: Anjop J. Venker-van Haagen
: Ear, Nose, Throat, and Tracheobronchial Diseases in Dogs and Cats
: Schlütersche
: 9783899930931
: 1
: CHF 64.70
:
: Veterinärmedizin
: English
: 248
: DRM
: PC/MAC/eReader/Tablet
: PDF
Ear, Nose, Throat, and Tracheobronchial Diseases in Dogs and Cats is the first textbook to provide a complete overview of all ENT diseases, both common and rare. It includes such problems as inflammation of the outer ear, deafness, nasal discharge, swallowing disorders, and cough. Detailed and up to date clinical information gives insight into ENT function and dysfunction for teachers and researchers, veterinarians in practice and veterinary students.

Six chapters give key information on functional considerations, aetiology, clinical signs, diagnosis, and therapy of ENT disorders. Special diagnostic and imaging techniques are described in detail. Approximately 180 top quality illustrations emphasize and supplement the specific features of the diseases and disorders described in the text. A detailed index gives easy access to the content of this book.

This unique textbook will provide a highly useful and informative reference guide to everyday practice, based on the author’s 35 years as a specialist in ear, nose, throat, and tracheobronchial diseases in companion animals.
1.4 Congenital diseases of the ear (S. 19)

The auricle and the external ear canal are derived from mesenchymal condensations from branchial arches 1 and 2. The middle ear cavity is formed as a lateral extension of the first pharyngeal pouch. The eustachian tube develops from an entodermal extension of the first pharyngeal pouch. The ossicles arise from branchial arches 1 and 2. The tympanic membrane is a three-layered structure consisting of an inner mucosal layer of entodermal origin, a middle layer of mesodermal origin, and an outer layer of ectodermal origin. The inner ear consists of a membranous and a bony labyrinth. The membranous labyrinth is derived from the ectoderm, whereas the bony labyrinth (otic capsule) is derived from the mesoderm and neural crest surrounding the primordial membranous labyrinth.

1.4.1 Congenital deformity of the external ear

Congenitalmalformation of the auricle is rare in dogs and cats, or at least affected pups and kittens are rarely met in veterinary practice. It is usually not medically necessary to correct a defect of the auricle, and thus these difficult, esthetically unsatisfactory, and painful reconstructions are ethically undesirable. Veterinarians in the Netherlands do not encourage surgical intervention when the auricle is healthy and »ear cropping« without a medical indication is prohibited.

Congenital atresia of the ear canal is rarely detected because the malformation is not visible from the outside. In most cases it is the medial part of the ear canal that is undeveloped and a patent canal does not reach the tympanic membrane. The abnormality is usually unilateral and the resulting unilateral deafness is not always detected early in the animal’s life. If atresia of the ear canal is found without clinical signs, it is advisable to refrain from intervention, but if there is an abscess of the middle ear, it requires drainage followed by antimicrobial therapy. Middle ear disease may recur and the owner should be advised to return the animal promptly if it shows signs of ear pain. Surgical reconstruction is not a justifiable option.

