Pathogenesis of Influenza D Virus in Cattle.

UNLABELLED: Cattle have been proposed as the natural reservoir of a novel member of the virus family Orthomyxoviridae, which has been tentatively classified as influenza D virus (IDV). Although isolated from sick animals, it is unclear whether IDV causes any clinical disease in cattle. To address this aspect of Koch's postulates, three dairy calves (treatment animals) held in individual pens were inoculated intranasally with IDV strain D/bovine/Mississippi/C00046N/2014. At 1 day postinoculation, a seronegative calf (contact animal) was added to each of the treatment animal pens. The cattle in both treatment and contact groups seroconverted, and virus was detected in their respiratory tracts. Histologically, there was a significant increase in neutrophil tracking in tracheal epithelia of the treatment calves compared to control animals. While infected and contact animals demonstrated various symptoms of respiratory tract infection, they were mild, and the calves in the treatment group did not differ from the controls in terms of heart rate, respiratory rate, or rectal temperature. To mimic zoonotic transmission, two ferrets were exposed to a plastic toy fomite soaked with infected nasal discharge from the treatment calves. These ferrets did not shed the virus or seroconvert. In summary, this study demonstrates that IDV causes a mild respiratory disease upon experimental infection of cattle and can be transmitted effectively among cattle by in-pen contact, but not from cattle to ferrets through fomite exposure. These findings support the hypothesis that cattle are a natural reservoir for the virus. IMPORTANCE: A novel influenza virus, tentatively classified as influenza D virus (IDV), was identified in swine, cattle, sheep, and goats. Among these hosts, cattle have been proposed as the natural reservoir. In this study, we show that cattle experimentally infected with IDV can shed virus and transmit it to other cattle through direct contact, but not to ferrets through fomite routes. IDV caused minor clinical signs in the infected cattle, fulfilling another of Koch's postulates for this novel agent, although other objective clinical endpoints were not different from those of control animals. Although the disease observed was mild, IDV induced neutrophil tracking and epithelial attenuation in cattle trachea, which could facilitate coinfection with other pathogens, and in doing so, predispose animals to bovine respiratory disease.

Influenza D virus infection in Mississippi beef cattle.

A new member of the Orthomyxoviridae family, influenza D virus (IDV), was first reported in swine in the Midwest region of the United States. This study aims to extend our knowledge on the IDV epidemiology and to determine the impact of bovine production systems on virus spread. A total of 15 isolates were recovered from surveillance of bovine herds in Mississippi, and two genetic clades of viruses co-circulated in the same herd. Serologic assessment from neonatal beef cattle showed 94% seropositive, and presumed maternal antibody levels were substantially lower in animals over six months of age. Active IDV transmission was shown to occur at locations where young, weaned, and comingled calves were maintained. Serological characterization of archived sera suggested that IDV has been circulating in the Mississippi cattle populations since at least 2004. Continuous surveillance is needed to monitor the evolution and epidemiology of IDV in the bovine population.

Cantharidin toxicosis in 2 alpacas.

Two adult alpacas were presented for recumbency and reluctance to rise. Cantharidin toxicosis was suspected based on clinical and ancillary diagnostic findings. The diagnosis was confirmed by gas chromatography-mass spectrometry of gastric contents and urine. Despite medical treatment, neither alpaca survived. Blister beetle toxicosis has not been previously described in camelids. Challenges in treatment of affected ruminants or pseudoruminants are noted.

Toxicose à la cantharidine chez 2 alpagas. Deux alpagas adultes ont été présentés pour décubitus et une réticence à se lever. La toxicose à la cantharidine a été soupçonnée en se fondant sur des résultats diagnostiques cliniques et auxiliaires. Le diagnostic a été confirmé par chromatographie en phase gazeuse et spectromètre de masse du contenu gastrique et de l'urine. Malgré un traitement médical, les deux alpagas n'ont pas survécu. La toxicose aux cantharides n'avait pas été décrite antérieurement chez les camélidés. Les difficultés du traitement des ruminants ou des pseudoruminants sont signalées.(Traduit par Isabelle Vallières).

Severe anemia associated with Mycoplasma wenyonii infection in a mature cow.

The clinical findings, diagnostic tests, and treatment of clinical anemia in a mature Angus cow infected with the hemoplasma Mycoplasma wenyonii are described. Mycoplasma wenyonii has been previously reported to cause clinical anemia in young or splenectomized cattle; however, infection has not been associated with severe anemia in mature animals.

Acute respiratory distress syndrome in an alpaca cria.

A 7-hour-old alpaca was presented for lethargy and depression. The cria responded favorably to initial treatment but developed acute-onset dyspnea 48 hours later. Acute respiratory distress syndrome was diagnosed by thoracic imaging and blood gas analysis. The cria was successfully treated with corticosteroids and discharged from the hospital.

Nonsteroidal anti-inflammatory drug-associated renal papillary necrosis in a white-tailed deer (Odocoileus virginianus).

Renal papillary necrosis was diagnosed during postmortem examination of a juvenile white-tailed deer (Odocoileus virginianus) from Oklahoma. The deer was surgically treated for a Salter Harris type II fracture of the proximal tibia of the left hind limb. The animal was administered multiple nonsteroidal anti-inflammatory drugs (NSAIDs), including meloxicam, flunixin meglumine, and ketoprofen for pain management. At postmortem examination, gross lesions included a proximal tibial Salter Harris type II fracture with an associated fibrinonecrotizing myositis and bilateral renal papillary necrosis. Histologically, the kidneys exhibited coagulation necrosis of the renal medulla and renal papilla, thrombosis of renal blood vessels, and interstitial medullary edema. The gross and microscopic lesion coupled with the clinical history of multiple NSAID administration suggests NSAID-induced renal papillary necrosis.

Detection of an antigenic group 2 coronavirus in an adult alpaca with enteritis.

Antigenic group 2 coronavirus was detected in a fecal sample of an adult alpaca by reverse transcription-PCR. The presence of alpaca coronavirus (ApCoV) in the small intestine was demonstrated by immune histochemistry with an antinucleocapsid monoclonal antibody that reacts with group 2 coronaviruses. Other common causes of diarrhea in adult camelids were not detected. We conclude that nutritional stress may have predisposed the alpaca to severe ApCoV infection.