. Scientific Frontline: Early study connects dogs’ cancer survival with which microorganisms live in their gut

Tuesday, February 17, 2026

Early study connects dogs’ cancer survival with which microorganisms live in their gut

There are more than 87 million domesticated dogs in the U.S. alone, and approximately one in four will develop cancer
Image Credit: Scientific Frontline

Scientific Frontline: "At a Glance" Summary

  • Main Discovery: Analysis of 51 dogs undergoing cancer immunotherapy reveals a significant correlation between gut microbiome composition and survival duration, identifying 11 specific bacterial types as predictive indicators of longevity.
  • Methodology: Researchers administered a novel cancer vaccine to dogs with various malignancies and utilized pre-treatment rectal swab samples to map the specific microbial presence against post-treatment survival rates.
  • Key Data: The study isolated 11 distinct bacterial species linked to survival outcomes from a core microbiome where 240 species account for over 80% of the total microbial community.
  • Significance: This research establishes the gut microbiome as a potential non-invasive biomarker for prognosis and a modifiable target to enhance the efficacy of cancer immunotherapy in veterinary medicine.
  • Future Application: Clinical practice may eventually utilize microbiome analysis to predict patient response to treatment and employ specific interventions to optimize gut flora for improved vaccine performance.
  • Branch of Science: Veterinary Oncology and Microbiology
  • Additional Detail: The experimental vaccine functioned by stimulating the canine immune system to block two specific proteins known to signal cancer cell growth and division.

Canine cancer patients receiving a new form of immunotherapy lived longer or shorter depending on the composition of their microbiome, the community of organisms living in their gut.

Results of the clinical trial led by Oregon State University scientists were published in Veterinary Oncology Link is external.

The findings signal new hope for the nearly half of U.S. households with at least one dog Link is external, suggesting that personalized medicine and better outcomes may one day be realities for the roughly 6 million dogs diagnosed with cancer each year, OSU’s Natalia Shulzhenko Link is external said.

There are more than 87 million domesticated dogs in the U.S. alone, and approximately one in four will develop cancer at some point in its life. More than 4 million dogs die of cancer annually; about half of all dogs that reach age 10 will succumb to cancer, the leading cause of canine death.

“Our study is a first step toward using the gut microbiome as a tool to develop prognoses and to manipulate cancer, not just in dogs, but potentially as a model for human treatments as well,” said Shulzhenko, who studies host-microbiota interactions at OSU’s Carlson College of Veterinary Medicine.

Co-led by Andrey Morgun of the OSU College of Pharmacy, the research involved 51 dogs of various ages and breeds that had been diagnosed with a range of malignancies, including cancer of the bones and blood vessels. Each dog was treated with a new type of cancer vaccine designed to trigger its immune system to block two cancer cell proteins that tell the cells to grow and divide.

Prior to treatment, the scientists collected rectal swab samples from the dogs for microbiome analysis. Trillions of organisms make up the canine microbiome, with 240 species accounting for more than 80% of the microbial community Link is external.

Amid all of those organisms, some connections were clear, Shulzhenko said. Scientists found 11 specific types of bacteria that were linked to how long the dogs lived – some were positive indicators, associated with longer survival, while others were associated with shorter survival.

“In the future, an analysis of a microbiome swab could help predict how well a dog might respond to a cancer treatment,” she said. “This allows pet owners and vets to make more informed decisions about care. And now that we know certain bacteria are linked to survival, we can explore ways to ‘fix’ a dog's gut microbiome to help the vaccine work better and help the dog live longer.”

Additional information: The collaboration included scientists from the National Cancer Institute, Yale University and the Bridge Animal Referral Center, as well as OSU’s Vini Karumuru, Stephanie Nuss, Marina Elliott, Isaiah Shriver, Chih-Min Chao and Ryan Berriatua.

Funding: The National Cancer Institute of the National Institutes of Health provided funding for the study, as did the Canine Cancer Alliance and the Biomedical Sciences Department of the Carlson College of Veterinary Medicine.

Published in journal: Veterinary Oncology

TitleGut microbiota of dogs with cancer receiving anti-EGFR/HER2 immunization reveals potential biomarkers of patient survival

Authors: Richard R. Rodrigues, Vini Karumuru, Stephanie Nuss, Marina Elliott, Isaiah Shriver, Chih-Min Chao, Ryan C. Berriatua, Hester A. Doyle, Chelsea Tripp, Mark J. Mamula, Amiran Dzutsev, Andrey Morgun, and Natalia Shulzhenko

Source/CreditOregon State University | Steve Lundeberg

Reference Number: vet021726_01

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