Changes

==Clinical signs and locations of sinonasal pathology==

==Clinical signs and locations of sinonasal pathology==

 

===Nasal discharge===

===Nasal discharge===

*Prevents dessication of the mucosal epithelium

*Prevents dessication of the mucosal epithelium

*Contains antimicrobial substances

*Contains antimicrobial substances

*Immunoglobulin - IgA

*Immunoglobulin - [[IgA]]

**IgA produced by mucosal plasma cells

**[[IgA]] produced by mucosal plasma cells

**IgA can attach to specific pathogen antigens (viruses, bacteria) trapping them in the mucus for clearance

**[[IgA]] can attach to specific pathogen antigens (viruses, bacteria) trapping them in the mucus for clearance

*Lysosyme

*Lysosyme

**Direct action on bacterial cell walls

**Direct action on bacterial cell walls

***Pharynx - pharyngitis

***Pharynx - pharyngitis

**Type

**Type

***Grossly many inflammatory processes (eg: response to viral or bacterial infection) in the URT will begin as a serous discharge, and then progress to a catarrhal exudate, and then to purulent/pseudomembranous/haemorrhagic as neutrophils are recruited

***Grossly many inflammatory processes (eg: response to viral or bacterial infection) in the URT will begin as a serous discharge, and then progress to a catarrhal exudate, and then to purulent/pseudomembranous/haemorrhagic as [[Neutrophils|neutrophils]] are recruited

***Serous - transparent fluid exudate (acute inflammation)  

***Serous - transparent fluid exudate (acute inflammation)  

***Catarrhal - mucous exudation (acute to subacute inflammation)

***Catarrhal - mucous exudation (acute to subacute inflammation)

**Clinical disease most severe in young calves - can develop mucosal ulcerative lesions in the oesophagus and forestomachs and viraemia with multiorgan infection.

**Clinical disease most severe in young calves - can develop mucosal ulcerative lesions in the oesophagus and forestomachs and viraemia with multiorgan infection.

**Cause of abortion >5 months of gestation  

**Cause of abortion >5 months of gestation  

*Cytomegaloviruses  

*Cytomegaloviruses  

**Porcine cytomegalovirus

**Porcine cytomegalovirus

**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. ''P.multocida'' adheres poorly to mucous membranes, and therefore requires a predisposing nasal insult to assist colonisation eg: co-infection with ''B.bronchoseptica''; or 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. ''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

****Turbinate bone atrophy is permanent and progressive

***'Non-progressive' atrophic rhinitis

***'Non-progressive' atrophic rhinitis

****Due to infection of the nasal turbinates by ''Bordatella bronchoseptica'' strains alone, that carry a gene that encodes for a dermonecrotic toxin.

****Due to infection of the nasal turbinates by ''Bordatella bronchiseptica'' strains alone, that carry a gene that encodes for a dermonecrotic toxin.

****Turbinate bone can regenerate by the time of slaughter

****Turbinate bone can regenerate by the time of slaughter

**'Snuffles' in rabbits

**'Snuffles' in rabbits

****Most often ''P.multocida'' and/or ''B.bronchoseptica'' infection of the nasal mucosa

****Most often ''P.multocida'' and/or ''B.bronchiseptica'' infection of the nasal mucosa

****Clinical signs (nasal discharge, sneezing) result from an acute to chronic rhinitis.  

****Clinical signs (nasal discharge, sneezing) result from an acute to chronic rhinitis.  

*''Streptococcus equi''  

*''Streptococcus equi''  

**''Streptococcus equi subsp. equi''

**''Streptococcus equi subsp. equi''

***Can infect the respiratory tract (nasal cavity, paranasal sinuses, trachea and bronchi/bronchioles)

***Can infect the respiratory tract (nasal cavity, paranasal sinuses, trachea and bronchi/bronchioles)

***URT infection can be indistinguishable clinically from Strangles, but does not cause suppurative lymphadenitis (cf: ''S.equi subsp. equi'')

***URT infection can be indistinguishable clinically from Strangles, but does not cause suppurative lymphadenitis (cf: ''S.equi subsp. equi'')

====Fungal infections====  

====Fungal infections====  

====Parasitic infections ====

====Parasitic infections ====

*''Oestrus ovis'' larvae in the nasal cavity of sheep and goats = Nasal bots

*''Oestrus ovis'' larvae in the nasal cavity of sheep and goats = Nasal bots