Ungulate Bocaparvovirus 1

Formerly known as Bovine parvovirus (BPV)

Also known as Haemadsorbing Enteric Virus

Description

Ungulate bocaparvovirus 1 is a member of the parvivirus group, with three significant sub-species: BPV1, 2 and 3.

BPV most commonly causes diarrhea in very young calves and causes respiratory and reproductive disease in adult cattle. This virus is found in cattle worldwide. Transmission is both vertical (from the cow to her fetus, passing through the placenta from the cow’s bloodstream) and horizontal (oral-fecal route, with animals ingesting feed or water contaminated with feces containing the virus).

The virus is hardy and resistant to most chemical and physical challenges (withstanding heat and cold).

Watery diarrhea is often the only clinical sign in young calves. Reproductive infection in adult cattle causes abortion and the birth of weak or stillborn calves. Respiratory signs such as coughing, difficult breathing and nasal discharge also can occur.

The clinical signs of BPV infection may be made worse by concurrent gastro-intestinal tract infections.

Signs

• Diarrhea in young calves
• Respiratory signs (difficult breathing, nasal discharge) in adult cattle
• Occasional abortion

Cause

Bocaviruses were first described in animals in the early 1960s. Humans, cattle, and dogs serve as natural hosts. There are currently 25 known species in this genus including Ungulate bocaparvovirus 1. Diseases associated with this genus include acute respiratory illness in humans. In cattle infection may cause diarrhea or mild respiratory signs and occasional abortions.

These viruses generally infect the gastrointestinal and respiratory tracts. Some viruses may cross the placenta and infect the fetus.

In the lab, immunofluorescence (IF), PCR, haemagglutination, ELISA and electron microscopy can identify and diagnose the virus.

Aborted fetuses are swollen with extra fluid. Immunofluorescence (IF) can be used to detect the virus in fetal organs. Post-mortem examination of infected calves generally reveal intestinal lesions.

Bovine bocavirus is now recognized as the founder virus sequence in a broader species called Ungulate bocaparvovirus 1, which is the new type species. In cattle, six species of parvovirus have been reported: ungulate bocaparvovirus 1 (UBPV1), bovine adeno‐associated virus (BAAV), ungulate erythroparvovirus 1 (UEPV1), ungulate tetraparvovirus 1 and 2 (UTPV1 and 2), and ungulate copiparvovirus 1 (UCPV1).

Four of these species (BAAV, UTPV1, UBPV6 and BPV2) were detected in a recent study of respiratory viruses identified in western Canadian beef cattle by genomic sequencing, looking at their association with bovine respiratory disease. UTPV1, previously known as bovine hokovirus, was the most prevalent virus in that study, and was detected in 35.3% of the cattle tested.

UBPV6, the second most prevalent virus, previously known as bovine parvovirus 1, was present in 23.5% of the total cattle in the stody. BAAV, UTPV1, UBPV6 and BPV2 have not been established as pathogenic agents related to respiratory diseases.

Prevention

There are currently no effective vaccines for this virus in cattle. At one time there was a vaccine that could be given to pregnant cows to protect their newborn calves from this type of scours, but there wasn’t much use of the vaccine because this disease has not been considered very serious in calves.

Appropriate hygiene (keeping calves in an uncontaminated environment) is probably the best prevention.

Treatment

Supportive care for calves with diarrhea (fluids to prevent dehydration) and possible antibiotics to prevent or treat secondary bacterial infection can be useful. Anti-inflammatories and supportive care for cattle with respiratory disease (and sometimes antibiotics to prevent or treat secondary bacterial infection) can help.