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This article was published in 1974
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Comparative Efficiency and Safety Indexes of Anthelmintics Against Fascioia hepatica in Sheep and Cattle.
Noel J. Campbell, Veterinary Research Officer, Veterinary Research Station, Glenfield.
These tables have been compiled from published and unpublished information. The safety index is a measure of the efficiency and toxicity of a compound. It is defined as the ratio of the maximum tolerated dose and the minimum dose producing 90% reduction in fluke burdens. Drugs with low safety indexes (less than 2) are likely to experience toxicity problems and the higher the safety index the less problems may be expected.
The therapeutic dose rates of drugs for use in cattle approximate the 90% efficient dose rate for adult fluke and the safety indexes have been calculated as defined above. Some drugs for use in sheep are marketed at greater than 90% efficient dose rates for adult fluke to achieve high activity against both immature and adult fluke at a single dose rate. The safety index for sheep have therefore been calculated using the recommended dose rate instead of the 90% efficient dose rate.
| DRUG | MAXIMUM TOLERATED DOSE * (mg/kg) | MATURE FLUKE (12 weeks old) | MARKET RECOMMENDATIONS (mg/kg) | COMMENTS. | |
|---|---|---|---|---|---|
| 90% Efficient Safety Dose (mg/kg) | Safety Index + | ||||
| Carbon Tetrachloride | Unknown | 0.1 ml/kg | 0.1 ml/kg pure CCL4 | Intramuscular injection, 11ml/100kg. Not more than 10ml. per injection site. Max. dose 30 ml for animals 270kg and above. ** | |
| Hexachloroethane | 1,200 | 300 | 4 | 300 | Efficient ** against paramphistone |
| Hexachlorophene | 30 | 15 | 2 | 16 | Efficient ** against paramphistone |
| Oxycloxanide | 50 | 10-15 | 4 | 13 | 22ml/100kg. Maximum dose 60 ml for animals 270kg and above. |
| Bromsalans | 150 | 30 | 5 | 30 mg/kg | ** |
| Rafoxanide | 90 | 7.5 | 12 | 7.5-10 mg/kg | |
| Nitroxynil | 40 | 8 | 5 | 10 mg/kg | Subcutaneous injection. |
* That dose producing no serious clinical symptoms in adult cattle - may be less in stressed cattle.
** May be associated with increased susceptibility in some animals and/or temporary depression of milk production.
+ Safety Index = maximum tolerated dose/minimum 90% efficient dose.
MARKET RECOMMENDATIONS - ADULT SHEEP.
| DRUG | Maximum Tolerated Dose * (mg/kg) | DOSE (mg/kg) | SAFETY INDEX + | EFFECTIVE AGAINST HAEMONCHUS | COMMENTS | |
|---|---|---|---|---|---|---|
| Immature Fluke (6 weeks old) | Mature Fluke (12 weeks old) | |||||
| Carbon tetrachloride | 0.5 ml/kg | 1-4ml pure CCL4 | ** | 10 | + | |
| Hexachloroethane | 1,200 | 300 | 4 | + | Effective against Paramphistomes. | |
| Hexachlorophene | 30 | 15 | 2 | Effective against Paramphistones. | ||
| Clioxanide | 100 | Adult Fluke 20 Immature Fluke 40 |
2.5 | + | Low efficiency against immature fluke when swallowed into the abomasum. | |
| Oxycloxanide | 60 | 15 | 4 | |||
| Rafoxanide | 45 | 7.5 | 4.5 | 4.5 | + | 7.5 ml/kg 50% effective against 4 week old fluke. |
| Bromsalans | 55 | 20 | 3 | 3 | 90% effective against 8 week old fluke & 70% effective against Haemonchus | |
| Brotianide | 27 | Adult 5 Immature 7.5 |
3.6 | 5.4 | ||
| Nitroxynil | 40 | 10 | 4 | 4 | + | |
| Diamphenethide | 400 | Adult 120 Immature 80 |
5 | 3.3 | Highly effective against fluke aged 1-8 weeks at 80 mg/kg. | |
* That dose producing no serious clinical symptoms in adult sheep, 8 weeks after infection with 1,000 viable metacercariae.
** No entry - not effective or not recommended.
+ Safety Index = Maximum tolerated dose/Market dose rate.