Zoetis Vetscan Imagyst Allegedly Misclassified Dog's Cancerous Tumor, Leading to Second Surgery and Death

In October 2025, Columbia Veterinary Hospital in The Dalles, Oregon reportedly used Zoetis's Vetscan Imagyst AI to analyze a rapidly growing neck mass in an 11-year-old Belgian Tervuren. The system allegedly classified the mass as inflammatory, while a later biopsy found aggressive cancer. The hospital alleges the first surgery failed to remove all cancer, requiring a second operation; the dog died from complications. Zoetis allegedly later apologized and said similar incidents had occurred.

Risk classification

• Primary risk domain: 7 AI system safety, failures, & limitations
• Primary risk subdomain: 7.3 Lack of capability or robustness

The AI system failed to perform reliably by misidentifying an aggressive cancerous tumor as an inflammatory lesion, demonstrating a lack of diagnostic capability.

Additional risk subdomains

• 5.1 Overreliance and unsafe use: The veterinarians relied on the AI's diagnostic output to perform surgery without waiting for a confirmatory laboratory biopsy.

Causal factors

• Entity: AI
• Intent: Unintentional
• Timing: Post-deployment

The incident was caused by the Vetscan Imagyst AI system misdiagnosing a tumor after being deployed in a veterinary hospital.

EU AI Act risk tier

• Risk tier: 2 High Risk

High Risk: The AI system is used as a diagnostic tool in healthcare (specifically veterinary medicine), which has significant implications for safety and animal welfare.

AI system and alleged parties

• AI system: Vetscan Imagyst (Zoetis)
• AI purpose: Medical Diagnosis Support; Image Classification
• Behaviour type: Assistant
• Alleged developer: Zoetis, AI diagnostic system developers
• Alleged deployer: Veterinarians, Columbia Veterinary Hospital (The Dalles, Oregon), AI diagnostic system deployers
• Alleged harmed parties: Unnamed 11-year-old Belgian Tervuren, Pets, Pet owners, Epistemic integrity, Dogs, Animal life

Harm severity

Highest direct severity in any category: Minor. Severity is scored from Negligible to Catastrophic in each harm category, for harm the reports describe as caused directly or indirectly by the AI system.

• Physical: direct Negligible, indirect Negligible
• Infrastructure: direct Negligible, indirect Negligible
• Property: direct Negligible, indirect Negligible
• Financial: direct Minor, indirect Negligible
• Environmental: direct Negligible, indirect Negligible
• Malicious content: direct Negligible, indirect Negligible
• Differential treatment: direct Negligible, indirect Negligible
• Civil rights: direct Negligible, indirect Negligible
• Democracy: direct Negligible, indirect Negligible
• Privacy: direct Negligible, indirect Negligible
• Psychological: direct Negligible, indirect Negligible
• Epistemic: direct Negligible, indirect Negligible
• Child sexual exploitation and abuse: direct Negligible, indirect Negligible

Financial

Reported: Yes, the veterinary hospital is seeking at least $50,000 in damages.

Directly caused: The hospital purchased the AI system and incurred legal and operational costs, seeking at least $50,000 in damages.

Indirectly caused: N/A

Inferred additional harm: Other veterinary clinics that experienced similar misdiagnoses likely suffered unquantified financial losses from surgeries, refunds, or legal disputes.

People affected

• Occurrences reported: 1
• People reportedly exposed: 1

Potential causes

Management

• Misleading Marketing Practices: Zoetis marketed the tool as expert-level without disclosing its limitations.
• Failure to Address Known Issues: Management knew of similar incidents with other users but did not resolve them.

Technology

• AI Software Misclassification: AI system misidentified a cancerous tumor as an inflammatory lesion.
• Post-Incident Report Alteration: The company altered the original AI report after the misdiagnosis was reported.

Data Inputs

• Tissue Sample Interpretation Failure: System failed to correctly analyze features in the provided tissue sample.

Human Factors

• Overreliance on AI Output: Vets relied solely on the AI diagnosis to perform the initial surgery.

Process and Methods

• Lack of Pre-Surgical Biopsy: Vets did not wait for a confirmatory biopsy before performing the surgery.
• Inadequate Limitation Disclosure: Zoetis failed to provide clear warnings about the AI system's limitations.

Information quality

• Classification confidence: High
• Reason for confidence: The report is a detailed news article describing a specific lawsuit with concrete facts, dates, and parties involved. The role of the AI system is explicitly stated.

A domestic civil lawsuit in Oregon involving an AI veterinary tool that misdiagnosed a dog's tumor. The incident is a commercial product failure with negligible implications for national security, critical infrastructure, or sovereign interests.

• Overall national security impact: Negligible
• Response level: Minor
• Scope: Single nation
• Primary target: United States
• Alleged perpetrator: Unknown

Threat characteristics

• Imminence: Long-term. The incident is a completed domestic product liability issue and does not represent an active national security threat or crisis.
• Autonomy: Human-supervised. The AI tool provided diagnostic recommendations, but human veterinarians retained ultimate oversight and decided on the surgical course of action.
• Novelty: Established threat. AI classification errors and false positives/negatives in medical imaging are well-documented and established technical limitations.

Impact by dimension

• Physical security: Negligible. The incident involves a veterinary diagnostic tool for animals and poses no threat to human physical safety or critical national infrastructure.
• Information security: Negligible. No intelligence compromise, espionage, or information warfare operations are associated with this commercial veterinary product failure.
• Sovereignty: Negligible. This is a private civil lawsuit and commercial product dispute, with no impact on state authority, governance, or constitutional processes.
• Economic security: Negligible. The financial impact is limited to a domestic civil lawsuit seeking 50,000 dollars, presenting no systemic risk to national economic or technological security.
• Societal stability: Negligible. The incident is a localized veterinary medical error that does not impact human rights, civil liberties, or broader societal stability.