Cone-beam computed tomography of the head in standing equids.

BACKGROUND: Computed tomography in standing horses has revolutionized diagnostic imaging. The O-arm®, a cone beam computed tomography (CBCT) scanner with a gantry opening of 96.5 cm is routinely used for image-guided spine and neurosurgery in humans. The aim of this study is to describe the set-up and first experiences using the O-arm® to achieve CBCT imaging of the head in standing horses. CT imaging of the predefined region of interest (ROI) was tested on 2 cadaveric heads, concentrating on centering issues within the gantry, as well as determining the number of scans needed per ROI. All horses presented with head-related diseases and subjected to a CBCT examination between February 2015 and November 2016 for CBCT were included. Per scan, a limited field of view, i.e. a cylindrical volume of 21 cm in diameter and 16 cm in height was acquired within 13 s. Depending on the dimensions of the ROI, the minimum number of scans could range from one to six, if the entire equine head is to be examined in an adult horse. RESULTS: Sixty-eight horses were included, five of which had a follow-up CBCT exam, and two of which were presented twice for two different indications (75 clinical cases). A total number of 449 acquired three-dimensional (3D) scans were recorded for these 75 cases. Two-hundred and forty-two 3D scans (54%) were considered as diagnostic quality. The imaging procedure was generally well tolerated by the sedated, standing equid, and diagnostic studies were performed in 73 out of 75 cases (97.3%). Motion artefacts and inadequate centering of the ROI were the most common reasons for non-diagnostic quality images and repeat scans of the same ROI. CONCLUSIONS: CBCT is a valuable imaging modality for the equine head. Advantages of the O-arm® compared to a conventional multi-slice helical CT for imaging of the head in standing equids include the rapid image acquisition, the gantry's mobility in all dimensions, and the free movability of the entire imaging unit. Disadvantages include the considerable sensitivity to motion artefact, increased scatter, low soft tissue contrast and the limited dimensions of the field of view.

The Relationship between Brachycephalic Head Features in Modern Persian Cats and Dysmorphologies of the Skull and Internal Hydrocephalus.

BACKGROUND: Cat breeders observed a frequent occurrence of internal hydrocephalus in Persian cats with extreme brachycephalic head morphology. OBJECTIVE: To investigate a possible relationship among the grade of brachycephaly, ventricular dilatation, and skull dysmorphologies in Persian cats. ANIMALS: 92 Persian-, 10 Domestic shorthair cats. METHODS: The grade of brachycephaly was determined on skull models based on CT datasets. Cranial measurements were examined with regard to a possible correlation with relative ventricular volume, and cranial capacity. Persians with high (peke-face Persians) and lower grades of brachycephaly (doll-face Persians) were investigated for the presence of skull dysmorphologies. RESULTS: The mean cranial index of the peke-face Persians (0.97 ± 0.14) was significantly higher than the mean cranial index of doll-face Persians (0.66 ± 0.04; P < 0.001). Peke-face Persians had a lower relative nasal bone length (0.15 ± 0.04) compared to doll-face (0.29 ± 0.08; P < 0.001). The endocranial volume was significantly lower in doll-face than peke-face Persians (89.6 ± 1.27% versus 91.76 ± 2.07%; P < 0.001). The cranial index was significantly correlated with this variable (Spearman's r: 0.7; P < 0.0001). Mean ventricle: Brain ratio of the peke-face group (0.159 ± 0.14) was significantly higher compared to doll-face Persians (0.015 ± 0.01; P < 0.001). CONCLUSION AND CLINICAL RELEVANCE: High grades of brachycephaly are also associated with malformations of the calvarial and facial bones as well as dental malformations. As these dysmorphologies can affect animal welfare, the selection for extreme forms of brachycephaly in Persian cats should be reconsidered.

To see or not to see: non-invasive imaging for improved readout of drug treatment trials in the murine model of secondary alveolar echinococcosis.

Alveolar echinococcosis (AE) is an emerging zoonotic disease caused by the cestode Echinococcus multilocularis. The secondary infection model of AE is based on intraperitoneal injection of disease-causing metacestodes into the peritoneal cavity of mice, which allows investigations on novel drugs or immunotherapeutical treatment options in vivo. So far, such in vivo studies assessed exclusively the parasite weight at the endpoint of a given treatment period. We here developed an ultrasound (US)-based scoring system that allows to follow-up parasite development in the living animal, and provides insights into parasite growth during the treatment phase. By this method a statistically significant difference between untreated and medicated mice with E. multilocularis infection was observed at 2 months post-infection, and the growth curve of the parasite load was described by a linear mixed model. High correlation and similar levels of variation were observed for the standard method based on parasite weight measurement, the novel US-based scoring system, as well volume segmentation by post-mortem magnetic resonance imaging. Thus, US-based scoring in the live animal has the potential to assist the 3R concept by contributing to the refinement and reduction of animal use in experimental echinococcosis.

