Reproductive losses due to Neospora caninum in a beef herd in Argentina.

Reproductive losses in a beef herd of 857 heifers with a pregnancy rate of 86.3% are described. After pregnancy testing, 69 abortions were seen during a 3 month period. Before calving season, three heifers had delivered pre-mature non-viable calves. Serum samples from 58 of 69 aborted heifers were available for serological tests. In order to compare the seroprevalence in non-aborted vs. aborted heifers, 214 pregnant animals were bleed during the abortion storm. In addition, blood samples were collected from two heifers with pre-mature calves and from 16 heifers with their calves prior to colostrum intake. All available serum samples were tested for Neospora caninum antibodies using an indirect fluorescence antibody test (IFAT). Fifty-nine of 290 (20.3%) evaluated heifers were seropositive. Heifers that aborted and heifers with pre-mature calves were more likely to be seropositive than pregnant heifers and heifers with normal calves [odds ratio (OR), 12.01; 95% CI, 6.18-23.30]. Vaginal mucus from four aborted heifers, and samples from two aborted foetuses and three pre-mature calves were available. Laboratory tests for Tritrichomonas foetus, bacterial and viral isolation, and histological examination were performed. Culture from vaginal mucus and foetal samples were negative. Histological lesions consistent with neosporosis and positive immunohistochemistry (IHC) to N. caninum were found in one aborted foetus and in one pre-mature calf. It is the first description of reproductive losses because of N. caninum in beef herds in Argentina.

Ergotism and photosensitization in swine produced by the combined ingestion of Claviceps purpurea sclerotia and Ammi majus seeds.

Poisoning of domestic animals happens frequently in the southeast of Buenos Aires Province (Argentina). Intoxications are produced mainly by the ingestion of plants and mycotoxins, but animals are rarely affected simultaneously by both types of agents. One herd of pigs suffered simultaneous intoxications by ergot alkaloids from Claviceps purpurea sclerotia and furocoumarins from Ammi majus seeds. Pigs were fed a diet composed of wheat (poor quality) or corn and protein and vitamin supplements. This diet was completed with forage sorghum. Nervous signs were first observed 5-7 days after the initiation of feeding the suspect ration. These signs were followed by cutaneous irritation. Snout ulcers, eyelid edema, and conjunctivitis were observed in several piglets. Ten days after the start of feeding the incriminated ration, 8 abortions were observed. Many of the sows that were nursing piglets developed udder edema and teat cracking. Dermal lesions were observed in most of the animals with unpigmented areas in the skin but not in a Duroc-Jersey boar. Removal of the incriminated diet and feeding of another diet prepared with good-quality wheat allowed all the animals to recover in 15 days. The herd experienced normal pregnancies and parturitions, litter sizes, and piglet weights when fed a cleaned portion of the poor-quality wheat. No photosensitization lesions were observed. Examination of impurities in the suspected wheat indicated the presence of 2.2% of A. majus seeds and 0.14% of C. purpurea sclerotia. The quantitative analysis indicated the presence of 3.2 g xanthotoxin and 0.65 g bergaptene/100 g A. majus seeds and 0.73 g ergot alkaloids (expressed as ergonovine) per 100 g of C. purpurea sclerotia. Qualitative analysis demonstrated the presence of ergotamine, ergocristine, and ergonovine. These results indicate that clinical signs and lesions were caused by the ingestion of large quantities of these biologically active compounds.

Fusarium crookwellense-produced zearalenone in maize stubble in the field.

Waste grain and vegetative material (stems and leaves) collected from a maize field several months after harvest was analysed by bi-dimensional thin layer chromatography for the presence of aflatoxins, deoxynivalenol, ochratoxin A, sterigmatocystin, T-2 toxin and zearalenone. Deoxinivalenol (0.7 mg/kg) and T-2 toxin (4.1 mg/kg) were found in the grain and zearalenone (3.0 mg/ kg) was found in the stem and leaf. No other toxins were detected. The stubble was examined for the presence of potentially toxigenic Fusarium species, and F. poae, F. moniliforme var. subglutinans and F. crookwellense were isolated and identified. When these isolates were cultured on cracked corn, only F. crookwellense was found to produce micotoxins and then only zearalenone was detected. As corn stubble is commonly grazed in Argentina and in other countries, these findings identify a further source of mycotoxins that may adversely affect animal health and productivity.

Experimental toxicity of verbesina encelioides in sheep and isolation of galegine.

Verbesina encelioides is a widely distributed weed in Argentina. Although it has been suspected as poisonous, there seem to be no previous reports of its toxicity in this country. Its biological activity was evaluated through an experiment in sheep. Four 5-y-old sheep, averaging 33 kg in body weight, were given a single dose of 1.0, 3.2, 5.0 or 6.3 g of dried plant material (17.9% dry matter)/kg body weight orally in a water suspension. Forty-eight hours later, the animals given 5.0 g or 6.3 g showed dullness and lack of appetite. The higher dosed sheep became recumbent a few hours later and died 60 h after dosing without showing further signs. The other animals showed no signs. Necropsy of the dead sheep showed severe lesions in different organs: liver, kidneys, lungs, lymph nodes and digestive tract. Hydrothorax was also observed. The animal receiving 5.0 g/kg was sacrificed after 72 h to determine the degree of recovery or lesions. Microscopically, severe glomerulonephrosis and congestion in the liver, with cellular degeneration and fatty changes were observed. Additionally, hemorrhagic lymph nodes, and hemorrhagic and edematous lungs were noted. No gross nor microscopic lesions were found in the sheep receiving 5.0 g/kg. Mice injected ip with the chromatographic extract died in less than 15 min. Galegine was identified in the plant material. The minimum toxic dose of 5-6 g/kg indicates a high toxicity when compared to other poisonous plants of the southeastern area of Buenos Aires province, Argentina.