Page 361 - Feline Cardiology

376 Section L: Comorbidities

few days to weeks; 20% of cats refuse it under any cir- Cats that have both asthma and heart disease may
cumstance (Padrid 2006). A logical approach in a cat pose a diagnostic dilemma to their owners when signs
with concurrent asthma and heart disease is to attempt of respiratory compromise occur and it is unclear
aerosolized treatment and determine whether the cat whether bronchoconstriction or congestive heart failure
will tolerate it, in which case it can be continued, or is at fault. Some owners develop a very accurate ability
resists it, causing patient and client stress and warrant- to discern between the two after several crises and reso-
ing discontinuation. lutions, but a wide range of signs, including wheezing,
Additional methods to manage feline asthma without retching/cough, respiratory noise, discomfort, vocaliz-
corticosteroids should be an integral part of optimal ing, gasping, and obvious distress may occur with similar
treatment. A cornerstone of such treatment is the reduc- frequency in individual cats with congestive heart failure
tion of environmental triggers and exposures. Methods and asthmatic airway disease. Therefore, a cat in this
for decreasing allergic stimuli include elimination of condition should be brought to the veterinary hospital
volatile-scented products from the cat’s immediate envi- promptly and given supplemental oxygen and an oppor-
ronment, such as carpet-fresheners, scented kitty litter, tunity to rest, and a radiographic diagnosis can be made
and strong perfumes; reduction or elimination of air- when proper radiographs can be obtained quickly and
borne particulates, including tobacco smoke, house safely. Nonspecific, blanket treatment such as the simul-
dust, and clay-based kitty litter; and nonspecific reduc- taneous administration of both a diuretic (e.g., furose-
tion of airborne irritants through installation of an air mide 3 mg/kg IV) and a bronchodilator (e.g., terbutaline
purifier system. 0.01 mg/kg IM) may be provided initially in cats with
Other medications may be considered (Padrid 2008). such severe dyspnea when they have a documented pre-
Cyproheptadine (2–4 mg/cat PO q 12h), an antihista- vious history of both disorders, and when this tempo-
mine used for appetite stimulation in cats, decreases rary measure is felt to be necessary to allow the patient
serotonin release in bronchial smooth muscle and may to survive long enough for radiographs to confirm the
be beneficial in cats already receiving aerosol fluticasone diagnosis and focus the treatment plan.
and albuterol or other beta-2 agonist. Aminophylline or
theophylline (10 mg/kg PO q 8–12h) may provide mild CONCURRENT CARDIAC DISEASE AND OTHER
bronchodilation, and trivial diuretic effects. The DISORDERS TREATED WITH GLUCOCORTICOIDS
sustained-release preparations (e.g., Theo-Dur) are not
absorbed as predictably as the plain (anhydrous) forms The adverse effects of injectable or oral glucocorticoids,
and are not recommended. Zafirlukast and other leukot- as described above, are relevant to many other important
feline diseases that are immune-mediated or neoplastic.
riene inhibitors have not demonstrated dramatic effi-
Comorbidities cacy and are not widely recommended in feline asthma. In general, oral and parenteral glucocorticoids are not
strictly contraindicated in feline heart disease, but the
Empirical antibiotic therapy also is not routinely recom-
risk they carry of triggering congestive heart failure
mended due to the scarcity of clinically significant bac-
terial infection in asthmatic cats.
if available. If no other option exists, glucocorticoids
Finally, where geographically appropriate, cats sus- means an alternative form of treatment should be sought
pected of having asthma should be tested for heartworm should be prescribed (because a majority of cats with
disease (see Chapter 23) because clinical signs may be heart disease likely tolerate such treatments), preferably
identical, and treatment of heartworm infection has oral rather than repositol injectable, along with a basic
both respiratory and cardiovascular benefits. discussion with the owner about signs of congestive
In cats with concurrent asthma and heart disease, it heart failure that would warrant an immediate recheck—
is important to choose a beta-1 selective blocker if beta the same discussion that takes place at discharge of any
blockade is instituted for the heart disease. Nonselective cat with substantial structural heart disease.
beta blockers such as propranolol and carvedilol by defi-
nition also antagonize beta-2 receptors, which are prom- Inflammatory Bowel Disease
inent in bronchial smooth muscle and which cause Since glucocorticoids are an inexpensive and often-
bronchodilation. Therefore, antagonism of beta-2 recep- effective treatment for inflammatory bowel disease
tors may trigger asthmatic decompensation and should (IBD), management of cats that have concurrent heart
always be avoided. Even selective beta-1 blockers may disease and inflammatory bowel disease involves two
exert some beta-2 blocking effects at higher dosages, so important approaches: search for and treatment of pos-
an asthmatic feline patient should be carefully moni- sible underlying causes (to create a true diagnosis of
tored for exacerbation of lower airway disease when idiopathic IBD), and use of treatments other than glu-
starting even a selective beta blocker. cocorticoids for palliation of intestinal inflammation.