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Limberneck, Western Duck Sickness, Duck Disease, Alkali Poisoning

Botulism is a severe neuroparalytic disease caused by exposure to botulinum neurotoxins (BoNTs), which are produced by anerobic, spore-forming, ubiquitous microorganism called Clostridium botulinum. There are several different strains of C. botulinum, with each strain producing its own type of toxin---categorized as type A through E. Certain strains are more abundant in particular regions and cause infection to specific species. Waterfowl are most commonly affected by type C and C/D, although type A and E toxins have also been reported.

Waterfowl, both domestic and wild, are at an increased risk of botulism, due to their dabbling habits in water and mud. C. botulinum is widespread in soil however requires certain environmental conditions to be met in order for it to produce toxins; these conditions include:
  • Warm temperature (optimum growth temperature is between 25°C and 42°C)
  • An anaerobic environment (absence of oxygen)
  • A high protein source

Clinical Signs of Botulism in Ducks

Characteristic clinical signs of botulism in ducks is a progressive, symmetrical, flaccid paralysis with weakness, muscle tremors, stumbling, and recumbency. The bird's legs are usually affected first, progressing to the wings (presented as drooped wings), neck (presented as the inability to hold their head erect), and eyelids. Ducks may appear lame and often might stand up and walk a few steps before falling. Others may be found sitting and reluctant to move. The speed of progression varies, depending on the amount of the toxin ingested and the form of the disease. Usually botulism signs develop within 24 hours to 17 days after exposure to the toxin.
Clinical Signs of Botulism

How do Ducks Get Botulism?

Ducks can get botulism through eating or dabbling in contaminated soil, water, decaying matter, spoiled feed, or from eating maggots harboring C. botulinum toxins. Decaying animals or vegetation provide both a protein source as well as an anaerobic environment to C. botulinum. Botulism Type C spores exist along the bottoms of various water sources, which begin to thrive as oxygen levels drop and water temperatures rise.
Maggot Carcass Cycle


Limp neck (unable to hold head upright)
Using wings to move
Droopy eyelids
Muscle tremors


  • History
  • Clinical signs
  • Physical exam
  • Laboratory tests


MethodMethod Summary
Supportive careRelocate duck to a quiet, isolated area such as a dog kennel or cat carrier. Provide fresh water in a small container, however making sure it's not too large as birds can easily drown.
Call your veterinarianObtain and administer an antitoxin, toxoid vaccine for botulism
Activated charcoalAdministered orally at 1 g/kg of body weight, twice a day for the first 24 to 48 hours.
Tube feeding

Reported Cases

  • Case 1: Botulism in a Chickens Botulism was diagnosed in a flock of backyard chickens. 14 out of 16 backyard chickens were found dead or recumbent and barely able to move (“crawling” according to owner). No significant gross or microscopic lesions were seen in birds submitted for necropsy. Clostridium botulinum toxin type A was detected in the liver of one chicken, confirming a diagnosis of type A botulism. Ref

  • Case 2: Botulism in a Ducks Botulism was diagnosed in ducks from three different locations in southern California; at each location several birds were affected. In one outbreak, type C botulism was confirmed while the type of botulism could not be determined in the other two outbreaks. Ref


  • Inspect water sources for dying or dead animals (such as mice or rats), and promptly dispose of the carcass properly, dump out the water, disinfect the container, and refill with fresh, clean water.
  • Properly store animal feed
  • Remove any dead organisms from the premises immediately.
  • Don't allow birds access to long-standing stagnant pools of water or mud puddles, especially during hot weather conditions.


Risk Factors

  • Hot weather combined with strong rain showers
  • Exposure to decaying carcasses or vegetation
  • Feeding or dabbling in stagnant water puddles or slow moving water sources.
  • Letting ducks eat maggots, especially those that have just came from decaying vegetation or a decomposing body.