By Don “Doc” Sanders
Dogs with a malfunctioning esophagus are commonly diagnosed with a condition called megaesophagus. As the name implies, this condition involves a dilated and enlarged esophagus. With megaesophagus, the esophagus is more or less paralyzed, making it difficult for an affected dog to swallow food. Megaesophagus is a frustrating health issue for dog owners and their veterinarians, and it drastically shortens a dog’s life.
I suspect you may not be aware of this health condition, unless you’ve had a dog with the malady. A dog with megaesophagus accumulates food in its dilated esophagus. This prevents the food from passing into the stomach.
Veterinary experts believe that this limitation could be caused by a restriction in the cardia, the valve connecting the esophagus to the stomach, or a failure of musculature in the esophagus to push the food through the cardia. Just an FYI: This complication may occur in humans after COVID infection.
The symptoms in dogs include retaining food in the esophagus and vomiting after eating. Food retention causes vomiting, from four to 19 times a week. Seventy-four percent of dogs diagnosed with megaesophagus ultimately are humanely put down. The reason for this: The lack of satisfactory treatments and a seriously deteriorating quality of life.
However, hope is on the horizon. A Washington State University (WSU) veterinary research team selected 10 dogs with megaesophagus. They treated five of them with a human smooth muscle stimulating drug, sildenafil, for 14 days. It reduced the dogs’ incidence of vomiting by more than 50%. Video fluoroscopy scans of the treated dogs showed that dog food was not hanging up in the dogs’ esophagus as it had prior to the treatment. The other five dogs were used as the control group and given their usual diet and medications — but not the sildenafil — as a part of this preliminary study. The control dogs’ food continued to hang up in the esophagus and continued to cause vomiting.
After the first 14-day trial, and a seven-day clearance time for both groups, the initial five control dogs were given sildenafil for 14 days and the initial sildenafil treatment group became the control group, receiving their usual diet and care, but no sildenafil.
The dogs that were treated with sildenafil in the second 14-day trial demonstrated similar positive results as the dogs treated with sildenafil in the first trial. They also experienced a 50% reduction of food accumulating in the esophagus. The control group in the second 14-day trial relapsed with vomiting as food got hung up in their enlarged esophagus.
Certainly, a 50% reduction in 10 dogs is nothing to write home about, but up until now there has been no effective treatment for megaesophagus, from which dogs eventually die. The treated dogs in this research trial regained some of their body weight.
I know that many of you are dog lovers and that you will likely find the WSU trial to be encouraging.
But you may be wondering why in the world am I writing about this? I think this is a great example of how a drug developed for another specific purpose is discovered to be useful for a medical condition totally unrelated to its original purpose.
I shared with you another example of this in my December 2021 Ohio’s Country Journal column about ivermectin, one of the greatest drugs developed since Arthur Fleming discovered penicillin. You may know what a sham it was when government eggheads decreed vaccination for COVID was the only option and recommended against taking ivermectin — even though ivermectin had a history of being effective against COVID. It took more than two years for these fumblebums to admit that ivermectin used early in a COVID infection was very effective.
So, what is sildenafil? Sildenfil is a human drug that is very useful for its effect on smooth muscles. You’ll likely recognize its commercial name: Viagra! Need I say more?