耳镜检查评估耳道

王帆

Otoscopic evaluation of the ear canal

耳镜检查评估耳道

作者：Lynette K.Cole

翻译：郑江涛 校对：王帆

The most common ear disease of the dog and cat is otitis externa, which may be present in 10% to 20% of the canine population and 2% to 10% of the feline population . Common clinical signs of otitis externa are head shaking and scratching the ears. Some animals show few clinical signs until the otitis is severe, however. When evaluating a patient with otitis externa, it is important to determine the primary cause as well as the predisposing and perpetuating factors of the otitis so as to manage the otitis properly. The first diagnostic procedure that should be performed on a patient with a complaint of otitis externa is an otoscopic examination.

犬和猫最常见的耳病是外耳炎，可能存在于10%至20%的犬科动物和2%至10%的猫科动物中。外耳炎常见的临床症状是摇头和抓耳。然而，一些动物在耳炎严重之前很少表现出临床症状。当评估患有外耳炎的患者时，重要的是确定原发病因、易感因素和持久因素，以便正确处理耳炎。对主诉为外耳炎的患者要首先进行的诊断性检查是耳镜检查。

Anatomy of the ear

耳部解剖

Knowledge of the normal structures in the ear canal and their appearance otoscopically is essential to interpret abnormal findings. Therefore, a complete otic examination should be performed on every patient that is anesthetized so as to become comfortable with the morphology of the ear canal and the location of the tympanic membrane.

了解耳道的正常结构和它们在耳镜下的外观是解释异常表现的关键。因此，应对每个麻醉患者进行完整的耳部检查，以熟悉耳道的形态和鼓膜的位置。

Pinna

耳廓

The pinna has vastly different conformations in the dog depending on breed, although there is little variation in the cat. The size and shape of the auricular cartilage determine the appearance of the pinna. The auricular cartilage of the pinna is covered by skin. The cartilage is thin at the apex of the pinna and then thickens at its proximal end, where it is rolled into the form of a tube. The anthelix is a low transverse ridge located on the medial wall of the initial proximal part of the ear canal. The tragus, an irregular quadrangular plate of cartilage, forms the lateral boundary of the initial portion of the ear canal just opposite to the anthelix. The antitragus is a thin elongated piece of cartilage caudal to the tragus and separated from it by the incisura intertragica (intertragic incisure). Distal to the antitragus is the cutaneous marginal pouch. Rostral to the tragus is the medial crus of the helix, which is separated from the tragus by the tragohelicine incisure (Fig. 1). The inner pinna has a decreasing amount of hair from the distal to proximal part. A few fine hairs are found at the entrance to the ear canal .

根据品种的不同，犬的耳廓有很大的不同，但猫的耳廓几乎没有变化。耳廓软骨的大小和形状决定了耳廓的外观。耳廓软骨被皮肤覆盖。软骨在耳廓的顶远端较薄，然后在其近端变厚，在那里它被卷成管状。对耳轮是一个低的横脊，位于耳道开口近端的内侧壁上。耳屏，一种不规则的四角形软骨板，形成耳道开口部分的侧边界，与对耳轮相对。对耳屏是耳屏尾部的一块细长的软骨，通过耳屏间切迹（耳屏间切迹）与耳屏分开。对耳屏的远端是皮肤边缘小袋。耳屏的吻侧是内侧耳轮，通过耳屏耳轮切迹（图1)，与耳屏分隔开。耳廓内侧的毛发量从远端到近端逐渐减少。在耳道入口处发现一些细毛。

Fig. 1. Anatomic features of the right external ear of the dog. M, medial; L, lateral.

图1.犬右外耳的解剖学特征。M，内侧；L，外侧。

Ear canal

耳道

The vertical ear canal begins at the level of the tragus, antitragus, and anthelix. The vertical ear canal runs for about 1 inch, extending ventrally and slightly rostrally before taking a medial turn and forming the horizontal ear canal. The horizontal ear canal is composed of auricular cartilage. At the base of the horizontal ear canal, there is a separate band of cartilage, the annular cartilage. The deeper portion of the annular cartilage of the horizontal ear canal is connected with the osseous external acoustic meatus by fibrous connective tissue. This arrangement of separate rings of cartilage gives the external ear flexibility.

垂直耳道始于耳屏、对耳屏和对耳轮。垂直耳道延伸约1英寸，在内侧转弯并形成水平耳道之前，向腹侧和稍微向嘴侧延伸。水平耳道由耳软骨构成。在水平耳道的底部，有一条单独的软骨带，即环状软骨。水平耳道环状软骨的较深部分通过纤维结缔组织与骨性外耳道相连。这种分离的软骨环的排列赋予了外耳灵活性。

The ear canal is lined by skin, which contains sebaceous glands, ceruminous glands (modified apocrine glands), and hair follicles. These adnexal structures are more numerous in the vertical ear canal than in the horizontal ear canal of the dog. Hair follicle density in the horizontal ear canal of normal Greyhounds and mixed-breed dogs decreases from the distal to proximal portion of the canal, whereas there is no significant difference in the apocrine or sebaceous glands along the length of the horizontal ear canal.

