In this study the interaction of clinical, biochemical hematological and electrocardiographic findings on 47 diarrheic calves at the ageof 1-30 days were evaluated. The results showed that on the basis of clinical findings (skin fold test persistence and capillary refill time), body fluid loss were estimated 8.09±0.20% and 8.10±0.28%, respectively. This difference was not statistically significant (P>0.05). On the basis of haematocrit, body fluid loss was estimated 6.33±0.35%. Statistical analysis indicated that fluid loss estimated by haematocrit evaluation was significantly less than clinical evidences (P<0.05). The evaluation of heart rhythm in affected calves revealed in 15 cases (31.9%) normal sinus rhythm, in 22 cases (46.8%) sinus tachycardia, in 5 cases (10.6%) sinus bradycardia associated with sinus arrhythmia, and in 5 cases (10.6%) atrial standstill together with other arrhythmias such as sinus arrest and sinoatrial block. The last 5 cases were suffering from sever hyperkalaemia. Correlation test showed that there was no significant relationship between serum electrolyte levels, including K+, and electrocardiograph parameters (P>0.05), but there was a significant correlation (P<0.05) between time of skin fold duration, capillary refill time, haematocrit and serum level of K+. Thus, by using multiple regression test, predication equation of serum level of K (mEc,/I) as dependant factor was acquired according to skin fold duration time (SKF in seconds), capillary refill time (CRT in seconds) and haematocrit (PCV in %), as independent factors:K=0.082+0.330(CRT)+0. 132(PCV)+0.014(SKf);r2=0.408.
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