Flowmetry and spectrophotometry for the assessment of intestinal viability in horses with naturally occurring strangulating small intestinal lesions.

BACKGROUND: Ancillary diagnostic methods to enhance the accuracy of viability assessment have not been established for use in clinical practice. OBJECTIVES: To assess intestinal microperfusion measured by Laser Doppler Flowmetry and Spectrophotometry (LDFS) in naturally occurring small intestinal strangulations of different origins and to compare this between viable and non-viable segments. STUDY DESIGN: Prospective clinical trial. METHODS: Forty horses undergoing colic surgery for naturally occurring small intestinal strangulations were included. Tissue oxygen saturation (tSO2), haemoglobin (tHB) and blood flow (tBF) were determined by LDFS before and after release of the strangulation. Intestinal biopsies were taken in cases that underwent intestinal resection or intraoperative euthanasia and assessed using a semi-quantitative mucosal injury score (MIS). The LDFS measurements were compared between the different categories of strangulation causes and histopathological injury using parametric and non-parametric tests (p < 0.05). RESULTS: Strangulations by pedunculated lipomas had lower tBF (13.9 ± 18 arbitrary units [AU]) than epiploic foramen entrapments (65.2 ± 61 AU; CI -1.697 to -0.2498; p = 0.005). Segments with MIS > 5 showed lower tBF during strangulation than segments with MIS < 4 (mean difference 61.1 AU; CI -1.119 to -0.07361; p = 0.03). This did not differ significantly following release of strangulation. Furthermore, there was a positive correlation between the inflammatory cell count and tBF during strangulation (r 0.34; CI 0.01 to 0.60; p = 0.04). The tSO2 and tHB did not differ between the different categories of lesions or injury. MAIN LIMITATIONS: No biopsies could be taken from the intestinal segments that did not undergo resection. The duration of strangulation could not reliably be ascertained. CONCLUSIONS: Blood flow measurements in naturally occurring strangulating lesions show a varying degree of ischaemia in different causes of strangulation. Intestinal blood flow measurements prior to release of the strangulation could potentially contribute to the identification of mucosal injury, yet a high individual variability and other contributing factors need to be considered.

Potential impact of natural conditions on the rostral oral health: a study of horses in Iceland.

OBJECTIVE: In the context of a study of Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH), elderly Icelandic horses were examined in their originating country. The subject of this survey was the impact of dental treatment and keeping and feeding management on the health of the rostral oral cavity. ANIMALS: A total of 170 horses (aged ≥ 15) located in different areas of Northwest, West, and South Iceland. METHODS: The horse owners completed a questionnaire about keeping, feeding, and preventative dental care. The horses were clinically examined with particular attention to gingival and dental disorders of the rostral mouth, such as gingivitis, fistula, gingiva retraction, enlargement of the roots and dental calculus as well as integrity of incisors, bite angle, and tooth mobility. RESULTS: Most of the horses were kept on pasture all year with little supplementary feeding. The frequency of dental treatment in Iceland was low. Only a few horses were affected by tooth loss, gingivitis, gingival recession, and incisor calculus. Calculus occurred more frequently and more severely in canines than in incisors. The findings did not depend on the location of the horse. CLINICAL RELEVANCE: Assuming that the remarkable health of the rostral oral cavity in elderly Icelandic horses was not caused by preventive dental care, it is likely that it was due to living conditions in Iceland. Continuity, intensity of chewing, and nativeness of forage might promote the health of incisors and tissue surrounding the tooth even in elderly horses.

Widespread prevalence of Equine Odontoclastic Tooth Resorption and Hypercementosis detected in German Icelandic horse population: impact of anamnestic factors on etiology.

