Page 696 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Petroleum Chapter | 50 661

VetBooks.ir been published (Coppock et al., 1995a; Maxie and can contain other metallic substances. Lead grease has
excellent water repellence properties. Lead grease is also
Youssef, 2007; Coppock and Christian, 2012).
a hazard to livestock. Motor oils generally contain addi-
SELECTED TOXIC SUBSTANCES tives to prevent foaming, to keep carbon deposits in sus-
pension and to reduce friction and wear of parts at high
Antihydrates and Antifreezes temperatures, viscosity improvers, pour-point improvers
and antioxidants. Synthetic oils can contain molybdenum
Chemicals are used in the upstream oil and gas industry and surfactants. Antiwear additives such as zinc diakyl-
to prevent the formation of hydrates and freezing of dithiophosphate compounds are added to lubricants
water. Surfactants, polymers (e.g., polyvinylcaprolactam) to reduce friction. Micronized metals can be added to
and antifreezes are used as antihydrate and antifreezing lubricating oils. Many additives are mixtures of sub-
agents. Methanol can be used to prevent freezing of water stances and most companies closely guard their intellec-
in pipes, and to prevent hydrate formation in gas wells tual property.
and pipelines. Intoxication of cattle by methanol has been
reported (Rousseaux et al., 1982). A herd of 600 cows
had access to methanol barrels stored on a lease and two VETERINARY MEDICAL USE
cows were found dead. Rumen contents from the two OF PETROLEUM
dead cows contained 370 mg of methanol/100 mL of
Uses of mineral oils in the food industry include lubri-
rumen fluid. Clinical signs of experimentally induced
cants in manufacturing of human foodstuffs, direct addi-
methanol poisoning in cattle were like those reported for
tion to foodstuffs and as a pharmaceutic. Mineral oils
field exposures (Fritz and Coppock, 1992). Diethylene
are highly refined naphthenic or paraffinic distillates
glycol is used in oil and gas operations. Research has
free from unsaturated and aromatic compounds, and
shown that cattle are a species sensitive to diethylene gly-
other substances that influence color, taste and render
col (Fritz and Coppock, 1992; Khan et al., 1992). A dose
unacceptable properties. As a prophylactic for bloat in
of 1.5 mL/kg of body weight is fatal to a cow. Diethylene
ruminants, purified mineral oils are mixed with surfac-
glycol is toxic to the eye, liver, kidney, and nervous sys-
tants (pasture spray oil) and sprayed on alfalfa (lucerne)
tem. Diethylene glycol induced ocular changes that are
forage before grazing. Spray oil formulations have been
similar in appearance to those of pinkeye. Diethylene
used for over 100 years as pesticides. Prolonged oral
glycol causes a unique lace-like hypertrophy of the peri-
exposure to mineral oil can deplete fat soluble vitamins.
neuronal amphicytes in the Gasserian ganglion in cattle.
There is historical record of various crude, refined
This lesion has not been reported in laboratory animals.
petroleum fractions and waste petroleum being used as
Other glycols such as monoethylene glycols and ethylene
veterinary medicaments. Lamp paraffin (kerosene) and
glycol are used in oil and gas production (see Chapter 49
other kerosene-like products were used as a veterinary
entitled Alcohols and Glycol).
medicament for treating animals with intestinal hel-
minths, frothy bloat and diarrhea, and crude oil was used
Grease and Motor Oil as an aperient. Used motor oil has been used for tick
control. The unpredictable adverse reactions of orally
Lithium (Li) grease intoxication has occurred in cattle. administered kerosene are anorexia, ptyalism, indiges-
Wallace and Blodgett (1996) reported Li poisoning in one tion, irritation of the digestive tract, respiratory difficul-
cow after the animal consumed Li-grease, and Johnson ties, and death.
et al. (1980) reported on Li poisoning in 19 out of 90 ani-
mals. In both incidents, the source of Li-grease was in
discarded drums that had been used previously for trans- TOXICOLOGY OF PETROLEUM
porting and storing grease. In the incident reported by Ingestion of Petroleum by Livestock
Wallace and Blodgett (1996), the cow was euthanized and
in the incident reported by Johnson et al. (1980), all 19 Numerous reports that exist in the scientific literature
animals died. In the animals that consumed Li-grease, show that cattle ingest crude petroleum and other oilfield
clinical signs included muscular tremors, ataxia, stiffness, substances (Coppock et al., 1995b). Cattle are attracted
apparent disorientation, ptyalism, diarrhea, rapid respira- to and will ingest several gallons of petroleum (Monlux
tion, and periodic seizure-like activity. The concentrations et al., 1971; Oehme, 1977). Deaths have occurred after
of Li in grease for the incidents reported were 2050 μgof cattle drank tractor paraffin and vaporizing oil (Eaton,
Li/g of grease and 1250 μg of Li/g of grease, respectively 1943). Heifers drank gasoline (Albert and Ramey, 1964),
(Wallace and Blodgett, 1996; Johnson et al., 1980). and Messerli (1969) reported that cattle greedily ingested
Lithium can also be present in produced water. Grease diesel oil flowing from a storage tank. Cattle have drunk