耳道内壁为皮肤，皮肤内有皮脂腺、耵聍腺（改良的顶浆腺）和毛囊。这些附属结构在犬的垂直耳道中比在水平耳道中更多。正常灵缇犬和混血犬的水平耳道中的毛囊密度从耳道的远端到近端逐渐减少，而顶浆腺或皮脂腺沿水平耳道的长度没有显著差异。

Tympanic membrane

鼓膜

The tympanic membrane separates the external ear canal from the middle ear. It is a semitransparent membrane that is thin in the center and thicker at the periphery. The normal tympanic membrane is concave. It is divided into two sections, the small upper pars flaccida and the larger lower pars tensa. The pars flaccida is the pink, small, loosely attached region forming the upper quadrant of the tympanic membrane, which contains small blood vessels (Fig. 2). In some dogs, the pars flaccida (or a structure in the region of the pars flaccida) may appear prominent and bulging (Fig. 3). One opinion is that this bulging region is edematous tissue hanging down from the dorsal wall of the horizontal ear canal adjacent to the tympanic membrane and is an early change associated with an underlying hypersensitivity disorder. The pars tensa occupies the remainder of the membrane. It is a thin, tough, pearl-gray structure with radiating strands. The pars tensa is attached firmly to the surrounding bone by a fibrocartilaginous ring. This fibrocartilaginous ring, known as the annulus fibrocartilaginous, is attached to the osseous ring of the external acoustic meatus by fibrous tissue. The manubrium of the malleus attaches to the medial surface of the tympanic membrane. The outline of the manubrium of the malleus, the stria mallearis, may be visualized when the tympanic membrane is viewed externally (see Fig. 2). In the dog, the manubrium has a hook that points rostrally.

鼓膜将外耳道与中耳分开。它是一种半透明的膜，中心薄，周边厚。正常的鼓膜是凹陷的。它分为两个部分，上方较小松弛部和下方较大的紧张部。松弛部是形成鼓膜上象限的粉红色、小的、松散附着的区域，其中含有小血管（图2).在一些犬中，松弛部（或松弛部区域的结构）可能出现突出和隆起（图3).一种观点认为，该隆起区域是从邻近鼓膜的水平耳道背侧壁垂下的水肿组织，是与潜在的过敏症相关的早期改变。紧张部占据膜的其余部分。它是一种薄而坚韧的珍珠灰色结构，呈放射状。紧张部通过纤维软骨环牢固地附着在周围的骨上。该纤维软骨的环型结构，称为纤维软骨环，通过纤维组织附着在外耳道的骨环上。锤骨柄附着于鼓膜内侧面。当从外部观察鼓膜时，可以看到锤骨柄的轮廓，即锤纹（见图2).在犬上，锤柄有一个指向嘴侧的钩子。

Fig. 2. Normal canine tympanic membrane. A, pars flaccida; B, pars tensa; C, stria mallearis.

图2.正常犬鼓膜。A，松弛部；B，紧张部；C，锤纹。

Fig. 3. Tympanic membrane of a dog illustrating a prominent pars flaccida (or a structure in the region of the pars flaccida) A, pars flaccida.

图3.犬的鼓膜显示了突出的松弛部（或松弛部区域的结构）。

Performing the otoscopic examination

进行耳镜检查

A complete otoscopic examination should be performed on every animal with otitis externa. The examination is performed either with a handheld otoscope or a video otoscope. Both ears should be examined even if a unilateral otitis externa is suspected. In some instances, a mild otitis that has been overshadowed by disease in the opposite ear may be present in the ‘‘unaffected’’ ear. If both ears are affected, examination of the less severely affected ear should be performed first. The otoscopic cone should be changed between the examination of each ear if a handheld otoscope is used, or the video otoscope should be wiped clean between the examination of each ear with a gauze sponge moistened with isopropyl alcohol. The ear should be assessed for inflammation, exudate, stenosis, and proliferation.

应对每只患有外耳炎的动物进行全面的耳镜检查。使用手持式耳镜或视频耳镜进行检查。即使怀疑患有单侧外耳炎，也应检查双耳。在某些情况下，被另一只耳朵的疾病所掩盖的轻度耳炎可能出现在“未患病”的耳朵中。如果两只耳朵都患病，应首先检查患病较轻的耳朵。如果使用手持耳镜，则在每只耳朵的检查之间应该更换耳镜锥形头，或者在检查每只耳朵之间，用蘸有异丙醇的纱布海绵将视频耳镜擦拭干净。应评估耳部是否有炎症、渗出物、狭窄和增生。

The otoscopic examination can be quite frustrating for the veterinarian presented with an animal with otitis. A proper otoscopic examination requires adequate restraint. Animals with painful ears may require sedation or general anesthesia so as to perform a complete otoscopic examination. In addition, some animals may require an ear flush before an examination is possible. If the ears are erythematous, proliferative, stenotic, or ulcerated, administration of topical or systemic glucocorticoids for 2 to 3 weeks is necessary to decrease the inflammation and pain so as to properly examine the ears.

耳镜检查对于患有耳炎的动物的兽医来说是相当令人沮丧的。正确的耳镜检查需要足够的约束。耳朵疼痛的动物可能需要镇静或全身麻醉，以便进行完整的耳镜检查。此外，一些动物在检查前可能需要进行耳部冲洗。如果耳朵出现红斑、增生、狭窄或溃疡，则需要外用或全身使用糖皮质激素2至3周，以减轻炎症和疼痛，从而正确检查耳朵。

To evaluate the ear, the tip of the cone of the otoscope or the video otoscope should be placed at the intertragic incisure (Fig. 4). To visualize the entire length of the ear canal and the tympanic membrane, the external ear canal needs to be gently extended into a straight line by grasping the ear pinna and pulling it up and outward while inserting the otoscope. The otoscope is then advanced into the horizontal ear canal as the canal is straightened.

