The electrocardiogram is a written register of electric changes that take place in the heart during a heart cycle. The voltage changes are the result of depolarization and repolarization of heart muscle fibers that produce electric changes able to reach body surface and that are detected by electrodes connected to a galvanometer called electrocardiograph. Heart problems are detected with the electrocardiogram, but it is necessary to know the normal values of canine electrocardiogram in a tropical country because values can change compared with normal values reported in other places. The purpose is to show variations of electrocardiogram values from clinically healthy canines from Bogotá D. C at 2600 mosl, Fusagasugá at 1700 mosl and Girardot at 326 mosl. Studied animals were separated in six groups depending on the altitude over sea level and the animal weight (less than 15 Kg and more than 15 Kg). The electrocardiograms were taken with a one channel portable electrocardiograph and derivations I, II, III, aVR, aVL, aVF, CV6LL, CV6LU, CV5RL and V10 were included. Significant differences of electrocardiogram values were observed in derivation II, in relation to the altitude over sea level and to the animals weight, which acquires importance when a diagnose of heart abnormalities is needed from animals located at different altitudes over sea levels.

This research was conducted with students of fourth semester of Veterinary Medicine program at La Salle University, Bogotá, Colombia, who validated four learning objects in a virtual environment (AVA) to determine whether or not they promoted collaborative work from the strategy-based in learning by problems. It began with the design of activities to put into learning objects and intentionally promote collaborative work, from a real problem of hemodynamics in animals. The methodology was qualitative and performed the pedagogical model, focusing on cognitive theory and the constructivist approach, in which the objects were at the Moodle platform that was created under this approach. Also it was performed the technologic and communicative modelling. The methodological steps for the technology was supported in the GRACE method for engineers. The results were induced by observing through the case study. As a result it was determined that one of the features that should have the learning objects to promote collaborative work, without the intervention of the teacher as a tutor, is to include some of the strategies of collaborative learning as used in this research is that learning is based in problems. Another important feature of learning objects to promote collaborative work is to have, adequate links to go through forums, chat, or other tools (not used in this research) as the blog or wiki. The forum was a collaborative work, which was scarce in the beginning, and although all were present that were autonomous in their learning, was a certain fear to seek help from peers here, but when they found a greater degree of difficulty to solve a problem, began to ask or request permission to work with others, then collaborative learning took place, as all came to not only at the level of the object (know the concepts) but at the aim level (apply the knowledge).

The Dirofilaria immitis or heartworm is a worldwide distribution disease spread by mosquitoes of the Aedes, Anopheles, Culex and Taeniorhynchus kind; in humans, this filaria causes skin and lung lesions, though some cases of human dirofilariasis have already been reported with different locations, such as large mesenteric vessels, peritoneal vessels, the spermatic cord and even the right side of the heart. Unlike in dogs, there is no filaremia in humans. The most common symptoms are: retrosternal pain, coughing and hemoptysis. A fibrotic nodule (with a diameter from one to three centimeters) is often asymptomatic and can only be identified in chest X-rays as a coin-shaped lesion. Around fifty cases have been reported in humans in the United States, although cases have also been reported in Japan, Asia, Australia, Brazil and Argentina. A research was carried out at La Salle University in order to determine the frequency with which Dirofilaria immitis occurs in dogs in Bogotá D.C. (2600 meters over sea level) through the Elisa Petchek® enzyme test, which is specific and does not show any crossed reactions with other parasites, thus providing a quick and accurate diagnosis of the disease. A frequency of 1% was found of dogs that came out positive with Dirofilaria immitis. Considering that the dog population in this city is of approximately 8000 the possible number of animals that would come out positive for the parasite would be of around 8,000 dogs, which could potentially spread the disease to humans through a mosquito bite. The number of dogs exposed to the heartworm disease in the world is increasing, and due to the fact that dirofilaria is rarely seen in humans, its prevention depends largely on the reduction of the disease’s prevalence in dogs, since, even in Colombia specific antibodies were detected against the antigens of the adult Dirofilariaimmitis worms complex in individuals from an isolated Tikuna community in the Colombian Amazon.