What does otitis look like in a rat? - briefly
Otitis in a rat appears as swelling and reddening of the ear canal, frequently accompanied by serous or purulent discharge and crust formation; affected animals often scratch the ear or hold their head at an angle. Advanced inflammation may cause ulcerated tissue and noticeable hearing impairment.
What does otitis look like in a rat? - in detail
Otitis in rats presents with a recognizable set of external and internal changes. The outer ear may appear swollen, with the pinna becoming thickened and less pliable. Redness or a purplish hue often accompanies the edema, and the fur surrounding the ear can become matted or lost due to scratching.
Inside the auditory canal, the skin frequently shows erythema, exudate, or crust formation. Purulent discharge may be evident, ranging from thin serous fluid to thick, yellow‑green pus. The canal walls can become hyperplastic, narrowing the passage and making visual inspection difficult.
The tympanic membrane, when visible, typically loses its normal translucent sheen. It may appear opaque, thickened, or perforated, and the underlying structures can be obscured by inflammatory debris. In severe cases, the membrane may be retracted or bulging, indicating pressure changes within the middle ear.
Behavioral signs accompany the physical findings. Affected rats often exhibit head shaking, ear scratching, or rubbing against cage bars. They may tilt the head toward the affected side, show reduced responsiveness to auditory stimuli, or display signs of discomfort when the ear is palpated. Reduced food intake and lethargy can develop if the infection progresses.
Diagnostic confirmation usually involves otoscopic examination, followed by cytology of any discharge to identify bacterial or fungal organisms. Imaging, such as radiography or computed tomography, can reveal bony involvement, middle‑ear fluid accumulation, or mastoid extension.
Treatment protocols generally include systemic antibiotics selected based on culture results, topical antimicrobial ointments applied to the external canal, and anti‑inflammatory agents to reduce swelling. In chronic or refractory cases, surgical debridement of the canal and removal of granulation tissue may be necessary.
Key clinical indicators:
- Swollen, reddened pinna with loss of fur
- Purulent or serous discharge from the ear canal
- Thickened, opaque or perforated tympanic membrane
- Head tilt, ear scratching, and reduced auditory response
- Radiographic or CT evidence of middle‑ear fluid or bone changes
Recognition of these signs enables prompt intervention, reducing the risk of complications such as chronic otitis, hearing loss, or spread of infection to adjacent structures.