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| | ==In Pigs== | | ==In Pigs== |
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| − | ===Atrophic Rhinitis=== | + | ===[[Atrophic Rhinitis]]=== |
| − | [[Image:Severe atrophic rhinitis.jpg|right|thumb|100px|<small><center>Severe atrophic rhinitis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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| − | *Atrophy of nasal turbinates and distortion and shortening of the snout
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| − | *Caused by co-infection of the nasal mucosa with
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| − | **''[[Bordetella bronchiseptica]]''
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| − | ***Appears to facilitate colonisation of nasal epithelium by the toxigenic ''Pasteurella''
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| − | **Toxin-producing strain of [[Pasteurella multocida|''Pasteurella multocida'']] capsular type D (or sometimes A)
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| − | ***Experimental evidence shows that the toxin acts directly on bone cells of the nasal turbinates to cause bone loss, each pathogen can cause atrophy itself but greater damage when together
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| − | *Exacerbated by adverse dietary and managemental factors
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| − | *In rapidly growing young pigs (4-12 weeks old)
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| − | *Clinical signs
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| − | **Progressive facial deformity with [[Nasal Cavity Inflammatory - Pathology#Infectious causes of rhinitis|rhinitis]], catarrhal nasal discharge
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| − | **Sneezing, coughing, can progress to dyspnoea and anorexia
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| − | *Gross pathology
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| − | **Overlying skin on shortened snout is thrown into folds
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| − | **Deviation of the snout to most affected side
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| − | **Various loss of turbinate bone, ventral usually more affected
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| − | **Deviation of nasal septum away from affected chamber
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| − | **Inflammatory, haemorrhagic and ulcerative lesions in the nasal mucosa
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| − | *Micro pathology
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| − | **Reduction in the amount of bone in the turbinates
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| − | **No osteoid laid down between osteoblasts and existing bone
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| − | **Increased fibrous tissue
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| − | **Non-specific mucosal inflammation
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| − | *2 forms of the disease
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| − | **''''Progressive' atrophic rhinitis'''
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| − | ***Due to infection of the nasal turbinates by P.multocida strains carrying the toxA gene that encodes for an osteolytic toxin. [[Pasteurella multocida|''P.multocida'']] adheres poorly to mucous membranes, and therefore requires a predisposing nasal insult to assist colonisation eg: co-infection with [[Bordetella bronchiseptica|''B.bronchiseptica'']] or [[Cytomegalovirus|Porcine cytomegalovirus (inclusion body rhinitis)]]
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| − | ***Turbinate bone atrophy is permanent and progressive
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| − | **''''Non-progressive' atrophic rhinitis'''
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| − | ***Due to infection of the nasal turbinates by ''[[Bordetella bronchiseptica]]'' strains alone, that carry a gene that encodes for a dermonecrotic toxin.
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| − | ***Turbinate bone can regenerate by the time of slaughter
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| − | *''[[Bordetella bronchiseptica]]'' also causes [[Bronchi and Bronchioles Inflammatory - Pathology#Infectious causes of bronchitis or bronchiolitis|broncho]][[Lungs Inflammatory - Pathology#Infectious causes of pneumonia|pneumonia]]
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| | ===Necrotic laryngitis in pigs=== | | ===Necrotic laryngitis in pigs=== |