Íslenskar landbúnaðarrannsóknir - 01.09.1974, Page 15

SHEEP PARASITES IN ICELAND 13
One can not preclude a seasonal variation
in number of larvae in faeces. Some of the
data suggest this but not unequivocally.
Moreover, no clear resistance to M. capillaris
can be seen.
A hypothesis concerning the changes in
number of M. capillaris in sheep faeces is
illustrated in Fig. 16.
Dictyocaulus filaria.
The larvae of D. filaria found, were so few
that it is difficult to interpret the results (Fig.
10 and 11). However, the following observa-
tions can be mentioned.
No larvae were found in lambs up to 1 Vz
months of age (Group X). From the age of
Lorvae pr. g Group IV foeces Lambs bom May 1972. J>Females J[ \ \
jíHf k
s 1 0 1872 N ' D
Lambs born May 1972. S>Femalej Tbiabendazole GroupV.

s 1 O 1872 N D
Fig. 10. Larvae of Dictyocaalus filaria in faeces
of lambs (age 4—7 months) (Group IV and V).
Thiabendazole 1 Group II. Adult sheep S)>adult ewes * odult ram —,
N 1 D 1 j ' F W A M J J A S 0 H 0
1971 ,372
Fig. 11. Larvae of Dictyocaulus filaria in faeces of lambs (age 6 months — l‘/2 year) and adult sheep
(older than 2 years) (Group I and II).