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| | Causes [[Strangles|Strangles]] | | Causes [[Strangles|Strangles]] |
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| − | *Epidemiology
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| − | **[[Respiratory Bacterial Infections - Pathology#Strangles|Strangles]] is a highly infectious disease of horses caused by ''Streptococcus equi'' subsp. ''equi''
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| − | **[[Respiratory Bacterial Infections - Pathology#In Horses|upper respiratory tract disease of horses]] with fever and abscessation of regional lymph nodes
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| − | **Causes [[Nasal Cavity Inflammatory - Pathology#Strangles|rhinitis]], [[Nasopharynx Inflammatory - Pathology|pharyngitis]], lymphadenitis and [[Muscles Inflammatory - Pathology#Abscesses|myositis]]
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| − | **Outbreaks in groups of young horses
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| − | **Transmitted via purulent exudate discharging from upper respiratory tract or from lymph nodes
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| − | **Chronic, carrier state can occur with bacteria im the guttural pouch
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| − | **A mild, atypical form can occur
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| − | **''S. equi'' shed for 4 weeks beyond clinical resolution
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| − | *Clinical signs
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| − | **Incubation period 3 to 6 days
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| − | **Fever, depression, anorexia
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| − | **Purulent nasal discharge
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| − | **Swollen, painful regional lymph nodes, especially submandibular
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| − | **Abscessation and rupture of lymph nodes
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| − | **Guttural pouch empyema
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| − | **100% morbidity; 5% mortality
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| − | **Death can occur from pneumonia, breathing difficulties from swollen lymph nodes or [[Muscles Degenerative - Pathology#Ischaemia|purpura haemorrhagica]](an immune-mediated disease)
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| − | **Bastard strangle may occasionally occur, with abscessaation in many organs of the body
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| − | **''S. equi'' may be involved in [[Bacterial skin infections - Pathology#Systemic bacterial infections|cutaneous lesions]]
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| − | *Diagnosis
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| − | **Clinical signs and history
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| − | **Mucoid colonies with beta-haemolysis
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| − | **Sugar fermentation allows differentiation of ''S. equi'' from ''S. zooepidemicus'' and ''S. equisimilis''
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| − | **PCR to detect asymptomatic carriers
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| − | *Treatment and control
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| − | **Penicillin administration to in-contact animals
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| − | **Isolation of affected animals
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| − | **Quarantne in-coming animals
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| − | **Avoid overcrowding and mixing different age groups
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| − | **Disinfection of equipment
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| | *Caused by very pathogenic ''Streptococcus equi subsp. equi'' | | *Caused by very pathogenic ''Streptococcus equi subsp. equi'' |
| | *Haemolytic streptococci of Lancefield group C are common inhabitants of the equine nasopharynx | | *Haemolytic streptococci of Lancefield group C are common inhabitants of the equine nasopharynx |
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| | *Attaches to nasopharyngeal epithelial cells, then mucosa, lymphatics and lymph nodes | | *Attaches to nasopharyngeal epithelial cells, then mucosa, lymphatics and lymph nodes |
| | *Multiplies extra-cellularly | | *Multiplies extra-cellularly |
| − | *Gross pathology
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| − | **Initial bilateral nasal discharge, serous becoming purulent
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| − | **Catarrhal conjunctivitis may be present
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| − | *Less frequently, complications can occur as follows :
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| − | **Purulent inflammation may extent to [[Guttural Pouches Inflammatory - Pathology|guttural pouches]] or [[Lungs Inflammatory - Pathology#Infectious causes of pneumonia|lungs]], [[Paranasal Sinuses Inflammatory - Pathology#Infectious causes of sinusitis|sinusitis]]
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| − | **Bacteraemia with metastatic abscesses - most often to the mesenteric and mediastinal lymph nodes, less frequently, other organs such as [[Liver - Anatomy & Physiology|liver]], kidney and brain can be involved - '''Bastard strangles'''
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| − | **Retropharyngeal abscesses can rupture onto the skin of neck or into the [[Guttural Pouches Inflammatory - Pathology|guttural pouch]] resulting in '''guttural pouch empyema or chondroid formation''' - carrier state
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| − | **[[Muscles Degenerative - Pathology#Ischaemia|'''Purpura haemorrhagica''']]: an acute vasculitis causing urticaria and extensive oedema of ventrum, head and distal limbs
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| − | **[[Larynx Degenerative - Pathology#Laryngeal hemiplegia|Laryngeal hemiplegia]] due to enlarged retropharyngeal lymph nodes
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| − | **Compression of cranial nerves
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| − | *Interview with Professors Josh Slater and Ken Smith providing an interesting insight into the pathogenesis, prevalence and possible prevention of ''Streptococcus equi'' infections in horses - listen to [http://www.rvc.ac.uk/Review/Podcasts/RVC_Podcast_12.m4a Strangles podcast]
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| | [[Category:Streptococcus species]][[Category:Horse Bacteria]] | | [[Category:Streptococcus species]][[Category:Horse Bacteria]] |
| | [[Category:To_Do_-_Bacteria]] | | [[Category:To_Do_-_Bacteria]] |
| − | [[Category:Respiratory_Bacterial_Infections]]
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| − | [[Category:Respiratory_Disorders_-_Horse]]
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