Feline Head Research Articles

Mandibular fracture repair techniques in cats: a dentist's perspective.

Feline head trauma injuries are common in general practice, often resulting in mandibular fracture. An understanding of the recent advances in the field of mandibular fracture repair will facilitate evidence-based decision-making in clinical practice. Feline maxillofacial and oral anatomy brings unique challenges in comparison with dogs. It has been commonplace to adapt techniques and equipment that are better suited to other body regions or are species-inappropriate for use in feline maxillofacial surgery, and this has traditionally resulted in high morbidity. This review presents an overview of the diagnosis of, and decison-making for, maxillofacial trauma in cats, specifically with reference to the feline mandible. The challenges associated with the management of these injuries are presented. Techniques for repair that can be employed in general practice, as well as more advanced surgical options, are discussed, as well as the indications for invasive vs non-invasive management. Underutilised methods involving composite dental materials and their versatility for the repair of mandibular fractures in cats, and miniplates for caudal mandibular fractures in cats, are specifically covered, as well as other recent advances in the field, including three-dimensional printing and custom-printed implants. Management of feline facial fractures is an often neglected topic, with very few published studies choosing to focus on head trauma outcomes in cats. Where available, however, this review draws on the published literature, as well as the authors' own clinical experience.

Earliest hunting scene in prehistoric art.

Humans seem to have an adaptive predisposition for inventing, telling and consuming stories1. Prehistoric cave art provides the most direct insight that we have into the earliest storytelling2-5, in the form of narrative compositions or 'scenes'2,5 that feature clear figurative depictions of sets of figures in spatial proximity to each other, and from which one can infer actions taking place among the figures5. The Upper Palaeolithic cave art of Europe hosts the oldest previously known images of humans and animals interacting in recognizable scenes2,5, and of therianthropes6,7-abstract beings that combine qualities of both people and animals, and which arguably communicated narrative fiction of some kind (folklore, religious myths, spiritual beliefs and so on). In this record of creative expression (spanning from about 40thousand years ago (ka) until the beginning of the Holocene epoch at around 10ka), scenes in cave art are generally rare and chronologically late (dating to about 21-14ka)7, and clear representations of therianthropes are uncommon6-the oldest such image is a carved figurine from Germany of a human with a feline head (dated to about 40-39ka)8. Here we describe an elaborate rock art panel from the limestone cave of Leang Bulu' Sipong4 (Sulawesi, Indonesia) that portrays several figures that appear to represent therianthropes hunting wild pigs and dwarf bovids; this painting has been dated to at least 43.9ka on the basis of uranium-series analysis of overlying speleothems. This hunting scene is-to our knowledge-currently the oldest pictorial record of storytelling and the earliest figurative artwork in the world.

Radiotherapy isocenters verified by matching to bony landmarks of the canine and feline head differ when localized using volumetric versus planar imaging.

The "gold standard" for verification of patient positioning before linear accelerator-based stereotactic radiation therapy is kilovoltage cone-beam computed tomography (kV-CBCT), which is not uniformly available or utilized; planar imaging is sometimes used instead. The primary aim of this study was to determine if the position of the bony skull, when used as a surrogate for isocenter verification, is different when orthogonal megavoltage (MV) portal or kilovoltage (kV/kV) radiographs are used for image guidance, rather than kV-CBCT. A secondary aim was to determine the influence of intra-observer variability, body size and skull conformation on positioning, as determined using these three imaging modalities. Dogs and cats receiving radiotherapy of the head were recruited for this prospective analytical study. Planar (MV portal and kV/kV images) and volumetric (kV-CBCT) images were acquired before treatment, and manually coregistered with reference images. Differences in skull position when matched based on MV portal, kV/kV images and kV-CBCT were compared. A total of 65 subjects and 148 unique datasets were evaluated. The Wilcoxon rank-sum test was used to evaluate effects of transitioning between imaging modalities. When comparing magnitude of shifts in MV to kV-CBCT, MV to kV/kV and kV/kV to kV-CBCT, there were statistically significant differences. Results were not measurably impacted by body size, skull conformation or interobserver differences. Based on shift magnitude and direction, an isotropic setup margin of at least 1 mm should be incorporated within the planning target volume when MV or kV planar imaging is used for position verification.

