Botulism in waterfowl: case report in Argentina

Area of Science:

• Veterinary Medicine
• Wildlife Toxicology
• Ecology

Background:

• Botulism, a neuroparalytic disease caused by Clostridium botulinum, significantly threatens wild birds, particularly waterfowl.
• Outbreaks are increasing, potentially linked to climate change and environmental factors.
• Wild bird botulism surveillance and regulation often lag behind human health standards.

Purpose of the Study:

• To document a natural outbreak of type C botulism in waterfowl.
• To investigate the environmental conditions contributing to the outbreak.
• To highlight the impact of delayed detection on wild bird populations.

Main Methods:

• An outbreak in Saavedra, Argentina, in January 2021 involving approximately 300 waterfowl was investigated.
• Clinical signs, necropsies, and laboratory analyses were conducted.
• Detection of botulinum neurotoxins (BoNTs) type C in biological samples and water confirmed the diagnosis.

Main Results:

• The outbreak was attributed to environmental conditions favoring Clostridium botulinum proliferation.
• Clinical signs included progressive weakness, paralysis, and difficulties with locomotion.
• Microscopic examination revealed mild congestion, hemorrhage, and pulmonary edema; no gross lesions were observed.
• Type C botulinum toxin was confirmed in feces, serum, and lagoon water.

Conclusions:

• This is the first report of waterfowl botulism in central Argentina.
• The outbreak emphasizes the severe impact of botulism on wild bird populations.
• Early detection and intervention are critical to mitigate losses and protect wild bird populations.