Íslenskar landbúnaðarrannsóknir - 01.09.1974, Page 16

14 ÍSLENSKAR LANDBÚNABARRANNSÓKNIR
Fig. 12. Effect of thiabendazole on the number of eggs of „other strongyles" in faeces of sheep
(Group II and III).
fi/2—4 months the lambs were not studied,
but larvae were found in 4 month old lambs.
Apparently 4 month — IV2 year old sheep
harbour more larvae than adult sheep, which
indicates that some resistance is developed
against D. filaria.
In approximately Va of the sheep no larvae
were ever found.
A hypothesis concerning the changes in
number of D. filaria larvae in sheep faeces
is illustrated in Fig. 16.
CONTROL OF NEMATODES
WITH ANTHELMINTICA
The most commonly used anthelmintica for
sheep in Iceland are thiabendazole (Thiben-
zol sales were about 60% of the market in
1973) and tetramizole (Ripercol and Tetra-
mizol sales were about 25% and 15% of
the market). In 1973 the equivalent of
750.000 usual doses of sheep anthelmintics
were used in Iceland. The number of adult
sheep in Iceland in 1972 was about 830.000.
A very small number of farmers give their