Clinicopathologic findings of naturally occurring Rabbit Hemorrhagic Disease Virus 2 infection in pet rabbits

Abstract

Two pet rabbits were presented with an acute decrease in appetite and activity.Rabbit 1 showed severe hypothermia, bradycardia, arrhythmias, a heart murmur, dyspnea, occlusion of the nares with secretions, icterus, dehydration, and gaseous gastrointestinal dilation. The urine was dark yellow. Rabbit 2 was overweight, apathetic, and dehydrated; this animal presented with a heart murmur, gastric dilation, and intermittent nystagmus with dorsal strabismus in the right eye. Blood gas, electrolyte, hematology, plasma clinical biochemistry analysis, coagulation profile, plasma protein electrophoresis, urinalysis, and radiographic examinations were performed. The main shared findings were moderate thrombocytopenia, markedly decreased aspartate aminotransferase and alanine aminotransferase activities and fibrinogen concentrations, prolonged prothrombin and activated partial thromboplastin times, profoundly increased alkaline phosphatase and gamma-glutamyl transferase (GGT) activities, and high bile acid and bilirubin concentrations. Rabbit 1 also had respiratory acidosis, marked hypoglycemia, hyperphosphatemia, and a profoundly increased creatine kinase activity. Gastric dilation was observed on both radiographic exams. A low urinary pH of 5-6, marked bilirubinuria and proteinuria, and high urinary GGT levels were present in both patients. Marked icterus developed before death, which occurred within 22 and 30 hours post admission in rabbits 1 and 2, respectively. The necropsy of rabbit 1 showed a markedly accentuated hepatic lobular pattern, pulmonary hemorrhages, pericardial effusion with adhesions, peritoneal petechiae, and icteric and hemorrhagic abdominal fat.Histopathologic findings included hemorrhagic diathesis, severe centroacinar and midzonal hepatocellular necrosis, severe necrosuppurative bronchopneumonia, and moderate cardiomyocyte necrosis. A liver PCR assay was positive for Rabbit Hemorrhagic Disease Virus (RHDV) 2 (RHDV2) and negative for classic RHDV. This is the first description of the gross clinicopathologic abnormalities associated with naturally occurring RHDV2 infection in pet rabbits. K E Y W O R D Shemorrhagic, hepatic failure, liver necrosis, rabbit, RHDV2, virus

RHDV2 epidemic in UK pet rabbits. Part 1: clinical features, gross post mortem and histopathological findings

“…Subacute forms of the disease can occur with rabbits showing milder clinical signs and surviving. In contrast to laboratory investigations, detailed accounts of the clinical features of RHD in naturally occurring outbreaks are rare (Soliman et al 2016, Bonvehí et al 2019. Although deaths from RHD are included in mortality surveys of meat rabbits, these animals had minimal observation prior to death (Rosell & de la Fuente 2009, Rosell & de la Fuente 2016.…”

Immune cell pathology in rabbit hemorrhagic disease

“…[7], Bonvehí et al . [18], Alexandrov et al . [19], Fuchs and Weissenbock [20], and Ferreira et al .…”

“…Some aspects of the pathological features of RHD are described by Vallejo et al [7], Bonvehí et al [18], Alexandrov et al [19], Fuchs and Weissenbock [20], and Ferreira et al [21]. However, little attention was paid to alterations in hematopoietic cell populations.…”

Clinical and pathologic findings in an outbreak in rabbits of natural infection by rabbit hemorrhagic disease virus 2 in the northwestern United States

“…[6][7][8]18 However, reported mortality rates, clinicopathologic findings, and overall virulence of RHDV2 vary in the literature. 5,13,14 During the initial RHDV2 outbreak in France in 2010, the disease was characterized by pathologic findings similar to those described for RHDV1, including hemorrhages in multiple tissues. The outbreak resulted in prolonged and high mortality rates of 80-90%, 1022466V DIXXX10.1177/10406387211022466Natural outbreak of rabbit hemorrhagic disease virus 2Williams et al…”

“…17 Although epidemiologic and geographic data regarding RHDV2 outbreaks in Europe are documented extensively, 2,6,7,15,17,18 published reports of clinicopathologic findings in natural outbreaks of RHDV2 are relatively scarce. One case report outlined the clinical and pathologic findings in 2 pet rabbits naturally infected with RHDV2 in Spain 5 ; both rabbits had a 1-d history of hyporexia or anorexia and lethargy. A blood chemistry panel revealed marked increases in gamma-glutamyl transferase, alkaline phosphatase, bile acids, and bilirubin with decreased activity of aspartate aminotransferase and alanine aminotransferase, suggestive of severe liver damage in both animals.…”