Feline head trauma: a CT analysis of skull fractures and their management in 75 cats.

The aim of this study was to describe and evaluate the configurations and management of feline skull fractures and concurrent injuries following head trauma. Medical records and CT images were reviewed for cats with skull fractures confirmed by CT that were managed conservatively or with surgery. Details of signalment, presentation, skull fracture configuration, management, re-examination, and complications or mortality were recorded and analysed. Seventy-five cats (53 males, 22 females) with a mean age of 4.8 ± 3 years met the inclusion criteria. Eighty-nine percent of cats had fractures in multiple bones of the skull, with the mandible, upper jaw (maxilla, incisive and nasal bones) and craniofacial regions most commonly affected. Temporomandibular joint injury occurred in 56% of cats. Road traffic accidents (RTAs) were the most common cause of skull fractures, occurring in 89% of cats, and caused fractures of multiple regions of the skull. RTAs were also associated with high levels of concurrent injuries, particularly ophthalmic, neurological and thoracic injuries. A more limited distribution of injuries was seen in non-RTA cats. Equal numbers of cats were managed conservatively or surgically (47%). Mortality rate was 8% and complications were reported in 22% of cats. Increasing age at presentation and presence of internal upper jaw fractures were risk factors for development of complications. No risk factors were identified for mortality. RTAs were the most common cause of feline skull fractures and resulted in fractures in multiple regions of the skull and concurrent injuries occurred frequently. Problems with dental occlusion were uncommon post-treatment. An increased risk of implant loosening and malocclusion was seen with palatine and pterygoid bone fractures and hard palate injuries. This study provides useful additional information regarding feline skull fractures, concurrent injuries and management techniques following head trauma.

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Companion readers are offered a sneak preview of the latest addition to the BSAVA manual series, the BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, second edition.

Dual targeting of EGFR and ERBB2 pathways produces a synergistic effect on cancer cell proliferation and migration in vitro

Members of the epidermal growth factor receptor (EGFR/ERBB) gene family are frequently dysregulated in a range of human cancers, and therapeutics targeting these proteins are in clinical use. We hypothesized that similar pathways are involved in feline and canine tumours and that the same drugs may be of clinical use in veterinary patients. We investigated EGFR and ERBB2 targeting using a panel of feline and canine cell lines. EGFR and ERBB2 were targeted with siRNAs or tyrosine kinase inhibitors (TKIs) and their effect on cellular proliferation, colony formation and migration was investigated in vitro. Here we report that EGFR and ERBB2 combined siRNA targeting produced synergistic effects in feline and canine cell lines similar to that reported in human cell lines. We conclude that dual EGFR and ERBB2 targeting using TKIs should be further evaluated as a potential new therapeutic strategy in feline head and neck and mammary tumours and canine mammary tumours.

Evaluation of hypoxia in a feline model of head and neck cancer using 64Cu-ATSM positron emission tomography/computed tomography

BackgroundHuman and feline head and neck squamous cell carcinoma (HNSCC) share histology, certain molecular features, as well as locally aggressive and highly recurrent clinical behavior. In human HNSCC, the presence of significant hypoxia within these tumors is considered an important factor in the development of a more aggressive phenotype and poor response to therapy. We hypothesized that feline head and neck tumors, particularly HNSCC, would exhibit hypoxia and that 64Cu-diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM) positron emission tomography/computed tomography (PET/CT) would permit detection of intratumoral hypoxia.Methods12 cats with measureable head and neck tumors were given 64Cu-ATSM and iodinated contrast for PET/CT scan. The presence or absence of hypoxia was also assessed using an intratumoral fluorescent life-time probe to quantitate pO2 and pimonidazole immunohistochemical staining in biopsy specimens. In two cats, intratumoral O2 and 64Cu-ATSM uptake was measured before and after treatment with anti-angiogenic agents to determine the effect of these agents on hypoxia.ResultsEleven of twelve feline tumors demonstrated significant 64Cu-ATSM uptake, regardless of malignant or benign etiology. The presence (and absence) of hypoxia was confirmed using the fluorescent O2 detection probe in nine tumors, and using pimonidazole staining in three tumors. Squamous cell carcinomas (HNSCC) demonstrated the highest degree of hypoxia, with Tmax/M ratios ranging from 4.3 to 21.8. Additional non-neoplastic tissues exhibited 64Cu-ATSM uptake suggestive of hypoxia including reactive draining lymph nodes, non-malignant thyroid pathology, a tooth root abscess, and otitis media. In two cats with HNSCC that received anti-vascular agents, the pattern of 64Cu-ATSM uptake was altered after treatment, demonstrating the potential of the feline model to study the modulation of tumor oxygenation.ConclusionFeline HNSCC serves as a clinically relevant model for the investigation of intratumoral hypoxia including its measurement, modulation and targeting.

