Elizabeth Taylor said she was trying to protect 6-year-old Roscoe by giving him Trifexis, a monthly combo pill made for heartworm, parasite and flea prevention.
"I feel like I poisoned my dog" said Elizabeth Taylor.
"First time he got a little sick, but I didn't think anything of it. The second time he got very sick," Taylor said.
Taylor said Roscoe, an English pointer mix, was never the same after taking the medication.
"He was lethargic, he was cold, he was shaking, shivering, he had bloody stool, he was vomiting," Taylor said.
For three weeks, despite round-the-clock care and trips back and forth to the vet, Roscoe's health deteriorated and he was eventually put down.
Jessie Grissom, Taylor's daughter, said, "He wouldn't bark. He was shy to come around. He knew that we were there for him, but it's almost like he didn't want us to see him like that."
Taylor recalled the last trip to the vet.
"The last doctor said, 'There is nothing we can do about him. I gave it everything I had,'" Taylor said.
Desiree Pederson's dog Wyatt was on Trifexis for two years.
"We noticed he was licking his paws all the time. He was starting to get an upset stomach and having accidents in the house," Pederson said.
But it was a commercial for Trifexis, listing the side effects, that caught the Pedersons' attention.
Pederson said they had finally put two and two together.
"Oh my God, everything that my dog was experiencing was exactly what was going on," said Pederson. "Within 30 days, my dog no longer had red eyes, the itchy paws stopped, the constant licking of them, he wasn't throwing up, there were no food allergies."
Taylor and Pederson both found they are not alone. There are a number of Facebook pages and posts about Trifexis warning dog owners about the risk.
The Food and Drug Administration approved Trifexis in January 2011. Since then, Local 6 News found out the FDA has received nearly 78,000 complaints and nearly 1,500 reports of dog deaths that owners believe are linked to Trifexis, which includes euthanization.
The report also indicates adverse drug reactions -- the list is 31 pages long.
The FDA cautions there is no solid evidence linking Trifexis to any dog's death. The reports are simply complaints from owners and vets in which the pill is suspected
Local 6 contacted Trifexis' maker, Elanco, and were provided with a statement, "There continues to be no established link between Trifexis use and death."
Dr. John Bass was a vet for more than 35 years and is familiar with Trifexis.
"We have had a problem with nausea," he said. "With some animals it will cause nausea and/or vomiting."
Bass recommended owners have a plan B.
"There are several products that are out there," Bass said. "Trifexis is not the only one, it's one of the better ones, but it's not the only one. If they're not comfortable with that, there is always another product they can try."
Taylor's family said they'll definitely be using another heartworm product for their new rescue pups.
"I'm not a doctor," Pederson said. "I can't prove 100 percent, but I can only tell you that the dog was 100 percent better once we removed the Trifexis."