Inf. diseases II - Ruminant respiratory disease 1/2 Flashcards
BOVINE RESPIRATORY DISEASE complex
is most common in what age group?
more commonly in young animals during period between passive and active immunity
Alt. Terminology in use for bovine respiratoy disease (BRD) complex (4)
Enzootic pneumonia
“Shipping fever”
Pneumonic pasteurellosis – Pasteurella spp and Mannheimia spp
Atypical interstitial pneumonia – Dictyocaulus viviparus
Clinically BRD appears
BRD = bovine respiratory disease (complex)
as pneumoenteritis
Many pathogens affect resporatory tract and intestinal tract at the same time.
Bacterial spp. that contribute to BRD (4)
BRD = bovine respiratory disease (complex)
Mannheimia haemolytica,
Pasteurella multocida,
Histophilus somni,
Arcanobacterium pyogenes
Viruses that contribute to BRD (6)
BRD = bovine respiratory disease (complex)
Bovine Respiratory Syncytial Virus (BRSV),
Bovine Herpesvirus-1
Bovine Viral Diarrhea Virus (BVDV)
ParaInfluenza 3 (PI3)
Bovine Coronavirus
Bovine Adenovirus
BRSV
Bovine respiratory syncytial virus
Bovine respiratory syncytial virus (BRSV) is an infectious disease of cattle, caused by Paramyxovirus, and characterized by (3)
fever, infection of upper respiratory tract and bronchopneumonia
BRSV causative agent
genus
family
type (RNA/DNA)
Bovine respiratory syncytial virus (BRSV)
Genus Pneumovirus,
family Paramyxoviridae
RNA virus
serotypes of BRSV?
subtypes?
2 serotypes
3 antigenic subtypes: A, AB and B
BRSV was named for its characteristic..?
cytopathic effect – the formation of syncytial cells
What is a syncytial cell?
A large cell-like, multinucleated structure formed by the joining together of two or more cells.
Host range of BRSV
cattle
Human RSV is pathogenic to calves, but BRSV is not zoonotic!
BRSV More severe clinical disease can be seen in
1-3 month-olds
Maternal antibodies do not prevent clinical disease.
Mortality in this age group is 5-20%.
Morbidity of BRSV in herd
Morbidity 80-100%
Spreads quickly within the herd.
On primary introduction to herd: severe pneumonia in all age groups.
When is BRSV most common?
Seasonality – more common during fall and winter.
Reinfections during summer months.
BRSV found where in the world?
Has been isolated in most European countries, North-America, Australia, Japan and Africa.
Basically everywhere except South America, Middle East and Asia minus Japan.
Transmission of BRSV.
Excretion: nasal discharge
Aerogenic mode of transmission
(Fomites – including human)
Route: respiratory
IP: of BRSV
IP: 3-5 days
Clinical signs of BRSV
Fever (40–42°C), depression, decreased feed intake,
increased respiratory rate, cough, and nasal and lacrimal discharge – common signs.
More severe cases:
Dyspnea in the later stages of the disease
Subcutaneous emphysema may occur
Secondary bacterial pneumonia is a frequent occurrence!
Recovery in 1-2 weeks
Post mortem signs of BRSV
Diffuse interstitial pneumonia with subpleural and interstitial emphysema along with interstitial edema
so BOTH emphysema and edema!
Bronchopneumonia
Material for diagnosis of BRSV. (2)
Nasal swabs
Lungs, trachea, bronchial LNs
Lab analyses for diagnosis of BRSV. (2)
Virus identification – PCR
Antibodies – serology (ELISA)
Tx of BRSV.
no specific Tx!
Mainly supportive care – IV fluids and electrolytes for dehydration.
In severe cases also NSAIDs can be used
ABs if secondary infections
BRSV Secondary bacterial infections are common, name 3 spp. of bact.
M. hemolytica
P. multocida
H. somni (Histophilus)
Can you vaccinate against BRSV?
Vaccines are available – efficacy is debatable.
Also in Estonia
Bovine parainfluenzavirus-3 (PIV-3) is a contagious disease of cattle, caused by Parainfluenzavirus-3, and characterized by
fever, catarrhal infection of upper respiratory tract and pneumonia.
Causative agent of PIV-3.
genus, family, DNA type
Bovine parainfluenzavirus-3 (PIV-3)
Genus Respirovirus,
family Paramyxoviridae
RNA virus
Closely related to PIV-3 viruses of sheep and humans.
Host range of PIV-3
Host range: cattle
In humans: isolation without clinical disease
demographic affected most by PIV-3?
season?
More severe illness is seen young animal from 10 days of age to 1 year.
Especially during fall and winter.
Endemic and sporadic disease.
Where in the world is bovine PIV-3 found?
Isolated in many European countries, USA, Japan and other.
Endemic and sporadic disease.
Transmission of bovine PIV-3?