为了评估耳朵，耳镜或视频耳镜的锥形头应放置在屏间切迹处（图4).为了观察耳道和鼓膜的整个长度，在插入耳镜的同时，抓住耳廓并将其向上向外拉，使外耳道轻轻延伸成一条直线。然后，当耳道变直时，将耳镜推进到水平耳道中。

Fig. 4. Position of the video otoscope at the intertragic incisure of the right ear.

图4.视频耳镜在右耳耳屏间切迹的位置。

Video otoscopy

视频耳镜检查

The uses and indications of the video otoscope in veterinary medicine have recently been reviewed. The video otoscope has several advantages over the handheld otoscope. First and foremost, the superior optics of the video otoscope provide a high degree of magnification, allowing greater visualization and detailed resolution of the ear canal and tympanic membrane. The magnified image on the monitor is far superior to the view obtained through a handheld otoscope. The intense light source brightly illuminates the ear, aiding in the visualization of the structures in the ear canal. The light is positioned at the tip of the endoscopic otoscope rather than at the base of the cone as with the handheld otoscope. This eliminates the problem of blocking or shadowing the visual field when instruments or catheters are introduced into the ear. When using the video otoscope on the patient in the examination room, the client is able to visualize the ear and participate in the evaluation of the ear disease, which may result in increased client compliance to use the prescribed medications, allow appropriate diagnostics to be performed, and return for scheduled re-evaluations. The video otoscope may also be used in the sedated or anesthetized patient for ear flushing procedures. Through the working channel on the endoscopic otoscope, under direct visualization, the ears can be flushed; foreign objects, debris, or parasites may be retrieved with grasping forceps; biopsies may be obtained with biopsy forceps; and a myringotomy may be performed with a tomcat catheter. With an attachable double-port adapter available on some units, suction and saline may be used simultaneously to clean the ear completely while continually visualizing the ear canal and tympanic membrane. This allows one to visualize any small tears in the tympanic membrane, which would be noted as bubbles emerging from the tear. This is not possible with the handheld otoscope, because the light reflects off the fluid and prevents visualization. Images of the ear canal and tympanic membrane before, during, and after any procedure may be captured for printing or downloading onto a compact disk for the medical record. Thus, at subsequent re-evaluations, the condition of the ear may be reviewed using these images. One disadvantage is that the diameter of the tip of the endoscopic otoscope sometimes makes it difficult to use in cats, small dogs, or stenosed ear canals. The handheld otoscope’s smallest diameter cone also has these disadvantages, however.

视频耳镜在兽医学中的应用和适应症最近已被审查。与手持耳镜相比，视频耳镜有几个优点。首先也是最重要的是，视频耳镜的卓越光学性能提供了高度的放大倍率，使耳道和鼓膜具有更高的可视性和详细的分辨率。监视器上的放大图像远优于通过手持耳镜获得的视图。强烈的光源明亮地照亮耳朵，有助于耳道内结构的可视化。灯位于内窥镜耳镜的尖端，而不是像手持耳镜那样位于锥体的底部。这消除了当器械或导管被引入到耳朵中时阻挡或遮蔽视野的问题。当在检查室中对患者使用视频耳镜时，客户能够看到耳朵并参与耳部疾病的评估，这可能会增加客户使用处方药物的依从性，允许进行适当的诊断，并返回进行预定的重新评估。视频耳镜也可用于镇静或麻醉患者的耳冲洗程序。通过内窥镜耳镜上的工作通道，在直接观察下，耳朵可以被冲洗；异物、碎片或寄生虫可用抓钳取出；活组织检查可用活组织检查钳进行；鼓膜切开术可用公猫导管进行。通过某些设备上提供的可连接的双端口适配器，可以同时使用吸力和盐水来完全清洁耳朵，同时持续观察耳道和鼓膜。这使得人们可以看到鼓膜中的任何小裂口，这将被记录为从裂口中出现的气泡。这在手持耳镜中是不可能的，因为光线会反射液体并阻止可视化。耳道和鼓膜的图像，在任何过程期间和之后，都可以被捕获以打印或下载到医疗记录的光盘上。因此，在随后的重新评估中，可以使用这些图像来检查耳朵的状况。一个缺点是内窥镜耳镜尖端的直径有时使其难以在猫、小犬或狭窄的耳道中使用。然而，手持耳镜的最小直径锥体也具有这些缺点。

The video otoscope is inserted into the ear canal as described previously, with the tip of the endoscopic otoscope positioned at the intertragic incisure. The examiner next looks at the monitor while extending the pinna and passing the endoscopic otoscope into the horizontal ear canal. It is important to standardize the orientation of the video otoscope in relation to the position of the animal to maintain consistency for evaluation of the ear canal and tympanic membrane. If the orientation is incorrect, it is difficult to recognize abnormalities in the ear.