1.4.2 Congenital deafness

Deafness that is detected soon after birth may be acquired or inherited and itmay occur in any puppy or kitten, whether purebred or of mixed breeding. Acquired deafness may result from viral infections, severe malnutrition, or the ototoxic side effects of drugs or other chemicals. Because all dogs and cats are born deaf, deafness in a puppy or kitten is not abnormal up to a certain age. The earliest discriminating hearing tests reported in cats were performed at the age of 7 days. Measurements of cochlear potentials via an electrode in the round window were found to be conclusive about the presence or absence of hearing in cats over 7 days of age. In 4 puppies (2 beagles, 2 wolfhounds) brain stem auditory evoked potentials were recorded from surface electrodes at the base of the auricles and on the midline over the parietal bone. The click stimulus was a rectangular wave 0.2 ms in duration at a repetition rate of 10 per second, delivered via two microphones (acting as speakers) at opposite ends of the cage. The intensity was 80 dB SPL and 90 dB SPL asmeasured at the center of the cage, in which the puppies were placed without sedation. For the recording of bone-conducted brain stem evoked potentials the puppies were taken out of the cage, leaving the electrodes in place. The same stimulus was used but was applied via a bone conductor pressed against the skull by hand, maintaining the pressure that resulted in the best response signal. Testing was performed every other day from the 3rd to the 27th day after birth. Brain stem evoked potentials were first observed on the 7th day after birth in the 2 beagles and on the 11th day in the 2 wolfhounds, in both cases using the bone-conducted stimulus. Using air-conducted stimuli, the first brain stem evoked potentials were observed on the 25th day in the beagles and on the 27th day in the wolfhounds. While the number of puppies in this pilot study was small, the results indicate that, technically, puppies may be able to hear by 5 to 7 days after birth.
Contents6
Abbreviations9
Preface10
1 The Ear12
1.1 Functional considerations12
1.1.1 The ear as sensory organ12
1.1.2. Middle ear matches different impedances13
1.1.3 Organ of Corti, sensory organ for hearing14
1.1.4 Ascending and descending pathways for hearing16
1.1.5 Vestibular organ, the key to postural reflexes and eye movement16
1.2 History and clinical signs17
1.2.1 History17
1.2.2 Clinical signs18
1.2.3 Physical examination20
1.3 Special diagnostic techniques20
1.3.1 Otoscopic examination21
1.3.2 Diagnostic imaging of the ear23
1.3.3 Tympanometry26
1.3.4 Neurological examination for vestibular dysfunction27
1.3.5 Hearing tests27
1.4 Congenital diseases of the ear30
1.4.1 Congenital deformity of the external ear30
1.4.2 Congenital deafness30
1.5 Inflammatory diseases of the ear32
1.5.1 Primary and secondary skin diseases of the auricle32
1.5.2 Perichondritis and chondritis of the auricle34
1.5.3 Cold agglutination and cutaneous vasculitis of the auricle35
1.5.4 Inflammatory diseases of the external ear canal35
1.5.5 Inflammation of the tympanic membrane41
1.5.6 Inflammatory disease of the middle ear41
1.5.7 Labyrinthitis45
1.6 Tumors of the ear46
1.6.1 Malignant tumors of the auricle46
1.6.2 Malignant tumors of the external ear canal47
1.6.3 Tumors of the middle ear48
1.7 Trauma to the ear48
1.7.1 Trauma to the auricle48
1.7.2 Auricular hematoma49
1.7.3 Trauma to the external ear canal49
1.7.4 Trauma to the tympanic membrane50
1.7.5 Trauma to the temporal bone51
1.8 Ototoxicity52
1.9 Hearing in dogs and cats53
1.9.1 Hearing and hearing loss in dogs54
1.9.2 Brain stem auditory evoked responses in dogs54
1.9.3 Hearing and hearing loss in cats57
1.9.4 Brain stem auditory evoked responses in cats57
References58
2 The Nose and Nasal Sinuses62
2.1 Functional considerations62
2.1.1 Regulation and conditioning of the inspiratory and expiratory airflow62
2.1.2 Mucosal cleaning63
2.1.3 Olfaction64
2.1.4 Specific functional systems64
2.2 History and clinical signs64
2.2.1 History64
2.2.2 Clinical signs65
2.2.3 Physical examination66
2.3 Special diagnostic techniques66
2.3.1 Diagnostic imaging67
2.3.2 Rhinoscopy68
2.3.3 Olfactory tests70
2.4 Congenital diseases of the nose and nasal sinuses71
2.4.1 Congenital malformation of the nasal plane71
2.4.2 Nasal dermoid sinus cysts73
2.4.3 Congenital cerebrospinal fluid fistula73
2.4.4 Congenital malformation of the frontal sinuses73
2.4.5 Congenital ciliary dysfunction73
2.5 Rhinitis and sinusitis74
2.5.1 Infectious rhinitis and sinusitis74
2.5.2 Noninfectious rhinitis and sinusitis79
2.6 Tumors of the nasal plane, the nasal<