ANATOMIC VARIATIONS OF FELINE INTERNAL AND EXTERNAL JUGULAR VEINS

We evaluated 50 feline head and neck computed tomography examinations to determine the prevalence of vascular variation in the internal and external jugular veins. We identified three distinct anatomic conformations of the internal jugular vein. No variation of external jugular vein morphology was detected. Feline patients can have different internal jugular vein morphology that should be recognized for surgical planning.

Multimodal therapeutic approach and interdisciplinary challenge for the treatment of unresectable head and neck squamous cell carcinoma in six cats: a pilot study

Feline head and neck squamous cell carcinoma (SCC) is a loco-regional disease harbouring a poor prognosis. The complex anatomic location precludes aggressive surgical resection and tumours recur within weeks to few months. Response to chemotherapy and local control after radiation therapy has been disappointing. In this study, a multimodal approach including medical treatment (thalidomide, piroxicam and bleomycin), radiation therapy (accelerated, hypofractionated protocol) and surgery was attempted in six cats. Treatment was well tolerated. Three cats with sublingual SCC were alive and in complete remission at data analysis closure after 759, 458 and 362 days. One cat with laryngeal SCC died of renal lymphoma after 51 days and the other with maxillary SCC died of a primary lung tumour 82 days after diagnosis. In both cats, the SCC was in complete remission. Only one cat developed metastases after 144 days. These encouraging preliminary results merit further evaluation in future trials.

Identification of tumour initiating cells in feline head and neck squamous cell carcinoma and evidence for gefitinib induced epithelial to mesenchymal transition

Feline oral squamous cell carcinoma is considered a highly invasive cancer that carries a high level of morbidity. Despite aggressive surgery, patients often succumb to disease, the tumour having inherent insensitivity to radiation and chemotherapy. In this study we sought to identify cells within the feline SCC1 line that have stem cell properties, including inherent resistance mechanisms. When feline cells were subjected to harsh growth conditions, they formed sphere colonies consistent with a stem cell phenotype. Utilising CD133, we were able to identify a small fraction of cells within the population that had enhanced sphere-forming ability, reduced sensitivity to radiation and conventional chemotherapy and demonstrated resistance to the EGFR-targeting drug, gefitinib. In addition, long-term culture of feline SSC1 cells in gefitinib caused a change in cell morphology and gene expression reminiscent of an epithelial to mesenchymal transition. Taken together, these results suggest that feline SCC may be driven by small subset of cancer stem cells.

Head trauma in the cat: 1. Assessment and management of craniofacial injury

Feline trauma is commonly seen in general practice and frequently involves damage to the head. While craniofacial injuries following trauma vary widely in severity, affected cats can often be severely compromised in terms of their neurological, respiratory and cardiovascular status, and their management can be challenging in both the short and long term. They need prompt stabilisation and careful monitoring in the initial period to maximise prospects of a successful outcome. Many cats with severe facial trauma will require surgery to stabilise skull fractures or address injuries to the eyes, with its inherent issues surrounding pain management, ensuring adequate nutrition and the necessity for ongoing hospitalisation. Cats with head trauma benefit from imaging of the injured areas as well as thoracic radiography. Imaging the skull can be challenging and is best performed under general anaesthesia. In unstable patients this can be delayed to prevent any associated morbidity. The clinical evidence base relating to injury to the feline head is limited, despite its relative frequency in general practice. This review focuses on the initial approach to craniofacial (in particular, ocular and jaw) trauma, and outlines simple techniques for management of soft tissue and bone injuries. Much of the information is based on the authors' clinical experience, as there is a paucity of well-described clinical case material.