如前所述，将视频耳镜插入耳道，内窥镜耳镜的尖端位于屏间切迹处。检查者接着看监视器，同时伸展耳廓并使内窥镜耳镜进入水平耳道。重要的是使视频耳镜相对于动物位置的方向标准化，以保持耳道和鼓膜评估的一致性。如果方向不正确，则很难识别耳朵中的异常。

Handheld otoscopic equipment

手持耳镜设备

The handheld otoscope (Welch Allyn, Skaneateles, New York) consists of a 3.5-V otoscope head, handle, and polypropylene specula. The 3.5-V otoscope head is available as a pneumatic or operating head. Both are equipped with a halogen lamp with fiberoptic illumination; however, the pneumatic otoscope head has a rotating lens with ultraseal, whereas the operating otoscope head has an open system with a rotatable lens and speculum. The rechargeable handle contains either a nickel-cadmium battery or lithium ion battery. The lithium ion battery is half the weight of the nickel-cadmium battery and does not need to be discharged between charging cycles. The polypropylene specula in the appropriate length for a canine ear are available in 4-, 5-, 7-, and 9-mm diameters, whereas there are short specula for a small feline ear in 2.5- and 3-mm diameters. All may be autoclaved, boiled, or cleaned with standard germicides.

手持耳镜由3.5-V耳镜头、手柄和聚丙烯镜组成。3.5 V耳镜头可用作气动或操作头。两者都配有带光纤照明的卤素灯；然而，气动耳镜头具有旋转透镜，而手术耳镜头部具有带有可旋转透镜和窥器的开放系统。可充电手柄包含镍镉电池或锂离子电池。锂离子电池的重量是镍镉电池的一半，并且不需要在充电周期之间放电。适合犬耳的聚丙烯锥形头有4、5、7和9毫米直径，而适合小猫耳的锥形头有2.5和3毫米直径。所有这些都可以高压灭菌、煮沸或用标准杀菌剂清洗。

Video otoscopic equipment

视频耳镜设备

There are currently two manufacturers of veterinary video otoscopes. Karl Storz Veterinary Endoscopy-America (Goleta, California) produces the Karl Storz Video Otoendoscope system. The otoendoscope is a straightforward telescope of 0 with a length of 8.5 cm, tip diameter of 5 mm, and 2-mm working channel, which is fully immersible and ethylene oxide (ETO) sterilizable. The Vetcam XL camera is a digital single-chip camera of high resolution with automatic exposure control, automatic white balance, and a fully soakable lens and camera head. The standard coupler on the camera is adaptable to all major rigid and flexible endoscopes, allowing for expandability into other forms of endoscopy. Camera and light source upgrades as well as longer telescopes are available for those interested in expanding into other disciplines of endoscopy and for visualization of the tympanic bulla, respectively. MedRx (Seminole, Florida) produces the Video VetScope. The MedRx VetProbe is a telescopic probe of 0 with a length of 7 cm, tip diameter of 4.75 mm, and a 2-mm working channel, which is fully immersible, ETO gas sterilizable, and autoclavable. The MedRx Digital camera is a single-chip videocamera of high resolution with a white balance control button and automatic iris. An additional endocoupler and adapter are available to adapt to rigid and flexible endoscopes. The working channel available on both the video otoscopes allows the passage of 5-French or smaller catheters, endoscopic forceps, and video otoscopic-compatible curettes.

目前有两家兽医视频耳镜制造商。Karl Storz美国兽医内窥镜生产Karl Storz视频耳内镜系统。耳内窥镜是一种简单的望远镜，长度为8.5厘米，尖端直径为5毫米，工作通道为2毫米，可完全浸入水中，并可用环氧乙烷（ETO）消毒。VetCam XL相机是一款高分辨率的数字单芯片相机，具有自动曝光控制、自动白平衡以及完全可浸泡的镜头和摄像头。摄像机上的标准耦合器适用于所有主要的刚性和柔性内窥镜，允许扩展到其他形式的内窥镜。相机和光源的升级以及更长的望远镜可用于那些有兴趣扩展到内窥镜检查的其他学科和鼓泡的可视化。分别是MEDRX生产视频VETSCOPE。MedRx VetProbe是一种长度为7 cm、尖端直径为4.75 mm、工作通道为2 mm的伸缩式探头，该工作通道是完全可浸入的、可用ETO气体消毒的并且可高压灭菌的。MedRx数码相机是一款高分辨率的单芯片摄像机，配有白平衡控制按钮和自动光圈。额外的内窥耦合器和适配器可用于适应刚性和柔性内窥镜。两个视频耳镜上可用的工作通道允许5-French或更小的导管、内窥镜钳和视频耳镜兼容的刮匙通过。

Evaluation of the ear canal and tympanic membrane

耳道和鼓膜的评估

Normal appearance of the ear canal and tympanic membrane

耳道和鼓膜外观正常

The normal ear canal is light pink and smooth and contains minimal exudate. The diameter of the opening of the vertical ear canal varies based on breed, but the diameter of the normal vertical ear canal where it apposes the horizontal portion is 5 to 10 mm . Hair may be present in the ear canal, and in some dogs, a tuft of hair is present in front of the tympanic membrane.

正常耳道呈淡粉色、光滑、渗出物极少。垂直耳道的开口的直径根据品种而变化，但是与水平部分并置的正常垂直耳道的直径为5至10mm.耳道内可能有毛发，有些犬的鼓膜前有一簇毛发。

The normal tympanic membrane is translucent, and the stria mallearis should be visible as described previously. Using the handheld otoscope, complete visualization of the tympanic membrane and the stria mallearis, even in the normal ear, is not possible without rotation of the otoscope dorsally and rostrally. Using the video otoscope solves this problem, however, because the entire tympanic membrane is visible, illuminated, and magnified.

