Pharyngeal dermoid cyst causing partial upper airway obstruction in a cat.

Case summary: A 2-year-old cat was presented with nasopharyngeal stridor and stertor. Radiographs of the upper neck region showed a mass lesion in the nasopharynx. A nasopharyngeal polyp was suspected, but an attempt at endoscopic removal failed, owing to fragmentation of the mass and excessive haemorrhage. A sample was taken and histology confirmed a dermoid cyst. CT was performed and the lesion was described as most likely to be a dermoid cyst, consistent with the histopathological findings. Surgical exploration and subsequent complete removal of the mass led to a full recovery. Relevance and novel information: The nasopharyngeal location represents a previously unreported location of a dermoid cyst. This report raises awareness of dermoid cysts as a potential differential diagnosis within the nasopharyngeal region and highlights the importance of pre-interventional diagnostic imaging.

The slope of the pelvis is variable in dogs but does not show correlation with femoral subluxation.

The aim of this study was to investigate the variability of the slope of the pelvis in different dog breeds and the correlation between pelvic slope and femoral subluxation. The sacrum-pelvis angle (SPA), the angulation between the sacrum and the axis of the ilium was created to represent the differences in the slope of the pelvis on lateral pelvic radiographs. The Norberg angle (NA) was used to quantify the femoral subluxation on hip-extended radiographs. Archived standard ventrodorsal hip radiographs and lateral lumbosacral radiographs of the same dogs were retrieved and a single observer measured the SPA and the NA in each case. A total of 180 dogs from six different breeds were sampled. The SPA varied between 40° and 71.5° and the NA between 71.2° and 113.9°. The findings indicated that there are significant individual and interbreed variations in the slope of the pelvis. However, no significant relationship between the slope of the pelvis and femoral subluxation could be identified.

Novel approach to magnetic resonance imaging of epileptic dogs - T2 relaxometry of the brain with emphasised hippocampus.

Hippocampal sclerosis is the most common imaging finding of intractable human epilepsy, and it may play an important role in canine and feline epileptogenesis and seizure semiology, too. The magnetic resonance imaging (MRI) criteria of hippocampal sclerosis are T2 hyperintensity, shrinkage and loss of internal structure. The detection of these changes is often challenging by subjective visual assessment of qualitative magnetic resonance (MR) images. The recognition is more reliable with quantitative MR methods, such as T2 relaxometry. In the present prospective study including 31 dogs with idiopathic epilepsy and 15 control dogs showing no seizure activity, we compared the T2 relaxation times of different brain areas. Furthermore, we studied correlations between the hippocampal T2 values and age, gender and skull formation. We found higher hippocampal T2 values in the epileptic group than in the control; however, these findings were not statistically significant. No correlations were found with age, gender or skull formation. In the individual analysis six epileptic dogs presented higher hippocampal T2 relaxation times than the cut-off value. Two of these dogs were also evaluated as abnormal in the visual assessment. Individual analysis of hippocampal T2 relaxation times may be a helpful method to understand hippocampal involvement in canine epilepsy.

Morphological evaluation of experimental autologous rectus fascia sheath vascular grafts used for arterial replacement in a dog model.

Although experimental autologous patch or tubular conduit vascular grafts made from the internal rectus fascia sheath (IRFS) have been reported in the literature, thorough morphological evaluation and verification of the histological arterialisation of such grafts are lacking. Four purpose-bred Beagle dogs were utilised to create eight arterial internal rectus fascia sheath (ARFS) grafts implanted between bisected ends of the external iliac arteries. Four out of the eight ARFS grafts were patent after three months. Haematoxylin-eosin and Azan staining verified that the grafts gained a vessel-like layered structure with the presence of large amounts of collagen fibres. Although the inner surface of the intact IRFS was originally covered with claudin-5-negative and pancytokeratin-positive mesothelial cells in control samples, the internal cells of the ARFS grafts became claudin-5 positive and pancytokeratin negative like in intact arteries. Spindle-shaped cells of the wall of ARFS grafts were α-smooth muscle actin (α-SMA) positive just like the smooth muscle cells of intact arteries, but α-SMA immunoreactivity was negative in the intact IRFS. According to these findings, the fibroblast cells of the ARFS graft have changed into myofibroblast cells. The study has proved that ARFS grafts may be used as an alternative in arterial replacement, since the graft becomes morphologically and functionally similar to the host vessel via arterialisation.

Subarachnoid pressures and cardiorespiratory parameters during cisternal myelography in isoflurane anaesthetized dogs.

