What is the Accuracy of Using Human Drug Testing Techniques for Dogs?
In the human medical community, urine testing is the most common means of screening for illegal and prescription drug abuse. Urine test kits are readily available over-the-counter. They are reliable, inexpensive, and provide quick results. The drugs most commonly evaluated are amphetamines/methamphetamines, cocaine, marijuana, opiates, and barbiturates.
Our canine patients can experience accidental or intentional exposure to many of the same substances. According to the ASPCA Animal Poison Control Center, the top five illicit drugs consulted on are marijuana, cocaine, psilocybin, Ecstasy, and crystal methamphetamine.
Of those listed, only psilocybin did not make the former group. Psilocybins, or classes of mushrooms, are not routinely tested by physicians unless there is a high index of suspicion. It can be detected in urine, but only in a laboratory. The turnaround time and cost would not be practical in the veterinary world.
In one animal study, urine drug screening accurately identified amphetamines, methamphetamines, barbiturates, opiates, and benzodiazepines. Cocaine was not evaluated in this study, but it is detectable in canine urine with the OTC kits.
Samples from the urine test kits were analyzed by gas chromatography/mass spectrometry. Results were dependent on several factors, including adequate amounts of the drug present in the urine, an appropriate amount of time between exposure and collection, proper specimen handling, solubility, and drug metabolism. Results were confirmed for all classes except marijuana. Even with careful techniques, it was not detectable by OTC means or gas chromatography/mass spectrometry.
There are hundreds of chemicals found within the marijuana plant, but THC is the principal psychoactive ingredient. Researchers found that dog urine contains a large number of metabolites, many of them different from the human ones. Only15% comprisedTHC, thus adding to the difficulty of detecting it.
Marijuana is the most common illicit drug exposure seen in dogs, but until better tests are available, clinicians must rely on history, physical exam, and intuition to diagnose marijuana toxicity. The human urine drug test kits are still valuable and accurate tools for proving many other illicit and prescription drug toxicities in our canine patients.