Shigellosis in Lemurs: Severe Bacterial Enteritis in Primates

Shigellosis is a bacterial infection of the intestinal tract caused by Shigella species. In nonhuman primates, including lemurs, it can cause severe enteritis or dysentery, with inflammation of the colon, diarrhea, blood or mucus in the stool, dehydration, and sometimes systemic illness. In some animals, infection may be mild or even unapparent, while others become very sick very quickly.

This condition matters for two reasons. First, lemurs can deteriorate fast because ongoing diarrhea leads to fluid and electrolyte losses. Second, Shigella is zoonotic, meaning it can spread between primates and people through fecal-oral contamination. That makes prompt veterinary care, careful hygiene, and isolation especially important in homes, sanctuaries, and zoological settings.

In primate facilities, shigellosis has long been recognized as an important infectious disease, often associated with stress, crowding, sanitation breakdowns, or exposure to infected human handlers or other primates. Because signs overlap with other causes of diarrhea, your vet will need testing to confirm the cause and guide treatment.

Shigellosis is caused by infection with Shigella bacteria, most often after fecal-oral exposure. In practical terms, that means a lemur becomes infected by ingesting bacteria from contaminated hands, food, water, dishes, enclosure surfaces, bedding, or feces. In nonhuman primates, humans and other primates are important sources of infection, and outbreaks are more likely when sanitation slips or animals are housed under stressful conditions.

Stress does not create the bacteria, but it can make disease more likely or more severe. Transport, social disruption, crowding, concurrent illness, poor enclosure hygiene, and sudden husbandry changes may all increase risk. In group settings, one infected animal can expose others quickly.

Lemurs with diarrhea do not always have shigellosis. Other bacterial infections, parasites, dietary problems, toxins, inflammatory bowel disease, and viral disease can look similar. That is why your vet will usually recommend testing rather than assuming the cause from symptoms alone.

Your vet will start with a history and physical exam, paying close attention to hydration, body temperature, stool character, appetite, and how quickly signs developed. Because diarrhea in primates can become dangerous fast, the first priority is often assessing stability and deciding whether immediate fluid support or hospitalization is needed.

Testing commonly includes fecal diagnostics and bloodwork. Fecal testing may involve direct examination to look for parasites and a fecal culture or PCR to identify bacterial pathogens such as Shigella. Blood tests like a CBC and chemistry panel help your vet evaluate dehydration, inflammation, electrolyte changes, and organ involvement. In more severe cases, your vet may also recommend imaging, repeated bloodwork, or additional infectious disease testing to rule out other causes of enteritis.

Because Shigella can be zoonotic and antimicrobial resistance is a growing concern, confirming the organism and, when possible, checking antibiotic susceptibility can be especially helpful. That helps your vet choose a treatment plan that fits both the lemur's condition and the public health risk.

Prevention centers on hygiene, biosecurity, and reducing fecal-oral spread. Wash hands before and after handling the lemur, food dishes, bedding, or feces. Clean and disinfect enclosure surfaces regularly, remove stool promptly, and keep food and water sources protected from contamination. If multiple primates are present, avoid sharing bowls, enrichment items, or cleaning tools between enclosures unless they have been disinfected.

Human health matters too. Because people can carry and spread Shigella, anyone with diarrhea or recent gastrointestinal illness should avoid contact with lemurs, their food, and their enclosure. Gloves, dedicated clothing, and careful waste handling are especially important in sanctuaries, rescue settings, and breeding groups.

Quarantine new arrivals, monitor stool quality closely during stressful transitions, and contact your vet early if any diarrhea develops. Fast action can protect the sick lemur and reduce the chance of an outbreak affecting other primates or human caregivers.