Massive goitre (struma parenchymatosa) in geese

Area of Science:

• Veterinary Pathology
• Endocrinology
• Avian Health

Background:

• A severe goitre outbreak occurred in a flock of 2300 six-month-old geese.
• This is the first reported case of naturally occurring goitre in geese unrelated to rapeseed meal feeding.
• Pathological findings included growth retardation, increased thyroid weight, and altered thyroid hormone levels (undetectable thyroxine (T4), low triiodothyronine (T3)).

Purpose of the Study:

• To investigate the cause and potential treatment of naturally occurring goitre in geese.
• To evaluate the efficacy of iodine supplementation in affected geese.
• To assess the impact of iodine on thyroid hormone levels and clinical signs.

Main Methods:

• Ten affected geese were divided into two groups: one received iodine supplementation, and the other served as a control.
• Clinical signs, pathological findings, serum thyroid hormone levels (T3, T4), and response to thyrotropin-releasing hormone (TRH) were monitored over 55 days.
• Histological examination of thyroid tissue was performed.

Main Results:

• Iodine supplementation significantly improved clinical signs and thyroid hormone levels in treated geese.
• Untreated geese showed no improvement or worsening of goitre signs.
• Both treated and untreated groups showed some improvement in thyroid hormone levels and TRH responsiveness, indicating complex etiology beyond simple iodine deficiency.
• Histology confirmed struma parenchymatosa.

Conclusions:

• Iodine deficiency is a significant factor in goose goitre, but not the sole cause.
• Iodine supplementation is an effective treatment for clinical signs and hormonal imbalances associated with goose goitre.
• Further research is needed to identify other potential goitrogenic substances involved in this disorder.