, 2018;Whitehead et al, 2018) and evidence that midges feed on dogs challenge the assumption that dogs play only a limited role in AHS epidemiology and this should be re-examined (Oura, 2018). It has been suggested that dogs no longer be considered dead-end hosts of AHSV but rather considered hosts with the potential of onward transmission (Oura, 2018).…”

“…The cELISA and iELISA are not serotype-specific and are better suited for serological surveys because of their potential for high throughput, and high sensitivity and specificity in horses and substantially lower cost (Maree and Paweska, 2005;Dennis et al, 2019;WOAH, 2022c). Viral neutralization, cELISA and iELISA have all been previously used in dogs for AHSV antibody detection (McIntosh, 1955;Alexander et J o u r n a l P r e -p r o o f van Sittert et al, 2013;Whitehead et al, 2018) despite not having been validated for use in dogs. Dogs (Canis lupus familaris) are the only non-equid species that have been reported to develop the fatal pulmonary form of AHS (Theiler, 1906;Piercy, 1951;van Rensburg et al, 1981;van Sittert et al, 2013;O"Dell et al, 2018).…”

“…Dogs (Canis lupus familaris) are the only non-equid species that have been reported to develop the fatal pulmonary form of AHS (Theiler, 1906;Piercy, 1951;van Rensburg et al, 1981;van Sittert et al, 2013;O"Dell et al, 2018). Outbreaks of AHS in dogs have been reported intermittently and AHS is almost invariably fatal for the dog when clinical signs have developed (Bayley, 1856;Bevan, 1911;Piercy, 1951;Haig, 1956;van Rensburg et al, 1981;van Sittert et al, 2013;O"Dell et al, 2018;Whitehead et al, 2018). Until recently, all known naturally occurring AHS cases in dogs were attributed to dogs consuming AHSV-infected horse meat (Bevan, 1911;Piercy, 1951;Haig, 1956;van Rensburg et al, 1981).…”

“…Until recently, all known naturally occurring AHS cases in dogs were attributed to dogs consuming AHSV-infected horse meat (Bevan, 1911;Piercy, 1951;Haig, 1956;van Rensburg et al, 1981). However, studies conducted by van Sittert et al (2013), O'Dell et al (2018 and Whitehead et al (2018) all reported AHS cases in dogs in the absence of horse meat consumption raising the possibility of a vector-borne AHSV transmission to dogs (van Sittert et al, 2013;O"Dell et al, 2018;Whitehead et al, 2018).…”