Many dogs with chronic right heart failure ultimately require triple diuretic therapy. A dog with a prior diagnosis of right
heart failure due to dilated cardiomyopathy or chronic valvular disease is typically receiving a combination of pimobendan
(0.25-0.3 mg/kg PO BID), ACEI (0.5 mg/kg PO BID), spironolactone (2 mg/kg PO BID) and furosemide (1-5 mg/kg PO BID to TID).
Once the dose of furosemide required to minimize abdominocentesis frequency is 4-5 mg/kg PO TID, the addition of a third diuretic
may be useful. The third or rescue diuretic of choice in advanced right (refractory ascites) and left heart failure (refractory
pulmonary edema) is hydrochlorothiazide. When serum albumin levels begin to decline significantly due to progressive loss
of appetite and/or increased frequency of abdominocentesis, then there is little left to do clinically. Most animals feel
great following abdomino- centesis. When this fails to occur, it represents an ominous prognosis sign that is typically recognized
by the owner.
If right heart failure is a new finding, further diagnostics such as an echocardiogram may be useful to determine the cause
and guide more specific therapies when indicated. For example, dogs that develop severe pulmonary hypertension often develop
right heart failure and may benefit from sildenafil (1-3 mg/kg BID) in addition to palliative intermittent abdominocentesis
and optimized diuresis. Pleural effusion is rarely of sufficient severity to cause clinical signs in canine heart failure;
however, if it is contributing to clinical signs it should be removed.
Severe "clinically significant" cough is a common complaint in dogs with end-stage chronic valvular disease. Severe cough
in the absence of dyspnea and tachypnea is typically related to left mainstem bronchial compression alone or in combination
collapsing trachea and/or COPD. Clinically significant cough can be defined as a cough that based on frequency and/or severity
limits the dogs and/or owner's ability to sleep and enjoy normal activities.
When managing chronic cough, it is important to grade the severity of the cough (with the owner) because many of these coughs
cannot be cured. The clinical goal in many cases is a reduction in the cough frequency and/or severity, i.e., one that does
not impair the dog's and/or owner's ability to sleep and enjoy normal activities. Poor owner communication regarding the ultimate
goal of cough palliation leads to unrealistic expectations on the part of the owner and dooms us to failure. Animals with
left mainstem bronchial compression may benefit from mild increases (25 percent) in diuretic dose. If they are normo- tensive,
then additional afterload reduction may be useful. An oral or inhaled bronchodilator may help, and finally a cough suppressant
may be employed to achieve and maintain a goal of "tolerable" cough.
Additionally, dogs with concurrent collapsing trachea and/or COPD may benefit from therapies such as broncho- dilator, short
courses of antibio- tics, tapering course of corticosteroids, cough suppressants, environmental modification and weight loss.
by Johnny D. Hoskins DVM, PhD, Dipl. ACVIM
Dr. Hoskins is owner of Docu-Tech Services. He is a diplomate of the American College of Veterinary Internal Medicine with
specialities in small animal pediatrics. He can be reached at (225) 955-3252, fax: (214) 242-2200 or e-mail: