A challenging case: Blindness and a history of cutaneous nodules in a cat - Veterinary Medicine
  • SEARCH:
Medicine Center
DVM Veterinary Medicine Featuring Information from:

ADVERTISEMENT

A challenging case: Blindness and a history of cutaneous nodules in a cat
Ocular signs, a decreased appetite, and previous skin nodules were the only clues that this indoor-only cat had a life-threatening disease.


VETERINARY MEDICINE


ADDITIONAL DIAGNOSTIC PROCEDURES


Figure 1. Cytologic examination of the vitreous fine-needle aspirate stained with Diff-Quik (Dade Behring) revealed multiple Cryptococcus species organisms. Cryptococcus species appear as a yeast organism surrounded by a thick nonstaining capsule that can reach up to 30 m thick.
To rule out systemic fungal disease, thoracic radiography and abdominal ultrasonography were performed. The thoracic radiographic examination results were normal. Abdominal ultrasonography revealed a small amount of echogenic gravity-dependent debris in the bladder and evidence of chronic renal disease with multiple renal infarcts. The spleen was subjectively enlarged but exhibited normal echogenicity and was homogeneous. No evidence of systemic fungal infection or neoplasia was found on imaging studies.


Figure 2. Cytologic examination of the vitreous fine-needle aspirate stained with Diff-Quik revealing multiple red and white blood cells and Cryptococcus species organisms.
To rule out ocular mycoses, the cat was anesthetized, the left eye was routinely prepared for surgery, and vitreous paracentesis of the left eye was performed. A focus of vitreous debris was localized using indirect ophthalmoscopy. A 20-ga needle was used to puncture the bulbar conjunctiva and underlying sclera about 7 mm posterior to the limbus at the 1-o'clock position. The needle was directed caudomedially to the debris focus, and a vitreous sample was obtained by aspiration. Cytologic examination of the aspirate revealed occasional neutrophils and monocytes and numerous Cryptococcus species organisms (Figures 1 & 2).

TREATMENT AND FOLLOW-UP

The cat was treated for ocular cryptococcosis with 10 mg/kg itraconazole orally once daily.

The cat was presented for a recheck ophthalmic examination about three weeks after treatment was initiated. The examination revealed improvement of intraocular inflammation characterized by decreased aqueous flare and the absence of aqueous cellular debris. The retinal detachment and granulomatous infiltrates were resolved in the left eye, and perivascular edema was still present. However, both pupils remained dilated and fixed, and marked vitreous debris present in the right eye prevented visualization of the retina. Dazzle reflexes remained poor bilaterally. Intraocular pressure results were low normal (right eye = 8 mm Hg, left eye = 7 mm Hg). The owner was advised to continue the itraconazole.

The patient was not presented for subsequent recommended recheck examinations but was presented three months later for euthanasia. The cat now weighed 3.8 lb (1.7 kg), having lost 4.2 lb (1.9 kg), and was no longer eating or drinking. Physical examination revealed severe cachexia and generalized weakness, dehydration, absent menace response, and fixed and dilated pupils. On neurologic examination, the cat appeared to have normal mentation, but the severe muscle weakness made it difficult to assess ambulation and reflexes. The owner declined further diagnostic tests, and a postmortem examination was not performed.


ADVERTISEMENT

Source: VETERINARY MEDICINE,
Click here