OBJECTIVE: To measure subarachnoid pressures, systemic circulatory and respiratory effects, and to calculate cerebral perfusion pressure during cisternal myelography. STUDY DESIGN: Prospective clinical study. ANIMALS: Forty-three client owned dogs with clinical signs of spinal disease, weighing 6-56 kg. METHODS: Dogs were premedicated with butorphanol and diazepam intravenously (IV) and anaesthesia was induced with propofol and maintained with isoflurane vaporized in oxygen. Ventilation was spontaneous. Heart and respiratory rates, invasive mean arterial blood pressure (MAP), end tidal carbon dioxide and isoflurane concentration were measured continuously. Initial subarachnoid pressure (SaP0 ) was measured in the cisterna magna with a needle pressure gauge. Iohexol 0.3 mL kg(-1) was injected at a rate of 4.1 mL minute(-1) into the cerebellomedullary cistern. The SaP was recorded during and at 120 seconds after contrast administration. The maximum SaP (SaPmax ) and minimum calculated cerebral perfusion pressure (CPPmin ) were recorded for each case. RESULTS: Prior to contrast injection, mean ± SD, MAP was 73 ± 20 mmHg and SaP0 was 10 ± 3 mmHg. The cerebral perfusion pressure (CPP) was 64 ± 20 mmHg. The contrast injection increased the SaP0 to 73 ± 33 mmHg (SaPmax ). After injection, MAP increased to 97 ± 25 mmHg and the CPP decreased to 14 ± 34 mmHg. A negative correlation was found between the lowest CPP and body weight (ρ = -0.77, p < 0.0001). Nine dogs had bradycardia, apnoea and hypertension, 21 dogs had at least one of these signs. The number of clinical signs showed significant correlation with body weight (ρ = -0.68, p < 0.0001), SaPmax (ρ = -0.66, p < 0.0001) and CPPmin (ρ = -0.73, p < 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE: Cerebral perfusion can severely decrease during cisternal myelography using the standard dose of iohexol. Bradycardia, apnoea and systemic hypertension were associated with decreased CPP.

Pressure-volume index-based volume calculation of contrast medium for atlanto-occipital myelography in dogs.

Subarachnoid pressure recordings were made during atlanto-occipital myelography in 45 dogs with clinical signs of spinal disease. Iohexol was injected at a dosage of 0.3 ml/kg body weight and simultaneous pressure values were recorded in the cerebellomedullary cistern. The mean subarachnoid pressure was 9 ± 3 mmHg before and 70 ± 32 mmHg at the end of administration. From the pressure change induced by the volume load, the pressure-volume index (PVI) of the subarachnoid space was calculated and found to be in close correlation with body weight and the crown-rump length (r = 0.94 and 0.87). Using the estimated PVI values, the appropriate volume of contrast medium can be calculated for an animal according to body weight. Dogs of a large body size require relatively less contrast medium than small-sized dogs (range 0.17-0.35 ml/kg). This calculated volume is unlikely to increase the subarachnoid pressure above 40 mmHg as a specific pressure limit. Using these data, simplified recommendations for the choice of contrast medium volumes have been generated.

Experimental results of using autologous rectus fascia sheath for venous patch grafts in dogs.

Autologous vascular patch grafts developed from the internal rectus sheath were implanted onto the bilateral common iliac vein and jugular vein of 4 experimental beagle dogs. During the development and implanting of the grafts no technical difficulties or perioperative complications were encountered. The follow-up lasted 6 months and 3 months in the case of the common iliac vein grafts and the jugular grafts, respectively. In the postoperative period, the morphological and functional characteristics of the implanted venous sections were examined by Doppler ultrasonography and CT angiography. Normal patency was detected, and none of these check-ups showed obturation or stenosis. The histological survey showed no mesothelial cell layer, but the insides of the grafts showed total restructuring and were covered by a normal endothelial layer. No difference could be detected between samples harvested 3 and 6 months after implanting. The immunohistochemical examinations using anti-claudin-5 and anti-CD31 antibodies confirmed the preliminary results of the histological examinations that the luminal surfaces of the implanted grafts developed a differentiated monolayer endothelium which was free of degenerative and inflammatory signs. The control examinations show the suitability of the internal rectus sheath as a venous wall donor.

Vertebral osteomyelitis and meningomyelitis caused by Pasteurella canis in a dog--clinicopathological case report.

A clinicopathological case study of vertebral osteomyelitis caused by Pasteurella canis in a 2.5-year-old male Jack Russell Terrier is presented. The case was characterised by a chronic course with signs of spinal pain and acute paraplegia. The diagnosis was established by radiography, myelography, post-myelographic CT examination, and laboratory tests including routine blood work and cerebrospinal fluid (CSF) cytology, and confirmed by postmortem pathological and microbiological examinations. Diagnostic imaging showed severe osteolysis, ventral spondylosis and spinal cord compression at the 4th and 5th lumbar vertebrae. The blood tests revealed mild leukocytosis and anaemia, while CSF cytology showed lymphocytic and mononuclear pleocytosis. Necropsy demonstrated severe osteomyelitis and meningomyelitis, but the source of infection could not be established. To the authors' knowledge, this is the first description of canine vertebral osteomyelitis caused by this organism.