Why Are Grapes Toxic to Dogs? Student Researcher Wants to Find Out

Alongside her faculty mentor, Penelope Pando is investigating why a specific chemical compound is deadly for dogs but not humans.

Most dog owners know: if a dog eats grapes or raisins, call the vet right away. Within hours, the dog could become ill. Within days, their kidneys could fail.

Penelope Pando is a dog lover. Fortunately, her family’s three dogs have never been poisoned by grapes. Still, she’s working hard in the labs at Massachusetts College of Pharmacy and Health Sciences (MCPHS) to figure out why such a small fruit can be so toxic to these beloved pets.

“Chocolate is another toxic substance for dogs, but it’s well understood, including what happens and how to treat it,” explained Pando, who is a Medical and Molecular Biology student at MCPHS. “I’m looking into what the toxic component in grapes does mechanistically to cause illness in dogs but not humans.”

Veterinarians suspect that the toxic component is tartrate. Most people are familiar with this substance in its powdered form, cream of tartar. This hypothesis arose just a couple years ago after a dog who ate homemade play dough made with cream of tartar suffered kidney failure. The discovery piqued the interest of Dr. Greg Landry, whose research interests focus on nephrology.

“This project was a lucky coincidence,” said Landry, PhD, an Associate Professor of Pharmacology and Toxicology. “I was approached by a colleague who knew about my expertise in kidney toxicity. When the ASPCA Poison Control Center connected the dots between the tartrate in the play dough and the high concentration of tartrate in grapes, it was the perfect fit.”

Pando started working with Dr. Landry on a different research project on how lead exposure can lead to the formation of kidney stones through the Summer Undergraduate Research Fellowship Program. When that project ended, he invited Pando to continue working on one of his other research projects. She chose to investigate tartrate toxicity in dogs.

Over the last year, she has made significant progress. She successfully earned funding through the Center for Research and Discovery Mini Grant program two years in a row, allowing her to purchase experiment kits that have been instrumental in guiding the direction of her work.

“I consider this the first project I started from scratch,” Pando said. “Working with Dr. Landry on projects like this has completely changed my career trajectory.”

Meant to Be in a Lab

Pando came to MCPHS for the Premedical Health Studies program with plans to attend medical school. A New York native, she wanted to be in a city, just not as big of a city.

“I went to a small high school, so I was gravitating toward a smaller institution in Boston,” she recalled. “A friend came to MCPHS for nursing, so I went on a tour and was sold.”

After her second year as an undergrad, Pando wanted to get involved with research to build her resume. She explored the online database created by the Center for Research and Discovery to connect students and faculty mentors, hoping to collaborate on a research project that aligned with her own interests. She found Dr. Landry by accident.

“I had never heard of him. He’s in the School of Pharmacy, so there was no crossover with our programs. I sent him an email asking about the projects he was working on, and after that first conversation, I knew I wanted to work with him.”

Halfway through their first project together, Pando’s vision for her future changed.

“Dr. Landry jokingly said one day that he didn’t think I was going to medical school,” Pando said. “At the end of that first summer, I told him he was right.” That fall, Pando changed her major to Medical and Molecular Biology. After graduation in the spring, she plans to attend graduate school and earn her Doctor of Philosophy in toxicology.

“I love being in the lab and I’m very hands-on with my work. I want to be the one running experiments. Dr. Landry’s research has sparked an interest in how specific compounds impact functions in the body and their relationship to human diseases, so that’s what I hope to pursue with my next degree.”

An Invaluable Experience

Pando treats her laboratory responsibilities as a part-time job. She’s in there most days of the week, balancing several experiments. She dedicates most of that time to the tartrate toxicity project, which she said has impacted her academic success.

“I’m taking Dr. Landry’s toxicology class now, and the amount of crossover between the course material and the research is insane. There’s no better word for it.”

Beyond science, Pando feels more prepared than ever to pursue an advanced degree in a field she only discovered through her research work. “Dr. Landry has challenged me and exposed me to multiple research methods, which has prepared me very well for graduate school,” she said.

“Penelope has been an irreplaceable partner in my research laboratory,” Dr. Landry added. “She functions at the level of a graduate student or postdoctoral fellow. I can completely depend on her.”

While Pando will do as much work on this project as possible before graduation, it will outlast her tenure at MCPHS. She said she hopes another student will take over the work and figure out why dogs shouldn’t eat grapes. She also encourages others to take the chance, like she did, to begin their own research journeys.

“If there’s a professor researching something you’re interested in, just send the email or go talk to them,” she said. “Take advantage of all the opportunities this school has to offer.”