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Also known as IBR
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== Introduction<br> ==
Caused by:[[Bovine Herpesvirus 1]]
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: aerosol transfer
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====Pathogenesis====
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This disease is also known as IBR&nbsp; and is caused by [[Bovine Herpesvirus 1]] through aerosol transmission and close contct of infected animals. It is a highly infectious disease of cattle, causing upper respiratory tract disease. The virus is a herpesvirus, meaning it has the ability to lie latent for a long period of time until reactivated by stress.
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*BHV-1 infects the respiratory mucosal epithelial cells (intranuclear inclusion eosinophilic inclusion bodies)from nasal mucosa down to bronchioles
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BHV-1 infects the respiratory mucosal epithelial cells (intranuclear inclusion eosinophilic inclusion bodies)from nasal mucosa down to bronchioles, which leads to neutrophilic inflammation of varying severity.<br>
**Leading to neutrophilic inflammation of varying severity: serous -> catarrhal -> purulent nasal discharge, sneezing, coughing
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*Dypsnoea, anorexia
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*Rhinotracheitis that can develop into bronchopneumonia
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*Clinical signs include coughing, discharge, lacrimation, and increased respiratory rate
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*Clinical disease most severe in young calves - can develop mucosal ulcerative lesions in the oesophagus and forestomachs and viraemia with multiorgan infection
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*Generally high morbidity, low mortality, but up to 75% mortality if concurrent with [[Bovine Virus Diarrhoea Virus|BVDV]], caused by meningo-encephalitis
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====Diagnosis====
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<br>
*Virus isolation and immunofluorescence
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====Control====
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== Clinical Signs<br> ==
*'''Vaccination''':
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**Two '''live attenuated''' vaccines are available in the UK, one is temperature-sensitive
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***Both given intranasally
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***Neither protect against re-infection when given during clinical outbreak, but can lessen the severity of the disease
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**'''Inactivated''' vaccines: intranasal/intramuscular administration
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***gE deletion makes this a '''marker vaccine'''
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***ELISA for gE deletion can enable culling of carrier animals
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*IPV has mostly been made obsolete by AI
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[[Image:IBR nasal cavity.jpg|right|thumb|100px|<small><center>IBR in nasal cavity (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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Depending on severity, one will see serous, catarrhal or purulent nasal discharge, sneezing, coughing, dyspnoea and anorexia. There will be a rhinotracheitis that can develop into bronchopneumonia. An increased respiratory rate will also be present. Pregnant cows will also be seen to abort at 5 months or later in gestation.<br>
[[Image:IBR trachea.jpg|right|thumb|100px|<small><center>IBR in trachea (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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Clinical disease most severe in young calves, which can develop mucosal ulcerative lesions in the oesophagus and forestomachs and viraemia with multiorgan infection.&nbsp;
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*URT infection with serous nasal discharge, increases respiratory rate, coughing and moderate fever,from nasal mucosa down to bronchioles
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There is generally a high morbidity with low mortality, but up to 75% mortality if concurrent with [[Bovine Virus Diarrhoea Virus|BVDV]], caused by meningo-encephalitis. Signs can be made more severe by secondary bacterial infection such as Pasturella or Mycoplasma.  
*[[Rhinitis|Rhinitis]], [[Pharyngitis|pharyngitis]], [[Laryngitis|laryngitis]], [[Tracheitis|tracheitis]], [[Bronchitis|bronchiolitis]]
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*Morbidity is high, mortality is low
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*Highly infectious URT disease of cattle
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*Spread by movement of animals, aerosol transmission - requires close contact between animals
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*Early stages (only first few days) may show [[Cellular Inclusions|intracellular inclusions]] in the respiratory mucosal epithelial cells
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*Leading to neutrophilic inflammation of varying severity.... serous -> catarrhal -> purulent
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*With secondary bacterial infection (eg: ''[[:Category:Pasteurella and Mannheimia species|Pasturella spp.]], [[:Category:Mycoplasmas|Mycoplasma spp.]], [[Fusobacterium necrophorum]])'' can lead to fibrinous to necrotizing inflammation; mucosal sloughing, ulceration... pyrexia, dyspnoea ... [[Aspiration Pneumonia|inhalation pneumonia]]... death
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*Underlying hyperaemic inflammatory response
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*Can become latent following primary infection
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*Clinical signs:nasal discharge, sneezing, coughing, lacrimation, and increased respiratory rate
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*Clinical disease most severe in young calves - can develop mucosal ulcerative lesions in the oesophagus and forestomachs and viraemia with multiorgan infection
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*Cause of abortion >5 months of gestation
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*May contribute to [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of calves|Enzootic pneumonia of calves]]
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May cause cutaneous skin infections.
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== Diagnosis ==
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Clinical signs are suggestive. Definitive diagnosis can be achieved by virus isolation and immunofluorescence.
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<br>Caused by herpes virus 1 in cows. Results in abortion late in gestation 3-6 weeks after exposure.
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On microscopic examination of infected tissue, one will see intrnuclear inclusion bodies, which are indicative of the virus.<br>
Abortion occurs soon after foetal death.  Foetus may be autolysed.  Intranuclear inclusions present in liver.
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[[Category:Respiratory Diseases - Cattle]]
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<br>
[[Category:To_Do_-_Clinical/Viruses]]
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[[Category:Respiratory_Viral_Infections]]
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== Control ==
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'''Vaccination '''is avaliable and commonly used in the UK. Both vaccines avaliable in the UK are given intranasally and n<span style="font-weight: bold;"</span>either protect against re-infection when given during clinical outbreak, but can lessen the severity of the disease. There are also '''Inactivated''' vaccines: intranasal/intramuscular administration, which have a&nbsp;gE deletion making this a '''marker vaccine'''. There is an&nbsp;ELISA for gE deletion, which can enable culling of carrier animals.&nbsp;IPV has mostly been made obsolete by AI
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<br>
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== References<br> ==
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[[Image:IBR nasal cavity.jpg|thumb|right|100px|<small><center>IBR in nasal cavity (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]] [[Image:IBR trachea.jpg|thumb|right|100px|<small><center>IBR in trachea (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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Andrews, A.H, Blowey, R.W, Boyd, H and Eddy, R.G. (2004) Bovine Medicine (Second edition), Blackwell Publishing<br>Divers, T.J. and Peek, S.F. (2008) Rebhun's diseases of dairy cattle Elsevier Health Scieneces<br>Radostits, O.M, Arundel, J.H, and Gay, C.C. (2000) Veterinary Medicine: a textbook of the diseases of cattle, sheep, pigs, goats and horses Elsevier Health Sciences<br> <br><br>
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[[Category:Respiratory_Diseases_-_Cattle]] [[Category:To_Do_-_Review]] [[Category:Respiratory_Viral_Infections]]
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