The anthelmintic efficacy of ivermectin (IVM) delivered from a sustained-release (SR) bolus was evaluated against natural infections with gastrointestinal tract nematodes in 12 crossbred beef heifers in spring. The 12 calves were randomly allotted to 2 groups of 6 calves each. Group-1 calves were treated with an SR bolus designed to deliver 8 mg of ivermectin/d. Group-2 calves were nontreated controls. Cattle groups were kept in separate concrete-floored pens (grass hay nutrition) and slaughter was performed at 35 days after treatment. Fecal egg counts for group-1 calves remained zero after treatment, except for detection of < 1 egg/g of feces in 1 calf at the time of slaughter; counts in nontreated calves increased. Mean and range of Ostertagia ostertagi inhibited larvae in nontreated calves were 27,093 and 10,622 to 56,368, respectively. Efficacy of the IVM SR bolus was 100% against O ostertagi developing fourth-stage larvae (L4) and inhibited early L4, Haemonchus placei adults, Cooperia punctata and C spatulata adult males, Cooperia spp adult females, Cooperia spp L4, Trichostrongylus colubriformis adults, Bunostomum phlebotomum adults, and Oesophagostomum radiatum adults. Efficacy for O ostertagi and T axei adults was 99.9%. Numbers of nontreated calves infected with C pectinata adult males and Oes radiatum L4 were too low to evaluate efficacy. Calves treated with the IVM bolus gained 10.2 kg, whereas nontreated calves lost 1.8 kg. Abomasal lesions were dearly greater in nontreated calves on the basis of index comparisons of abomasal weight and total live weight and gross pathologic features.

Anesthesia was induced in 8 healthy llamas by administration of guaifenesin and ketamine, and was maintained with halothane in oxygen. On 2 separate experimental days, atracurium was given to induce 95 to 99% reduction of evoked hind limb digital extensor tension (twitch). For the first part of the study, atracurium was given iv as repeat boluses, with muscle twitch strength being allowed to return without intervention to 75% of baseline after each bolus before the subsequent bolus was given. A total of 5 bolus doses of atracurium was given. For the first bolus, 0.15 mg/kg of body weight iv, and for subsequent boluses, 0.08 mg/kg, induced desired relaxation. Onset of relaxation was slightly more rapid for repeat, compared with initial, bolus. Duration of relaxation and recovery time were similar to initial and repeat doses. Maximal twitch reduction was observed in 4 +/- 0.2 minutes (mean +/- SEM). Duration from maximal twitch reduction to 10% recovery was 6.3 +/- 0.4 minutes. Twitch recovery from 10 to 50% of baseline took 11.6 +/- 0.6 minutes. Twitch recovery from 10 to 75% recovery took 19.5 +/- 1.1 minutes. Recovery from 10% twitch to 50% fade took 12.8 +/- 0.5 minutes. Fade at 50% recovery of twitch was 39 +/- 0.02%. Significant (P < 0.05) animal-to-animal variation was observed in twitch recovery times. For the second part of the study, atracurium was initially given IV as a 0.15-mg/kg bolus, followed by infusion for 1 to 2 hours. Infusion rate required some early adjustment to maintain desired relaxation, but the rate that prevailed was 1.07 +/- 0.07 ml/kg/h (0.4 mg of atracurium/ml of saline solution). Recovery of muscle twitch was similar to that previously mentioned for repeat bolus administration, At the end of the study, edrophonium (0.5 mg/kg) with atropine (0.01 mg/kg, IV) was effective in antagonizing residual neuromuscular blockade by atracurium. All llamas recovered without injury from anesthesia, although 1 llama had a rough recovery. It was concluded that atracurium can provide neuromuscular blockade by either repeat bolus administration or continuous infusion in llamas.

This study was carried out to evaluate the efficacy of water soluble formulation of diclazuril (1%) in the prevention and control of mixed Eimeria infection in two experimental (semifield) trials and testing efficacy of this medicament in controlling of natural field case of mixed Eimeria infection. The experimental (semifield) trials carried out each on 150-day-old broiler chicks, as they were divided into 3 equal separate subgroups. Infected groups were orally received 1ml of an inoculum containing 50.000 sporulated oocysts of Eimeria tenella, E. acervulina and E. necatrix/ chick at 14 days of age. Diclazuril (1%) liquid at dose of 1 ml / 4 liter of drinking water for 2 successive days just after appearance of bloody dropping (at the 5th day post infection). Birds were given prophylactic diclazuril dose (1 ml / 8 liter) at the 7th day before the experimental inoculation. In both trials were oocyst count (shedding) in the dropping, dropping score, lesion score, body weight gain % and mortality rate were evaluated. Groups treated with diclazuril either in the prophylactic and curative studies gave significant and satisfactory improvement in the assessment criteria when compared with infected non medicated groups. A field trial was conducted 2 commercial broiler chicken farm consisted of 2 flocks aged 33 days; 6000 birds each. Flock (1) was kept as control positive infected non medicated group, whereas flock (2) was medicated with diclazuril (1%) at dose of 1 ml / 4 liter of the drinking water for 2 successive days. The results revealed more reduction in total oocyst count, lesion score and the mortality rate in the medicated than the infected non-treated group. The results proved that diclazuril (1%) liquid is effective in prevention and control of both experimental and field infection field circulating Eimeria species still sensitive to the drug.

Polyvalent clostridial vaccine has been prepared according to L+ dose of C. perfringens type B and D, C. septicum, C. oedematiens, the optical density of C. chauvoei, and flocculation test of C. tetani. The vaccine has been evaluated in guinea pigs, rabbits and sheep. It gave high protective immunity in guinea pigs in challenge test (100% protection), the sera of vaccinated rabbits gave high titers more than the permissible limit. Sera of vaccinated sheep showed high antibody titer and good immune response which revealed that the vaccine able to protect sheep against clostridial diseases. The recent formulation of polyvalent clostridial vaccine is very useful tool for production of highly antigenic multicomponent clostridial vaccine used for control of different clostridial diseases.