Special Veterinary Pathology

Oestrogenic mycotoxicoses

OESTROGENIC MYCOTOXICOSIS

• Fungus Fusarium roseum and other species of Fusarium produce a mycotoxin, zearalenone, also known as F-2 toxin which as oestrogenic activity
• These fungi are contaminants of maize
• A disease of sow, vulvovaginits is known to result from ingestion of this toxin
• The toxicosis (condition resulting from poisoning) stimulates oestrus and results is enlarged vulvae, mammary glands and teats and sometimes prolapse of the vagina
• Sows are infertile and may show nymphomania, or pseudopregnancy
• Ovaries are atrophic, and uterus and cervix grossly enlarged
• Ingestion in early pregnancy leads to embryonic death
• In young male pigs, feminization occurs with testicular atrophy and gynecomastia (abnormally large mammary glands in the male, sometimes secreting milk)

Lesions

• Microscopic lesions include ovarian follicular atresia (degeneration of follicles), oedema and cellular proliferation of all layers of the uterus and ductular proliferation in the mammary glands
• Stillbirths, small litters and neonatal mortality may also occur
• In males, signs of feminization include testicular atrophy, swelling of the prepuce and enlargement of the mammary gland
• Zearalenone toxicity is suspected to be responsible for similar events and reduced fertility in cattle