Influence of two types of self-retaining retractors on multifidus muscle blood flow during dorsolateral thoracolumbar hemilaminectomy in dogs.

OBJECTIVES: To assess the influence of the use of Gelpi and Grevel retractors on multifidus muscle blood flow during hemilaminectomy, using a dorsolateral approach, for acute disc extrusion in dogs as measured by laser speckle contrast imaging (LSCI). METHODS: Blood flow in the multifidus muscles was measured intra-operatively using LSCI prior to insertion of the retractors, immediately after hemilaminectomy and removal of the retractors, and after 10 minutes of lavage of the surgical site. Plasma creatine kinase levels were measured preoperatively and 12-24 hours postoperatively. RESULTS: Muscular blood flow was significantly decreased following retraction and remained lower than initial values 10 minutes after lavage in all dogs. The decrease in blood flow was significantly greater with Gelpi retractors (n = 8) than with Grevel retractors (n = 10). No significant relation was found between the duration of retraction and postoperative changes in creatine kinase levels or blood flow. CLINICAL SIGNIFICANCE: Findings in this study demonstrate a drop in blood flow within the multifidus muscles using the dorsolateral approach regardless of retractor type used. Gelpi retractors seem to have greater influence on muscular blood flow than Grevel retractors. Further studies are warranted to confirm this second finding.

[The canine neuronal ceroid-lipofuscinosis: a review]. / Die neuronale Ceroid-Lipofuszinose beim Hund: Eine Übersicht.

The present article gives a survey over the current scientific knowledge of the canine neuronal ceroid-lipofuscinosis (NCL). NCL is a heterogenous group of lysosomal storage diseases in humans and animals. In consequence of a gene mutation, there is an accumulation of ceroid-lipofuscin in neurons, cells of the retina and the skin and other cells. The stored ceroid-lipofuscin in neurons leads to an impaired cell function and subsequently to cell death. Recently, the underlying genetic defect was discovered in several dog breeds. Genetic testing permits an ante mortem diagnosis of the disease, which up to now was only possible with a positive biopsy result. Another advantage is the identification of carrier animals to eliminate the deleterious alleles.

Le présent travail donne un aperçu ainsi qu'un résumé des connaissances actuelles sur la Céroïde-lipofuscinose neuronale (CLN) chez le chien. La CLN constitue un groupe hétérogène de maladies lysosomales chez l'homme et les animaux. Suite à une mutation génétique, il se produit une accumulation de céroïde-lipofuscine dans les cellules nerveuses, les cellules de la rétine, dans la peau ainsi que dans d'autres cellules du corps. L'accumulation de céroïde-lipofuscine dans les neurones conduit à une détérioration progressive de leurs fonctions et, finalement, à la mort de ces cellules. Le défaut génétique à l'origine de cette affection a été récemment identifié chez le quelques races de chiens. Des tests génétiques permettent de diagnostiquer la maladie sur des animaux vivants, ce qui n'était jusqu'alors possible que par biopsie. Il est en outre possible d'identifier les porteurs hétérozygotes et de les exclure de l'élevage.

Use of contrast-enhanced fluid-attenuated inversion recovery sequence to detect brain lesions in dogs and cats.

BACKGROUND: The diagnostic value of a contrast-enhanced T2-weighted FLAIR sequence (ceFLAIR) in brain imaging is unclear. HYPOTHESIS/OBJECTIVES: That the number of brain lesions detected with ceFLAIR would be no greater than the sum of lesions detected with nFLAIR and ceT1W sequence. ANIMALS: One hundred and twenty-nine animals (108 dogs and 21 cats) undergoing magnetic resonance imaging (MRI) of the head between July 2010 and October 2011 were included in the study. METHODS: A transverse ceFLAIR was added to a standard brain MRI protocol. Presence and number of lesions were determined based on all available MRI sequences by 3 examiners in consensus and lesion visibility was evaluated for nFLAIR, ceFLAIR, and ceT1W sequences. RESULTS: Eighty-three lesions (58 intra-axial and 25 extra-axial) were identified in 51 patients. Five lesions were detected with nFLAIR alone, 2 with ceT1W alone, and 1 with ceFLAIR alone. Significantly higher numbers of lesions were detected using ceFLAIR than nFLAIR (76 versus 67 lesions; P = 0.04), in particular for lesions also detected with ceT1W images (53 versus 40; P =.01). There was no significant difference between the number of lesions detected with combined nFLAIR and ceT1W sequences compared to those detected with ceFLAIR (82 versus 76; P =.25). CONCLUSION AND CLINICAL IMPORTANCE: Use of ceFLAIR as a complementary sequence to nFLAIR and ceT1W sequences did not improve the detection of brain lesions and cannot be recommended as part of a routine brain MRI protocol in dogs and cats with suspected brain lesions.

