The ByHeart infant formula botulism litigation continues to expand as investigators trace the contamination back through the dairy supply chain.

Earlier this week, plaintiffs filed a Third Amended Complaint in Wescott et al. v. ByHeart, Inc., et al., pending in the U.S. District Court for the Western District of Washington. The amendment adds Organic West, Inc. and Dairy Farmers of America, Inc. as defendants. The join ByHeart, Inc. and Target Corporation, which were previously named in the lawsuit. 

According to the complaint, all defendants—new and existing—are strictly liable, negligent, and in breach of express and implied warranties for their respective roles in manufacturing, processing, distributing, and selling infant formula and its component ingredients that were contaminated with Clostridium botulinum. The contamination caused 51 cases of infant botulism across 19 states.

The Third Amended Wescott Complaint sets out the increasingly clear genetic link between the finished ByHeart product, the contaminated whole milk powder used as an ingredient, and the sickened infants. 

It states, in relevant part:  

  1. As of January 23, 2026, the FDA confirmed that two more samples collected during its investigation tested positive for Clostridium botulinum type A. One such sample was an unopened, finished product sample of ByHeart powdered infant formula. Whole genome sequencing (WGS) analysis demonstrated that the Clostridium botulinumdetected in the finished product sample was a genetic match to a clinical isolate obtained from an infant sickened in the outbreak. 
  2. The Clostridium botulinum detected in the finished ByHeart infant formula sample also genetically matched two isolates obtained from samples of whole milk powder—an ingredient used by ByHeart in the manufacture of its powdered infant formula—which were collected and tested by ByHeart as part of its internal investigation.
  3. A second whole milk powder sample was collected by the FDA from a supplier to ByHeart and analyzed by the New York Department of Health’s Wadsworth Laboratory. WGS analysis showed that the Clostridium botulinumfound in that sample of whole milk powder is a genetic match to the Clostridium botulinum detected in the finished product sample of ByHeart’s infant formula.
  4. The whole milk powder sample collected by the FDA that tested positive for Clostridium botulinum type A was made from whole milk supplied by Defendant Organic West.
  5. Organic West transported whole milk to Defendant Dairy Farmers of America for processing into whole milk powder at a facility owned and operated by Dairy Farmers of America in Fallon, Nevada.
  6. Following the processing of whole milk into whole milk powder, Dairy Farmers of America delivered, shipped, and/or sold the whole milk powder back to Organic West, which subsequently distributed and/or sold it to ByHeart for use as an ingredient in ByHeart’s powdered infant formula.
  7. Organic West has halted the sale of the whole milk powder used in any product intended for babies and children.

https://www.marlerblog.com/files/2026/02/29-1-Redlined-Third-Amended-Complaint.pdf