“The literature tells us that many dogs with the disease die from aspiration pneumonia or are humanely euthanized due to poor quality of life within eight months of diagnosis,” said Dr. Jillian Haines, a veterinarian at Washington State University who co-led the study.

Liquid sildenafil was shown to relax the smooth muscle of the lower esophagus so it will open to let food pass to the stomach. Besides some rare gastrointestinal irritation, there are no side effects to dogs at the dose used in the study.

The research was published in the American Journal of Veterinary Research.

WSU veterinarians used videofluoroscopy to monitor liquid and later, blended wet food as it traveled down the esophagus.

Ten dogs with megaesophagus enrolled in the study were administered either a placebo or sildenafil for two weeks at a time. The dogs then went one week without either drug. Then the placebo and sildenafil groups were switched.

Their owners were tasked with logging regurgitation episodes but were not informed of which drug their dog had been taking.

There wasn’t a significant difference between the placebo and sildenafil during a 30-minute videofluoroscopy, where veterinarians use a moving X-ray to examine how food is swallowed.

However, the study found nine out of the 10 owners reported reduced regurgitation during the two weeks when liquid sildenafil was administered.

Dogs that showed severe signs of the disease didn’t show as positive of results. In those cases, the researchers found it was harder to get the drug into the stomach for absorption.

While the study is promising, still much is to be known about the drug. Researchers hope future studies will investigate sildenafil’s use in veterinary medicine.

Source: Medindia