Recurrent transient paresis in a turkey flock.

Area of Science:

• Veterinary Medicine
• Animal Pathology
• Poultry Science

Background:

• A turkey flock experienced recurrent episodes of extreme leg weakness and mortality between 8 and 15 weeks of age.
• Flock mortality reached approximately 12%, impacting 4800 out of 40,000 turkeys across four open-confinement units.

Purpose of the Study:

• To investigate the cause of unexplained posterior paresis and mortality in a commercial turkey flock.
• To identify potential etiological agents or toxicants contributing to the observed clinical signs.

Main Methods:

• Clinical and post-mortem examinations, including gross and histological assessments.
• Immunological and virological testing, serum chemistry analysis, and toxicological screening of feed, water, soil, and tissues.
• Therapeutic trials involving supportive care and administration of Type C botulism antitoxin, alongside mouse bioassays for botulism toxin detection.

Main Results:

• No significant gross or histological lesions were identified in affected turkeys.
• Immunology, virology, and serum chemistry provided uninformative results. Toxicological analyses did not reveal common toxicants.
• Supportive care frequently led to full recovery; however, botulism toxin detection attempts using mouse bioassays were unsuccessful despite antitoxin showing some benefit.

Conclusions:

• The cause of posterior paresis and mortality in the turkey flock remained undetermined, despite ruling out common infectious agents and toxicants.
• The partial response to Type C botulism antitoxin suggests a possible, yet unconfirmed, role for botulism or a related neurotoxin.
• Further investigation is warranted to elucidate the etiology of this condition in poultry.