Ear Cytology

Question 1

Cause of Otitis (6)

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Answer 1

• Conformation of the ear canal.
• Organisms
• Skin Disease
• Trauma
• Habits (swimming, living outdoors)
• Tumors

Question 2

Diagnosis of Otitis

Answer 2

• History
• Otoscopic Examination
• Physical Exam
• Cytology of Ear Swab

Question 3

Cytologic Examination

Answer 3

Smears of ear canal secretions should be evaluated for:

• bacteria: rods, cocci
• yeast
• fungal hyphae
• mites
• neoplasia
• foreign body

Question 4

Bacteria

Answer 4

• Bacterial concentration is usually low.
• Many are pathogenic under certain circumstances.
• Bacterial infections reveal large number of bacteria and phagocytes.
• Staphylococcus or Streptococcus, large numbers of cocci.
• Creamy, dark-yellow or light brown otic discharge.
• Large numbers of rods, usually Pseudomonas aeruginosa or Proteus mirabilis.
• Thick, sweet smelling, pale yellow discharge.
• Combination of rods and cocci can also be found.
• When routine therapy is ineffective, c/s is indicated.

Question 5

Fungi

Answer 5

• Malassezia pachydermatis (Malassezia canis), Pityrosporum canis and Pityrosporum pachydermatis.

Question 6

Fungi

Mycotic Infections

Answer 6

• Malassezia: broad based budding, gram pos yeast that can be a normal inhabitant of ear.
• Peanut shaped, round or oval.
• Found in 49% normal k-9’s.
• Found in 23% normal feline.

> 10 Malassezia / hpf = yeast overgrowth.

• Copious, dark brown, exudate w/a sweet odor.
• Bacterial & yeast infections can occur simultaneously.
• Other fungi, candida, aspergillus, & microsporum rarely cause otitis.
• When yeasts are unidentified c/s is indicate.

Question 7

Mites

Answer 7

• Otitis externa is secondary to ear mites.
• Otodectes cynotis
• Signs can develop with as few as 2-3 mites.
• Dry reddish-brown or black, granular discharge.
• Discharge consists of cerumen, epidermal cells, inflammatory cells.
• Secondary bacterial, yeast infections can occur.
• Cytology: larvae, eggs, adult mites.
• Mites, usually wash off w/staining procedure.
• Demodex canis is rare.

Question 8

Neoplasia

Answer 8

• Any tumor that can occur on skin - ear.
• Benign: polyps, papillomas, & basal cell tumors.
• Malignant: ceruminous gland adenocarcinoma, squamous cell carcinoma, carcinoma.
• Infection is usually secondary to tumor.
• Fine needle aspirate of tumor to id mass.

Question 9

Ear Cytology History

Questions

Answer 9

1. Does it involve 1 or both ears?
2. When did it start?
3. How long has it been going on?
4. What does it look like?
5. Has any treatment been attempted (home remedies or otherwise)?
   * if so when and what?
   * did they see any improvement, stayed the same, or has it gotten worse?
6. Any change in food?
7. Any change in environment?
8. Any other pets in household? If so, are they showing any problems?

Question 10

Ear Cytology History
(Questions)
Expand on Question 4

Answer 10

What does it look like?

• Shaking head
• Scratching head
• Rubbing head/face along furniture or ground
• Crying
• Odor, what does it smell like
• Discharge
  
  • wax
  • blood
  • pus, color
  • clear fluid
• Protrusions from ear
• Swelling of face
• Swelling of ear
• Head tilt