K.-D. Budras

Brachycephalic Feline Noses: CT and Anatomical Study of the Relationship between Head Conformation and the Nasolacrimal Drainage System

Aims A study was designed to evaluate the influence of head conformation on the course of the nasolacrimal drainage system (NDS) in 31 brachycephalic and 15 mesocephalic cats using computed tomography (CT), CT-dacryocystography and anatomical methods. Findings The higher the degree of brachycephalia, the more the facial bones and upper canine teeth are displaced dorsally (ie, the more pronounced the dorsorotation). Dorsorotation leads to abnormal dislocation of the ventral nasal concha and to almost horizontally rotated upper canine teeth, and thus a steeply oriented NDS. In severe brachycephalia the NDS is forced to pass below the canine tooth (adopt a V-shaped course) and the drainage function seems to be inefficient. Practical relevance The rotation of the upper canine teeth appears to provide a basis for classification of brachycephalia in cats. The authors recommend that breeders avoid breeding from individuals affected by this condition and to give preference to cats with longer facial bones.

Magnetic resonance imaging of plantar soft tissue structures of the tarsus and proximal metatarsus in foals and adult horses

OBJECTIVES The object of this study was to describe previously defined soft tissue structures by using spin and gradient sequences in a 0.5 Tesla magnetic resonance system in order to improve the characterisation of tendon and ligaments at the plantar region of the equine tarsus and metatarsus while considering possible age-related variations. METHODS Cadaveric hindlimbs from twenty-two Warmblood horses with an age range from one month to twenty-five years were examined in spin and gradient echoes. The proximal suspensory ligament from six limbs was dissected to assign the signal intensities histologically. For statistical analysis, horses were divided into two groups (≤3 years and >3 years) for evaluating signal intensity and homogeneity of the plantar tendons and ligaments. RESULTS Focal increase of the signal intensity within the deep digital flexor tendon was significantly more present in horses older than three years. Signal alterations of the long plantar ligament were seen without a significant dependency to age. The accessory ligament of the deep digital flexor tendon could not be visualized on all images within the region of interest. The morphology of the proximal suspensory ligament was not affected by age-related changes. CLINICAL RELEVANCE Spin and gradient echoes in MRI were suitable to identify and assess soft tissue structures at the plantar aspect of the equine tarsus and proximal metatarsus. Age-related appearance must be considered when interpreting magnetic resonance images.