"Acute or chronic inflammation of the external auditory canal epithelium in dogs, sometimes associated with auricular disease or otitis media." The main symptoms are itching of the ear, erythema of the auricle and ear canal, excessive secretions (earwax) in the ear and have a peculiar smell. In severe cases, it may become purulent and emit a foul smell, and even hyperplasia and occlusion of the ear canal. Because of itching, sick dogs and cats often show shaking head, scratching ears, rubbing ears and other behaviors. The pain in the ear caused the animal's head to tilt and droop to the affected side.
Causes of Otitis Externa Dog
There are three main causes of the disease, which are classified as primary, susceptible and persistent:primary
(1) Parasites. Mites are the most common endo-ear parasites. Mites cause 50% of external otitis in cats and 5-10% in dogs. Most cats have an immune response that prevents further infection. Demodex may be confined to the auricle, but other parts of the skin may also be infected. Cats can cause ceruminous otitis externa when infected. Scabietes scabietes, ear mites, flies and lice fleas mostly parasitism in the auricle, and rarely cause diseases of the external auditory canal. Ixodes ticks and chigger mites can invade the auricle and external auditory canal. There are spinous ear ticks, and stump Rostrum megning can also cause external ear canal disease.
(2) Foreign bodies. Plant prickle, setaria. Dirt and dandruff. Powder medicine. The shedding of hair.
(3) specific reactions. In those dogs with specific reactions, allergic otitis externa occurs in more than 50%. Otitis externa may be the only clinical sign.
(4) food allergy. Allergic otitis externa occurred in 80% of dogs with food allergy. Otitis externa may be the only clinical sign.
(5) Contact allergy. Contact allergy should be suspected in cases in which the ear disease worsens significantly further during the course of treatment.
(6) abnormal keratinization. The most common is dermatoseborrheic disease. Fatty acids have stimulatory effects on the ear canal epithelium. "Other causes of dyskeratosis include hypothyroidism, masculinizing syndrome, Sertoli cell or stromal cell tumors, and abnormal ovarian function."
(7) Immune skin diseases. These include pemphigus foliaceus, pemphigus erythematosus, cutaneous lupus erythematosus, systemic lupus erythematosus, pemphigus vulgaris, bullous pemphigoid, and drug eruptions. The symptoms of the auricle are more obvious than those of the ear canal.
(8) Tumor. Inflammatory polyps in dogs can present as unilateral otitis externa. Other tumors include sebaceous adenoma, basal cell tumor, mastocytoma, ceruminous gland tumor, fibroma, fibrosarcoma, chondroma, chondrosarcoma, squamous cell carcinoma and trichoepithelioma.
(9) Other diseases. Cellulitis in young animals (asphyxia in young animals). Zinc-responsive skin diseases. Fatal limb dermatitis in cattle head.
Susceptibility to
(1) abnormal ear configuration; Narrowing of the ear canal. The large, droopy auricle and hairs in the ear canal reduce ventilation, increase temperature and humidity in the ear. The Labrador retriever, American Cocker spaniel, and English flyhound all had a higher number of hair follicles and apocrine glands.
(2) Ear canal epithelial injury. Due to long-term ear wet or improper cleaning after wiping dry. The function of the cuticular barrier was lost and the epithelial layer was invaded.
(3) ear canal obstruction. Epithelial swelling caused by acute inflammation can narrow the ear canal. The tumor obstructs the ear canal.
(4) systemic diseases. Feline leukemia, feline immunodeficiency, canine parvovirus disease, and canine distemper.
persistence
(1) Bacteria. Changes in the environment of the ear or ear canal provide conditions for bacterial multiplication. A normal ear contains a small amount of bacteria. "Bacteria associated with otitis externa are Staphylococcus intermedia, Staphylococcus surface, Streptococcus, Pseudomonas, Proteus, and Escherichia coli."
(2) Fungi. Malassezia is the most common fungus that infects the ear. Others are Candida, Aspergillus, Trichophyton, Microsporum.
(3) Otitis media. Otitis media is mostly bacterial, which can make otitis externa recur.
(4) Progressive pathological changes. "Obstruction of the ear canal increases earwax formation, reduces the natural ability to remove it, and makes manual cleaning and topical application difficult."
Otitis Externa Dog Symptoms
Animals show discomfort, shake their head frequently, wipe or scratch their ears, which may cause scratches, abrasions, bleeding or hematoma on the ear shell. Early examination of the affected ear showed congestion and swelling of the ear shell and the external opening of the ear canal. Some have ear canal redness and swelling. There was tenderness at the root of the ear when pressed. There is more scale in the ear canal or the ear canal surface is stained with exudate. In severe cases, the ear canal was obviously swollen, the epithelium was ulcerated, and the ear canal flowed with yellowish serous to dark purulent otorrhea. Otorrhea fluid adheres to the coat at the root of the ear. Severe cases can cause increased body temperature and ear canal obstruction and hearing loss.Diagnostic criteria of otitis externa dog
1, comprehensive skin history examination, because the ear is a continuation of the skin.2, must do otoscopy examination. The infected and less infected ears were examined first. Do a sterile culture. Cytological examination of the exudate. "The presence of erythema, mucosal exfoliation or ulceration, tissue hyperplasia, exudates (changes in color and odor), or masses was also observed." Check the status of the eardrum.
3. Diagnosis requires further examination or therapeutic diagnosis. Bacterial or fungal culture or drug susceptibility testing. Examination of skin samples and testing of anti-scabies treatments. Hypoallergenic food test. Intradermal test or in vitro blood allergy test. If a drug reaction is suspected, topical or systemic medication should be stopped. A biopsy was performed to establish the presence of proliferative or immunologic disease. Check the level of estrogen or testosterone in the body, if it is sex hormone disease, can consider doing birth control surgery. The thyroid gland was examined. Check for other systemic diseases that can affect the ear.
Treatment for otitis externa in dogs
1. Clean the ear canal (not suitable for animals with ruptured eardrums). Remove the ear canal and auricle hair, and use cerumolytic agents if necessary. Because cerumen is irritating to the ear canal, it should be rinsed thoroughly from the ear canal. Do not use cotton swabs.2. Local treatment. Compound drug (Otomax) was used daily.
3. Systemic medication. Otitis externa complicated with otitis media should be treated with systemic medication.
4. Surgical treatment. Resection of the external ear wall of the ear canal, the vertical ear canal, the total ear canal and the lateral ear bubble bone incision were performed.
