Читать книгу Canine and Feline Epilepsy - Luisa De Risio - Страница 168

Ethylene glycol colorimetric spot tests are available for use with urine and serum. However, these tests can give false negatives in cats as the ethylene glycol toxic dose in cats can be below the detectable level of the ethylene glycol test kit. False positive results can occur in animals administered medications containing propylene glycol (diazepam, activated charcoal). A quantitative test kit has recently been evaluated and may aid in timely diagnosis of ethylene glycol exposure (Scherk et al., 2013). Laboratory tests for rapid analysis of serum, plasma or urine for ethylene glycol and glycolic acid also have been reported (Smith and Lang, 2000; Van Hee et al., 2004). Birefringent crystals may be detected in urine 3 h (in cats) and 5 h (in dogs) after ingestion. Anion gaps greater than 40–50 mEq/l are also suggestive of ethylene glycol intoxication. Signs of acute renal failure (azotaemia, hyperkalaemia, hyperphosphataemia) are usually seen approximately 12–48 h post-ethylene glycol ingestion. Moderate to severe hypocalcaemia is frequently present. Serum osmolality as high as 450 mosm/kg serum and an osmole gap as high as 150 mosm/kg serum may be detected 3 h after ethylene glycol ingestion. Both the gap and the measured osmolality may remain elevated for approximately 18 h after ingestion. Ultrasonographic changes vary from mild to marked increases in renal cortical echogenicity. Another diagnostic procedure that may help in the early diagnosis of ethylene glycol intoxication is examination of the oral cavity, face, paws, vomitus and urine with a Wood’s lamp to determine whether they appear fluorescent. Many antifreeze solutions contain sodium fluorescein, a fluorescent dye that aids in the detection of leaks in vehicle coolant systems (Thrall et al., 2006).