Aujeszky's disease in hunting dogs after the ingestion of wild boar raw meat in Sicily (Italy): clinical, diagnostic and phylogenetic features

Abstract

Background: Aujeszky's disease is caused by Suid Herpes Virus-1 and species belonging to the genus Sus scrofa are the main reservoir hosts. This virus, however, is capable of infecting and causing severe disease, with an almost constant fatal outcome in other species, both domestic and wild (carnivores, monogastric herbivores and ruminants). Moreover, the possibility of transmission to humans has been demonstrated. This study reports and describes the clinical, diagnostic, pathological and phylogenetic aspects of two cases of Aujeszky's disease in two hunting dogs following the ingestion of infected wild boar raw meat. These cases are contextualized in the province of Messina (Sicily), where a high prevalence of Aujeszky's disease has been recorded (average of 12,20% in the period 2010-2019) in farmed pig, and with evidence of spread to other species. A severe outbreak in cattle has recently been reported in these areas. Nevertheless, cases of Aujeszky's disease in dogs are rarely reported and this study represents the first well-documented report in this species in Sicily.

Case presentation: After a wild boar hunt, two dogs showed neurological symptoms and intense itching unresponsive to therapy. Diagnosis of Aujeszky's disease was made based on clinical suspicion, anamnestic information and confirmed by the isolation of the virus from the brain of both dogs. In addition, molecular typing, sequencing and phylogenetic analysis of the Real-Time PCR products were performed. The sequences studied were placed in the Italian Clade 1 along with the sequences obtained from wild boars and hunting dogs from Italy and France.

Conclusions: The finding of this disease in non-natural hosts in Sicilian multi-host epidemiological contexts suggests that the risk of inter-species transmission is concrete and that attention should be paid to developing disease control programs in these territories. The data obtained from genome sequencing of the two SuHV-1 isolates contribute to the enrichment of the GenBank with unknown sequences and the phylogenetic analysis implementation.

Keywords: Aujeszky; Hunting dogs; Interspecies transmission; Italy; Sicily; SuHV-1; Wild boar.

Fig. 1

Dog 1: Injuries of traumatic origin due to intense itching in the peri-ocular region

Fig. 2

Dog 2: Injuries of traumatic origin due to intense itching in the peri-ocular region, cheek and labial region

Fig. 3

Dog 2: Examination of the splanchnic cavities and inspection of stomach contents. Highlighting of the presence of wild boar meat and offal

Fig. 4

Dog 2: Evidence of hyperemia affecting the meninges and meningeal vessels

Fig. 5

Phylogenetic tree based on partial sequencing of the UL44 gene. The tree was obtained using the maximum likelihood method and the HKY85 + I + G model with 1000 bootstrap replicates. The bootstrap percentage values are indicated at nodes. The Italian sequences are underlined

Fig. 6

Phylogenetic tree based on partial sequencing of the US8 gene. The tree was obtained using the maximum likelihood method and the HKY85 + I + G model with 1000 bootstrap replicates. The bootstrap percentage values are indicated at nodes. The Italian sequences are underlined