Paranasal sinus cysts in the horse: Complications related to their presence and surgical treatment in 37 cases.

BACKGROUND: Paranasal sinus cysts (PSC) are a common cause of equine secondary sinusitis. The outcome and associated complications have not been frequently reported. OBJECTIVES: To review the associated clinical signs, associated morbidities and outcomes of horses treated for PSC. STUDY DESIGN: Retrospective multicentre case series. METHODS: Retrospective analysis of case records and telephone follow up survey. RESULTS: Subjects were 37 horses 1-24 years old that were presented with nasal discharge (n = 31), facial swelling (n = 25) and epiphora (n = 19). Radiography and computed tomography allowed identification of the cyst-induced changes including concomitant tissue destruction (n = 31), leading among other things to local nerve damage causing headshaking (n = 6) and unilateral blindness (n = 1). Radiographic changes to adjacent dental apices were present in 10 horses. Horses over 10 years old showed more of the named associated problems. Post-operative complications included surgical site infection (SSI) (n = 11), nasofrontal suture periostitis (n = 6) and sequestration (n = 1) following removal of the PSC via osteotomy. The long-term response to treatment was available for 28 cases with 22 horses (78.6%) fully cured, 4 (14.3%) partially cured and 2 (7.1%) not responding to treatment. In 7 horses (18.9%) there was recurrence of the cyst post-operatively. MAIN LIMITATIONS: Due to the study being a multicentre retrospective case series with collection of data over an extended period, there may be inconsistency in data recording and absence of reporting of some findings. CONCLUSIONS: Overall, the diagnosis and treatment of sinus cysts is relatively straightforward and carries a good prognosis. In long-standing cases complications secondary to the expansive growth of cysts will dramatically affect the prognosis for full recovery due to pressure-induced changes to facial bones, cheek teeth and nerves. These secondary complications mainly occurring in older horses may be due to a combination of a relatively longer period of affection and the inflexibility of older horses' bones. Cyst recurrence following treatment can occur in up to 19% of cases.

The association between oral examination findings and computed tomographic appearance of the equine temporomandibular joint.

BACKGROUND: The temporomandibular joint (TMJ) forms the junction between the maxilla and mandible. Movement of the jaw and resulting masticatory forces have been extensively studied in the horse; however, less is known about the inter-relationship between this joint and oral and dental pathology. OBJECTIVES: To determine the association between specific oral and dental pathologies and anatomical variations of the TMJ imaged with computed tomography (CT) in horses with asymptomatic TMJs. STUDY DESIGN: Retrospective cross-sectional study. METHODS: Horses (n = 201) from three practices with a complete oral examination and skull or upper cervical CT study were reviewed. Age, breed, sex, clinical presentation, oral examination findings, slice width and practice were recorded. Alterations in contour and density of the mandibular condyle, mandibular fossa and intra-articular disc were also documented. Logistic regression, corrected for clustering by practice, was used to determine whether CT anatomical variations were significantly associated with the oral examination findings. RESULTS: Horses categorised as having abnormal TMJs were older than those with normal TMJ. Horses with periodontal disease were less likely to have abnormal TMJ findings compared with horses with no oral pathology. In contrast, horses with infundibular disease were more likely to have TMJ abnormalities. MAIN LIMITATIONS: Due to the cross-sectional nature of the study, it was difficult to establish whether oral pathology preceded TMJ abnormalities. CONCLUSIONS: Despite examining over 200 horses of varying ages, the biological significance of the observed associations between oral, or dental disease and anatomically appreciable temporomandibular joint disorders remains uncertain.

Bacteraemia before, during and after tooth extraction in horses in the absence of antimicrobial administration.

