Changes

Cases of feline asthma may be divided into '''intrinsic''' and '''extrinsic''' disease.   

Cases of feline asthma may be divided into '''intrinsic''' and '''extrinsic''' disease.   

 

===Extrinsic asthma===

**'''Extrinsic asthma'''

Type I hypersensitivity in response to allergen challenge - mediated by [[IgE]]. Pathological changes include:

***Type I hypersensitivity in response to allergen challenge - mediated by [[IgE]]

*Exudate into airways - mucus/ cells

***Pathological changes:

*Thickened airway walls - oedema, glandular and smooth muscle hypertrophy, vascular congestion

****Exudate into airways - mucus/ cells

*Altered fluidity of mucus (associated with goblet cell hyperplasia) -> less effective mucociliary apparatus

****Thickened airway walls - oedema, glandular and smooth muscle hypertrophy, vascular congestion

===Intrinsic asthma===

****Altered fluidity of mucus (associated with goblet cell hyperplasia) -> less effective mucociliary apparatus

In a proportion of cats there is an increased propensity for the bronchial smooth muscle to contract (increased bronchial reactivity) -> airway constriction

**'''Intrinsic asthma'''

***A proportion of cats there is an increased propensity for the bronchial smooth muscle to contract (increased bronchial reactivity) -> airway constriction

==Signalment==

==Signalment==