Charles River Laboratories

Charles River Laboratories traces its origins to 1947, when veterinarian Henry Foster began breeding and supplying laboratory animals from a small loft overlooking the Charles River in Boston. What started as a modest animal-supply operation grew through decades of aggressive acquisitions into the world’s largest nonclinical contract research organization, serving pharmaceutical, biotech, agrochemical, and government clients globally.

A defining milestone was the 2004 merger with Inveresk Research Group, which transformed Charles River from primarily an animal supplier into a full-service nonclinical CRO. The 2018 acquisition of MPI Research brought the large Mattawan, Michigan facility—and its extensive dog and primate testing operations—into the Charles River portfolio.

In FY2025 (fiscal year ended December 27, 2025), the company reported total revenue of $4.015 billion across three segments: Discovery and Safety Assessment (DSA) at $2.402B (59.8%), Research Models and Services (RMS) at $846.1M (21.1%), and Manufacturing Solutions at $767.0M (19.1%). The company does not disclose “animal studies revenue” as a standalone line item, but the lower bound is at least 21.1% (RMS, centered on research models), with a mechanical upper bound of ~80.9% if one includes all DSA revenue—though DSA also includes non-animal work such as in vitro assays and bioanalytical services.

A January 2026 SEC filing disclosed a major leadership transition: James C. Foster stepping down as CEO and Chair, with COO Birgit Girshick appointed CEO effective May 5, 2026. The same filing revealed that Elliott Investment Management L.P. (an activist hedge fund) provided consent under a May 2025 cooperation agreement for board expansion—a signal of activist-investor influence on governance. In February 2026, the company stated it was progressing on a plan to divest businesses totaling approximately 7% of 2025 annual revenue, expecting completion by mid-2026.

Charles River is one of the largest users of dogs in laboratory research worldwide. A publicly available USDA annual report (APHIS Form 7023) for FY2022 under Registration Number 14-R-0144 reports 9,099 dogs used or held: 55 held but not yet used, 7,403 in studies involving no pain or distress, and 1,696 in studies involving pain or distress managed with drugs.

Facilities conducting dog studies

The company does not publish a public facility-species map linking specific sites to the species they house. However, the Mattawan, Michigan nonclinical facility is the best-documented site for dog testing. Its public facility page describes general toxicology and specialized study types including DART (developmental and reproductive toxicology), ototoxicity, ocular toxicology, and abuse liability studies as part of complete IND programs. It lists regulatory accreditations including AAALAC, FDA, EPA, USDA, and NRC.

Types of studies conducted on dogs

The company’s safety assessment services include general toxicology, safety pharmacology, DART studies, ototoxicity testing, ocular toxicology, and abuse liability evaluations. These are conducted to support IND (Investigational New Drug) applications submitted to the FDA. In the HSUS investigation, beagles were documented in a pesticide inhalation/ingestion study conducted for an agrochemical client (Corteva Agriscience), demonstrating that dog studies extend beyond pharmaceutical work into agricultural chemical testing.

Beagle sourcing

In stark contrast to its detailed disclosures about non-human primate sourcing (where the company has moved toward vertical integration via acquisitions of K.F. Cambodia Ltd. and Noveprim Ltd.), Charles River provides no comparable disclosure for dog/beagle suppliers. HSUS reporting from the Mattawan investigation stated the dogs came from “commercial breeders” but did not name the supplier. No company-confirmed beagle sourcing contract or purchase agreement with Marshall BioResources or any other named breeder appears in reviewed SEC filings, 10-K disclosures, or guidance materials.

Between April and August 2018, the Humane Society of the United States (HSUS) placed an undercover investigator inside Charles River’s Mattawan, Michigan nonclinical facility. The investigator worked as a laboratory technician, gaining access to animal housing areas and study operations. In March 2019, HSUS publicly released undercover video footage that generated widespread media coverage and public outrage.

What the investigation documented

• 36 beagles in a pesticide study: The investigation highlighted a cohort of 36 beagles being used in a pesticide toxicology study linked to Corteva Agriscience (formerly Dow DuPont agricultural division) and a compound associated with Adavelt. Dogs were subjected to forced oral dosing via gavage tubes.
• Force-feeding via gavage: Video showed beagles being restrained and force-fed test substances through tubes inserted into their stomachs, a standard but distressing method in toxicology studies.
• Dogs sourced from commercial breeders: HSUS reporting stated the beagles came from “commercial breeders” but the specific supplier was not publicly identified.
• Facility scale: The Mattawan site is one of the largest nonclinical testing facilities in North America, conducting studies on multiple species including dogs, non-human primates, rabbits, and rodents.

Aftermath and corporate response

Following public release of the footage, the pesticide study was terminated and the 36 beagles were released for rehoming. However, the corporate response focused primarily on the breach of confidentiality rather than the animal welfare findings. STAT News reported that a biotech client filed suit alleging trade-secrets violations after the undercover operative filmed experiments, framing the litigation around confidentiality and reputational harm. The company did not publicly acknowledge systemic welfare concerns or announce operational reforms specific to dog testing.

Charles River operates under overlapping regulatory frameworks: USDA Animal Welfare Act oversight, FDA GLP compliance for nonclinical studies, AAALAC voluntary accreditation, and DEA controlled substances licensing. Its enforcement record spans multiple agencies and issue areas.

Animal welfare protocols (company claims)

The company publicly describes its animal welfare framework through its “Animals in Research” messaging and its CHARTER program, which is aligned to the 3Rs (Replacement, Reduction, Refinement) and includes “education and training” related to humane animal care. However, breed-specific (beagle-specific) enrichment protocols, endpoints, and housing standards at the facility level are not publicly available in a way that allows independent verification or comparison across sites.

Charles River files federal LD-2 lobbying disclosures and is embedded in the biomedical research advocacy ecosystem. It is listed as a sponsor/partner of Americans for Medical Progress through the Biomedical Research Awareness Day (BRAD) program, which promotes public acceptance of animal research.

The company claims to have invested $500 million in alternative methods and 3Rs-aligned technologies, including an “Alternative Methods Advancement Project,” the Retrogenix platform for cell-based assays, development of virtual control groups using machine learning, and the planned acquisition of PathoQuest for pathogen detection.