After 12 hours, most of the EG may be metabolized or excreted. The amount of serum EG that remains in the body 12 hours after exposure may not be enough to generate a positive test result because it will likely fall below the sensitivity of the test. The kit can be used for cat and dog samples, but there are limitations in its diagnostic ability for feline patients because the kit detection limit and control levels are based on canine parameters. Because cats are known to be more sensitive to EG, the test may yield false-negative results if EG levels are below the test detection limit. Thus negative results should not rule out EG toxicosis in cats.
Positive results suggest a toxic level in cats.
Ingestion or administration of products containing propylene glycol or glycerol will elicit false-positive results. Glycerol is commonly found in suppositories and laxatives, cough syrup, hairball remedies, capsulated medications and vitamins, candy, topical skin creams and ointments, shampoos, liqueurs, and some activated charcoal suspensions. Ingestion or administration of these substances can elicit false-positive results. Another agent that may interfere with test results is metaldehyde, a common slug and snail poison. Exposure to metaldehyde may yield false-positive results.