Cytology samples can be taken from the ear using a cotton tipped swab or if the animal is sensitive and the ear is painful, a gloved finger may be gently inserted into the ear to collect discharge.
The sample should be taken if possible from the junction of the horizontal and vertical canals.Mar 2, 2020.
An ear swab examination reveals the presence of bacteria, fungi and parasites.
Determining the underlying cause of ear discharge, pain or itchiness can help determine appropriate treatment.
How Is an Ear Swab Examination Done? To perform an ear swab examination, a cotton tip applicator is placed within the ear canal..
Image Gallery: Normal vs Abnormal Ear Cytology
Cytology samples should be examined under low power magnification (100\xd7) to identify cell types and high power magnification (1000\xd7) to identify infectious organisms, especially bacteria..
Normal cytology
Occasionally, cocci and yeast in an animal with no clinical signs are within normal limits, but most fields will only contain translucent, large, polygonal cells without a nucleus, which are keratinocytes or skin cells.
Some of these keratinocytes are stained purple and may be cigar shaped.Nov 1, 2009.
Brainstem-evoked auditory responses are employed by some hospitals to measure hearing in dogs with otitis.
When available, this modality can be useful for prognosis when a clinician is assessing an ear to decide if it is irreversibly damaged and, therefore, unable to be treated with medical therapy.
Primary Factors
It is important to take a detailed clinical history and perform both a physical and dermatologic examination in order to start the process of diagnosing ear disease.
These steps can help determine contributing factors and allow the clinician to formulate a logical diagnostic plan.
Examples include:.
1) If allergy is considered a primary factor, the .
Diagnostic imaging techniques, such as radiography, CT, or MRI, should be considered if otitis media is thought to be present in order to confirm diagnosis and assist with prognosis and treatment recommendations.
Radiography can be performed but is an insensitive technique-otitis media can still be present in the face of normal radiographic finding.
Otoscopic examination is the method of choice to evaluate the external ear canal and may also assist with identification of an existing otitis media.
Diagnostic samples should be taken from the pinna, ear canal and, when otitis media is present or suspected, the middle ear.
Any discharge from the ear should also be collected and evaluated.
Cytology
Key points in the dog’s history and physical examination should give the clinician a high level of suspicion if otitis media is present.
History: Clues from the history may include reluctance to:.
1) Open the mouth.
2) Chew hard food.
3) Carry a bone.
4) Bark.
Physical Examination: The physical examination may reveal signs of cranial nerve damage, such.
Many primary triggers for otitis first present with signs on the pinna.
A careful inspection can identify primary lesions (Figure 2) and secondary lesions (Table 1); secondary lesions tend to be less useful diagnostically.
A minimum data base for the pinna should include: 1.
Cytology (impression smears and tape preparations).
2) Superficial and deep.
When lesions are present on the ear canal wall, samples should be taken directly from those lesions whenever possible.Impression smears, fine-needle aspirates, and biopsies can be taken from this site.
1) Impression smearscan be taken from ulcerative lesions by rolling a cotton swab firmly along the wall of the canal.
The swab is then rolled on a g.
