TDK conference 2016

Xylitol is a commonly used sugar substitute in households, but a highly toxic substance if administered to dogs. It causes acute hepatic damage and severe hypoglikemia, the latter because of pronounced insulin release. The goal of this study was to examine whether xylitol has the same effects on cats.

Our research involved six healthy cats. The cats were middle-aged and the average weight of the animals was 3,1 kg. They were not fed for 8 hours before the study so we could get the control blood samples and blood sugar values of each cat.

In our research we intended to see if any metabolic pathway is affected in any ways by xylitol ingestion, therefore the following blood parameters were checked: total protein, albumin, ALT, GGT, ALKP, GLDH, bile acids, urea, kreatinine, phosphate, sodium, potassium. The blood samples were taken from vena jugularis and collected into tubes with EDTA from each cat. Then the first dose of xylitol, 100 mg/kg, which was considered as the toxic dose for dogs was administered orally. Six hours after the ingestion blood was taken from the cats the same way as it has been described above. The exact procedure was repeated next day 24 hours after the ingestion. As the clinical status and the blood glucose levels of the cats were stable, the study was continued with a higher, 500 mg/kg dose after three days and again after a 3-day “wash-out” period, the 1000 mg/kg xylitol was also applied.

One of the main goals of the study was to follow the changes of blood glucose levels in the treated animals. For that the ears of the cats were scratched with a sterile needle and the blood was dripped on the automatic blood sugar analyser. Blood glucose levels were examined before the xylitol ingestion. After administering 100 mg/kg xylitol, blood sugar levels were measured 10, 20, 30, 40, 50 and 60 minutes after the ingestion and then in every hour until the sixth hour, then also the next day in the twenty-fourth hour. Since there was no sign of hypoglycaemia, this procedure was repeated in case of the dose of 500 mg/kg and 1000 mg/kg xylitol (after the 3 day washout periods).

As a result the blood glucose values were within reference ranges after every ingestion. There was no significant decrease (p<0.05, ANOVA) in blood sugar levels. In case of 100 mg/kg xylitol dosage, the average values were between 3.83 and 5.08 mmol/l. The 500 mg/kg dosage resulted in values between 3.74 and 5.57 mmol/l. The highest dose did not cause any anomalies either, the average blood sugar values ranged from 4.07 to 6.67 mmol/l. Furthermore all the examined blood chemistry values remained in the physiologic reference, which confirms that oral xylitol administration causes no harm neither on the liver nor on the kidneys.

In conclusion our research proved, that orally ingested xylitol, even at high doses is not toxic for cats in a short term study.