Page 92 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Epidemiology of Animal Poisonings in Asia Chapter | 4 59

VetBooks.ir largest eagles. The total population of the Steller’s Sea- Arsenic (As)
Eagle is estimated at 5000 6000 on the island of
As poisoning due to contamination of groundwater is one
Hokkaido. Pb poisoning of Steller’s Sea-Eagles in Japan
was first confirmed in 1996. By 2007, 129 Steller’s and of the most important causes of heavy metal poisoning in
domestic animals in several countries. However, other
White-tailed Eagles died from Pb poisoning. Necropsies
sources of intoxication include dips, sprays, powders, or
and radiographs also revealed pieces of Pb from rifle bul-
vegetation contaminated by pesticides containing As
lets and from shotgun slugs to be present in the digestive
(Selby et al., 1977).
tracts of poisoned eagles, providing evidence that a source
Dogs and cattle are intoxicated more frequently than
of Pb was spent ammunition from Pb-contaminated Sika
other animals; yet sporadic instances of poisoning have been
deer carcasses. Reacting to the eagle poisoning issue,
observed in sheep, cats, horses, and pigs. Reports from
Hokkaido authorities have regulated the use of Pb rifle
industrial cattle farm in Iran indicated poisoning is either
bullets since 2000. Despite the overwhelming evidence
peracute, acute, or chronic in nature. Frequently the initial
that Pb ammunition is toxic to wildlife and people and the
and only indication that a severe problem exists with pera-
broad support for eliminating its use, it remains widely
cute poisoning in a cattle herd is dead animals. Chronic
used by hunters (Saito, 2009). In the United States, Pb
intoxications are also observed in cattle (Bazargani et al.,
poisoning is on the decrease due to government
2007). In two other incidences, acute intoxication of As poi-
regulations to remove Pb from house paint in 1978.
soning has been reported in young dog and sheep. As is a
However, dogs can still be exposed to Pb through roofing
severe alimentary tract irritant in domestic animals, and
materials, rug padding, linoleum, and other aged house-
treatment in most instances are primarily symptom-based
hold materials (https://www.vetary.com/dog/condition/
and supportive (Selby et al., 1977; Javad et al., 2013).
lead-poisoning). It may be worth mentioning that
California, in 2013, passed the first state wide phase-out
of Pb ammunition for all forms of hunting (Anon, 2016).
Copper (Cu)
Cu poisoning is common in various parts of Asia. Acute Cu
Mercury (Hg)
toxicity results from ingestion of high Cu feeds, Cu salts,
Hg toxicosis has been reported in cats, pigs, calves, horses, pesticides, poultry litter, and other high Cu intakes of
and laboratory animals (rats, mice, mink, ferrets, and 20 100 mg/kg in sheep and young calves, and
guinea pigs) but rarely in dogs. Clinical signs and lesions 200 800 mg/kg in adult cattle. Chronic Cu toxicity occurs
of Hg intoxication depend on the species affected, dose when high levels of Cu are ingested over a period of time
obtained, route of administration, chronicity of exposure, but at doses below the acutely toxic level. Sheep are the
and the chemical form of the Hg involved (Gupta, 2010b). most susceptible species to chronic Cu toxicity because their
A sporadic outbreak of a curious disease occurred liver cells have a high affinity for Cu and they excrete Cu
among dairy cattle, from early February to late May into the bile at a very low rate, leading to a build-up of liver
1955, in Monbetsu District, Kitami Subprefecture of Cu concentration over time. One of the most common
Hokkaido in Japan (Katherine et al., 2010). This disease causes of toxicity in sheep is the accidental feeding of
was due to poisoning by ingested linseed meal treated feedstuffs intended for other livestock. Field investigation of
with mercurial fungicide, “Ceresan.” The characteristic one closed herd of 400 mixed-breed dairy goats from India
symptoms of this disease were dyspnea and depilation; was examined because of a decrease in milk production and
out of 29 cases, eight died while two were slaughtered. increase in mortality rate. Nine animals had died within a
The general symptoms were fever attack, salivation, diar- 1-month period. Goats were found to have been fed a min-
rhea, bloody feces, depression and anorexia, lacrimation, eral mix containing 3050 ppm Cu for 9 months prior to the
decrease in milk production, and cramps. In addition, par- onset of Cu toxicosis. Clinical signs were evident only in
tial and diffusive depilation, eczema, and swelling of the lactating goats and included anorexia and recumbency.
skin accompanied by itchiness on the entire body surface In the most severely affected goats, signs progressed to
were found. Bronchial catarrh was observed in about half neurologic abnormalities and death (Cornish et al., 2007;
of the cases, especially; it was distinct in the severe or Badiye et al., 2013).
moderate ones. Anemia on all mucous membranes and
petechial hemorrhages on the nasal and vaginal mucous
membranes, cardiac disturbance, and swelling of lymph- NONMETALS AND METALLOIDS
nodes were also noted in the severe cases. In some Selenium (Se)
instances, epistaxis, bloody milk, and nephritis were also
observed. In another incidents, renal problems have been Se has chemical and physical properties intermediate
reported in dogs (Farrar et al., 1994). between metals and nonmetals and is similar to those of