正常的鼓膜是半透明的，锤纹应该是可见的，如前所述。使用手持式耳镜，完全观察鼓膜和锤纹，即使在正常的耳朵中，如果不向背侧和嘴侧旋转耳镜，也是不可能看全的。然而，使用视频耳镜解决了这个问题，因为整个鼓膜是可见的、被照亮的和被放大的。

Abnormal appearance of the ear canal and tympanic membrane When evaluating the ear, one should note the condition of the ear canal (eg, erythema, stenosis, proliferation, ulceration); look for any foreign bodies or masses; note the presence, consistency, and color of any exudate; and evaluate the patency of the tympanic membrane.

耳道和鼓膜的异常外观在评估耳朵时，应注意耳道的状况（如皮肤发红、狭窄、增生、溃疡）；寻找任何异物或肿块；注意任何渗出物的存在、稠度和颜色；并评估鼓膜的完整性。

Inflammation as a result of any primary cause of otitis externa can result in edema and erythema. The swelling caused by the edema appears clinically as stenosis of the ear canal. Histopathologically, the epidermis is hyperplastic. There is gross enlargement and hypersecretion of sebaceous glands. A mixed infiltration of inflammatory cells migrates into the epidermis and dermis. In the early stages of otitis externa, intervention with anti-inflammatory drugs is important to stop the progression of the proliferative changes in the ear canal. Anti-inflammatory medications, such as oral and topical glucocorticoids, are indicated to reduce the inflammation and for pain control. If glucocorticoids are contraindicated in a patient, nonsteroidal anti-inflammatory medications may be used.

外耳炎的任何原发病因引起的炎症都可导致水肿和皮肤发红。由水肿引起的肿胀在临床上表现为耳道狭窄。组织病理学上，表皮增生。皮脂腺肿大，分泌亢进。炎性细胞的混合浸润移行至表皮和真皮。在外耳炎的早期阶段，抗炎药物的干预对于阻止耳道中增殖性变化的进展是重要的。抗炎药物，如口服和外用糖皮质激素，适用于减轻炎症和控制疼痛。如果患者禁用糖皮质激素，可以使用非甾体抗炎药。

With persistence of the ear disease, clinically, the ear canal continues to close down. Histopathologically, the sebaceous glands degenerate, become devoid of any cellular lining, fill with a colloidal cellular mass, and became elongated. The cord-like glands have little secretory activity. The apocrine sweat glands become enlarged and appear as sac-like structures filled with colloidal cellular debris. The openings of the ducts become plugged with keratin and secretory material. The dilated apocrine glands displace superficial sebaceous glands. In some cases, the apocrine glands atrophy and degenerate. There are aggregates of inflammatory cells in the epidermis and deeper layers of the dermis. The subcutaneous tissues thicken, resulting in occlusion of the external auditory canal. Clinically, there are variable degrees of nodular proliferation (Fig. 5). With time, the continued inflammation can lead to calcification and ossification of the auditory cartilages and fibrosis. A recent study documented that the changes that occur in the external ear canal in chronic otitis may be breed related, with moderate to severe hyperplasia and dilation of the apocrine glands occurring in more than 70% of Cocker Spaniels, whereas these changes were present in only 31% of the other breeds evaluated. Once these severe changes have occurred, it is usually not possible to resolve them even with antiinflammatory drugs; in many cases, surgical intervention is necessary.

随着耳部疾病的持续存在，临床上，耳道继续变狭窄。组织病理学上，皮脂腺退化，变得没有任何细胞衬里，充满胶状细胞团，并变得细长。线状腺体几乎没有分泌活动。顶浆汗腺变大，呈充满胶质细胞碎片的囊状结构。导管的开口被角蛋白和分泌物质堵塞。扩张的大汗腺取代了浅表的皮脂腺。在某些情况下，顶浆分泌腺萎缩退化。在表皮和真皮的更深层中有炎性细胞的聚集。皮下组织增厚，导致外耳道闭塞。临床上，有不同程度的结节增生（图5).随着时间的推移，持续的炎症可导致耳软骨钙化、骨化和纤维化。最近的一项研究证明，慢性耳炎中发生在外耳道的变化可能与品种有关，70%以上的可卡犬出现中度至重度的顶浆腺增生和扩张。而这些变化只出现在31%的其他品种中。一旦发生这些严重的变化，即使使用抗炎药物，通常也无法解决。在许多情况下，手术干预是必要的。

Fig. 5. Glandular proliferation of the vertical and horizontal ear canal of a dog.

图5.犬的垂直和水平耳道腺增生。

Ulcerations of the ear canal are uncommon; when present, they are usually associated with a gram-negative bacterial infection, such as Pseudomonas aeruginosa. Inappropriate cleaning of the ear canal with cotton-tipped applicators, especially in an infected ear, can also result in ulcerations. If the ear is infected, oral and topical treatment is determined based on otic cytology and bacterial culture and susceptibility testing (C/S). In addition, glucocorticoids may be necessary to decrease the pain and inflammation associated with the ulcerations. Topical ear cleaners containing alcohol should be avoided until the ulcers begin to heal.

