RED DEER–Herd health records are critical evidence if beef producers suspect cows were sickened following exposure to an oil or gas well leak.
As a result, producers need to keep good records to get to the bottom of a problem, said Alberta provincial veterinarian Gerald Hauer.
His office works with the provincial farmers’ advocate on oil and gas exposures and possible connections to animal health.
However, he said the onus is on the producer and local veterinarian to provide detailed health records so that a history can be established of the condition of animals before an incident occurs.
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“The only way you can made a really good case in a lot of these situations is with good health records,” he said.
Known and direct exposure that harms animals does occur, Hauer said, but it’s harder to make a case when animals that live close to oil and gas activity appear to be doing poorly without reason.
Alberta’s health of animals act requires that exposure to a known toxin be reported because it could affect food safety.
A veterinarian working closely with a producer can also help diagnose a change in animal condition and report the incident to the provincial veterinarian.
Lead poisoning continues to be the most common toxicity problem. It occurs when cattle lick old batteries that were improperly dumped in a pasture.
Alice Murray, a beef producer from Caroline, Alta., and a community relations officer with Shell Canada, said producers need to know the truth about what is happening to their animals because too often they assume that sour gas is the cause, which detracts them from further investigating the problem.
“As a livestock producer, things seem to happen and nothing makes sense,” she said during the recent Alberta Synergy conference in Red Deer.
“You need to know what the truth is.”
Oil companies, government and producers started a study in 1991 that monitored hundreds of animals in west-central Alberta for fertility and other performance results.
Murray said there were 800 wells in the area and plenty of anecdotes and assumptions. However, there was also little scientific evidence.
Beef herds were selected as sentinel markers of environmental health because they live outdoors and are more consistently exposed to potential environmental contamination through the air they breathe, water they drink and forage they eat.
“They are a living laboratory,” said Murray.
The Caroline study of nine herds eventually merged into the Western Interprovincial Scientific Studies Association study that involved 33,800 cows in 205 herds in Western Canada.
Results released in 2006 from the four-province study did not find direct connections to low level exposures of sour gas over a long period, she said.
Reproductive history on calving, abortions, stillbirths, calf weights and cow health were maintained. Necropsies were conducted whenever possible and problems such as non-pregnancy, late calving late, abortion, and calf death loss were monitored.
The study found that one-third of abortions submitted for a laboratory examination were linked to a bacterial infection, another third because of unknown causes and then a variety of reasons including congenital defects, neospora and animal stress.
About half the stillborn calves died as a result of calving difficulty, 53 percent had no diagnosis and the rest were caused by accidents or trauma, bacterial infections, congenital defects and hypothermia.
The examination of calves that died after the first 24 hours of birth found that many deaths were the result of scours, accidents or trauma, pneumonia, abomasal ulcers, infections and maternal neglect.
Underground dangers
•Natural gas is mostly methane, although it can occur as a mixture with other hydrocarbons such as ethane, propane, butane and pentane. It may also contain carbon dioxide, nitrogen, sulfur and helium.
•Sour gas is a natural gas that contains hydrogen sulfide (H2S). About one-third of Alberta’s natural gas is sour and the amount of H2S ranges from 20 to 80 percent. It carries a distinct rotten egg smell. Sulfur dioxide is a byproduct of burning or flaring sour gas when the H2S is converted into sulfur dioxide.
•Health concerns arise from H2S depending on the time exposed, frequency of exposure and concentration of the substance as well as sensitivity of the individual. At concentrations of 10 parts per million it can cause irritation of eyes, itchiness, blurred vision, sore throat, cough, nausea and difficulty breathing.
Source: Encana, Canadian Centre for Energy Education