OBJECTIVE: To compare anamnestic factors in Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) in affected and nonaffected horses to detect risk factors for horses developing EOTRH. ANIMALS: A total of 154 Icelandic horses, aged 15 years and older, examined at 22 locations in Lower Saxony, Germany. The investigations took place from October 2020 to December 2021. METHODS: Anamnestic data were collected using an owner-completed questionnaire. Horses underwent a thorough physical examination and CBC. The rostral oral cavity was clinically examined, and intraoral radiographs of the incisors were taken. Clinical and radiographic findings were scored. Based on the results, the study population was separated into "EOTRH-affected" and "EOTRH-healthy" horses. Both groups were compared to identify differences within the anamnestic factors. In case of inconclusive findings, some horses were classified as "suspicious". RESULTS: The diagnosis of EOTRH was made in 72.2% (109/151) of horses. The risk of contracting the disease increased with the age of the horse (P = .004). In addition, there was a predisposition for male animals (P = .032). Feeding, keeping, and dental treatments showed no significant influence, while place of birth seemed to influence horses developing EOTRH (P = .017). CLINICAL RELEVANCE: The results highlight how widespread EOTRH is among the German Icelandic horse population and the need for raising awareness of EOTRH, as many horses were not suspected of having EOTRH beforehand. Moreover, numerous etiological propositions exist, but, to date, no studies have investigated their relevance.

Early incisor lesions and Equine Odontoclastic Tooth Resorption and Hypercementosis: Reliability of radiographic findings.

BACKGROUND: In clinical practice, early diagnosis of Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) and other resorptive incisor diseases is difficult to achieve. The radiographic appearance of subtle pathological changes has not been described in detail and might be confused with age-related changes. OBJECTIVES: The study was performed to define typical radiographic signs of early incisor lesions and to evaluate the reliability of the radiographic findings. STUDY DESIGN: Descriptive and comparative study using post mortem clinical, radiographic, macroscopic and µCT examination. METHODS: The incisor region of 20 cadaveric horse heads, divided into three different age groups, was examined visually and by palpation. Intraoral radiographs were taken. After extraction, each incisor was macroscopically evaluated. Micro-computed tomography (µCT) scans were obtained. These scans were processed with Scry (v6.0, Kuchel & Sautter GbR) to obtain surface meshes which then were transferred to Meshlab (ISTI-CNR, version 2016.12). Attached tissues were virtually removed and surface curvature was computed to visualise and evaluate the quantity of unevenness (roughness) of the teeth's surface. Scoring systems for each diagnostic modality were developed. Scores were compared to describe and evaluate the radiographic appearance of early incisor lesions. RESULTS: The prevalence and severity of incisor lesions increased with age. Early, subtle lesions develop on the palatal/lingual side of incisors. While radiographically detected lesions were confirmed macroscopically and on the µCT scans, numerous teeth which were radiographically classified as healthy displayed lesions by macroscopic inspection (13.7%) and µCT analysis (58.1%). MAIN LIMITATIONS: Cadavers were studied and dental history was unknown. CONCLUSIONS: The detection of early and subtle incisor lesions indicating first signs of EOTRH on dorsoventral intraoral radiographs is limited due to the typical localisation of the lesions on the palatal/lingual side of the incisors.

Equine Incisor Lesions: Histologic Confirmation of Radiographic, Macroscopic, and Micro-Computed Tomographic Findings.

Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) and other incisor lesions are often diagnosed only in advanced stages. The incisors of 20 horses were examined radiographically, macroscopically, and via micro-computed tomography (µCT) to discriminate EORTH-affected teeth. Five categories from healthy to severely affected teeth were formed and teeth from each category were examined histologically to evaluate the opportunity of earlier radiographic diagnosis. Histologically, odontoclastic resorptive lesions, leukocytic infiltrations, and areas of irregular cementum and granulation tissue were observed. The extent and severity of histological findings were correlated to the µCT data. Micro-CT imaging was suitable to detect subtle irregularities in the dental substances which were referred to as resorptive lesions. Although histological examinations confirmed the presence of resorptive lesions, not all of them were classified as pathological conditions. Instead, repaired surface lesions were documented which were regarded as a physiological condition. Nevertheless, incisors which were radiographically regarded as healthy can also feature histological signs of EOTRH. Therefore, due to the possibility of misinterpreting radiographic findings combined with superimpositions on intraoral radiographs, the detection of early resorptive lesions remains challenging.

