RESUMEN
Eight of 600 Holstein heifers and cows died after ingestion of sweet clover silage (Melilotus sp) that contained excessive concentrations of dicumarol caused by mold infestation. The cattle developed subcutaneous hemorrhages and bled from the vagina, became weak, were unable to move, and died. To the best of our knowledge, this is the first report of sweet clover poisoning in cattle from California and is discussed in light of previous findings in the Midwest and Canada. Sweet clover poisoning is caused by dicumarol, a fungal metabolite produced from substrates in sweet clover, and is a common livestock problem in the Northern Plains and Canada. Sweet clover poisoning should be considered in livestock animals with clinical evidence of hemostatic dysfunction, prolonged coagulation times, subcutaneous hemorrhages, and hemorrhagic abortions. Definite diagnosis of moldy sweet clover poisoning can be accomplished by analysis of serum and feed samples for dicumarol concentrations.
Asunto(s)
Anticoagulantes/análisis , Enfermedades de los Bovinos/etiología , Dicumarol/análisis , Fabaceae/envenenamiento , Intoxicación por Plantas/veterinaria , Plantas Medicinales , Ensilaje/envenenamiento , Animales , Anticoagulantes/envenenamiento , California , Bovinos , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/mortalidad , Dicumarol/envenenamiento , Fabaceae/microbiología , Femenino , Hemorragia/etiología , Hemorragia/veterinaria , Intoxicación por Plantas/complicaciones , Intoxicación por Plantas/diagnóstico , Ensilaje/análisis , Ensilaje/microbiologíaRESUMEN
Sweet clover poisoning in cattle is caused by an anticoagulant (dicumarol) that is formed in moldy sweet clover hay. Previous experiments with vitamin K3 and vitamin K1 in therapy trials indicated that vitamin K1 was effective in reducing prothrombin times but vitamin K3 was not. As a possible alternative in the use of toxic sweet clover hays, vitamin K3 was evaluated to see if it would prevent hemorrhagic crises when fed to cattle consuming toxic sweet clover hay. Vitamin K3 levels of 0, 0.45, 4.5, 11, and 45 mg/kg body weight/day were fed to 173-235-kg steers consuming toxic (40-50 ppm dicumarol) sweet clover. The 45-mg K3/kg/day supplement was not palatable and had to be discontinued. The 0.45, 4.5, and 11-mg K3/kg/day supplements did not significantly reduce the prothrombin times as compared to the 0-mg K3/kg/day group.
Asunto(s)
Enfermedades de los Bovinos/prevención & control , Aditivos Alimentarios/uso terapéutico , Hemorragia/veterinaria , Intoxicación por Plantas/veterinaria , Vitamina K/uso terapéutico , Animales , Bovinos , Dicumarol/envenenamiento , Hematócrito/veterinaria , Hemorragia/prevención & control , Intoxicación por Plantas/prevención & control , Tiempo de Protrombina/veterinaria , Vitamina K/administración & dosificaciónRESUMEN
Some selected clinical and laboratory aspects of moldy sweetclover poisoning in cattle are reviewed. The prothrombin time is preferred when the disease is suspected. The bleeding time and whole blood clotting time test are also used. Dicoumarol is not always detectable in the suspected feed which may be due to sampling technique or inaccuracy in the laboratory assay. The most effective treatment is a whole blood transfusion. Vitamin K(1) (naturally occurring vitamin K) is an effective antidote but too expensive. Vitamin K(3) (synthetic vitamin K) in both the injectable and oral forms are not as effective as K(1) but are used extensively for treatment and prevention. Feeding the suspected feed for two weeks followed by a one week withdrawal successively or by dilution with other feeds will help to reduce the incidence of disease if other feeds are not available. Suspected feed should not be fed to cattle for at least three weeks before surgery or parturition.