Sinusitis

Sinusitis

• Often undetected unless it causes facial deformity or a draining tract onto the skin
• Seromucous sinuitis in not significant, often an extension of viral infection in nasal cavity
• Purulent sinusitis tends to obstruct drainage -> chronic purulent sinusitis
• Most important in horses due to their complex sinuses
• Primary:
  • Young horses are more prone as they are susceptible to Strangles
  • Following transient systemic Streptococcus infection
  • Rarely fungal infections
• Secondary:
  • Most common sequel to rhinitis
  • Dental or periodontal disease (maxillary sinus)
  • Penetrating infections from dehorning wounds and fractures of facial bones (frontal sinus)
  • Expanding mass

• Purulent inflammation of sinuses is likely to become chronic due to poor drainage
• Inflammation may block the drainage of the sinuses and cause distortion of the overlying bones
• May result in empyema, inspissated exudate, in horses

• In sheep often due to Oestrus ovis infection

Infectious causes of sinusitis

.	VIRAL	BACTERIAL	FUNGAL	PARASITIC
Dogs	.	secondary	A. fumigatus	Linguatula serrata
.	.	.	.	Capillaria aerophila
Cats	Feline Herpesvirus 1	secondary	Aspergillus fumigatus	Linguatula serrata sometimes
.	.	.	.	Capillaria aerophila
Horses	.	Strangles	Aspergillus spp.	.
.	.	Streptococcus equi subsp. zooepidemicus	.	.
Cattle	.	secondary	.	.
Sheep	.	.	.	Oestrus ovis larvae
Pigs	Inclusion body rhinitis	.	.	.

For an overview of respiratory infections see Respiratory System Inflammation - Pathology