Guttural pouch empyema secondary to a periocular foreign body

This report describes a 3‐year‐old gelding presenting with signs of injury to its left eye following an accident in which the horse crashed into a hedge. The first treatment attempted to treat infections in the eye and respiratory tract due to secretions identified in the trachea. The horse did not improve and further clinical and radiographic evaluations detected a guttural pouch empyema. Surgical drainage was performed and antimicrobial treatment continued. However, the horse presented with severe epistaxis and euthanasia was elected due to suspected arterial rupture. At necropsy, a round and stiff branch plant was found creating a fistula from the left orbit to the left guttural pouch. Another branch was found inside the pouch, confirming the origin of the persistent infection and severity of the tissue lesion.     

Guttural pouch empyema caused by Corynebacterium pseudotuberculosis in a pregnant mare

During medical management of mild colic in a 12‐year‐old Quarter Horse, mid‐gestation mare, unilateral purulent nasal discharge from the right nostril was noted. Endoscopic examination revealed guttural pouch empyema. Culture was positive for Corynebacterium pseudotuberculosis and negative for Streptococcus equi ssp. equi. A synergistic haemolysis inhibition titre of 1024 was consistent with C. pseudotuberculosis infection. Treatment included serial lavages and local infusion of antibiotics into the guttural pouches along with a 6‐week course of oral trimethoprim–sulfamethoxazole and rifampicin. Overall, no additional sites of infection were identified and the mare responded well to treatment, delivering a healthy, full‐term foal. This case emphasises that C. pseudotuberculosis, although uncommon, should be considered as a differential for guttural pouch empyema.     

Laser fenestration of the mesial septum for treatment of guttural pouch chondroids in a pony

OBJECTIVE: To describe removal of guttural pouch chondroids through a laser fenestrated mesial septum in a pony with an obstructed pharyngeal ostium of the left guttural pouch. STUDY DESIGN: Case report. ANIMALS: Pony. METHODS: Transendoscopic laser neodymium:yttrium aluminum garnet (Nd:YAG) fenestration of the mesial guttural pouch septum was made by contact method (bare fiber, 15-25 W, exposure time 4 seconds). Dissected tissue was removed by transendoscopic monopolar electrosurgery (loop electrode, cutting blade) and multiple chondroids of varying size were removed from the left guttural pouch through the fenestration. RESULTS: After removing all chondroids and repeated flushing of the left guttural pouch via the right side, inflammation of the guttural pouch membranes decreased remarkably. The pony was discharged with instructions for transendoscopic lavage once weekly and was reevaluated at 2 months. A permanent septal fenestration was observed and the pony was free of abnormal clinical signs and being used for carriage driving competitions. CONCLUSION: Nd:YAG laser fenestration of the mesial septum is an approach for access to guttural pouch chondroids. CLINICAL RELEVANCE: When guttural pouch empyema and/or chondroids is associated with adhesion of the pharyngeal ostium, laser fenestration of the mesial septum from the opposite guttural pouch should be considered as an alternative approach for access, rather than classic external surgical approaches.     

Functional anatomy observations of the pharyngeal orificeof the equine guttural pouch (Auditory tube diverticulum)

The pharyngeal orifice of the equine auditory tube has not been adequately described. Its larger size andposition, further rostral within the nasopharynx compared with other species, cannot be easily explained, but could be important for the proposed brain-cooling function of the guttural pouches; however, unlike other species, it may not be the sole regulator of auditory tube aeration. A ‘second orifice’ (representing the final entrance to the auditory tube diverticulum) deserves recognition in performing a role in air exchange between the auditory tube, diverticulum and middle ear. The results of this investigation suggest that regular guttural pouch ventilation during resting respiration does not occur. Previous reports may reflect, at least in part, a misinterpretation of air pressure measurements within the guttural pouches and nasopharynx. Small decreases in simulated inspiratory pressure consistently caused the passive opening of both the pharyngeal orifice and pouch ostium in horse cadavers suggesting that an active counter process may exist in the live horse to maintain closure of the guttural pouch openings during rest and light exercise. Intrinsic tone of the stylopharyngeus and pterygopharyngeus muscles may be part of this active process. The investigation offers theoretical evidence that opening of the equine auditory tubes to ventilate the guttural pouch occurs in two different ways, active and passive. The active process has two stages: (1) opening of the pharyngeal orifices by simultaneous contractions of the levator and tensor veli palatini, and pterygopharyngeus muscles; then (2) opening of the pouchostia by contractions of dorsal portions of the palatopharyngeus muscles. The alternative passive route involves reduction in tone of the stylopharyngeus and pterygopharyngeus muscles accompanied by increased inspiratory pressure.     

Traumatic bilateral stylohyoid bone fracture in an Appaloosa

An Appaloosa gelding presented for a traumatic puncture wound of the head ventral to the base of his left ear, bilateral epistaxis and upper respiratory compromise. The horse did not exhibit dysphagia or cranial nerve deficits. The horse suffered bilateral oblique fractures of both stylohyoid bones due to the traumatic incident, diagnosed upon endoscopy of the guttural pouches. Treatment consisted of anti‐inflammatory medication, broad‐spectrum antibiotics, guttural pouch lavage and dietary management with soft feeds. At a one‐month follow‐up examination, endoscopic evaluation revealed a union at both stylohyoid bone fracture sites. Guttural pouch mycosis was diagnosed in the left guttural pouch on the lateral wall at the entrance of the lateral compartment. The guttural pouch mycosis was treated with a nystatin and gentamicin flush, followed by a course of oral fluconazole. At the 3‐month re‐evaluation, the guttural pouch mycosis had completely responded to treatment.     

IMAGING BASILAR SKULL FRACTURES IN THE HORSE: A REVIEW

Due to the complex nature of the anatomy of the equine head, superimposition of numerous structures, and poor soft tissue differentiation, radiography may be of limited value in the diagnosis of basilar skull fractures. However, in many horses radiographic changes such as soft tissue opacification of the guttural pouch region, irregular bone margination at the sphenoccipital line, attenuation of the nasopharynx, ventral displacement of the dorsal pharyngeal wall and the presence of irregularly shaped bone fragments in the region of the guttural pouches are suggestive of a fracture of the skull base. These findings in conjunction with physical examination findings and historical information may lead to a presumptive diagnosis of a fracture. When available and when the patient will accommodate the equipment, computed tomography may give a definitive diagnosis owing to its superior resolution and differentiation of soft tissue structures.     

利用相似理论实现植物根系参数的动态预测

应用特殊设计的营养袋纸培系统试验方法,对大豆根系的生长过程进行了研究。结果表明,大豆根系在营养袋纸培系统中的生长曲线呈S形;该方法在一定程度上可模拟植物根系的实际生长过程。此外,利用相似理论获得了实际根系生长过程中的各根构型参数。