Bayer Animal Health filed the suit against Elanco, objecting to an April letter Elanco sent to veterinarians about the flea and tick marketplace. Bayer alleged that in the letter, Elanco released false advertising and created unfair competition that wrongfully misled veterinarians and distributors.

Bayer’s Animal Health Division manufactures and sells pet medicines such as Advantage II, K9 Advantix II and Advantage Multi products for flea, tick and heartworm prevention.

Elanco is a division of Eli Lilly and Company, a global pharmaceutical corporation.

Eli Lilly’s Elanco Companion Animal Health division produces pet medicines for flea and heartworm prevention such as Comfortis, Assurity and Trifexis.

In April 2011, Elanco mailed a "Dear Doctor" letter to veterinarians, veterinary clinics, distributors and distribution agents. In the letter, Elanco claimed that Bayer had shifted its support for veterinarians by working with large retailers and distributing product outside of the veterinary channel. Elanco stated that Bayer had begun selling Advantage and K9 Advantix products directly to pet retailers and websites, citing a direct correlation between the decline in veterinary-dispensed flea medication and the availability of flea and tick products online and through pet retailers.

In the letter, Elanco championed its technology called "Track and Trace" that is designed to identify all products and to help keep products within a strict veterinary/client/patient relationship. The technology allows Elanco to track its products and prohibit veterinarians who violate their corporate sales policies from purchasing Elanco products.

Since January 2010, Elanco said its Track and Trace program had revoked the ability of more than 230 veterinarians to purchase Elanco products because they failed to meet corporate sales policies, according to the letter mailed to veterinarians.

In early May, Elanco notified Bayer that it no longer distributed the letter, but would not agree to retract the letter. Bayer then filed a complaint challenging Elanco’s statements in the letter.

In a Nov. 18, 2011 settlement in a New York U.S. District Court, Elanco and Bayer agreed to a consent decree and a non-monetary resolution.

According to court documents, the decree prohibits Elanco from communicating without substantiation the following messages:

Elanco said it will continue to communicate and advertise the availability of flea and tick medicine such as Bayer’s Advantage II and Advantix II products through retail channels and over-the-counter merchants. It will also continue to promote its tracking system to ensure that its pet medicines are kept within the veterinarian/client relationship.

In a Nov. 21, 2011 news release, Bayer called the outcome "successful", saying the company was satisfied with the results of the suit. The company said it was pleased with the fact that Elanco can no longer disseminate false information about Bayer’s relationship with veterinarians.

In the release, Vice President and Head of Bayer Companion Animal Products Peter Ryan said Bayer will continue its support of veterinarians.

"Bayer has always been and remains steadfast in its support for veterinarians," Ryan said. "We are gratified to have obtained this relief in court and we look forward to continuing our longstanding relationship with and support of the veterinary community."

In a news release sent out the same day, Elanco maintained that Bayer’s lawsuit was unfounded.

"Elanco has always believed the lawsuit was without merit and continues to deny the allegations set forth in the complaint," said Eric Graves, senior director of Elanco Companion Animal Health.