Cattle exposed to diazinon may store the compound in their fat over the short term. One study showed that the compound cleared the cows within two weeks after spraying stopped. Application of diazinon to the skin of cows resulted in trace amounts in milk 24 hours after the application. Bird kills associated with diazinon use have been reported in every area of the country and at all times of the year. Birds are significantly more susceptible to diazinon than other wildlife.
Most fish are very sensitive to diazinon.
Rainbow trout have a LC50 of 90-140 ppb. In hard water, lake trout and cutthroat trout are somewhat more resistant. There is some evidence that saltwater fish are more susceptible than are freshwater fish. Bioconcentration ratios range from 200 in minnows to 17.5 for guppies. Other studies show that diazinon has been found to concentrate in fish 300-600 times the ambient water concentration.