Dan Taylor, DVM
As one of the more common feline emergency presentations, cats in respiratory distress pose challenges in realizing a diagnosis, providing appropriate treatments and determining a prognosis. This presentation provides enough difficulty that IVECCS’s 2015 theme was respiratory emergencies with several lectures focusing on feline respiratory conditions.
A variety of disease processes can cause respiratory distress in cats and while the causes are very different, the history, physical exam findings and even diagnostics can yield very similar results. Compound that with the fragile nature of felines in respiratory distress and we can be left to make potentially life-saving decisions without all of the needed information.
Cats with respiratory distress typically have a primary disease etiology of either congestive heart failure secondary to Hypertrophic Cardiomyopathy or feline asthma. However, other disorders such as pneumonias, pleural effusion, traumatic pneumothorax, diaphragmatic hernias and non-cardiogenic pulmonary edema are also possible.
Typically, these patients present with acute respiratory signs including increased rate and effort. Obviously, these signs do not differentiate between cardiac versus non-cardiac causes, but initially focusing on the signalment, mainly breed, may give more consideration to one cause. For example, a middle aged Maine coon may be more likely to have CHF. Additionally, history may help differentiate between cardiac and non-cardiac disease. An example may be a historical cough as cardiac cats do not cough.
Regardless of disease, prompt symptomatic treatment and stabilization are paramount in providing life-saving care to these patients. Typically, a brief assessment of vitals and a focused cursory exam are performed and then the patient is provided supplemental oxygen either via an oxygen mask, flow-by oxygen or oxygen cage. A mild sedative, such as butorphanol at 0.2mg/kg IM or IV, is used to relieve the anxiety associated with the inability to breathe normally. At times, it may be appropriate to treat empirically with either a dose of furosemide 1-2mg/kg IM or IV, a puff or two of albuterol or both in an attempt to stabilize these patients. Once a patient becomes more stable, further exam, diagnostics and treatments can be more safely accomplished.
Upon stabilization, a more thorough physical exam can be performed, focusing on the character of breathing, presence of abnormal lung sounds, absence of lung sounds, presence of gut sounds on thoracic auscultation and assessing for cardiac murmurs. As murmurs can accompany respiratory distress, the presence of a murmur does not confirm CHF as much as the absence of a murmur does not rule it out. Unfortunately physical exam findings rarely confirm a diagnosis in a cat with respiratory signs, making it necessary to perform chest imaging, thoracentesis and blood work to better narrow down a differential list.