naphthoquinones and Plant-Poisoning

Black walnut toxicosis was diagnosed in 10 horses at one stable. The time from exposure to shavings to development of clinical signs was 8 to 12 hours. Most common clinical signs were moderate to severe laminitis (Obel grade 2 or 3), pitting edema of the distal portion of the limbs, and rapid respiratory rate. Two horses had clinical signs of colic and 2 other horses had anorexia and lethargy. All 10 horses recovered without complications.

Topics: Animals; Anorexia; Colic; Edema; Horse Diseases; Horses; Lameness, Animal; Male; Naphthoquinones; Pigments, Biological; Plant Poisoning; Respiratory Insufficiency; Wood

Juglone, a toxic compound found in all parts of plants of the walnut tree family Jugans, was evaluated as the possible toxin involved in black walnut shaving-associated laminitis in the horse. Large amounts (up to 1 g) of this chemical administered per os inconsistently caused mild signs of laminitis in ponies. Topical application of juglone to the digits of horses caused local skin irritation but did not cause laminitis. Intravenous administration of juglone caused acute pulmonary edema in some individuals previously exposed to the compound per os or IV.

Topics: Animals; Foot Diseases; Hoof and Claw; Horse Diseases; Horses; Naphthoquinones; Plant Poisoning; Pulmonary Edema