Veterinarians continue to die by suicide at rates well above the national average, according to a statistical analysis published Thursday, which for the first time quantified increasing suicide deaths among female vets.

The analysis, which was conducted by researchers for the Centers for Disease Control and Prevention, or CDC, and published in the Journal of the American Veterinary Medical Association, reviewed the records of 11,620 veterinarians who died from 1979 to 2015.

It found that female vets were 3.5 times more likely to die by suicide than was the general population, while for the ratio was 2.1-to-1 male vets.

Overall, men accounted for about 82 percent of suicides by veterinarians during the study period, roughly a 4.6-to-1 ratio, compared to a male-to-female ratio of about 3.6-to-1 in the general population.

Research has consistently shown for more than 30 years that veterinarians are at significantly higher risk of suicide than is the general population, owing to a combination of factors that include occupational stress, depression and burnout.

"The veterinary school application process commonly selects for perfectionism to meet the rigorous veterinary school academic requirements," the CDC researchers said. "However, perfectionism has been associated with higher risk for developing mental illnesses, including anxiety and depression."

The researchers also noted that veterinarians have broad access to pharmaceuticals used in animal euthanization.

What's startling in the new analysis are the trends in suicides among female vets.

Women now make up 60 percent of veterinarians in the United States, and while the percentage of deaths by suicide among female vets has remained consistent since 2000, the raw number of such deaths has risen as women's representation in the profession has steadily grown, the analysis showed.

And women are far more likely to use poison than are men, who are most likely to kill themselves with firearms, according to the analysis. Almost two-thirds of female vets used pharmaceutical poison, compared to only a third of men.

That could partly be explained by demographics: Because the percentage of women entering veterinary school and graduating to full practice has been rising sharply in the last few decades, more women than men are likely to have been exposed to more recent vet school training that teaches euthanasia as an acceptable method to relieve suffering in animals, which the researchers said can be accompanied by a reduced fear of death.

Demographics and changing times also explain another striking finding: that small-animal veterinarians, like those who treat your pets, are far more likely to die by suicide than they were 30 years ago.

That's because pet medicine has become much more popular over that time as society has moved away from an agriculture-based culture, sharply reducing the number of vets who work in agriculture and other industries. The American Veterinary Medical Association separately reported that 75 percent of U.S. veterans "worked exclusively or predominantly in companion animal medicine" in 2017.

The researchers cautioned that the high rates of suicide theoretically could have been skewed by incomplete data, especially if wider research reveals that veterinarians are disproportionately less likely to die of other causes. Moreover, they said, "death certificates for veterinarians might be less likely to list suicide as the cause of death because of high social standing within the community."

But they said the data clearly "highlights the need for comprehensive suicide prevention strategies targeted toward this unique population."

Dr. Robert Redfield, director of the CDC, agreed.

"Our findings suggest mortality from suicide among veterinarians has been high for some time — spanning the entire 36-year period we studied," he said in a statement.

"This study shines a light on a complex issue in this profession. Using this knowledge, we can work together to reduce the number of suicides among veterinarians."