Equine Suture Exostosis: A Review of Cases from a Multicenter Retrospective Study.

Suture exostosis is an intriguing and not uncommon pathology that has to be included in the differential diagnosis for horses with swelling of the head. Although several singular case reports have been published, no large case series is available. The aim of this study is to report a multicentric retrospective collection of suture exostosis cases. Data concerning horses with suture exostosis in the facial region were collected retrospectively. Information regarding breed, age, gender, history, imaging findings, initiated treatment, response to treatment and follow up was recorded. One hundred and five cases of various breeds were reported. Analysis revealed the cases could be grouped into four entities: 45 developed following sino-nasal surgery, 23 following trauma, seven with underlying sinus pathology and 25 idiopathic. Treatment consisted of sequestra removal, plate fixation, antimicrobial and anti-inflammatory drugs or no treatment. Whereas initial localized pain fades within few days or weeks, resolution or reduction of the swelling was obtained in most cases after 3 months to 1.5 years. The etiopathogenesis of suture exostosis seems to consist of different entities. Identification of an underlying cause, particularly the presence of a bone sequester and infection is important to speed up resolution and before concluding an idiopathic case. When performing sinusotomies, it is important to provide as little trauma as possible to the surgical site in order to prevent suture exostosis as a complication.

Influence of Butorphanol, Buprenorphine and Levomethadone on Sedation Quality and Postoperative Analgesia in Horses Undergoing Cheek Tooth Extraction.

The aim of this prospective clinical trial was to compare the influence of butorphanol, buprenorphine and levomethadone on sedation quality and postoperative analgesia in horses undergoing cheek tooth extraction. Fifty horses were assigned to three groups prior to oral cheek tooth extraction. Horses were treated with acepromazine, followed by a detomidine bolus, one of the three opioids and both a nerve block and gingival anaesthesia. During the surgery, sedation was maintained with a detomidine constant rate infusion. After surgery, the quality of sedation, surgical conditions and severity of the extraction were assessed with a numerical rating scale. To evaluate differences in the quality of analgesia between the three treatments, postoperative pain was estimated with the Equine Utrecht University Scale for Facial Assessment of Pain. Additionally, several parameters that are associated with dental pain were added to this validated pain score, and blood samples were taken to measure serum cortisol. Our analysis showed lower pain scores and a greater analgesic effect with levomethadone and buprenorphine compared with butorphanol, with increased locomotor activity induced by buprenorphine. While cortisol values demonstrated higher response in horses treated with levomethadone and buprenorphine compared to butorphanol, these values could be biased by unrelated stressors.

Clinical effect of buprenorphine or butorphanol, in combination with detomidine and diazepam, on sedation and postoperative pain after cheek tooth extraction in horses.

The objective of this study was to compare effects of butorphanol (BUT) or buprenorphine (BUP), in combination with detomidine and diazepam, on the sedation quality, surgical conditions, and postoperative pain control after cheek tooth extraction in horses, randomly allocated to 2 treatment groups (BUT: n = 20; BUP: n = 20). A bolus of detomidine (15 µg/kg, IV) was followed by either BUP (7.5 µg/kg, IV) or BUT (0.05 mg/kg, IV). After 20 min, diazepam (0.01 mg/kg, IV) was administered and sedation was maintained with a detomidine IV infusion (20 µg/kg/h), with rate adjusted based on scores to 5 variables. All horses received a nerve block (maxillary or mandibular), and gingival infiltration with mepivacaine. Sedation quality was assessed by the surgeon from 1 (excellent) to 10 (surgery not feasible). A pain scoring system (EQUUS-FAP) was used to assess postoperative pain. Serum cortisol concentrations and locomotor activity (pedometers) were measured. Horses in BUP and BUT required a median detomidine infusion rate of 30.2 µg/kg/h (20 to 74.4 µg/kg/h) and 32.2 µg/kg/h (20 to 48.1 µg/kg/h), respectively (P = 0.22). Horses in the BUP group had better sedation quality (P < 0.05) during surgery and higher step counts (P < 0.001) postoperatively. Buprenorphine combined with detomidine provided a more reliable sedation than butorphanol. However, the EQUUS-FAP pain scale became unreliable because of BUP-induced excitement behavior.

