Guelph, Ont.The guidelines exist because the cancer exists. Vaccine-Associated Sarcoma, VAS, is a documented, studied, and feared complication in veterinary medicine. It forms at injection sites. It is aggressive. The industry response to the evidence, accumulated over decades, has been clear: avoid the interscapular site, the scruff of the neck, the place between the shoulder blades. Inject elsewhere. The guidelines say elsewhere. The risk is known. The precaution is established. The guidelines are not obscure.

On April 1, 2026, a veterinary clinic in Guelph administered vaccines to a dog at the interscapular site.

The dog's owner was not told. There was no discussion of the VAS risk, no disclosure that the injection site was the one the industry guidelines flag, no consent obtained for a decision that carries a documented cancer risk. The vaccines were administered. The dog went home.

Within days, a mass appeared at the injection site.

The fluid

Over three separate procedures at the same clinic, 2.17 litres of hemorrhagic fluid were drained from the mass. Hemorrhagic fluid is bloody fluid. 2.17 litres is not a minor accumulation. It is a substantial, recurring, treatment-requiring response at the precise location where the vaccine was injected. At the third procedure, a second veterinarian who examined the dog described the mass as highly suspicious for a vaccine reaction.

The clinic filed an adverse reaction report with the vaccine manufacturer. The report is internal documentation. It is also, by nature, an acknowledgement: this clinic, on this date, administered this product to this animal, and this is what happened afterward. The adverse reaction report exists. The case number is on file. The manufacturer received it. The owner obtained a copy.

2.17 litres of hemorrhagic fluid. Three procedures. An adverse reaction report filed with the manufacturer. The clinic filed the report. The clinic's own filing is the causation evidence.

The refund that was conditional on silence

The dog's owner asked for a refund and a referral to the Ontario Veterinary College, the province's specialist centre, for an independent evaluation. On May 11, 2026, the clinic's practice manager confirmed in writing that a refund of $990.84 would be provided. The next day, May 12, the clinic reversed the cancer risk assessment it had given, one day after the formal notice of a legal claim. The refund was not released. The OVC referral was held. Both the refund and the referral were withheld as leverage until the owner escalated the matter. On May 13, the OVC referral was finally provided. The refund was not.

On May 14, without the owner's knowledge or consent, the clinic made contact with a second veterinary clinic, requesting the dog's records. The owner had not authorized this contact. The owner learned about it afterward.

The verdict

A clinic administered vaccines at a site veterinary medicine has specifically identified as a sarcoma risk. The owner was not told. A mass formed at that site. 2.17 litres of fluid were drained. The clinic reported the adverse reaction to the manufacturer. The practice manager confirmed a refund in writing and then withheld it as a condition of silence. The OVC referral came only after escalation. The unauthorized records request happened after the claim was filed.

The claim is fifty thousand dollars. The issued court document is in the registry of the Ontario Small Claims Court in Guelph. The defendant has twenty days to file a Defence. The adverse reaction report with the manufacturer's case number is exhibit one. The practice manager's written refund confirmation is exhibit two. The clinic wrote both of them.