Page 698 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Petroleum Chapter | 50 663

VetBooks.ir other cows from a large herd, was necropsied. After inges- unhealthy. At 121 days after the initial examination, the
heifers were compared to siblings, and were found to
tion of oil this cow had a reduction in body weight.
have lost 50 100 kg. Because of apparent chronic, poor
Necropsy findings were: visible oil in the rumen, the
mucous membranes of the abomasum were stained black, health, 41 of the heifers were slaughtered approximately
and areas of inflammation were observed in the gut. There 124 days after the initial exposure and tissues submitted
was 213 mL of oil/L of rumen contents. In another report for histopathology. One heifer died during transport to
(Bumstead, 1949), cattle drank from a pool of oil. Two slaughter.
animals died, and all animals that had wandered into the
pool of oil showed clinical signs of intoxication. One Experimental Studies
heifer had severe enteritis, was dehydrated and had
cachexia. All animals receiving veterinary medical inter- Bystrom (1989) studied the acute toxicity of crude oil in
vention consisting of rapidly removed oil from the diges- cattle. The treatment groups (four animals in each group)
tive tract, and prophylactic treatment with an received 20, 40, 60 or 80 mL of sweet crude oil/kg of
antimicrobial chemotherapeutic recovered. In another body weight, or 80 mL of potable water/kg of body
report (Coale, 1947), five dairy cows drank crude oil that weight, respectively, administered per gavage. The analyti-
had escaped from a broken pipeline and were sold 90 days cal data for the crude oil has previously been described
later because of lost productivity. Gibson and Linzell (Coppock and Christian, 2012). Following exposure, daily
(1948) reported that dairy cows drank petroleum after mean rectal body temperatures were normal. Ruminal
5 gal (23 L) were mistakenly dumped in a water trough. motility was decreased after animals were dosed with oil
Clinical signs in six out of eight cows were central ner- and slowly increased to pretreatment values by day 8.
vous system (CNS) depression including coma, coughing, Vomiting occurred in 10 out of 12 of the animals dosed
salivating, head shaking, hypothermia, and petroleum odor with oil and, in some animals, vomiting was characterized
on respired air and from the milk. The diesel-like odor on by a projectile expulsion of oil. Emesis recurred after for-
the breath and from the milk persisted for 5 days. Three age or water was ingested. Ruminal tympanites was
animals died at 12, 24, and 48 h, respectively, after expo- observed in most the animals, but did not require medical
sure. During the interval between exposure and death, all intervention. Neurological abnormalities were not observed
the animals would eat and ruminate and were dull in tem- in control animals. Central nervous signs expressed by nys-
perament and were constipated. Forty-eight hours after tagmus, muscular tremors, and “petit mal-like” seizures
ingestion, two cows had abnormal respiratory sounds, were observed in treated animals. Depression was the most
which persisted for 14 days in one cow. The pathological common clinical sign observed. These effects were attrib-
findings were chemical pneumonia, and evidence of uted to the anesthetic-like effects of the volatile hydrocar-
inflammation in the mammary gland. Eaton (1943) bons. The neurological effects contributed to aspiration
reported clinical signs of vomiting and death after a lactat- pneumonia. Oil was identified in feces at 23 h after dosing
ing Shorthorn animal ingested approximately 1 gal for the 20 and 40 mL /kg groups, at 7 31 h for the 60 mL
(4.55 L) of tractor paraffin. Clinical signs of anorexia and /kg group, and at 5 19 h for the 80 mL /kg group. Feces
constipation were reported after cattle ingested tractor from the control animals did not contain oil. Head-space
vaporizing oil (tractor distillate) (Parker and Williamson, analysis on filled blood tubes showed that volatile hydro-
1951). Pathological findings were fatty changes in the carbon constituents from the oil were present in blood.
liver, degeneration of the kidney, and multiple small N-heptane was used as a representative hydrocarbon.
hemorrhages in the lungs. Barber et al. (1987) reported an Semiquantitative values for total light naphtha were esti-
environmental incident with aviation turbine fuel. Fifty- mated as high as 10 mg/L of blood. Aspiration of oil into
one heifers 12 18 months old were exposed to water in a the lungs, based on pathology findings, increased the levels
stream that had been contaminated with aviation turbine of N-heptane in the blood. Rowe et al. (1973) found that
fuel. The duration of exposure was not determined and, sweet crude oil was more toxic in cattle than was sour
when discovered, the contaminated waterway was imme- crude oil. Administration of 8 mL of sweet crude oil/kg
diately fenced, and the heifers were provided an alterna- body weight/day caused death within 7 14 days in four
tive source of drinking water. At the initial examination, out of five calves. For the same dose of sour crude oil, five
two heifers were dead, ataxia was observed in five ani- of five calves died between days 16 and 24; for kerosene,
mals. Over 3 weeks, eight heifers died or were euthanized five of five calves died between days 9 and 23.
in extremis. Animals that survived were dull, did not Administration of 37 mL of sweet crude oil/kg was fatal
show interest in strangers walking about the field, and had within a few minutes. Most of the surviving animals devel-
marked weight loss, and increased respiratory rate was oped pneumonia. Considerable variations have been
observed in some animals. Six weeks after the initial reported for the dose-response of cattle to petroleum sub-
examination, 41 of the surviving animals appeared stances. These effects can be due to presence of surfactants