Difference between revisions of "Atrophic Rhinitis"
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− | *''B. bronchiseptica'' causes [[ | + | *''B. bronchiseptica'' causes [[Rhinitis#Bacterial rhinitis|Atrophic rhinitis of pigs]] in association with [[Pasteurella multocida|''Pasteurella multocida'']] |
*Colonises nasopharynx | *Colonises nasopharynx | ||
*Infection must occur during first few weeks of life | *Infection must occur during first few weeks of life | ||
*Produces dermonecrotic toxin which damages osteoblasts, preventing bone formation | *Produces dermonecrotic toxin which damages osteoblasts, preventing bone formation | ||
*Leads to turbinate atrophy without distortion of the snout in uncomplicated infections | *Leads to turbinate atrophy without distortion of the snout in uncomplicated infections | ||
− | *[[ | + | *[[Rhinitis#Bacterial rhinitis|Atrophic rhinitis]] results when [[Pasteurella multocida|''Pasteurella multocida'']] colonises and produces osteolytic toxin, leading to bone resorption |
*Malformation of snout in growing pigs as well as poor growth | *Malformation of snout in growing pigs as well as poor growth | ||
*increases with high stocking density and poor ventilation | *increases with high stocking density and poor ventilation | ||
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*In rapidly growing young pigs (4-12 weeks old) | *In rapidly growing young pigs (4-12 weeks old) | ||
*Clinical signs | *Clinical signs | ||
− | **Progressive facial deformity with [[ | + | **Progressive facial deformity with [[Rhinitis#Infectious causes of rhinitis|rhinitis]], catarrhal nasal discharge |
**Sneezing, coughing, can progress to dyspnoea and anorexia | **Sneezing, coughing, can progress to dyspnoea and anorexia | ||
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*2 forms of the disease | *2 forms of the disease | ||
**''''Progressive' atrophic rhinitis''' | **''''Progressive' atrophic rhinitis''' | ||
− | ***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)]] | + | ***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 [[Porcine Cytomegalovirus|Porcine cytomegalovirus (inclusion body rhinitis)]] |
***Turbinate bone atrophy is permanent and progressive | ***Turbinate bone atrophy is permanent and progressive | ||
**''''Non-progressive' atrophic rhinitis''' | **''''Non-progressive' atrophic rhinitis''' | ||
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***Turbinate bone can regenerate by the time of slaughter | ***Turbinate bone can regenerate by the time of slaughter | ||
− | *''[[Bordetella bronchiseptica]]'' also causes [[ | + | *''[[Bordetella bronchiseptica]]'' also causes [[Bronchitis#Infectious causes of bronchitis or bronchiolitis|broncho]][[Pneumonia Overview#Infectious causes of pneumonia|pneumonia]] |
− | [[Category:Pig]] | + | [[Category:Respiratory Diseases - Pig]] |
[[Category:Respiratory_Bacterial_Infections]] | [[Category:Respiratory_Bacterial_Infections]] | ||
+ | [[Category:To Do - Respiratory]][[Category:To Do - Major]] |
Latest revision as of 15:45, 10 May 2011
- B. bronchiseptica causes Atrophic rhinitis of pigs in association with Pasteurella multocida
- Colonises nasopharynx
- Infection must occur during first few weeks of life
- Produces dermonecrotic toxin which damages osteoblasts, preventing bone formation
- Leads to turbinate atrophy without distortion of the snout in uncomplicated infections
- Atrophic rhinitis results when Pasteurella multocida colonises and produces osteolytic toxin, leading to bone resorption
- Malformation of snout in growing pigs as well as poor growth
- increases with high stocking density and poor ventilation
- Vaccine available
- Atrophy of nasal turbinates and distortion and shortening of the snout
- Caused by co-infection of the nasal mucosa with
- Bordetella bronchiseptica
- Appears to facilitate colonisation of nasal epithelium by the toxigenic Pasteurella
- Toxin-producing strain of Pasteurella multocida capsular type D (or sometimes A)
- 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
- Bordetella bronchiseptica
- Exacerbated by adverse dietary and managemental factors
- In rapidly growing young pigs (4-12 weeks old)
- Clinical signs
- Progressive facial deformity with rhinitis, catarrhal nasal discharge
- Sneezing, coughing, can progress to dyspnoea and anorexia
- Gross pathology
- Overlying skin on shortened snout is thrown into folds
- Deviation of the snout to most affected side
- Various loss of turbinate bone, ventral usually more affected
- Deviation of nasal septum away from affected chamber
- Inflammatory, haemorrhagic and ulcerative lesions in the nasal mucosa
- Micro pathology
- Reduction in the amount of bone in the turbinates
- No osteoid laid down between osteoblasts and existing bone
- Increased fibrous tissue
- Non-specific mucosal inflammation
- 2 forms of the disease
- 'Progressive' atrophic rhinitis
- Due to infection of the nasal turbinates by P.multocida strains carrying the toxA gene that encodes for an osteolytic toxin. P.multocida adheres poorly to mucous membranes, and therefore requires a predisposing nasal insult to assist colonisation eg: co-infection with B.bronchiseptica or Porcine cytomegalovirus (inclusion body rhinitis)
- Turbinate bone atrophy is permanent and progressive
- 'Non-progressive' atrophic rhinitis
- Due to infection of the nasal turbinates by Bordetella bronchiseptica strains alone, that carry a gene that encodes for a dermonecrotic toxin.
- Turbinate bone can regenerate by the time of slaughter
- 'Progressive' atrophic rhinitis
- Bordetella bronchiseptica also causes bronchopneumonia