Abstract 3293: Activity and safety of an antiangiogenic peptide in spontaneous head and neck squamous cell carcinoma in cats

Abstract Anginex is a rationally designed, synthetic peptide that inhibits proliferation of human and mouse endothelial cells and demonstrates anti-tumor activity in murine tumor models. The anti-tumor and anti-angiogenic activity of Anginex is attributable, at least in part, to its interaction with galectin-1, a carbohydrate binding protein. As an intermediate step in the clinical translation of Anginex and related anti-vascular agents, we are investigating the effects of Anginex in spontaneous feline head and neck squamous cell carcinoma (HNSCC). Feline HNSCC shares morphology, clinical behavior, and biologic features such as intratumoral hypoxia and expression of EGFR, COX-2, and mutant p53 with its human counterpart. Our objectives were to investigate the activity of Anginex in feline cells and provide evidence of its safety in a phase I trial in cats with HNSCC. To establish Anginex activity in vitro, we evaluated the effect of 24 hour exposure to Anginex doses ranging from 2.5 – 25 uM on proliferation of both feline aortic endothelial cells (FAECs) and feline HNSCC cells (SCCF1) using flow cytometry and labeling with propidium iodide and bromodeoxyuridine (BrdU). With increasing Anginex dose, we observed accumulation of FAECs in G1 and decreased uptake of BrdU. We observed no effect in SCCF1 cells. To investigate safety, cats were treated with Anginex in cohorts of at least three animals at doses of 1, 3, and 9 mg/kg daily for 5 days. Clinical, laboratory and histologic features were evaluated before and after treatment. There were no serious adverse events during treatment. Continuous variables including body weight and laboratory variables were compared before and after treatment using a Wilcoxon signed rank test. No statistically significant changes occurred in these parameters. These data indicate that Aniginex is active against feline endothelial cells specifically and appears to be safe in cats. We are currently investigating the effects of Anginex on tumor physiology and in combination with radiation therapy for feline HNSCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3293. doi:10.1158/1538-7445.AM2011-3293

