The technique is quite common with human patients undergoing intricate neurosurgery but this paper investigates how it may be utilised in canid ones, specifically dogs (Canis familiaris).
Image-guided neuronavigation functions on the basis of stereotaxy. The brain is conceived as a geometric entity that can be trisected by three spatial planes orthogonal to each other. These planes are the horizontal, frontal and sagittal ones based on the Cartesian co-ordinate system (Ganslandt, O., et al, 2002). Precise surgical guidance is available by referencing objects within this three-dimensional system in the brain with three-dimensional images aligned along parallel co-ordinate axes displayed on the console of a computer-workstation providing the surgeon with point-to-point imagery of the actual locations in the brain. This allows maximum accuracy of operation (Ganslandt, O., et al, 2002). This spatial accuracy afforded by functional imaging systems such as, primarily, magnetoencephalography (MEG), functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), when incorporated within the neuronavigation process, allows precise surgery near eloquent areas of the brain with minimum morbidity (Ganslandt, O., et al, 2002)....
Attempts to apply congruency in both morphological and behavioural characteristics of the domestic dog (Canis familiaris) immediately runs in several problems because there are innumerable breeds all over the world and the variety is so diverse that it is bewildering. Nevertheless, it is generally agreed that the domestic breed diverged from gray wolves (Canis lupus) 3,25,000 to 1 million years ago. The domestic dog is a very close relative of the wild gray wolf with only about 0.2% divergence in mitochrondrial DNA sequence (Jordana, J., et al, 1999). It is also acknowledged that the gray wolf is a breed that is found both in the New World and the Old and dogs probably originated from the Old World breed and crossed over with humans to the New World to form the special breeds found there today (Olori, J., 2005). This is even though the fond belief of dog-breeders in the New World is that their breeds are exclusively diverged from gray wolves there. At least, the early dog breeds in the New World were so while more recent breeds may have been bred down from the northern gray wolves that are large-bodied (Jordana, J., et al, 1999). There is also evidence to suggest that there are four distinct lineages that descended independently from gray wolves. Each lineage is called a clade (Olori, J., 2005). The comparative study conducted on 25 different breeds from different parts of the world on the morphological, though Canis familiaris is probably the most morphologically diverse species on earth, and behavioural traits of the domestic dog revealed that morphological data was more congruent than behavioural ones (Jordana, J., et al, 1999). In the context of the purpose of the paper it was found that the cranial profile varied from medium to large to small dogs in