The side effects of chemical drugs, the bio-environmental necessities, and the gradual universal inclination for natural products and drugs has brought about the rapid widespread expansion of the study and investigation of plant's effective substances and their medical properties. One of these medical plants is clove tree that contains a considerable amount of volatile oily essence which can be used as energizer, appetite stimulant, disinfectant of wounds, sedative in caries, and so on. Alleviating fever is also one of its medical attributes, the study of which, in spite of the urgent need for antipyretic drugs, has unfortunately been neglected.

In this study, 16 adult male mixed dogs, weighing 15-20 kg, were provided. To make sure of their health, they were observed for three weeks, while administrating vaccine and anthelminthic and also recording the average of temperature, heart beat, and respiratory rate. Then, after general anesthesia and preparation of the dogs, and following an experimental surgery, 12 dogs that had developed fever without administration of antibiotics, were randomly divided into four groups, each of three dogs. Then, at 9 o'clock, the first group was injected by clove oil 10 mg /kg, the second group by acetaminophen 10 mg/kg, the third by clove oil 20 mg/kg, and the last group (control group) by normal saline 2 ml. Each 5 minutes, for three succeeding hours, their temperature was measured rectally by a digital thermometer. The results of this study, which were attained through one-way ANOVA statistic model (SPSS software), revealed that clove oil has a specific antipyretic in balancing the natural temperature of body and even once injected in double dose to the febrile dogs it causes a slight hypothermia, and its effects are comparable to standard acetaminophen.