Lead Toxicity in Mute Swans

I
the blood constituents, reflecting an overall deterioration in
condition.
Typically, the birds were suffering from hypochromic
anaemia, with haemoglobin values below the reference range and MCHC
values below or equal to lower reference limit. While haematocrit
values did not always drop in tandem with the haemoglobin
concentration, the low mean cell haemoglobin values reflected
abnormalities in haemoglobin synthesis.
It is clear from the reference
values (Tables 1-2) that the values of haemoglobin (9g/100mls) reported
by Simpson et al., (1979) were indicative of anaemia.
Similarily, the
values of haematocrit (25%) reported by Bates~ al., (1968), for lead
poisoned Mallard Anas platyrhynchos (L) are similiar to the values
reported here for lead poisoned swans.
However, as mentioned earlier,
because of the large reference range for haematocrit these values
should be looked at critically before interpretation.
But mean cell
haemoglobin will detect this difference as it expressed in haemoglobin
concentration per the number of red cells. The rate and degree of
a-b
decrease of haemoglobin can be seen in specimens 978 (Table 7).
This demonstrates the toxicity of lead to the haemopoietic system.
In lead poisoned birds, the minimal (and apparently critical) total
protein level was 3lg/L (Table 7).
Janssen et al., (1986) noted a drop
in total protein in lead poisoned Condors to a level similiar to that
reported here.
The increase of some plasma enzymes, lactate
dehydrogenase (LDH) and aspartate aminotransferase (AST), are typical
of animals with large tissue destruction and muscle damage.
This
increase is due to muscle atrophy and damage resulting from acute lead
poisoning.
A rise in aspartate aminotransferase has also been reported
in lead pqisoned ducks (Eastin et al., 1983).
The raised cholesterol
levels are probably due to mobilisation of lipids due to physiological
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