Kidney failure occurs when most at least 75 percent of the kidney dies due to lack of blood flow. Keeping the blood flowing with ACE inhibitors may successfully deter kidney failure. Angiotensin-converting enzyme (ACE) inhibitors are often prescribed for dogs diagnosed with kidney disease. According to the Merck Veterinary Manual, ACE inhibitors, often in combination with other drugs, can often help at any stage of kidney disease in dogs.
According to veterinary pharmaceutical company Novartis, when a dog’s kidney begins to fail, it set off a chemical chain reaction which basically tells the kidney to give up fighting and just shut down. ACE inhibitors can stop this chemical chain reaction, depending on the individual dog’s situation.
According to Barbara Forney, VMD, ACE inhibitors stop angiotensin I from producing angiotensin II. This chemical has found to assist in constricting blood flow to the kidney by causing the blood vessels to narrow. In order to compensate for the narrowing blood vessels, the heart works harder to try and push the blood along, thus raising the dog’s blood pressure. This can eventually damage the heart.
“The Pill Book Guide to Medication for Your Dog and Cat” (Bantam Books; 1998) also notes that out of all the available ACE inhibitors for dogs, Enalapril (also known as Vasotec or Encard) gives dogs the least amount of side effects. Another brand that looks promising is Fortekor, because the liver filters some of it out of the dog’s body instead of just the kidneys.
“The Pill Book Guide to Medication for Your Dog and Cat” also notes that ACE inhibitors for dogs do not work as well if the dog is also given NSAID prescription or over the counter painkillers; diuretics like Lasix or vasodilators. An ACE inhibitor is enough of vasodilator for a dog. With vasodilators (which help to open up narrowed blood vessels) more is not better.
Dogs At Risk from Kidney Disease
Kidneys can become diseased for many reasons, according to “Dog Owner’s Home Veterinary Handbook” (Howell Book House; 2007.) Kidneys can fail due to trauma; bad side effects from drugs; poisoning or complications from other types of illnesses such as canine Lyme disease.
But there are some types of canine kidney diseases that are congenital. For example, polycystic kidney disease is found mostly in Cairn terriers and bull terriers. Renal dysplasia is found most often in many small dog breeds like cocker spaniels and Lhasa Apsos as well as the Alaskan Malamute and Standard poodle. ACE inhibitors may be used for all of these, as well as changes in diet and possibly dialysis.
“Dog Owner’s Home Veterinary Handbook.” Debra M. Eldredge, DVM, et al.; Howell Book House; 2007.
“The Pill Book Guide to Medication for Your Dog and Cat.” Matthew Hoffman, et al. Bantam Books; 1998.
Pet Place. “Enalapril (Encard)” http://www.petplace.com/drug-library/enalapril-enacard/page1.aspx
Pet Education. “Kidney Disease: Causes, Signs, Diagnosis and Treatment.” http://www.peteducation.com/article.cfm?c=1+1372&aid=350