## Facts

- Boehringer sold a canine joint supplement, Seraquin; VetPlus sold a competing product, Synoquin, in a market described as intensely competitive.
- VetPlus commissioned laboratory testing of Seraquin, focusing on whether it contained the amounts of active ingredients (especially chondroitin sulphate) claimed by Boehringer.
- VetPlus planned a comparative advertising campaign publicizing its test results and contrasting Seraquin with Synoquin, implying Seraquin contained less chondroitin than claimed.
- Boehringer disputed the reliability and interpretation of VetPlus’s tests, emphasizing that chondroitin sulphate is chemically heterogeneous and different tests may detect different forms.
- Boehringer sued for trade mark infringement and related claims and sought an interim injunction to stop the advertising before trial.
- The trial court denied interim relief; Boehringer appealed seeking prior restraint of the proposed campaign pending trial.

## Issues

1. Whether Boehringer showed it was more likely than not to succeed at trial on trade mark infringement and related theories based on the proposed comparative advertising.
2. Whether, given the speech-restraining nature of the requested order, interim relief was appropriate despite disputed technical evidence about the accuracy of the testing.
3. How the balance of justice favored or disfavored restraining comparative advertising pending a full trial.

## Decision

- The Court of Appeal dismissed the appeal and affirmed the refusal of an interim injunction.
- The court held Boehringer did not demonstrate it was more likely than not to succeed at trial.
- Given contested expert evidence and uncertainty about whether the advertising would ultimately be unlawful, the court declined to impose prior restraint on the campaign.
- The court accepted that comparative advertising is lawful in principle and should not be restrained lightly at an interim stage.

## Legal Principles

- Where interim relief would restrain publication of comparative advertising, the applicant must show a strong likelihood of success at trial, not merely an arguable case.
- Courts are cautious about prior restraints in commercial speech disputes, particularly where comparative claims may be legitimate if not misleading and consistent with honest practice.
- Significant disputes turning on complex scientific or technical evidence are generally unsuitable for determination on an interim application and weigh against pre-trial restraint.
- In the balance of justice, courts consider the risk of chilling lawful comparative advertising and the public interest in receiving information about competing products.

## Conclusion

The Court of Appeal refused to restrain VetPlus’s proposed comparative advertising before trial because Boehringer did not show a sufficient probability of ultimate success and the merits depended on contested technical evidence better resolved at trial.


Boehringer Ingelheim Ltd. v. VetPlus Ltd., [2007] E.T.M.R. 67 (Eng. C.A. 2007)