Effet clinique de la buprénorphine ou du butorphanol, en association avec la détomidine et le diazépam, sur la sédation et la douleur postopératoire après extraction de dents jugales chez le cheval. L'objectif de cette étude était de comparer les effets du butorphanol (BUT) ou de la buprénorphine (BUP), en association avec la détomidine et le diazépam, sur la qualité de la sédation, les conditions chirurgicales et la gestion de la douleur postopératoire après extraction des dents jugales chez les chevaux, répartis au hasard dans deux groupes de traitement (BUT : n = 20; BUP : n = 20). Un bolus de détomidine (15 µg/kg, IV) a été suivi soit de BUP (7,5 µg/kg, IV) soit de BUT (0,05 mg/kg, IV). Après 20 min, du diazépam (0,01 mg/kg, IV) a été administré et la sédation a été maintenue avec une perfusion IV de détomidine (20 µg/kg/h), avec un taux ajusté en fonction des scores de cinq variables. Tous les chevaux ont reçu un bloc nerveux (maxillaire ou mandibulaire) et une infiltration gingivale avec de la mépivacaïne. La qualité de la sédation a été évaluée par le chirurgien de 1 (excellent) à 10 (chirurgie impossible). Un système de notation de la douleur (EQUUS-FAP) a été utilisé pour évaluer la douleur postopératoire. Les concentrations sériques de cortisol et l'activité locomotrice (podomètres) ont été mesurées.Les chevaux en BUP et BUT ont nécessité un débit médian de perfusion de détomidine de 30,2 µg/kg/h (20 à 74,4 µg/kg/h) et 32,2 µg/kg/h (20 à 48,1 µg/kg/h), respectivement (P = 0,22). Les chevaux du groupe BUP avaient une meilleure qualité de sédation (P < 0,05) pendant la chirurgie et un nombre de pas plus élevé (P < 0,001) après l'opération. La buprénorphine associée à la détomidine a fourni une sédation plus fiable que le butorphanol. Cependant, l'échelle de douleur EQUUS-FAP est devenue peu fiable en raison du comportement d'excitation induit par le BUP.(Traduit par Dr Serge Messier).

Complex Odontoma in a Young Captive Reticulated Giraffe (Giraffa camelopardalis reticulata).

Complex odontoma is a rare odontogenic lesion reported in rodents (order: Rodentia) and odd-toed ungulates (order: Perissodactyla), to name a few, and only in bovine animals of the order Artiodactyla. A 3-year-old female giraffe presented with a steadily proliferating, firm mass in the rostral mandible. With further expansion and ulceration of the mass, the general condition of the giraffe deteriorated and it was euthanized. Post-mortem examination revealed greyish-white tissue with an irregular arrangement of yellowish hard tissue arranged in thin plates and intermingled areas of greyish soft tissue. Histologically, irregular proliferated odontogenic epithelium and mesenchyme, dentin, cementum and empty spaces, suggestive of decalcified enamel, were present. These findings are consistent with a diagnosis of complex odontoma, which should be added to the differential diagnoses of oral tissue proliferations in giraffes. To our knowledge, this is the first description of a complex odontoma in a giraffe.

A Rare Case of Vascular Proliferation in the Mandible of a Juvenile Horse.

