Streptococcus zooepidemicus ('Alpaca Fever') in Llamas: Respiratory Infection and Stress-Related Outbreaks

Streptococcus equi subsp. zooepidemicus is a bacterium that can cause respiratory disease and pneumonia in camelids. In South America, the condition commonly called alpaca fever has been associated with this organism. Merck Veterinary Manual notes that bacterial respiratory infections are relatively uncommon in North American camelids, but this syndrome is well recognized in South America, and stressful conditions often come before illness.

In llamas, the infection may start with upper airway signs and then move deeper into the lungs. Some animals show a gradual decline with fever, nasal discharge, and reduced appetite. Others can deteriorate much faster, especially if pneumonia becomes severe or the whole herd has been stressed at the same time.

This is not a condition to monitor casually at home. A llama that is breathing harder than normal, acting dull, or refusing feed needs veterinary attention because camelids can hide illness until they are quite sick.

The direct cause is infection with Streptococcus equi subsp. zooepidemicus, a streptococcal bacterium that can infect the respiratory tract. Merck Veterinary Manual specifically links this organism to the syndrome called alpaca fever in South American camelids.

Stress is a major trigger. Merck notes that stressful conditions often precede onset of this disease in camelids. In real-world herd settings, that can include transport, recent purchase or relocation, weaning, crowding, poor ventilation, abrupt weather changes, heavy parasite burden, nutritional strain, or mixing animals from different groups.

Stress does not create the bacteria, but it can weaken normal airway defenses and make spread within a group more likely. Shared airspace, close nose-to-nose contact, contaminated buckets or feeders, and delayed isolation of sick animals can all increase outbreak risk. Your vet may also look for other contributors, such as viral respiratory disease, aspiration, or another source of pneumonia that opened the door to secondary bacterial infection.

Diagnosis starts with a full exam, including temperature, breathing rate and effort, hydration, and careful listening to the lungs. Pneumonia in animals is typically diagnosed from the history, clinical signs, and thoracic imaging, with culture and sensitivity used to guide antibiotic choices. In a llama with suspected bacterial pneumonia, your vet may recommend bloodwork, chest radiographs or ultrasound, and sampling of nasal discharge or airway fluid for bacterial culture.

Culture matters because it helps confirm whether Streptococcus zooepidemicus is involved and which antibiotics are most likely to work. Merck notes that bacterial culture and sensitivity are important in pneumonia cases, especially when illness is severe or not responding as expected. In referral settings, airway sampling such as transtracheal wash or bronchoalveolar sampling may be discussed.

If several animals are sick, your vet may approach this as both an individual case and a herd-health event. That can mean checking exposed herd mates, reviewing recent stressors, and creating an isolation and monitoring plan while test results are pending.

Prevention centers on lowering stress and improving biosecurity. Because stressful conditions often precede alpaca fever in camelids, management changes matter. Reduce crowding, improve ventilation, provide shelter from weather extremes, avoid abrupt feed changes, and plan transport, weaning, and herd mixing as carefully as possible.

Separate any llama with fever, nasal discharge, or breathing changes right away and contact your vet. AVMA guidance on animal housing and welfare supports having areas for isolation of sick animals and quarantine of newly arriving animals, with housing designed to maximize biosecurity. For camelid herds, that means dedicated pens, separate water and feed equipment, and careful hand and boot hygiene between groups.

Quarantine new arrivals before mixing them with the herd, especially after transport or sale-barn exposure. Keep records of temperatures, appetite, and respiratory signs during the quarantine period. If your farm has repeated respiratory problems, your vet may recommend a herd-health review that looks at stocking density, airflow, parasite control, nutrition, and how animals are introduced or moved during stressful seasons.

There is no routine, widely used vaccine program specifically for this condition in llamas. That makes early recognition, stress reduction, and prompt veterinary care the most practical prevention tools for most pet parents and farms.