Glucosuria has been described in okapis, yet the etiology remained unclear.2,6 In August 2006 we tried to lower glucosuria by a dietary decrease of sugars and starch. During a period of 4.5 years, urine and feces of five okapis were analyzed to look for relationships between glucosuria and diet, stress, or pregnancy. An animal (born in 2008) remained non-glucosuric to age 2.5, whereas another one (born in 2006) became glucosuric near the age of three. The correlation between fecal cortisol and the urinary glucose/creatinine ratio (UR) was either negative (three animals) or positive (one animal), but never significant (p>0.05).5 Glucocorticoids increase free glucose by their insulin opposing effect, but stress appears to have no influence on glucosuria in okapis.4 The correlation between the new diet and the UR was negative but not significant (two older females, p>0.05) or positive and very significant (two animals, p<0.001).5 UR decreased during the second half of the pregnancy in two animals and the youngest became non-glucosuric with a significant (p<0.05) negative correlation between fecal progestogens and the UR.5 An increased fetal glucose demand might explain this, similar to the consumption of 60% of the glucose from the uterine circulation by the ovine placenta in late pregnancy.3 In conclusion, the new diet did not significantly reduce glucosuria in two animals and had no effect on the rising glucosuria in two others. Possibly, genetic research into benign renal disease, which is a known human inherited condition (autosomal recessive), might explain glucosuria in okapis.1
1. Feld LG. Renal glucosuria. www.emedicine.com. Accessed February 23, 2008. (VIN editor: link was not accessible as of December 9, 2020.)
2. Fleming GJ, Citino SB, Petric A. Glucosuria in captive okapi (Okapia johnstoni). J Zoo Wild Med. 2006;37(4):472–476.
3. Harding JE. The nutritional basis of the fetal origins of adult disease. Int J Epidemiol. 2001;30(1):15–23.
4. Kaneko JJ. Carbohydrate metabolism and its diseases. In: Kaneko JJ, ed. Clinical Biochemistry of Domestic Animals. 4th ed. San Diego, CA: Academic Press Inc.; 1989:44–85.
5. Petrie A, Watson P. Statistics for Veterinary and Animal Science. 2nd ed. Oxford, UK: Blackwell Publishing; 2006.
6. Vercammen F, Deken RD, Brandt J. Okapi (Okapia johnstoni) and glucosuria. In: Proceedings from the American Association of Zoo Veterinarians. 2008:247–249.