New Fragments and Further Excavation of the Bellerophon Mosaic from Croughton

New Fragments and Further Excavation of the Bellerophon Mosaic from Croughton. Michael Dawson and David Neal write: In 1991 part of a mosaic floor depicting Bellerophon slaying the Chimaera was exposed on land belonging to the Rowler Estate at Croughton, Northants.1 The pavement was photographed and reburied and the site subsequently assessed by English Heritage prior to scheduling in 1995. During the course of investigation, geophysical survey and trial-trenching established that the mosaic had been laid in a stone-built house, which was part of a more extensive settlement first occupied in the late second century. In 1998 the Rowler Estate changed hands and the potential to place the mosaic on display beneath a cover building was discussed by the new owner with English Heritage.2 In 2002 proposals to create a cover building were accepted in principle as the basis for a Scheduled Monument Consent application. As a result the Bellerophon pavement was fully excavated (fig. 1), together with an adjacent area to identify possible locations for stanchions and building foundations,3 where estate staff also believed a second mosaic had been discovered during the 1990s. The excavations indeed revealed the fragmentary remains of a second, probably figured pavement. The Bellerophon mosaic was first described (summarised here) and illustrated by Neal and Cosh.4 This note brings that description up to date, with the revised painting (fig. 2). The scheme of the mosaic comprises three panels, a central square (Panel A) flanked on the east and west sides by long rectangles (Panels B and C respectively). Panel A is a square defined by simple guilloche, with oblique bands of guilloche across the corners to create an octagon. Within, and tangential to, the sides of the octagon is a pair of interlaced squares in simple guilloche. In the spaces created by the interlaced squares are red triangles, and between the interlaced squares and the octagonal panel are grey and red lozenges with white centres outlined by grey dentilled bands. Three triangular panels at the corners of the panel survive and all contain a red heart-shaped leaf with curving stems. The central circle contains Bellerophon, viewed from the south, riding the winged horse Pegasus and slaying the Chimaera, all worked in a linear style. Bellerophon, shown looking behind him, holds a spear in his outstretched right hand. He wears a white tunic and breeches and across his chest and over his right shoulder is a red cloak, possibly fixed by a rounded grey brooch or clasp on his right shoulder. Pegasus is depicted with his hind legs stretched out behind him and, although damaged, the front legs also appear to have been extended originally as if flying. His wing passes in front of Bellerophon and its top edge is confused with, and parallel to, the spear. The Chimaera, with its feline head facing upwards, spits fire as a spear threatens to pierce its mouth. The mane is clearly represented on the front of the beast. From the back of the Chimaera rises the head of a goat, with its open mouth breathing fire. The tail, turned across the back of the animal, bears the head of a serpent. In front of the Chimaera are nine single grey tesserae on a field of white, which may be an attempt to represent water as a reference to Pegasus' spring-making qualities.5 To the right and left of Bellerophon's head are five red crosses, perhaps intended to represent stars in the sky as an allusion to the apotheosis of Pegasus as he rose into the heavens.6 Much of Panel B, on the east side, has been destroyed by ploughing, but what survives is almost identical to Panel C. The latter is bordered by a band of simple guilloche, outlined grey with red and white strands,

Surgical exploration of the head, neck and chest

Abstract Surgical diseases of the head, neck and thorax are considered a challenge by surgeons. Danial Brockman of the RVC introduces the BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery.

Feline head and neck squamous cell carcinoma: a natural model for the human disease and development of a mouse model

Head and neck squamous cell carcinoma (H/N SCC) is a devastating disease in humans and cats, and shares similar features between the two species. The large population of pet cats in the United States, along with the high incidence of oral SCC in the cat, makes the cat an attractive candidate as a natural model for the human disease. There are similarities in pathology, progression, outcome, resistance to treatment, possible aetiologies and p53 expression, and we discuss the benefits of the cat as a natural model. We describe the development of a nude mouse xenograft model of feline oral SCC using the SCCF1 cell line transfected with a luciferase expression construct. In vivo tumour growth and metastasis were measured using serial bioluminescent imaging, and tumours grew best in the subcutis. The cat and nude mouse models will be useful to investigate the pathogenesis and the molecular basis of H/N SCC, and for preclinical drug screening.

A device for feline head positioning and stabilization during magnetic resonance imaging

Minimization of head movement and reproduction of standard head positions are essential for reliable brain functional magnetic resonance imaging. Devices for stabilization and alignment of feline preparations are not available currently. We describe a system that involves minimal surgery, allows for both acute and chronic atraumatic positioning, and has the potential to be used for unanesthetized animals. The device uses non-metallic materials and stabilizes the head by means of an apparatus that fixes the head with nylon screws and dental cement in the frontal sinuses. Application of the head-stabilizing device decreases head movements by more than a factor of ten. Anatomical images show that this device provides 3 dimensional head placement at a precision comparable to that of a stereotactic frame, i.e. within 1 mm.

Emergency Management of the Head Trauma Patient: Principles and Practice

Management of the severely brain-injured dog or cat can be frustrating, especially considering the lack of proven effective therapies for head trauma patients. A working knowledge of the basic pathophysiology of head trauma and intracranial pressure (ICP) dynamics is essential to the logical treatment of head traumatized patients. Prevention and correction of hypotension and hypoxemia are necessary for preventing progressive increases in ICP. Mannitol is recommended in most cases of severe head trauma, but there is little evidence to support the use of glucocorticoids in acutely brain-injured dogs and cats. The role of surgical intervention for head-traumatized dogs and cats is still uncertain, but may be beneficial in some cases. Aggressive, expedient treatment and attentive patient monitoring are key aspects of successfully managing canine and feline head trauma patients.