Immunoglobulin E is produced in response to parasitic nematodes that undergo blood and tissue migrations. Results of our previous studies indicated that IgE and IgG respond to Dirofilaria immitis in experimentally infected dogs. To determine the association between treatment with the larvicide, diethylcarbamazine (DEC), and antibody responses and to examine the potential influence of infection with a nonfilarid intestinal nematode on isotype-specific immune responses, we monitored, by use of isotype-specific ELISA, separate IgE and IgG responses against D immitis in 4 groups (A-D) of 8 dogs experimentally coinfected with D immitis and Ancylostoma caninum. All dogs were monitored from 2 weeks before inoculation with D immitis, through postinoculation (PI) week 20. Group-B dogs received a daily regimen of 6.6 mg of DEC/kg of body weight. Group-C dogs received 4.95 mg of oxibendazole/kg daily. Group-D dogs received DEC and oxibendazole, equivalent to the daily doses given to dogs of groups B and C. All dogs given oxibendazole had no A caninum at necropsy. Of the groups receiving DEC, 3 group-B dogs each had 1 to 2 D immitis at necropsy. When results of chronologic IgE determination for all groups were statistically compared, only groups B and C had significant (P = 0.0148 and P << 0.00005, respectively) increases in IgE values. Group-C dogs had the highest IgE values from PI week 10 until the end of the study, whereas IgG values were statistically identical to those of group-A dogs. Group-B dogs given only DEC and having the least number of D immitis of all groups, had IgE values that peaked at PI week 6; values were significantly (P = 0.0002) higher than those for all other groups. In Group-B dogs, IgG values increased significantly (P << 0.00005) only at PI week 20 and were significantly (P << 0.00005) decreased after PI week 6, compared with values for all other groups. Group D containing 6 dogs infected with 1 to 18 D immitis found at necropsy had IgE values betwee.

Studies were undertaken to determine the efficacy of milbemycin oxime against the enteric adult stages of Trichinella spiralis and of albendazole against the muscle stage larvae in experimentally infected dogs and cats. Specific-pathogen-free Beagle pups (n = 6) and domestic shorthair kittens (n = 6) were inoculated with 7,500 first-stage larvae of Trichinella spiralis. Physical examination (including collection of blood and fecal samples) was performed weekly. During the first week after inoculation, all animals had mild gastrointestinal tract disturbances, but stages of T. spiralis were not observed in the feces. Beginning on postinoculation day (PID) 10, 3 pups and 3 kittens were treated with milbemycin oxime (1.25 mg/kg of body weight, PO, q 12 h) for 10 days. Muscle biopsy specimens were taken from dogs and cats on PID 26 and 29, respectively. Mean numbers of larvae per gram of muscle were 30.3 in the control and 37.7 in the treated dogs. Mean numbers of larvae per gram of muscle in the control and treated cats were 318.7 and 89.3, respectively. Two dogs and 2 cats were removed from the study at that time. The remaining animals, 2 each of the control and milbemycin oxime-treated animals, were given albendazole (50 mg/kg, PO, q 12 h) for 7 days starting at PID 31 and 34 in dogs and cats, respectively. Muscle biopsy specimens were again taken at PID 46 and 49, for dogs and cats, respectively; mean numbers of larvae recovered from muscle were 0.6 for dogs and 13.5 for cats.

Four groups of 18 beef calves each were used to evaluate effects of different treatments on parasite control and weight gains. The investigation extended from November 1986 (weaning) to October 1987. Group-1 calves were treated with ivermectin (200 micrograms/kg of body weight, SC) at approximately 6-week intervals for a total of 8 treatments; group-2 calves were given the same dosage of ivermectin by the same route of administration as group-1 calves in November, March, and July; group-3 calves were given fenbendazole paste (5 mg/kg, PO) at the same times as group-2 calves; and group-4 calves served as untreated controls with provision for ivermectin salvage treatment. All groups grazed on individual pairs of larval-contaminated, 1.6-ha pastures. Highest (P < 0.05) initial worm counts in fall tracer calves were found in group 3 (Ostertagia ostertagi and Trichostrongylus axei adults) and group 4 (O ostertagi and Haemonchus adults). Fecal egg counts of group-1 calves were low throughout the experiment and pasture larval counts remained negligible after July. Egg counts and larval counts of other groups remained higher into summer. Worm counts, including O ostertagi inhibited early fourth-stage larvae (EL4), were highest (P < 0.05) in groups-3 and -4 spring tracer calves; numbers of O ostertagi EL4 were similarly high in groups 2, 3, and 4; and T axei counts were highest (P < 0.05) in groups-3 and -4 yearlings slaughtered in spring. Liveweights of group-1 calves were greater (P < 0.05) than in other groups from March 2 to October, and by July 2, group-2 calves had a liveweight advantage over group-4 calves. Group-3 calves had the lowest rate of gain from March to July and mean liveweight of the group was less (P < 0.05) than in all other groups from April to October. Only minimal worm numbers were recovered from groups-1 or -2 calves in October. Large numbers of O ostertagi and T axei were recovered from group-4 calves and O ostertagi from group-3 calves. A few calves in groups 3 and 4, but 365 kg in group 1, 328 kg in group 2, 316 kg in group 4, and 281 kg in group 3.

Anthelmintic resistance against commonly used anthelmintics (ivermectin, levamisole, morantel and fenbendazole) was studied in naturally occurring gastrointestinal (GI) nematodes in adult sheep of unorganized sheep farms of district Ludhiana (Punjab). After qualitative and quantitative screening of faeces of 100 sheep, fifty sheep having eggs per gram of faeces (EPG) 500 were randomly selected and divided into five equal groups. Ivermectin @ 200 ìg/kg body weight and levamisole @ 7.5 mg/kg body weight, injected subcutaneously, in two different groups, were 99.08 and 98.17 per cent effective,respectively. Whereas, fenbendazole @ 7.5 mg/kg body weight and morantel citrate @ 6.0 mg/kg body weight, orally was 66.28 and 95.41 per cent effective and the fifth group was kept as untreated control with natural exposure to gastrointestinal nematodes. Hence, it was concluded that the naturally occurring GI nematodes of sheep were susceptible for ivermectin and levamisole, suspected for resistance against morantel citrate and were resistant to fenbendazole.

Results on determination of residual quantities of fenbendazole and its metabolites in cattle meat, organs and tissues after administration of preparation Febolvet in dose of one bolus per one animal realized in the conditions of the Republic of Belarus were presented. Animals were killed in 35 and 80 days after administration of preparation. There were no strangulates in animals organs. Pieces of nephros, liver, cordis, fat and muscle tissue were chosen for residual quantity of fenbendazole and its metabolites evaluation. The level of carcasses bleeding was good at application of boluses of infested activity with fenbendazole. In 24-48 hours of keeping in refrigerator the drying crust was well-defined, muscle tissue in cut had firm texture and from light red to red color, cut areas were wet. Tendon was form and elastic. Soup was clear, flavored and without extraneous odors. Study of physical-chemical indexes estimated peroxidase activity, pH, presence of products of primary breaking of protein in 24 and 72 hours after killing. Biological value decreased slightly (on 1,04%). Veterinary-sanitary evaluation of cattle meat was conducted in the investigation. Research results showed no residual quantities of fenbendazole in the analyzed samples after application of long lasting boluses. Application of the analyzed boluses in case of cattle strongylatosis did not lower the veterinary and sanitary indexes of meat and did not render substantial effect on its quality