耳道溃疡不常见；当出现时，它们通常与革兰氏阴性细菌感染有关，如铜绿假单胞菌。用棉签不适当地清洁耳道，尤其是在感染的耳朵中，也会导致溃疡。如果耳朵受到感染，根据耳细胞学和细菌培养和药敏试验（C/S）确定口服和外部治疗。此外，糖皮质激素可能是必要的，以减少与溃疡相关的疼痛和炎症。在溃疡开始愈合之前，应避免使用含有酒精的外用洗耳液。

An animal with a tumor in the ear canal may present with clinical signs similar to any patient with chronic otitis externa. Any tumor in the ear canal needs to be biopsied for identification. This may be accomplished using alligator forceps through the handheld otoscope, although it is best performed using the biopsy forceps through the working channel on the video otoscope under guided visualization. In some instances, there is a secondary infection, and the exudate may inhibit visualization of the mass. It may be necessary to clean the ear before the examination. Depending on the amount of exudate, the animal may need to be anesthetized and endotracheally intubated to clean the ear completely. Once the ear canal is clean and a tumor is identified, a biopsy may be obtained. Tumors of the ear canal can arise from any of the structures of the ear canal, such as the squamous epithelium, glandular structures, and mesenchymal tissues. The tumors may be benign or malignant. The most common tumor found in the ear canal of the dog and cat is a ceruminous gland tumor. There is a greater tendency for malignancy and aggressive biologic behavior of these tumors in the cat than in the dog. Other tumors of the ear canal include squamous cell carcinoma (Fig. 6), papillomas, sebaceous gland tumors, and mast cell tumors. There are nonneoplastic diseases that can mimic tumors of the ear canal, including hyperplasia of the ceruminous glands, inflammatory polyps, ceruminal gland cysts, and nodular hyperplasia of the sebaceous gland.

在耳道中有肿瘤的动物可能表现出与任何慢性外耳炎患病动物相似的临床症状。耳道内的任何肿瘤都需要进行活检以确定。这可以使用鳄鱼钳通过手持式耳镜来完成，但最好在视频耳镜可视化下使用活检钳通过工作通道来完成。在某些情况下，有继发感染，渗出液可能会抑制肿块的显影。检查前可能需要清洁耳朵。根据渗出液的量，可能需要对动物进行麻醉和气管内插管，以彻底清洁耳朵。一旦耳道被清理干净并发现肿瘤，就可以进行活检。耳道肿瘤可起源于耳道的任何结构，如鳞状上皮、腺体结构和间质组织。肿瘤可以是良性的或恶性的。在犬和猫的耳道中发现的最常见的肿瘤是耵聍腺肿瘤。这些肿瘤在猫中比在犬中有更大的恶性倾向和侵袭性生物学行为。耳道的其他肿瘤包括鳞状细胞癌（图6）、乳头状瘤、皮脂腺肿瘤和肥大细胞瘤。存在可以模仿耳道肿瘤的非肿瘤性疾病，包括耵聍腺增生、炎性息肉、耵聍腺囊肿和皮脂腺结节性增生。

Fig. 6. Using video otoscopy, a mass was discovered at the junction of the vertical and horizontal ear canal in a 13-year-old Golden Retriever with a 4-month history of a unilateral recurrent Pseudomonas aeruginosa otitis externa. Histopathologically, the mass was identified as a squamous cell carcinoma.

图6.通过视频耳镜检查，在一只13岁的金毛猎犬的垂直和水平耳道交界处发现了一个肿块，这只金毛猎犬患有4个月的单侧复发性铜绿假单胞菌外耳炎。经组织病理学检查，该肿块被确定为鳞状细胞癌。

Foreign bodies can cause an acute, painful, unilateral otitis externa. Rarely, they may cause a bilateral otitis externa. Some of the more common foreign bodies include plant awns, impacted wax, and concreted otic preparations. The animal should be placed under general anesthesia to remove foreign bodies, especially if they are in close proximity to the tympanic membrane. With the aid of the video otoscope, grass awns may be removed using the grasping forceps through the working channel on the otoendoscope. Impacted wax and otic concretions should be dissolved with a ceruminolytic agent and then gently flushed out of the ear canal. In some instances, a curette is used to dislodge the obstruction. A curette is available with the video otoscope for this purpose and can be inserted through the working channel.

异物可引起急性、疼痛的单侧外耳炎。很少情况下，它们可能会引起双侧外耳炎。一些比较常见的异物包括植物的芒、嵌塞的耳垢和凝固的耳药。动物应在全身麻醉下取出异物，尤其是靠近鼓膜的异物。在视频耳镜的帮助下，可以使用抓钳通过耳镜上的工作通道去除草芒。应用耵聍溶解剂溶解嵌塞的耳垢和耳结石，然后轻柔冲洗出耳道。在某些情况下，使用刮匙去除阻塞物。为此，视频耳镜配有刮匙，可通过工作通道插入。

During the otoscopic examination, excessive amounts of exudate in the ear should be noted. The consistency, color, and amount of exudate should be recorded. One may get some clue as to the infective organism by the character of the exudate; however, cytologic evaluation of the exudate should always be performed to confirm the presence of these organisms. Depending on the organism(s) identified cytologically, bacterial C/S may be indicated.