A fast growing, circumscribed, unilateral swelling of the right mandible of a juvenile horse was observed. Within few weeks, the continuously growing mass reached dimensions ranging from 7 to 10 cm in diameter and resulted in loss of the first deciduous premolar of the affected side. The animal was euthanized due to lesion progression. Histologically the mandibular swelling consisted of numerous variably sized vascular structures, partly filled with erythrocytes and embedded in a loosely arranged fibrous stroma within the medullary cavity of the mandible. Juvenile mandibular angiomatosis was diagnosed. To the authors' knowledge this is the first description of this rare entity in the mandible of a foal.

Complications Following Mandibular Cheek Tooth Extraction in 20 Horses.

The objectives of this retrospective study were to describe the prevalence and characteristics of post-operative complications that occur following equine mandibular cheek tooth extractions and to assess for possible associated risk factors. Clinically significant post-extraction complications necessitating repeat referral developed following 20/302 (6.6%) mandibular cheek tooth extractions. Horses developing complications were younger than the overall population having mandibular cheek teeth extractions and the most commonly affected teeth were the Triadan 07 s and 09 s. Alveolar sequestration was the most prevalent complication, occurring in 18/20 horses (90%), with the complete alveolus sequestering in some cases. Post-extraction mandibular fistula formation occurred in 5/20 cases (25%) and mandibular abscessation in 4/20 cases (20%). All cases were successfully treated, including sequestrectomy, and wound debridement with some cases taking up to 5 months for resolution. Anatomical features of the equine mandibular alveoli and bone appears to make them more prone to develop extensive sequestration compared to published complications on maxillary alveolar bone. This requires good pre-operative examination including diagnostic imaging to identify cases of higher risk and thorough risk disclosure toward horse owners as well as owners' compliance.

Comparative studies on the histological characteristics of equine nasomaxillary aperture and paranasal sinus mucosa considering topographic and age-related differences.

BACKGROUND: Horses may acquire a range of paranasal sinus diseases. Clinical studies show slight differences regarding anatomical regions and age. Histopathological examination of tissue samples could play an important role in the diagnostic process. Therefore, detailed knowledge of the histological appearance of the paranasal sinus mucosa (PSM) and the nasomaxillary aperture mucosa (NAM) is essential. The objective of this study was to determine topographic and age-related differences within the healthy equine PSM. In addition, we aimed to gain detailed knowledge of the histological appearance of the NAM in comparison to the PSM. RESULTS: The PSM had an average height of 75.72 ± 44.48 µm with a two-row pseudostratified columnar epithelium of 13.52 ± 4.78 µm. The parameters mucosal height, epithelial height and number of goblet cells revealed significant dependency of the sample site and age group. The maxillary and dorsal conchal sinus showed the highest values for these parameters. In terms of age, younger horses showed a significantly higher total mucosal height in contrast to a significantly lower epithelial height than older horses. Positive correlation was seen between the epithelial height and number of goblet cells. The NAM had an average height of 820.27 ± 653.21 µm. Its pseudostratified epithelium was usually arranged in three rows and had an average height of 44.9 ± 12.78 µm. The number of goblet cells in the NAM was five times higher than in the PSM. Serous glands were found in only 4% of the PSM samples and 100% of the NAM samples. CONCLUSIONS: There are significant histological differences between different paranasal sinus sites and between different groups of age. This may be related to an altered susceptibility for certain pathologies. The striking difference in the histological appearance of the NAM compared to the PSM could be due to an enhanced role in mucociliary clearance. Further studies are necessary to improve the understanding of mucosal function in specific paranasal sinus compartments and mucosal changes generated by different diseases.

Antimicrobial Usage in Horses: The Use of Electronic Data, Data Curation, and First Results.

