Page 413 - The Veterinary Laboratory and Field Manual 3rd Edition

382 Susan C. Cork

Figure 8.14 There are often a lot of deaths at
lambing time but the presence of the occasional
deformed lamb may not necessarily indicate that
there is a disease present. Abnormalities like this
one-eyed lamb (‘cyclops’) occur during development,
abnormal embryos are usually reabsorbed or aborted
early in development. Occasionally some survive to
term but die shortly after birth. This lamb was one of
two, the other lamb was normal. Some mycotoxins,
plants or drugs may result in foetal abnormality (that
is, they are teratogenic). See also Plate 36.

Figure 8.15 This old ewe was found in a bog
shortly after lambing. The general appearance of
the animal indicates that she is seriously ill but it is
not possible to determine the cause of the problem
without taking a full clinical history and examining
the animal carefully. In many cases it will also be
necessary to take samples for laboratory diagno-
sis but if the animal is terminally ill the laboratory
results may be a bit misleading due to the develop-
ment of secondary metabolic changes which may
mask the primary cause of the problem. In this case
Figure 8.16 This old ewe has started to lose her the animal died and during the necropsy it became
wool after recovering from ketosis (twin lamb dis- clear that the ewe had a significant liver fluke bur-
ease). The ewe also had evidence of liver damage. den with liver damage which may have contributed
Although it would initially appear that the ewe had to the development of ketosis associated with the
a primary problem with her wool it was clear on fur- heavy demands of lactation and a period of unsea-
ther examination that she was slightly jaundiced and sonably cold weather.
was under weight. There was no evidence of mite
infection or any primary skin disease. The clinical
history and laboratory tests confirmed liver damage. can be found in the texts listed in the bibli-
Wool loss often follows a period of extreme physi- ography at the end of this chapter. Additional
ological stress. The animal made a partial recovery necropsy guidelines are available online and in
but was culled the following year. Appendix 2.

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