BACKGROUND: Transient bacteraemia can occur during tooth extraction in humans, and dogs and can lead to severe infectious sequelae. Several case reports describe distant site infections following equine tooth extraction, but the occurrence of bacteraemia during dental surgery has not been evaluated in the horse. OBJECTIVES: To determine if transient bacteraemia occurs during tooth extraction in horses, describe isolated organisms and compare these with those found in the diseased teeth. STUDY DESIGN: Prospective, observational study. METHODS: Blood was collected aseptically for blood culture before, during and after oral extraction of incisor, canine or cheek teeth from 20 adult horses undergoing dental extraction that had not received antimicrobial agents for at least 4 weeks prior to surgery. Bacteria found in blood cultures were compared with those found in swab samples obtained from the extracted teeth. RESULTS: Eighteen of 20 horses had positive blood cultures at one or more time points. Streptococcus spp., Actinomyces spp., Fusobacterium spp. and Prevotella spp. were most commonly found. Bacterial genera isolated from swab samples of extracted teeth largely corresponded with those identified in blood cultures. MAIN LIMITATIONS: This study was limited by its use of only conventional bacterial culture, the lack of statistical analysis to explore associations between gingiva score and the occurrence of bacteraemia, and the lack of an age-matched control group of horses not undergoing exodontia. CONCLUSIONS: Transient bacteraemia of oral origin commonly occurs during dental extraction in horses. As none of the horses developed complications associated with bacteraemia during the observation period after surgery, the significance of this bacteraemia remains uncertain. The Summary is available in Chinese - see Supporting Information.

[Examination of horses with acute colic - clinical pathology and diagnostic imaging]. / Untersuchung des akut kolikkranken Pferdes -labordiagnostische und bildgebende Verfahren.

The article summarizes the relevant clinical pathological assessment of horses with acute colic. A minimal laboratory evaluation should include the patient's haematocrit (or packed cell volume), total protein, and lactate concentration in the blood. Haematocrit and total protein provide an indication of the severity of dehydration (haematocrit < 0.45 l/l is evidence of no to mild dehydration whereas > 0.5 l/l points to a severe dehydration). The degree of dehydration is often associated with the severity of the colic. Additionally, the blood lactate concentration rises with increasing intestinal compromise with a concentration of > 4 mmol/l indicating a guarded prognosis. However, it is crucial to assess laboratory values only in the context of the clinical findings. If an abdominocentesis is performed, the leukocyte count and the protein and lactate concentrations offer valuable information regarding the type of colic, the severity of the lesion, further therapy, and prognosis of the colic. Reddish discolouration of peritoneal fluid may be a sign of a strangulating obstruction. Transcutaneous abdominal ultrasonography may provide a crucial insight into the colic cause and severity in a relatively short time, even for inexperienced examiners. In regards to small intestinal lesions, dilated small intestinal loops can often be imaged ultrasonographically before they can be palpated transrectally. The occurrence of free peritoneal fluid and dilated small intestine as well as the evaluation of the intestinal wall and the extent of the gastric wall, allow a better management of the acute colic patient. In ponies and foals, radiography as a further diagnostic imaging modality of the abdomen is of great value. It can help to visualise sand impactions, meconium impactions, or gastrointestinal atresia in the neonate.

[Examination of horses with acute colic: clinical and legal aspects]. / Untersuchung des akut kolikkranken Pferdes - klinische und forensische Aspekte.

The article provides hands-on advice and scientific background information regarding the management of the equine acute colic patient. It summarizes essential information on the patient's history, clinical examination, and legal aspects. The scope of the history is based on the clinical appearance of the patient. In horses with violent and barely controllable signs of pain, it is limited to colic-associated information such as onset, course and severity of colic signs, and the last time of defecation, as well as prior therapeutic intervention. In these patients, the clinical examination is focussed primarily on the assessment of cardiovascular parameters, rectal temperature, and the patient's behaviour. The nasogastric intubation is an essential part of the examination of a horse with colic to prevent a gastric rupture due to gastric distension. Transrectal palpation is equally important and should always be performed unless there are important reasons to object to this procedure. In most cases, a thorough patient history and clinical examination of an acute colic patient allows the examining veterinarian to make a tentative diagnosis and a prognostic evaluation. This helps with the decision to start a conservative or a surgical therapy. Due to the existing obligatory documentation requirement and the duty to inform patient owners, it is of utmost importance to promptly document one's findings, therapeutic measures, consultations, and information of the patient owner in written form. This supports further therapy and it can also be of relevance in a potentially resulting lawsuit.