The usage of antimicrobial drugs (AMs) leads to an increase in antimicrobial resistance (AMR). Although different antimicrobial usage (AMU) monitoring programs exist for livestock animals in Germany, there is no such system for horses. However, with the increasing usage of electronic practice management software (EPMS), it is possible to analyze electronic field data generated for routine purposes. The aim of this study was to generate AMU data for German horses with data from the Clinic for Horses (CfH), University of Veterinary Medicine Hannover (TiHo), and in addition to show that different processes of data curation are necessary to provide results, especially considering quantitative indices. In this investigation, the number of antimicrobial doses used and the amount and percentage of active ingredients applied were calculated. Data contained all drugs administered between the 1st of January and the 31st of December 2017. A total of 2,168 horses were presented for veterinary care to the CfH and 34,432 drug applications were documented for 1,773 horses. Of these, 6,489 (18.85%) AM applications were documented for 837 (47.21%) horses. In 2017, 162.33 kg of active ingredients were documented. The most commonly used antibiotic classes were sulfonamides (84.32 kg; 51.95 %), penicillins (30.11 kg; 18.55%) and nitroimidazoles (24.84 kg; 15.30%). In 2017, the proportion of Critically Important Antibiotics (CIA)-Highest Priority used was 0.15% (0.24 kg) and the proportion of CIA-High Priority used was 20.85% (33.85 kg). Of the total 9,402 entries of antimicrobial active ingredients, the three with the largest number used were sulfonamides [n = 2,798 (29.76%)], trimethoprim [n = 2,757 (29.76%)] and aminoglycosides [n = 1,381 (14.69%)]. Comparison between Administered Daily Dose (ADA) and Recommended Daily Dose of CfH (RDDCfH), showed that 3.26% of ADA were below RDDCfH, 3.18% exceeded RDDCfH and 93.55% were within the range around RDDCfH. This study shows that data generated by an EPMS can be evaluated once the method is set up and validated. The method can be transferred to evaluate data from the EPMS of other clinics or animal species, but the transferability depends on the quality of AMU documentation and close cooperation with respective veterinarians is essential.

Magnetic resonance imaging and computed tomography of equine cheek teeth and adjacent structures: comparative study of image quality in horses in vivo, post-mortem and frozen-thawed.

BACKGROUND: The use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens' conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI. RESULTS: The CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens' conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition. CONCLUSIONS: On comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.

Cephalometric Study of the Overjet Development in Warmblood Foals.

Class II malocclusion is the most frequently occurring congenital malocclusion in horses. Radiographic cephalometric procedures adopted from human dentistry were used to study the development of overjet in a population of 650 Warmblood foals. Thirteen foals were diagnosed with measurable overjet at the beginning of the study. The malocclusion in nine foals resolved spontaneously and four foals without overjet at 2 weeks of age developed the condition during the first year of life. A cephalostat used in human orthodontics to immobilize the patient's head while being radiographed was replaced by a researcher-made head-holding device, whose size was based on the results of a pilot study. Laterolateral digital radiographs of each foal's head (cephalograms) were taken at five time points until the age of 12 months. Thirteen cephalometric points were identified and nine distances were measured on each radiograph. Additionally, the angle between the long axis of the upper and lower incisors was evaluated. Cephalometric measurements proved to be useful to identify foals that showed spontaneous regression of the malocclusion over the study time between 9 and 16 weeks of age.

Cytological Examination of Secretions From the Paranasal Sinuses in Horses.

