Page 81 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

48 SECTION | I General

VetBooks.ir (e.g., urea poisoning, grain overload). Other common tox- caused chronic toxicity in veal calves in two different
farms (Vandenbroucke et al., 2010).
icoses involving cattle and pigs result from plants and
metals in ruminants and mycotoxins (Guitart et al.,
2010a; Garcı ´a-Arroyo et al., 2015). In Greece, chronic Cu Lead (Pb)
poisoning appears to be a rather common problem mainly
in sheep husbandry (Roubies et al., 2008). In a Spanish farmland property located only several
For wildlife, pesticides (mainly anticholinesterase and meters from a battery-recycling site that had been in oper-
anticoagulant agents) and metals (particularly Pb from spent ation for 20 years, the death of seven horses and one don-
ammunition) are common causes of poisoning (Samouris key was documented due to Pb poisoning. Unusual
et al., 2007; Mateo, 2009; Modra and Svobodova, 2009; findings have been reported involving horses: a 13-year-
Guitart et al., 2010b; Guitart, 2012; Berny et al., 2015; old 700 kg Irish Draught cross gelding presenting abnor-
Ruiz-Sua ´rez et al., 2015). Cyanobacteria toxicoses and bot- mal respiratory noise during exercise caused by bilateral
ulism involving waterfowl have also been reported (Modra recurrent laryngeal nerve dysfunction, was diagnosed in
and Svobodova, 2009; Guitart et al., 2010b). the United Kingdom subsequent to Pb toxicosis (Allen,
2010).
NONMETALS AND METALLOIDS Pb poisoning is very common for large animals, espe-
cially for cattle and sheep. In the United Kingdom, more
Fluorosis in the European Union has been observed fol- than 450 Pb incidents were investigated by the VLA
lowing the intake of borehole water with high levels of between 1998 and 2008, mostly related to discarded bat-
fluorosis in region-specific deep-lying clay layers, as teries, old paint, and geochemical sources (Payne and
reported, e.g., in the case of turkeys (Berny et al., 2010a). Livesey, 2010). In Austria, Belgium, Spain, and France,
A particular incident was reported in Belgium involving lethal cases involving cattle have also been reported due
cattle, following the use of calcium sulfate (CaSO 4 )asa to the ingestion of fragments of discarded batteries or the
binder agent in beet pulp resulting in a higher than normal contamination of pastures with ash residue from illegal
level of fluorosis (Vandenbroucke et al., 2010). Poisoning bonfires (Krametter-Froetscher et al., 2007; Guitart et al.,
with arsenic predominantly involved cattle, but rarely 2010a).
sheep (Sharpe and Livesey, 2005; Vandenbroucke et al., In the case of birds, there is extensive literature in
2010). Se toxicoses are also rare but two cases have been Europe documenting poisoning episodes due to the acci-
reported involving sheep in the United Kingdom (Sharpe dental ingestion of small Pb objects, namely spent ammu-
and Livesey, 2005) and pigs in Spain (Casteignau et al., nition and lost fishing weights. This kind of poisoning has
2006). long been recognized as a major cause of death in several
species (Mateo, 2009; Pain et al., 2009; Delahay and
METALS Spray, 2015; Berny et al., 2015). In Spain, waterfowl
mortality rates were conservatively estimated to be
Telephone calls to European poison centers, however, do 50,000 a year at the end of the last century, just before
not give us the full picture of animal poisoning. Probably the implementation of a ban on the use of Pb shot in the
more than any other single toxic agent, certain metals, wetlands of this country. Up to now, only about half of
especially Pb in the case of wild birds, still continue to the European countries had taken some type of restrictive
cause numerous suspected and confirmed animal poison- action against the introduction of Pb, mostly regulating
ing cases in Europe. the hunting of waterfowl over wetlands, and only four
countries (Belgium, Denmark, The Netherlands and
Sweden) totally or partially extended this measure to
Copper (Cu)
other zones (Mateo, 2009; Thomas and Guitart, 2010). It
Chronic Cu poisoning is a fairly common clinical prob- is worth mentioning that substantial amounts of metallic
lem in the Greek sheep industry (Roubies et al., 2008; Pb continue to remain in wetlands, riverine, and terrestrial
Guitart et al., 2010a). Field investigation of one case in ecosystems for decades or centuries and this represents a
Greece revealed the source of Cu to be a heap of litter source of continued risk of bird poisoning.
from a broiler farm to which the sheep had accidental The number of hunters and shooters in the entire
access. In the United Kingdom, three outbreaks of Cu European Union has been estimated to be about 9,000,000
poisoning, which killed at least 55 ewes, were detected and the Pb ammunition fired yearly about 40,000 t
in 2005 and 2006, associated with organic farming and (Thomas and Guitart, 2010). Very high concentrations of
2
the consumption of red clover (Trifolium pratense)and Pb shot (.150 per m in the first 10 20 cm of depth)
white clover (Trifolium repens). In Belgium, excessive have been reported in some EU wetlands. Consequently a
amounts of Cu in commercially prepared milk replacers high prevalence of Pb shot ingestion was found, although