Excretion:
respiratory secretions, milk, vaginal discharge, feces
Direct contact (droplets)
In utero ? – virus has been isolated from aborted fetuses
Route: respiratory
IP: of bovine PIV-3
IP: 1-5 days (mostly just 24h)
Clinical signs of bovine PIV-3. (4)
Are similar to BRSV!
Pyrexia
Cough
Serous nasal and lacrimal discharge.
Increased respiratory rate and breath sounds.
The severity of signs worsens with the onset of bacterial pneumonia.
Post mortem signs of bovine PIV-3. (3)
Cranioventral lung consolidation
Bronchiolitis
Alveolitis with marked congestion and hemorrhage
Material for diagnosis of bovine PIV-3. (4)
Nasal and ocular swabs
Blood
TBL (tracheobronchial lavage)
Lungs
Lab analyses for diagnosis of bovine PIV-3. (2)
Serology (ELISA) – antibodies from serum
PCR
Tx of PIV-3.
no specific Tx
ABs if secondary bacterial infections
NSAIDs can be helpful
Do you vaccinate for PIV-3?
Vaccines available
Almost always in combination with BHV-1 (bo herpes).
BHV-1
Bovine herpes virus 1
2 alt. names for Bovine herpes virus 1
Bovine infectious rhinotracheitis-pustular vulvovaginitis
“Red nose”
Bovine herpes virus 1 infection is a contagious disease of cattle, caused by Herpesvirus, and characterized by (2)
infectious rhinotracheitis and
infectious pustular vulvovaginitis
Causative agent of Bovine infectious rhinotracheitis-pustular vulvovaginitis.
genus, family, type
Bovine Herpesvirus 1 (BHV-1)
Genus Varicellovirus,
family Herpesviridae
DNA virus
Subtypes of BHV-1.
3 subtypes:
BHV-1.1 – respiratory subtype
BHV-1.2 – genital subtype
BHV-1.3 – encephalitic subtype, reclassified as separate virus BHV-5
Survival of BHV-1 in environment.
Survival at room temperature for 45 days
Host range for BHV-1.
cattle
Target age demographic for BHV-1.
All age groups are susceptible but most clinical cases in >6 month-olds.
Colostral immunity 1-6 months.
Most common: respiratory disease.
Where in the world is BHV-1 found?
Reported worldwide
Some countries are free (e.g. Finland) – eradicated.
Morbidity of BHV-1.
In dairy herds:
Morbidity 8-100%
Mortality of BHV-1?
Mortality 3-10% - often due to secondary bacterial infections.
Transmission of BHV-1.
Excretion: nasal, ocular and vaginal discharge, urine, sperm
Direct contact – venereal transmission, with sperm
Fomites (e.g. feed, water)
Aerogenic – respiratory form
Route: respiratory or genital
Pathogenesis of BHV-1.
Latent carriers in which virus mostly persist in the portal of entry.
Latent infections can reactivate with or without clinical symptoms.
During reactivation virus is shed in high titers.
In endemic herds all animals should be treated as potential source of BHV-1.
IP of BHV-1.
IP: 2-6 days
Disease forms of BHV-1.
respiratory and genital form
Resp. form of BHV-1 is called what?
Clinical signs of it?
Infectious bovine rhinotracheitis (IBR)
Upper resp. tract signs:
(Muco)purulent nasal discharge
Hyperaemia of the muzzle (red nose disease)
Conjunctivitis
+ Fever, Depression, Inappetence
Abortions may occur during the second half of pregnancy
Genital form of BHV-1 is called what?
Clinical signs of it?
Infectious pustular vulvovaginitis (IPV)
Pustular vulvovaginitis
Frequent urination
Elevation of the tailhead
Mild vaginal discharge
Vulva is swollen; small pustules (erosions then ulcers) on the mucosal surface.
Recovery in 10-14 days if no secondary bacterial infections occur.
Balanoposthitis – inflammation of the glans penis and the foreskin.
Clinical signs of BHV-1 in young calves?
generalized disease
Pyrexia, ocular and nasal discharges, respiratory distress, diarrhea, incoordination.
Eventually convulsions and death may occur in a short period after generalized viral infection.
In calves:
Morbidity 5-25%, mortality <100%
Post mortem signs of Bovine infectious rhinotracheitis-pustular vulvovaginitis. (4)
Rhinitis
Laryngitis
Tracheitis
Pustular lesions
Material for diagnosis of BHV-1. (5)
Swabs from nasal cavity, eyes and vagina
Lung, LNs, brain
Aborted fetuses and fetal membranes
Sperm and preputial discharge
Blood
Lab analyses for diagnosis of BHV-1. (3)
Virus identification or isolation
Serology – antibodies
On herd level: ELISA from collective milk sample (bulk tank milk)
Tx for BHV-1.
no specific Tx
ABs if secondary bacterial infections occur
Prevention & control of BHV-1.
Good farm management – biosecurity:
Hygiene
Removal of infected animals
Quarantine (4 weeks) for new animals
Natural mating should be avoided – use sperm from seronegative bulls
Vaccination
Vaccines available also in Estonia
