Topic 67 - Diseases caused by bovine respiratory syncytial virus and parainfluenza-3 virus Flashcards
What is the bovine parainfluenza 3?
It is a respiratory disease affecting mainly cattle
Occurence of bovine parainfluenza 3:
Worldwide
Causative agent for bovine parainfluenza 3:
Parainfluensa 3
Host(s) of bovine parainfluenza 3:
Mainly cattle, but also: sheep, goats and other ruminants
How is the bovine parainfluenza 3 virus introduced to a herd?
By introducing animals that are affected into the herd, several farms are endemic
When is it more common to see bovine parainfluenza 3?
Autumn and summer
Which age is it more common to observe bovine parainfluenza 3?
Younger animals, in growers
Pathogenesis of bovine parainfluenza 3:
- Aerosol infection
- Primary replication in respiratory epithelium, causing hyperaemia and necrosis Necrosis causing the clinical signs
- There is a hyaline membrane production in the alveoli
(4.) if there is a complication, more severe clinical signs are observed
Clinical signs for bovine parainfluenza 3:
Often mild or subclinical !!
Can see:
Fever
Nasal discharge
Cough
Sometimes conjunctivitis
In case of bovine parainfluenza 3, what can we see during pathology?
- Interstitial pneumonia, which is localised in the anterior lobes^
- Bronchitis
- Tracheitis
^bacterial complications can cover the lesions from the original disease !!
How can we diagnose bovine parainfluenza 3?
We look at clinical signs, pathology and history. Then we detect the antigen or the antibody
How can we detect antigen of bovine parainfluenza 3?
PCR
How can we detect antibodies of bovine parainfluenza 3?
ELISA, but with a paired serum
Treatment for bovine parainfluenza 3:
Antibiotics for bacterial complications
How to prevent bovine parainfluenza 3?
General epidemiological rules like control traffic, but since it is too widespread - there is a vaccine!
Which type of vaccine to use in case of bovine parainfluenza 3?
Can use liver or inactivated, and combined
Live vaccine is used intra nasal
When, at which age do we vaccinate for bovine parainfluenza 3?
In endemic areas, we vaccinate the pregnant cow in 3rd term and in 3-4 month old calves
When, at which age is the live vaccine given in case of bovine parainfluenza 3?
Given intra nasal from 3 weeks of age
What is bovine respiratory syncytial virus?
It is an important cause of pneumonia in calves
Occurrence of bovine respiratory syncytial virus
Worldwide
Causative agent for bovine respiratory syncytial virus
bovine respiratory syncytial virus (BRS)
How many serotypes does bovine respiratory syncytial virus have?
1
How many genotypes does bovine respiratory syncytial virus have?
6
Host(s) for bovine respiratory syncytial virus:
Main host = cattle
sheep and goat can also be infected
At what age is it more common to observe bovine respiratory syncytial virus?
Between 6-24 months of age
How is bovine respiratory syncytial virus introduced to a herd?
By introducing infected animals
Morbidity and mortality of bovine respiratory syncytial virus:
Morbidity = 100%
Mortality = 1-2% Depends on the management
When is bovine respiratory syncytial virus more frequently seen?
During autumn and winter
Pathogenesis of bovine respiratory syncytial virus:
- Aerosol infection
- There is a primary replication in mucus membrane of the upper airway, causing alveolitis, bronchitis and we see pneumonia
- In the lungs, a hyaline membrane is produced in the alveoli as a immunological reaction
- The hyaline membrane will cover the respiratory surface of the alveoli and gas exchange will be inhibited causing in ⭡air pressure which again causes lung emphysema
- The air will be accumulated and the air may get under the skin through the lymphatic vessels so we can observe air subcutaneously.
How is the immune reaction of bovine respiratory syncytial virus?
Good!
They have a long lasting protection
How is the recovery of bovine respiratory syncytial virus?
Fast recovery, but if complications appear the disease becomes more severe
Incubation time for bovine respiratory syncytial virus:
2-3 days
Clinical signs for bovine respiratory syncytial virus:
- High fever
- Laboured breathing
- Excruciating cough
- dyspnoea
- Nasal discharge small amount and clear without complications
- sub cutaneous emphysema around the scapula
- VERY TYPICAL: the posture of the animal = standing, not moving. Stretching the neck and a lower head - to have optimal inhalation
Pathological findings in case of bovine respiratory syncytial virus:
- Interstitial penumonia
- Alevolitis
- Emphysema
- In the trachea: heamoerhages, foam
Histopathological findings in case of bovine respiratory syncytial virus:
- syncytium !!
- Cytoplasmic inclusion bodies
How to diagnose bovine respiratory syncytial virus:
Look at the age of animal, clinical signs and pathology.
To confirm we detect agent or antibodies
How to detect antigen for bovine respiratory syncytial virus?
PCR
How to detect antibodies for bovine respiratory syncytial virus?
ELISA, but with paired serum only !!
Differential diagnosis of bovine respiratory syncytial virus:
- Parainfluensa - 3
- infectious bovine rhinotracheitis
Treatment for bovine respiratory syncytial virus:
- Rest ! it is best to do nothing, as long as there is no complications
- Antibiotics in case of bacterial complications
Prevention for bovine respiratory syncytial virus:
- General epidemiological measures such as close farms, isolation of age groups, hygiene, quarantine of new animals
- Vaccines
Which type of vaccines can we use for bovine respiratory syncytial virus?
Attenuated, live vaccine
Inacitvated vaccine, found in combination with others
When can we vaccinate against bovine respiratory syncytial virus, with inactivated vaccine?
At the age of 6 months old, the booster after 2-3 weeks
Without colostral immunity: 2-3 months !!!
How to give the live, attenuated vaccine for bovine respiratory syncytial virus:
Spray
Intra nasal
What are some advantages for live attenuated vaccine for bovine respiratory syncytial virus?
- Effects is NOT inhibited by maternal antibodies
- Gives good local immunity, and the infection can be prevented
