Upper airway disorders in dogs and cats include abnormalities of the nares, pharynx, larynx and trachea. The purpose of this manuscript is to highlight the most common upper airway disorders that we seen in canine and feline patients. A more detailed discussion will occur during the lecture.
Although feline asthma is among the most commonly diagnosed respiratory conditions in cats, there is still a lot of confusion about how to define or classify this condition or how to differentiate it from other lower respiratory tract problems.
"Allergic" rhinitis is a difficult and frustrating clinical condition in cats. Because of the relatively young age at which many cats are afflicted, we assume that Feline Herpes Virus –1 (FHV-1) is part of the pathophysiology.
Diagnostic tests are obviously required to confirm the presence of many respiratory diseases in small animals. However, respiratory medicine is an underdeveloped subspecialty in veterinary medicine, and there are relatively few sophisticated tests that are available to the clinician that actually diagnose specific pulmonary disorders.
The use of inhaled medications is certainly not a new phenomenon in feline medicine. It makes intuitive sense that local delivery of medication might result in different actions than systemic administration. There are two primary methods for delivering inhaled medications to cats: 1) use of metered dose inhalers (MDI) or 2) use of a nebulizer to aerosolize liquid medications.
Patients with respiratory distress are often frail and excessive stress may progress to respiratory arrest. Non-invasive techniques are essential to avoid exacerbation of tenuous circumstances. One must rely upon abridged and fragmented physical examinations in the most serious cases, accurate historical information, and noninvasive diagnostics.
Asthma in human beings is a chronic inflammatory disease within the lower airways (bronchi and bronchioles) that causes cough, wheeze and exercise intolerance. These clinical signs are the result of a decrease in airflow through airways that are narrowed from excessive mucus secrection, airway wall edema and bronchoconstriction.
Among the key frustrations is a lack of understanding about exactly what this condition represents (i.e. Is there really a causal relationship to some form of infection? is it immune-mediated? Allergic?...). Since it is a diagnosis of exclusion, there is also always a bit of doubt about whether or not I may have missed a primary nasal diseas.
Herpesvirus 1 (rhinotracheitis; FHV-1) and calicivirus (FCV) are the most common viral causes of sneezing and nasal discharge in the cat. If oral ulcers are present, calicivirus is most likely. If corneal ulcers are present, herpesvirus 1 is most likely. FHV-1 has now also been associated with chronic stomatitis, facial dermatitis, and endogenous uveitis. Viral rhinitis with or without secondary bacterial infection can be recurrent.