The objective of this study was to determine whether the assessment of cytological features of secretions from the paranasal sinuses represents a useful diagnostic tool in equine sinusitis to distinguish between different etiologies. Secretion samples from 50 horses with sinusitis and 10 healthy horses were taken transendoscopically from the drainage angle of the nasomaxillary aperture using a Swing Tip catheter. An additional direct sample from the caudal maxillary sinus was taken from all healthy horses after trephination. A direct sample was obtained from the affected sinus in 19 diseased horses after osteotomy. Samples were smeared on microscope slides and dyed using "Pappenheim stain" for cytological evaluation. Smears from horses with sinusitis (primary n = 14, dental n = 28, cyst n = 2, progressive ethmoidal hematoma [PEH] n = 2, traumatic n = 2, malignant neoplasia n = 2) were dominated by moderate to high numbers of neutrophilic granulocytes and moderate numbers of different epithelial cells, whereas samples from healthy sinuses revealed almost exclusively epithelial cells. Smears in dental-related sinusitis tended to contain more lytic cellular material than in other conditions. Horses with dental sinusitis also showed a higher intracellular and extracellular bacterial burden than horses with other underlying etiologies and healthy horses. The absence of bacteria in light microscopy did not exclude the evidence of pathogenic bacteria from bacterial culture in every case. Case numbers were too small to evaluate the diagnostic value for neoplastic conditions or PEH. In conclusion, cytological examination of secretions from the paranasal sinuses can provide an additional but limited ancillary diagnostic value in equine sinusitis.

Study of the relationship between overjet development and some skull bone measurements in Warmblood foals.

Overjet is defined as the projection of the maxillary incisors labial to their antagonists in a horizontal direction. This malocclusion in horses can lead to incorrect dental wear and is aesthetically undesirable. Whether lengthening of the maxilla or shortening of the mandible causes the condition has not yet been determined. Therefore, a measurement technique was developed to investigate the correlations between skull bone measurements in overjet-affected individuals. The position of the incisors in 650 Warmblood foals born in a private German stud was examined at two weeks of age, revealing the prevalence of overjet to be 2 per cent. Five measurements were made on each foal's head and comparisons with a second set of measurements that were made later in the foals first year showed a change in the presence or degree of overjet over time. Nine of 13 foals diagnosed with measurable overjet at the beginning of the study resolved spontaneously. Thirteen foals had no evidence of overjet at birth, of which four developed the condition during the first year of life. The methods used for measuring longitudinal changes in different skull bones and for the assessment of malocclusion in foals affected with overjet were considered effective.

A prospective study on the microbiological examination of secretions from the paranasal sinuses in horses in health and disease.

BACKGROUND: Diagnostics in equine sinusitis can be challenging and often require a combination of different imaging tools to ascertain its underlying aetiology. The bacterial flora of healthy and diseased paranasal sinuses, respectively, has only sporadically been assessed in horses. The objectives of this study were to determine whether assessment of microbiological features of secretions from the paranasal sinuses displays a useful diagnostic tool in equine sinusitis to distinguish between different aetiologies. Secretion samples from 50 horses with sinusitis and from 10 healthy horses were taken transendoscopically from the drainage angle of the nasomaxillary aperture using a guidable Swing Tip catheter. Bacteria found in healthy and diseased equine sinuses were compared. Endoscopic samples in all healthy and 19 diseased horses were compared with samples taken directly from the affected sinus after trephination. RESULTS: Eleven of the 14 horses with primary sinusitis revealed growth of Streptococcus equi ssp. zooepidemicus, with three samples yielding pure cultures. Anaerobes were found in 15 out of 26 samples from horses with dental sinusitis. Healthy sinuses revealed mainly α-haemolytic streptococci and coagulase-negative staphylococci or showed no growth. Enterobacteriaceae were found more frequently in secondary sinusitis. There were significant differences in the bacterial composition and diversity (P < 0.05) between primary sinusitis, dental sinusitis and healthy controls. The correlation between endoscopic and trephination samples was satisfying. CONCLUSIONS: Microbiological examination of secretions from horses with sinusitis collected transendoscopically can help to distinguish between primary and dental sinusitis. Therefore, it may display a feasible ancillary diagnostic tool, but does not replace a meticulous examination procedure including diagnostic imaging.

Effect of butorphanol, midazolam or ketamine on romifidine based sedation in horses during standing cheek tooth removal.

