Abstract
With the worm count at postmortem and egg count as criteria, Promintic, an injection formula of methyridine, was examined for anthelmintic effect upon Metastrongylus apri when administered to swine in a total dose containing 200 or 250 mg of active ingredient per kilogram of body weight. The dose was given at a time or divided into two equal aliquots to be given at 5 days' intervals by the subcutaneous route. The site of injection was an area posterior to each ear. The swine used were 2 litters of each 10 and 8 pigs. In each litter 2 pigs were left untreated.
The removal ratios, as compared with worm burdens in the untreated controls, at the dose of 200 mg (and 250 mg in parentheses) were 58.9 (55.2)% when administered on the 4th day, 91.6 (98.5)% on the 10th day, 87.7 (99.0)% on both the 10th and 15th days, 71.2 (86.0)% on the 20th day, 75.9 (87.4)% on both the 20th and 25th days, 63.1 (90.5)% on the 30th day, and 72.9 (74.4)% on both the 30th and 35th days of infection. In general, the 250 mg regimen was more effective than the 200 mg, and the two-dose regimen than the one-dose. It is suggested that the drug has a stronger action on male worms than on females.
On the 20th day of infection, no eggs were detected from the feces of the pigs treated earlier than this day. Eggs were found in the feces of many of the pigs treated on the 20th day or later and in those of the untreated controls.
No systemic reactions were noticed. It is concluded that an excellent effect will be achieved by this drug against immature lung worms with one dose of 250 mg/kg, as divided into two equal aliquots and injected subcutaneously at an area posterior to each ear.
