Introduction

Bovine coronavirus

Coronavirus

Coronaviruses are species in the genera of virus belonging to the subfamily Coronavirinae in the family Coronaviridae. Coronaviruses are enveloped viruses with a positive-sense single-stranded RNA genome and a helical symmetry. The genomic size of coronaviruses ranges from approximately 16 to 31...

 (BCV) is as a member of the Coronaviridae

Coronaviridae

Coronaviruses are enveloped, single-stranded, positive-sense RNA viruses with club-shaped surface about 120-160 nm in diameter that resemble a “corona”.-Virology:...

family which are enveloped, single-stranded, positive-sense RNA

RNA

Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....

 viruses with a club-shaped surface. Infection causes 'Calf Enteritis' and contributes to the 'Enzootic Pneumonia complex' in calves. It can also cause 'Winter Dysentry' in adult cattle. It can infect both domestic and wild ruminants and has a worldwide distribution. Transmission is horizontal

Horizontal transmission

Horizontal transmission is the transmission of a bacterial, fungal, or viral infection between members of the same species that are not in a parent-child relationship....

, via oro-fecal

Fecal-oral route

The fecal-oral route, or alternatively, the oral-fecal route or orofecal route is a route of transmission of diseases, in which they are passed when pathogens in fecal particles from one host are introduced into the oral cavity of another potential host.There are usually intermediate steps,...

 or respiratory routes.

Clinical Signs & Diagnosis

Infection normally occurs in calves between the ages of one week and three months. Gastrointestinal signs include profuse diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

, dehydration

Dehydration

In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...

, depression, reduced weight gain and anorexia

Anorexia (symptom)

Anorexia is the decreased sensation of appetite...

. Respiratory infection in the calf produces a serous to purulent nasal discharge. Clinical signs may worsen with secondary bacteria infection.

Infection in adults is normally subclinical

Subclinical infection

A subclinical infection is the asymptomatic carrying of an by an individual of an agent that usually is a pathogen causing illness, at least in some individuals. Many pathogens spread by being silently carried in this way by some of their host population...

, the exception being with Winter Dysentry, which affects housed cattle over the Winter months. Clinical signs include profuse diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

 and a significant drop in milk yield is seen in Winter Dysentry outbreaks.

A presumptive diagnosis can be made based on the history and clinical signs. Definitive diagnosis of an enteric coronavirus infection is achieved by performing electron microscopy or an ELISA

ELISA

Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...

 on a faecal or tissue sample. In respiratory disease, diagnosis is confirmed by performing a direct fluorescent antibody test

Immunofluorescence

Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on biological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specific biomolecule targets within a cell, and therefore allows...

 on nasal washes - which identifies the viral antigen.

The haemagglutination inhibition test can be used to establish the strain of coronavirus.

Treatment & Control

Animals should be treated symptomatically

Symptomatic treatment

Symptomatic treatment is any medical therapy of a disease that only affects its symptoms, not its cause, i.e., its etiology. It is usually aimed at reducing the signs and symptoms for the comfort and well-being of the patient, but it also may be useful in reducing organic consequences and sequelae...

. The disease can be controlled by vaccinating

Vaccination

Vaccination is the administration of antigenic material to stimulate the immune system of an individual to develop adaptive immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by many pathogens...

 the dam with a live vaccine (ATCvet code QI02

ATCvet code QI02

-QI02AA Inactivated viral vaccines:-QI02AA Inactivated viral vaccines:-QI02AA Inactivated viral vaccines::QI02AA01 Bovine viral diarrhea :QI02AA02 Bovine respiratory syncytial virus :QI02AA03 Bovine rhinotracheitis virus...

) whilst she is pregnant as this provides antibodies to the virus in the colostrum. Additional management factors such as insuring adequate colostrum

Colostrum

Colostrum is a form of milk produced by the mammary glands of mammals in late pregnancy. Most species will generate colostrum just prior to giving birth...

intake in newborn calves, using appropriate hygiene methods and ventilation of housing reduce disease incidence.