在耳镜检查过程中，应注意耳内渗出物过多。应记录渗出液的浓度、颜色和数量。我们可以通过渗出液的性质得到一些关于感染机体的线索。然而，渗出液的细胞学评估应始终执行以确认这些微生物的存在。根据细胞学鉴定的生物体，可指示细菌C/S。

In most cases of chronic otitis externa, the tympanic membrane is difficult, if not impossible, to visualize otoscopically on the initial examination. Otic flushing is necessary to clean the ear so as to allow visualization of the tympanic membrane. If the ear canals are ulcerated or stenotic, however, administration of oral and topical glucocorticoids for 2 to 3 weeks is needed to decrease the inflammation and open the ear canals to allow for a proper ear flush. For a deep ear flush, the animal should be endotracheally intubated and placed under general anesthesia. In this way, if a myringotomy is required or if the tympanic membrane is ruptured, the airway is protected to avoid aspiration of any fluid that may pass from the middle ear into the oral pharyngeal region via the Eustachian tube. In dogs with acute otitis externa, the incidence of otitis media is only 16% , whereas in dogs with chronic otitis externa, up to 88.9% may have concurrent otitis media. An intact tympanic membrane does not rule out otitis media and may be found in up to 72.5% of the ears of dogs with otitis media. In addition to allowing visualization of the tympanic membrane, the ear flush removes exudate that is irritating, masking a foreign body or tumor, serving as a nidus for infection, or capable of inactivating medications (eg, gentamicin, polymyxin B).

在大多数慢性外耳炎病例中，初次耳镜检查时很难（如果不是不可能）看到鼓膜。必须进行耳部冲洗以清洁耳朵，从而使鼓膜可视化。然而，如果耳道溃疡或狭窄，则需要口服和外用糖皮质激素2至3周，以减轻炎症并打开耳道，以便进行适当的耳部冲洗。对于深耳冲洗，应对动物进行气管内插管，并置于全身麻醉下。这样，如果需要进行鼓膜切开术或鼓膜破裂，气道受到保护，以避免吸入任何可能通过咽鼓管从中耳进入口咽区域的流体。在患有急性外耳炎的犬中，中耳炎的发病率仅为16%，而在患有慢性外耳炎的犬中，高达88.9%的犬可能并发中耳炎。完整的鼓膜并不能排除中耳炎，这在72.5%患有中耳炎的犬的耳朵中可以发现。除了可以看到鼓膜外，耳部冲洗液还可以去除刺激性渗出物，掩盖异物或肿瘤，作为感染的病灶，或能够灭活药物（如庆大霉素、多粘菌素B）。

If the tympanic membrane is ruptured, the animal has otitis media. Samples should be obtained from the middle ear for bacterial C/S and cytology. Using a handheld otoscope, a sterile otoscopic cone is inserted into the horizontal ear canal and a sterile swab (Calgiswab; Hardwood Products Company LLC, Guilford, ME) is passed into the middle ear cavity. The first swab is used for C/S. A second swab is passed into the middle ear cavity for cytologic analysis. If the video otoscope is used, an open-ended 3.5-French tomcat catheter attached to a 12-mL syringe is placed through the working channel of the endoscopic otoscope. One milliliter of sterile saline is flushed into the middle ear cavity and aspirated back. The fluid is then cultured. A second sample is obtained for cytologic evaluation. The middle ear is flushed repeatedly with saline using an open-ended 3.5-French tomcat catheter attached to a 12-mL syringe passed through an otoscopic cone or through the working channel on the endoscopic otoscope to remove any ear cleanser from the middle ear completely so as to reduce the chance of ototoxicity.

如果鼓膜破裂，则动物患有中耳炎。应从中耳获取样本进行细菌C/S和细胞学检查。使用手持耳镜，将无菌耳镜锥形头插入水平耳道，用无菌拭子进入中耳腔。第一个拭子用于C/S，第二个拭子进入中耳腔用于细胞学分析。如果使用视频耳镜，则通过内窥镜耳镜的工作通道放置连接到12mL注射器的开口3.5-French公猫导尿管。将一毫升无菌盐水冲入中耳腔并吸回。然后培养该液体。获得第二个样品用于细胞学检查。使用连接到12ml注射器的末端开口的3.5-French公猫导尿管，通过耳镜锥形头或通过内窥镜耳镜上的工作通道，用盐水反复冲洗中耳，以从中耳完全去除任何洗耳液，从而减少耳毒性。

If the tympanic membrane is abnormal (eg, hemorrhagic, bulging, opaque, brown, gray), a myringotomy should be performed to obtain samples for bacterial C/S and cytology and to allow flushing and drainage of the middle ear cavity. The myringotomy may be performed using either the handheld otoscope or the video otoscope. The video otoscope allows continual visualization and accurate positioning for the myringotomy procedure. The incision into the tympanic membrane can be made using an open-ended tomcat catheter, spinal needle, or Calgiswab. The choice is based on the type of otoscope used as well as personal preference. It is important to make the myringotomy incision in the caudoventral portion of the pars tensa (Fig. 7) to avoid damaging the delicate structures in the middle ear, such as the middle ear ossicles or the promontory. Using a handheld otoscope, an otoscopic cone is inserted into the horizontal ear canal and the tympanic membrane is visualized. Using a sterile Calgiswab, an incision is made blindly into the caudoventral quadrant of the pars tensa. The swab used for the myringotomy incision is submitted for bacterial C/S. A second swab is inserted into the original incision, and the sample obtained is used for cytologic analysis. If the video otoscope is used to perform the myringotomy, an open-ended 3.5-French tomcat catheter is placed through the working channel of the endoscopic otoscope, and under direct visualization, the tomcat catheter is used to make the incision into the caudoventral quadrant of the pars tensa. One milliliter of sterile saline is flushed into the middle ear cavity and aspirated back using a 12-mL syringe attached to the tomcat catheter. The fluid is then cultured. A second sample is obtained for cytologic evaluation. Once the samples have been obtained, the middle ear is flushed gently with saline through the tomcat catheter until the fluid aspirated back is clear.

