A thematic block is taught in the Veterinary Medicine Program at La Salle University’s Faculty of Agricultural Sciences that is relevant to the basic disciplinary training of future veterinarians. It is the theoretical and practical subject of the anatomy of the head of domestic species, which includes the head of horses. The study is addressed by testing the theory in the exercise of a dissection, and the exploration of the different structures that make up the head. This regional and systematic study includes angiology of the head, where emphasis is made on the branches of the common carotid artery as main vessel that irrigates the head. The common carotid artery ends in the occipital, internal carotid and external carotid arteries; the last one splits into two main terminal branches, namely: the internal maxillary artery and the superficial temporal. Generally, the internal maxillary artery follows a path that is repeated in almost all specimens that are dissected as described by different authors; however, in some cases there may variations in the path of the artery, such as in its branches. The purpose of this work is to inform about a case that arose in a regular class in the anatomy lab during dissection of a horse head where arteries were being studied macroscopically. Dissection showed a variation in the normal path of the internal maxillary artery at the level of lateral pterygoid muscle. The case involves an 11-year old mare that was put down by unqualified personnel outside the campus, and whose head was later severed and sent to the gross anatomy labs of the Veterinary Medicine program at the Faculty of Agricultural Sciences. Given its provenance, it was not possible to know the anamnesis, nor the history of the animal.

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.

Due to the lack of arterial gas values that meet our environmental conditions and the wide variety of out-of-date data in literature and used in everyday practice, obtained with different heights, breeds and equipment to the ones available in our context, it becomes necessary to generate our own knowledge adjusted to our reality. A random systematic measurement of arterial and venous blood was made on 100 healthy canines in the Bogota Savanna (Chia: 2652 m.a.s.l.; Cajica: 2558 m.a.s.l.; Sopo: 2650 m.a.s.l.; La Calera: 2718 m.a.s.l.; and Bogota: 2630 m.a.s.l.;), using the I-STAT^® analyzer with EG7+ cartridge. Reference values were found for gasometry, electrolytes, effective basis and pH. The values were compared between four groups by weight. Descriptive statistics were made for each parameter based on average, standard deviation and standard error, and the trust limits (95%) and the intervals with standard deviation (one and two deviations) were found. A decrease on PCO₂, PO₂, SO₂, bicarbonate and BE was evident. The pH was found to be slightly increased, similar to the one reported by authors at great heights and different (not statistically confirmed) from reports in literature, where height was not a variable. Even so, they are frequently used as reference in the practice of small animals; only PO₂ presented statistical differences by groups of weight. As a conclusion, effective regulation of blood pH was evident at 2600 m.a.s.l., with different bicarbonate values, PCO₂, PO₂, BE, which suggest the need to obtain and use reference values consistent with local conditions.