Phomopsis leptostromiformis

Abstract

DISTRIBUTION: Lupins are cultivated chiefly in the southern and south-western areas of the Cape province as a fodder crop.

BOTANICAL DESCRIPTION: Lupinus spp.: General: Spreading, erect, annual herb about 60 cm high. Leaves: Digitally compound with 7 to 11 narrow leaflets Flowers: Golden yellow, blue, white or pink. Fragrant and borne at the ends of branches. Fruit: The flat pod is slightly hairy and contains 4-5 seeds. • Phomopsis leptostromiformis (Diaporthe toxica) is a phytopathogen of most Lupinus spp. • Also grows saprophytically on the dead host under favourable conditions.

TOXIC PRINCIPLE: Cyclic hexapeptides. Phomopsin A – the principle toxin. Relatively stable toxin.

SYNDROMES: Hepatogenous photosensitivity primarily due to liver parenchymal damage.

SYSTEMS AFFECTED: Liver.

CLINICAL SIGNS: Acute lupinosis: • Sheep become sick in 2-3 days after lethal dose and die in 4-8 days. • Anorexia • Ruminal stasis• Constipation• Weakness• Icterus - Photosensitivity rare, but occurs Chronic syndrome: • Same as above, plus weight loss.

NECROPSY: Macroscopical findings: 1. Hepatosis Acute: white (also orange-yellow) swollen, fatty liver Chronic: markedly atrophic (especially left side, so-called boxing glove liver) fibrotic, nodular regeneration 2. Icterus 3. GI stasis.

HISTOPATHOLOGY: • Fatty degeneration, cholestasis • Anisonucleosis, megalocytosis, multinucleation and nuclear vesiculation.

TREATMENT: Symptomatic and supportive.