Magnetic resonance imaging signs of presumed elevated intracranial pressure in dogs.

The aim of this study was to describe magnetic resonance imaging (MRI) findings associated with presumed elevated intracranial pressure (ICP) in dogs and to evaluate whether MRI could be used to discriminate between dogs with and without elevated ICP. Of 91 dogs that underwent cranial MRI examination, 18 (19.8%) were diagnosed with elevated ICP based on neurological examination, fundoscopy and transcranial Doppler ultrasonography. The MRI findings that showed the strongest association with elevated ICP were mass effect (odds ratio [OR], 78.5), caudal transtentorial herniation (OR, 72.0), subfalcine herniation (OR, 45.6), perilesional oedema (OR, 34.0), displacement of the lamina quadrigemina (OR, 27.7) and effacement of the cerebral sulci (OR, 27.1). The presence of any two or more of the following MRI findings identified elevated ICP with a sensitivity of 72% and a specificity of 96%: compression of the suprapineal recess, compression of the third ventricle, compression of the fourth ventricle, effacement of the cerebral sulci and caudal transposition of the lamina quadrigemina. In conclusion, there is an association between MRI findings and elevated ICP in dogs; therefore, MRI might be useful to discriminate between dogs with and without elevated ICP.

[Intrathoracic esophageal perforation of unknown cause in four horses]. / Intrathorakale Ösophagusperforation ungeklärter Genese bei vier Pferden.

Three horses (age 17 - 23 years) were referred to the equine clinic of the University of Berne due to colic, fever, tachycardia and tachypnea. All horses showed pleural effusion. Clinical findings in 2 of the horses were highly suggestive of an intra-thoracic esophageal perforation. Severe septic pleuropneumonia without suspicion of an esophageal lesion was diagnosed in the 3rd horse. In addition, an 11 year old stallion was referred to the equine clinic for treatment of a presumptive large colon impaction. The horse was given laxatives after nasogastric intubation. Subsequent dramatic clinical deterioration and signs consistent with severe pleuropneumonia suggest that esophageal perforation had occurred when passing the nasogastric tube. All 4 horses were euthanized due to a poor prognosis. Esophageal perforation was diagnosed or confirmed post mortem in all cases. A hypertrophy of the tunica muscularis of the intra-thoracic esophagus was found in 3 of 4 horses.

Use of a 1.5 mm butterfly locking plate for stabilization of atlantoaxial pathology in three toy breed dogs.

The objective of this study was to describe the use of a titanium 1.5 mm locking plate in the stabilization of atlantoaxial pathology in three toy breed dogs. Two dogs with atlantoaxial subluxation and another dog with an axial fracture, confirmed by diagnostic imaging, were stabilized via a ventral approach with a 1.5 mm titanium 5-hole locking butterfly-plate. Surgical reduction and stabilization were assessed by computed tomography and radiography after surgery. Follow-up evaluation for resolution of neurological signs and possible complications was performed in all three dogs. For long-term assessment, a telephone follow-up was performed. A considerable improvement of neurological signs occurred within two to four weeks after surgery. An excellent clinical outcome was identified in all three patients. Adequate stabilization and resolution of neurological signs in all three dogs was achieved. The stabilization of atlantoaxial surgical conditions in toy breeds with the 1.5 mm titanium 5-hole butterfly locking plate appears to be an effective means of surgical treatment.

Primary prostatic haemangiosarcoma causing severe haematuria in a dog.

A 10-year-old, entire, male, mixed-breed dog was presented for severe haematuria and stranguria. Ultrasound revealed a large intraluminal urinary bladder blood clot and a prostatic space-occupying lesion. Invasion of the lesion into the prostatic urethra was detected ultrasonographically during compression of the urinary bladder. Post-mortem examination revealed primary prostatic haemangiosarcoma infiltrating the urethra. Haemangiosarcoma should be considered as a rare cause of prostatic mass lesions, haematuria or lower urinary tract signs in dogs.

Alarm substances of the stingless bee,Trigona silvestriana.

2-Nonanol, 2-heptanol, octyl decanoate, and octyl octanoate were identified from the heads ofTrigona silvestriana workers. When presented at the nest, 2-nonanol, 2-heptanol, and the mixture of the four compounds elicited angular flights, landing, and buzzing of guard bees. Octyl octanoate elicited a weaker response. No response was given to octyl decanoate, to the ether solvent, or to the control volatile, vanillin.