Changes

***Horse:

***Horse:

****Haemorrhagic nasal polyp

****Haemorrhagic nasal polyp

*****'Ethmoid haematoma', 'Progressive haematoma' - arise from the ethmoid region and can extend to fill the nasal cavity. They can be difficult to control as they can recur after surgery. Histology - multiple areas of acute to chronic haemorrhage within a fibrous tissue stroma.

*****'Ethmoid haematoma', 'Progressive haematoma' - arise from the ethmoid region and can extend to fill the nasal cavity. They can be difficult to control as they can recur after surgery.  

****Exercise-induced pulmonary haemorrhage ... see later lectures.

*****Histology - multiple areas of acute to chronic haemorrhage within a fibrous tissue stroma.

****Exercise-induced pulmonary haemorrhage

*Inflammatory disease

*Inflammatory disease

**Inflammation in the URT can be classified on:

**Inflammation in the URT can be classified on:

**Location

***Location

***Nasal cavity - rhinitis

****Nasal cavity - rhinitis

**Paranasal sinuses - sinusitis

****Paranasal sinuses - sinusitis

**Guttural pouch and eustachian tube - eustachitis

****Guttural pouch and eustachian tube - eustachitis

**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 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)

**Pseudomembrnaous - fibrin exudation

***Pseudomembrnaous - fibrin exudation

**Purulent - pus

***Purulent - pus

**Ulcerative

***Ulcerative

**Haemorrhagic

***Haemorrhagic

**Granulomatous (chronic inflammation)

***Granulomatous (chronic inflammation)

**Polypoid (chronic inflammation)

***Polypoid (chronic inflammation)

**Timecourse

**Timecourse

**Acute, subacute, chronic

***Acute, subacute, chronic

**Causes

**Causes

**Infectious agent - viral, bacterial, fungal, parasitic

***Infectious agent - viral, bacterial, fungal, parasitic

**Trauma or foreign body (eg: grass seed)

***Trauma or foreign body (eg: grass seed)

**Irritant or allergens

***Irritant or allergens

**Neoplasia

***Neoplasia

**Viral infections  

***Viral infections  

**Herpesviruses

****Herpesviruses

**Bovine herpesvirus -1

****Bovine herpesvirus -1

**Infectious bovine rhinotracheitis (IBR)

*****Causes Infectious bovine rhinotracheitis (IBR)

**Highly infectious URT disease of cattle  

*****Highly infectious URT disease of cattle  

**High morbidity, low mortality

*****High morbidity, low mortality

**Aerosol transmission - requires close contact between animals

*****Aerosol transmission - requires close contact between animals

**BHV-1 infects the respiratory mucosal epithelial cells (intranuclear inclusion eosinophilic inclusion bodies)from nasal mucosa down to bronchioles

*****BHV-1 infects the respiratory mucosal epithelial cells (intranuclear inclusion eosinophilic inclusion bodies)from nasal mucosa down to bronchioles

**leading to neutrophilic inflammation of varying severity.... serous -> catarrhal -> purulent nasal discharge, sneezing, coughing.

******leading to neutrophilic inflammation of varying severity.... serous -> catarrhal -> purulent nasal discharge, sneezing, coughing.

**with secondary bacterial infection (eg: Pasturella spp., Mycoplasma spp., Fusobacterium necrophorum) can lead to fibrinous to necrotizing inflammation; mucosal sloughing, ulceration... pyrexia, dyspnoea ... inhalation pneumonia... death.

******with secondary bacterial infection (eg: Pasturella spp., Mycoplasma spp., Fusobacterium necrophorum) can lead to fibrinous to necrotizing inflammation; mucosal sloughing, ulceration... pyrexia, dyspnoea ... inhalation pneumonia... death.

**Clinical signs include coughing, discharge, lacrimation, and increased respiratory rate.

*****Clinical signs include coughing, discharge, lacrimation, and increased respiratory rate.

**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

**Inclusion body rhinitis  

*****Causes Inclusion body rhinitis  

**Disease of suckling piglets 1-5 wks of age

*****Disease of suckling piglets 1-5 wks of age

**Clinical signs: those associated with acute/subacute rhinitis (ie: serous nasal discharge, progressing to catarrhal or purulent discharge with time and secondary bacterial infections; sneezing; pyrexia)

*****Clinical signs: those associated with acute/subacute rhinitis (ie: serous nasal discharge, progressing to catarrhal or purulent discharge with time and secondary bacterial infections; sneezing; pyrexia)

**Morbitity high, mortality low

*****Morbitity high, mortality low

**Histology: large basophilic intranuclear inclusion bodies in the nasal and sinus respiratory epithelium with lymphocytic infiltration of the mucosa.

*****Histology: large basophilic intranuclear inclusion bodies in the nasal and sinus respiratory epithelium with lymphocytic infiltration of the mucosa.

**Can develop viraemic stage, with inclusions in other organs eg: renal tubular epithelium. Piglets can die during this phase.

*****Can develop viraemic stage, with inclusions in other organs eg: renal tubular epithelium. Piglets can die during this phase.

**Equine herpesvirus - 1, 4

****Equine herpesvirus - 1, 4

**Feline herpesvirus -1

****Feline herpesvirus -1

**Feline viral rhinotracheitis

*****One of the causes of Feline viral rhinotracheitis

**Viruses and bacteria are involved in the complex. The most frequent aetiologic agent is FHV-1, and less frequently feline calicivirus and/or Chlamydophia psittaci (NB: previously called Chlamydia psittaci var felis)

*****Viruses and bacteria are involved in the complex. The most frequent aetiologic agent is FHV-1, and less frequently feline calicivirus and/or ''Chlamydophia psittac''i (NB: previously called Chlamydia psittaci var felis)

**All three agents infect URT respiratory epithelium, although FHV-1 has the highest affinity for this epithelium

*****All three agents infect URT respiratory epithelium, although FHV-1 has the highest affinity for this epithelium

**Feline calicivirus more frequently infects the oral mucosa -> ulcerative stomatitis

*****Feline calicivirus more frequently infects the oral mucosa -> ulcerative stomatitis

**C.psittaci more frequently infects the conjunctival epithelium -> chronic conjunctivitis

*****C.psittaci more frequently infects the conjunctival epithelium -> chronic conjunctivitis

**Infection of the respiratory epithelium by FHV-1 results in a typical neutrophilic rhinitis with intraepitheial intranuclear eosinophilic inclusion bodies, with expected clinical signs

**Infection of the respiratory epithelium by FHV-1 results in a typical neutrophilic rhinitis with intraepitheial intranuclear eosinophilic inclusion bodies, with expected clinical signs

**Resolution of clinical signs usually occurs by 7-14 days.

**Resolution of clinical signs usually occurs by 7-14 days.