Monkeys Escape from Overturned Truck on Mississippi Highway

In a sudden accident on Tuesday, Oct. 28, 2025, a vehicle carrying a troop of lab‑raised rhesus monkeys veered over onto its side on Interstate 59 north of mile marker 117 near Heidelberg, Mississippi in Jasper County.

The Crash and Escape

The truck was traveling from a New Orleans, Louisiana facility related to Tulane National Biomedical Research Center to a test facility in Florida, according to law‑enforcement sources.

Containment, Kills, and the One on the Loose

The reaction was fast. With assistance from the Mississippi Department of Wildlife, Fisheries & Parks, teams were sent by the sheriff's office to trace, contain or put down escaped animals.

Disease Anxieties and Contradictory Claims

Perhaps the most frightening element of this incident is the public health aspect. The sheriff's department claimed that the monkeys had diseases such as herpes, hepatitis C and COVID-19, and were a risk to humans without PPE.

A Species Under Investigation: Rhesus Monkeys

Rhesus monkey (macaca mulatta) are one of the most common non‑human primates used for biomedical research due to their genetic relatedness to humans as well as their facility in being acclimatized to lab settings.

Key Issues Raised by the Accident

1. Transport Safety & Regulation

The fact that the crates were marked "Live Animals" but wound up scattered alongside a high-traffic interstate indicates failure somewhere along the transport chain: either in securing the load, truck maintenance, driver training, or regulatory enforcement. Safe animal transport is not only an issue of animal welfare—it also protects public safety. 

2. Animal Welfare Concerns

Although the initial concern was containment and public health, there is a sad cost in animal welfare: nearly all escapees were euthanized. One remains lost. The morality of euthanizing non‑domestic primates in these situations is complicated, but public safety usually wins out in crisis situations. It is a sobering reminder of how helpless research animals are when things go awry.

3. Public Health and Communication

Conflicting messages regarding the status of the animals as disease carriers erode trust and obfuscate response. Authorities threaten aggressive, disease-carrying monkeys on one side, yet the purported source institution insists they are not contagious. Consistent, accurate communication is key to controlling public fear and facilitating response.

4. Wildlife & Human Interface

A loose monkey in Mississippi—a place where rhesus macaques are not indigenous—highlights the challenge when research animals escape into public areas. There is danger to humans, danger to the animal, and danger of disruption of the ecosystem if non‑native animals come in contact with the environment. Tracking and containment is a matter of urgency.

5. Regulation of Research Animal Logistics

This event also brings to mind other questions: Who possessed the animals? Who was transporting them and for what purpose? Loan, transportation and utilization of non-human primates in research are complex processes with multiple stakeholders—and when things go awry the chain of custody and blame can be obscured. The public is entitled to clarity.

What Happens Next?

In the short term, the missing single primate continues to be the main concern—both in terms of potential public safety threat and concern for the animal itself. Local authorities continue searching and request the public: do not approach any monkeys you encounter, call 911 instead.

In the longer term, we can expect:

Investigation into what caused the overturn: driver fatigue, mechanical failure, road conditions?

Regulatory analysis of how live-animal transports are performed: licensing, vehicle check, crate design, emergency preparedness.

Public health surveillance, in the event that any exposures were made—even if the primates are certified as non-infectious.

Media and public scrutiny regarding openness: what organization owned the monkeys, where they were headed, under what conditions they were shipped?

Review of wildlife protocols: What might the ecological impacts have been, had the animal actually escaped into the wild? Thankfully it appears containment was mostly successful.

Reflection: A Moment of Caution and Change

While this is a very unusual occurrence—a truck of laboratory monkeys rolling over on a Mississippi road—it all nonetheless resonates with concerns that are more and more pertinent: human-animal borders, research procedures, shipping logistics, and how we cope with risk in an era in which non-native species and laboratory-bred creatures are on the move.

For the public, it's a reminder that—in the haze of "accidents are rare"—when accidents do happen the consequences can reverberate: from highway dangers to animal losses, to possible (though unlikely) public health risks. For regulators and institutions, it reminds them that safe transport of animals is not merely a matter of welfare in the abstract—it's a matter of human safety, environmental integrity, and trust in science.

For the single monkey yet to be found, this is perhaps a nightmarish experience: by himself, in strange country, fleeing. And for the people surrounding that section of I‑59, this event will stick with them as a moral: when technology and the highway collide, anything can occur.

Generally about 16 lb, although the older males are heavier, these animals are prone to bold and inquisitive behaviour—actions that can become very dangerous when housing fails.

But Tulane's press release rebutted: they claimed the primates in question were not theirs, and explained that the animals were not contagious.

This inconsistency brings up a concerning lack of communication and openness, leaving the residents and responders with misleading information.

As of the most recent information available, all but one of the monkeys have been killed. One was still unaccounted for as of reporting, and warnings to the public were issued not to approach any loose primates.

The vehicle overturned at mile marker 117 on I‑59, north of Heidelberg. There were "Live Animals" crates crumpled at the scene and, by way of video imagery, rhesus monkeys were seen crawling in tall grass alongside the interstate.

The monkeys, officials said, weighed around 40 lbs each (far heavier than the 16 lb average frequently cited) and were "aggressive to humans" that needed to be handled with personal protective equipment (PPE).

The sheriff's department cautioned that if the animals escaped the scene of the wreck, they would need to be shot.

What ensued was equal measures of drama and alarm: some of the primates opened their crates and dispersed along the roadside. All but one of those escapees have since been shot according to the Jasper County Sheriff's Department. The incident raises serious questions regarding transport safety, animal welfare, public health and emergency response.