如果鼓膜异常（如出血、凸起、不透明、褐色、灰色），应进行鼓膜切开术，以获取细菌C/S和细胞学样本，并对中耳腔进行冲洗和引流。鼓膜切开术可使用手持式耳镜或视频耳镜进行。视频耳镜允许鼓膜切开术手术的连续可视化和精确定位。鼓膜中的切口可以使用末端开口的公猫导尿管形成、脊椎针，或Calgiswab。根据使用的耳镜类型以及个人喜好进行选择。重要的是在鼓膜紧张部的尾腹部分进行鼓膜切开术（图7）避免损伤中耳的精细结构，如中耳听小骨或隆突。使用手持耳镜，将耳镜头插入水平耳道并观察鼓膜。使用无菌CALGISWAB，在紧张部的尾腹象限盲切。提交用于鼓膜切开术切口的拭子以检测细菌C/S。将第二个拭子插入原来的切口中，并将获得的样本用于细胞学分析。如果使用视频耳镜进行鼓膜切开术，通过内窥镜耳镜的工作通道放置开口3.5-French 公猫导尿管，在直接观察下，使用公猫导尿管在紧张部的尾腹象限进行切口。将1毫升无菌盐水冲入中耳腔，并用连接在公猫导尿管上的12毫升注射器吸回。然后培养该液体。获得第二个样品用于细胞学检查。一旦获得样本，通过公猫导尿管用盐水轻轻冲洗中耳，直到吸回的液体变干净。

The normal tympanum has been shown experimentally to heal in 21 to 35 days. Therefore, if the ear is kept free from infection after the myringotomy procedure or if the membrane was already ruptured, the tympanic membrane should heal. Possible complications of ear flushing and myringotomy are Horner’s syndrome, facial nerve paralysis, vestibular disturbances, and deafness. Owners should understand these complications and sign a consent form before the procedure.

实验表明，正常鼓膜可在21至35天内愈合。因此，如果在鼓膜切开术后耳朵没有感染，或者如果膜已经破裂，鼓膜应该愈合了。耳部潮红和鼓膜切开术可能的并发症有霍纳综合征、面神经麻痹、前庭功能障碍和耳聋。宠主应了解这些并发症，并在手术前签署同意书。

Fig. 7. Proper position for performing a myringotomy using an open-ended tomcat catheter. The incision is made into the caudoventral quadrant of the pars tensa. The dog’s right tympanic membrane is pictured. R, rostral; C, caudal; D, dorsal; V, ventral.

图7.使用开放式Tomcat导管进行鼓膜切开术的正确位置。切口位于紧张部的尾腹象限。图为犬的右鼓膜。R，嘴侧；C，尾侧；D，背侧；V，腹侧。

Assessment of the ear canal

耳道评估

Once the ear canal has been evaluated otoscopically, samples obtained for otic cytology and C/S, the ear flushed, and a myringotomy performed (if necessary), it is important to address the primary causes as well as predisposing and perpetuating factors associated with the otitis. Additional diagnostics may be required to determine these causes and factors. Specific treatment for any infections should be implemented immediately. Potentially ototoxic medications should be avoided if possible in cases of otitis media.

一旦耳镜检查评估耳道，获取样本用于耳细胞学和C/S，冲洗耳朵，并进行鼓膜切开术（如有必要），重要的是要解决与耳炎相关的主要原因以及诱发和持续因素。可能需要额外的诊断来确定这些原因和因素。应立即对任何感染实施特定治疗。在中耳炎的情况下，应尽可能避免使用具有潜在耳毒性的药物。

Summary

总结

Otoscopic evaluation of the external ear canal and tympanic membrane is the first diagnostic procedure that should be performed in animals presented with otitis externa. It is important to become familiar with the normal structures of the ear to identify any abnormalities. The video otoscope greatly enhances visualization of these structures as well as aiding in retrieval of foreign bodies, biopsy of masses, and performance of a myringotomy. In some cases, a complete otoscopic examination is not possible on the first visit, and the animal may require anti-inflammatory medications or otic flushing to visualize the entire ear canal as well as the tympanic membrane. The purpose of the otoscopic examination is to address the otitis by evaluating the condition of the ear, looking for any masses or foreign bodies; noting the presence, consistency, and color of any exudate; and evaluating the patency of the tympanic membrane. Once a complete otic evaluation has been performed, additional diagnostics as well as a treatment plan can be formulated.

外耳道和鼓膜的耳镜检查是对患有外耳炎的动物进行的第一个诊断程序。熟悉耳朵的正常结构以识别任何异常是很重要的。视频耳镜大大增强了这些结构的可视性，并有助于异物取出、肿块活检和鼓膜切开术。在某些病例，不可能在第一次就诊时进行完整的耳镜检查，并且动物可能需要抗炎药物或耳冲洗来观察整个耳道以及鼓膜。耳镜检查的目的是通过评估耳朵的状况来处理耳炎，寻找任何肿块或异物；注意任何渗出物的存在、稠度和颜色；并评估鼓膜的开放性。一旦进行了完整的耳部评估，就可以制定额外的诊断和治疗计划。

追赶时间

maomaoya

感谢老师分享！努力学习中。