Every Claim You Make, Every Step You Take…CVM Will Be Watching You

Promotional claims do not receive the most attention with respect to FDA enforcement these days, and veterinary promotion is no exception.  Indeed, most Center for Veterinary Medicine (CVM) Warning Letters arise because products advertised are actually new animal drugs.  But this year, CVM has issued two notable warning letters and one Untitled Letter concerning the promotion of animal drugs that caught our attention because of the level of detail and specificity included.  The detail with which CVM reviewed these promotions is reminiscent of OPDP/DDMAC letters of yore.

Let’s take a look at these letters:

Back in January 2025, CVM issued a Warning Letter to animal drug sponsor Elanco Animal Health.  Elanco is the manufacturer of recently approved Zenrelia (ilunocitinib tablets) (September 2024), which is indicated for “control of pruritus associated with allergic dermatitis and control of atopic dermatitis in dogs at least 12 months of age.”  Zenrelia comes with serious warnings, including a boxed warning against the use of Zenrelia during vaccination.  However, several of Zenrelia’s promotional materials—specifically, FDA looked at a consumer-directed website, a product brochure and risk tracker, and a slide deck—omitted the specific phrase “from modified live virus vaccines” from the boxed warning found in the Important Safety Information.   The omission of the one short phrase, the Warning Letter says, is “misleading” because fatalities in the vaccine safety study used to support the New Animal Drug Application “occurred after administration of a MLV DHPP vaccination, a core vaccination for all dogs.”  The omitted phrase therefore provided “material facts that may be relevant to prescribing veterinarians and dog owners.”   CVM also objected to the truncation of other information about the timing of vaccines in these promotional materials.

Zenrelia promotional materials also included claims about clinical data that the Agency found actionable.  The Warning Letter alleged that the veterinarian product website made claims about a Vaccine Safety Study relied upon for approval that directly conflict with the PI.  Further, information presented on the adverse reaction data was inconsistent with the PI.  And, going into detail about the primary effectiveness endpoint, FDA raised concerns about claims allegedly exaggerating the speed of action for Zenrelia (i.e. that it is effective on “Day 1”) and insinuating  misleading comparative claims.

Not long after, in February 2025, FDA raised similar objections to promotional materials for Aurora Pharmaceutical’s three products, Altren (altrenogest) for suppression of estrus in mares, SwineMate (altrenogest) for synchronization of estrus in pigs, and Barrier (imidacloprid and moxidectin) for the prevention of heartworm in dogs, the first two which have “serious user safety warnings” and the third a boxed warning regarding exposure.  Reviewing the company website, CVM determined that it included “false or misleading claims and representations about the safety and effectiveness of these products,” thereby misbranding the product.  With respect to Altren, the webpage fails to contain any risk information, and a Product Sheet presents benefits and effectiveness information in a large, bulleted format while the risk information is in a smaller font on the second page.  It also omits risk information about the handling of the product.  For SwineMate, CVM objected to omission of information related to risks to humans, as well as important animal safety warning language, creating “a misleading impression about the consequences associated with using the drug.” The website also fails to include adequate directions for use.  And its Product Sheet suffers from the same infirmities as the Altren Product Sheet.  Finally, the website for Barrier for Dogs fails to contain any risk information, including the boxed warning from the PI.  And the Barrier Product Sheet included seven pages of benefit information, but risk information is presented only on a single page, in a smaller font, at the end of the brochure.

Finally, CVM issued an Untitled Letter in February 2025 to Zoetis due to promotional claims found on its Petcare YouTube Channel about the Company’s Librela (bedinvetmab injection), Solensia (frunevetmab injection), and Revolution Plus (selamectin and sarolaner topical solution).  FDA here cited false and misleading claims and representations about the risks associated with these products.  Specifically, the Librela ads show before and after treatment with no risk information, thereby making efficacy claims without fair balance, particularly because the Important Safety Information is not visible unless the viewer clicks on the “more” button to expand the text box.  Additionally, a video for Librela and two videos for Solensia contain voice-overs that discuss risk information related solely to the potential for self-injection by veterinary professionals who administer the drug without identification of the risks to the animal.  CVM stated that the “videos are misleading because they are aimed at the pet owner, yet they omit important safety and risk information for the animal species the drug is approved to treat. While there is some animal-related risk information included in superimposed text at the bottom of the video screen for a portion of the video….”  The safety text that is included is also small and difficult to read compared to the effectiveness claims.  Finally, a video for Revolution Plus titled “How to Apply REVOLUTION PLUS to Your Cat” is misleading because pictures of a child hugging a cat to whom Revolution has been applied implies that there are no safety concerns regarding humans interacting with any part of the cat after application of Revolution Plus, which is in direct conflict with the information in the Human Warnings section.

Zoetis and Elanco have previously been the target of CVM complaints about their promotion: Of 10 ULs issued by CVM re advertising since 2014, Zoetis received 4 – one in 2025, 2023, 2018 and 2016 and Elanco received 2 ULs – 1 in 2018 and another in 2015.

The allegations in the Warning Letters are serious, but that’s not why they’re so interesting.  They are that interesting because it’s not every day that we see Warning Letters and Untitled Letters with this level of promotional scrutiny coming out of CVM.  FDA really delved into the claims and the support for the claims on a level typically reserved for human drugs.   FDA’s review here of the claims for these animal products is reflective of the high standards to which FDA holds all promotion—human or otherwise.   We note that CVM has issued even more enforcement actions in 2025 than on the human side: OPDP has issued 2 Untitled Letters so far in 2025 compared with CVM’s 3 enforcement actions.  While OPDP has been scaling back its enforcement, CVM might be stepping it up.

Let this serve as reminder to veterinary companies: FDA is watching.