304 Chronic Fluorine Intoxication in Domestic Animals.
of affected animals have been observed (7, 18, 101). Similar symptoms were
induced by administering fluorine compounds to goats and cows (7, 19) or
by feeding lambs on hay grown in the vicinity of an aluminium factory uti-
lising cryolite as a flus (107). A condition of the bones resembling osteoma-
lacia has been reported in these last animals (73) . Giving fluorine compounds
or hay from affected regions to guineapigs has been reported to result in the
development of most of the symptoms of the disease (20, 21, 22, 23, 24).
Apart from the reduction in breaking strength of the bones (17, 104) the
characteristic skeletal changes were not apparent. Histological examination
of the bones from animals grazing in the vicinity of a Swiss aluminium factory
has revealed a condition which has been described to be typical of osteomalacia
(6). Affected animals are reported to recover when confined in byres and
fed on hay produced elsewhere (64) or when the water supply contaminated
with an effluent containing fluorine was replaced by one from an adjacent
source (8).
While most observers seem agreed that fluorine plays the major role either
directly or indirectly in the etiology of these maladies, it has been suggested
(65) that the effect of these effluents is due to the acid they contain causing
the mobilisation of calcium for its neutralisation. This contention, however,
leaves unexplained the well-defined specific effects which are usually apparent,
and the belief (104) that the symptoms are due to a general acid intoxication
is not supported by a number of investigators (35, 61, 110). The effects
which result from giving excess of minerals acids to herbivora differ from the
symptoms described which resemble very closely those of experimentally
induced chronic fluorosis. It is not improbable, however, that the simul-
taneous ingestion of excess of uncompensated acid may accentuate the changes
brought about by the ingestion of fluorine, and this more particularly in her-
bivora. Some attempts to produce characteristic bone lesions by feeding
cattle with sodium fluoride (10) sodium bifluoride and sodium fluorsilicate
(62) or by flue dust from a superphosphate factory (74, 112) have not been
successful, but it would seem that these failures may be ascribed to the brief
duration of the experiments, none of which was continued for longer than
three months.
A malady which appears to be the result of fluorine ingestion occurs
among cattle fed with lees from distilleries which use hydrofluoric acid or
alkaline fluorides to limit the growth of extraneous organisms during fermen-
tation. There seems to be no general agreement however as to the harmful
effects. Some authors (52, 75) consider that the lees exert no toxic effects
while others (71) claim that continual ingestion is followed by thickening of
the joints and other skeletal changes in cattle. The use of alkaline fluorides
to control fermentation is discouraged in Germany mainly because farmers
refuse to use the lees, believing them to be injurious (114). Such materials
contain about 0.06 g. sodium fluoride per litre which would imply that a
500 kg. cow consuming 70 litres a day would ingest 4 mg. of fluorine per kg.
body-weight, an amount which has been demonstrated experimentally to
exert harmful effects in cattle when mixed in the food (92, 101). Further-
more, as the toxicity of fluorine compounds appears to be increased when in-
gested in solution (41, 115) the possibility of chronic fluorosis arising in cattle
fed on lees containing fluorine is apparent.