BACKGROUND: Standing surgery, especially dental procedures, are commonly performed in horses. This leads to an increasing demand for reliable sedation protocols. Therefore, it was the purpose of this study to investigate the influence of butorphanol, midazolam or ketamine on romifidine based sedation in horses during cheek tooth removal. METHODS: Forty horses presented for tooth extraction were divided in four groups using matched pair randomization. Group R was sedated with romifidine (bolus 0.03 mg/kg, followed by a constant rate infusion (CRI) 0.05 mg/kg/h) and group RB with romifidine (same dose) and butorphanol (0.02 mg/kg; CRI 0.04 mg/kg/h). Group RM received romifidine (same dose) and midazolam (0.02 mg/kg; CRI 0.06 mg/kg/h) whereas group RK was administered romifidine (same dose) and ketamine (0.5 mg/kg; CRI 1.2 mg/kg/h). If sedation was not adequate a top up bolus of romifidine (0.01 mg/kg) was administered. The quality of sedation and the conditions for tooth extraction, the level of ataxia, chewing, head and tongue movement were evaluated by using a scoring system. The investigator was blinded to the applied sedation protocol. Furthermore, serum cortisol concentrations before, during and after the procedure were analyzed to gain more information about the stress level of the horses. RESULTS: Horses in group RM showed significantly less chewing and tongue activity compared to horses sedated with romifidine alone or with butorphanol additionally, but also significantly higher levels of ataxia. The quality of sedation was significantly better if romifidine was administered in combination with ketamine compared to romifidine alone. Furthermore, horses of group RK needed less additional romifidine boli compared to all other groups. Blood cortisol concentrations during surgery in groups RB and RM remained unchanged. Horses of group R showed higher cortisol concentrations during sedation compared to horses of groups RB and RM. CONCLUSION: Romifidine alone at an initial bolus dose of 0.03 mg/kg followed by a constant rate infusion of 0.05 mg/kg/h was insufficient to obtain an adequate level of sedation and led to increased stress levels, whereas the addition of butorphanol inhibited the stress response. The combination of romifidine with either midazolam or ketamine improved sedation quality and surgical conditions.

Comparison of computed tomography and high-field (3.0 T) magnetic resonance imaging of age-related variances in selected equine maxillary cheek teeth and adjacent tissues.

BACKGROUND: Modern imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) have the advantage of producing images without superimposition. Whilst CT is a well-established technique for dental diagnostics, MRI examinations are rarely used for the evaluation of dental diseases in horses. Regarding equine endodontic therapies which are increasingly implemented, MRI could help to portray changes of the periodontal ligament and display gross pulpar anatomy. Knowledge of age-related changes is essential for diagnosis, as cheek teeth and surrounding structures alter with increasing age. The aim of the present study was to highlight the advantages of CT and MRI regarding age-related changes in selected equine cheek teeth and their adjacent structures. RESULTS: The CT and MRI appearances of the maxillary 08 s and 09 s and adjacent structures were described by evaluation of post-mortem examinations of nine horses of different ages (Group A: <6 years, B: 6-15 years, C: ≥16 years). Most of the tissues selected were imaged accurately with MRI and CT. Magnetic resonance imaging gives an excellent depiction of soft endo- and periodontal units, and CT of hard dental and bony tissues. Negative correlation between dental age and pulpar sizes was found: 71.3% of the changes in pulp dimensions can be explained by teeth aging. Pulpar sizes ranged from 14.3 to 1.3 mm and were significantly smaller in older horses (p < 0.05). A common pulp chamber was present in 33% of the teeth with a mean dental age of 2.25 years. Ninety-four percent of the 08 and 09 alveoli of all groups were in direct contact with the maxillary sinus. An age-related regression was found (R2 = 0.88) for the distance between alveoli and the infraorbital canal. CONCLUSIONS: The present study provides information about the dental and periodontal age-related morphology and its visibility using different imaging techniques. These results aid in evaluating diagnostic images and in deciding which is the superior imaging modality for clinical cases.