Ramipril is another ACE inhibitor that is now available in the United States. Ramipril is converted in vivo to its active
form, ramiprilat, which is eliminated in the bile and urine. No adjustment of the recommended oral dosage of ramipril is needed
in dogs with moderate renal impairment.
In addition, the dose rate of ramipril recommended for dogs (0.125 mg/kg once daily) proves to be adequate in most cases and
improved the clinical signs in the cats with hypertensive and normotensive cats suffering from hypertrophic cardiomyopathy
(HCM). Side effects occur infrequently in dogs and cats. Not to be used in hemodynamically relevant stenoses (e.g. aortic
stenosis, mitral-valve stenosis) or obstructive hypertrophic cardiomyopathy. If signs of apathy or ataxia (potential signs
of hypotension) occur during treatment with ramipril, the drug should be discontinued and treatment resumed at 50 percent
of the original dose once signs have subsided.
The use of ACE inhibitors in dogs with hypovolemia/severe dehydration (e.g. as a result of diuretic treatment, vomiting and/or
diarrhea) can lead to acute hypotension. Ramipril treatment not only appears to be safe in combination with furosemide but
also with feline thyrostatic therapy.
B vitamins and folic acid
Both cobalamin and folic acid are integral components of the metabolism of homocysteine. Hyperhomo-cysteinemia in human patients
is associated with increased risks for both venous and arterial thrombosis as well as cardiac mortality.
Folate therapy (combined supplementation of vitamins B6, cobalamin and folic acid) has been demonstrated to significantly
lower homocysteine levels. However, lower homocysteine levels have resulted in variable success for the prevention of peripheral
vascular events in human trials.
Arterial thromboembolism (ATE) in cats often present to veterinary practices. In light of the strong data in human cardiology
supporting hyperhomocysteinemia as a risk factor for peripheral vascular disease, similar data has been analyzed in cats.
Interestingly, no differences in homocysteine or folate levels were found between groups of normal cats, cats with cardiomyopathy
(CM), and cats with CM and ATE. Cobalamin concentrations, however, were lower in both the cats with CM alone and cats with
combined CM and ATE. The current empiric dose recommendation for B vitamin complex adjunct therapy in cats is 12.5 mg once
daily. More research is needed to determine if cats truly benefit from B12 or folate therapy. As veterinarians attempting
above all to do no harm, combined B vitamin therapy seems to be a reasonable adjunct to more traditional therapies in our
efforts to decrease the risk of feline arterial thromboembolism.
What's your question?
Send your pediatric/geriatric related questions to: Pediatric/Geriatric Protocol, DVM Newsmagazine, 7500 Old Oak Blvd., Cleveland,
OH 44130. Your questions will be answered by Dr. Hoskins in upcoming columns.
Dr.Johnny Hoskins is owner of DocuTech 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: