Feline uveitis:aqueous flare intensity excellent clinical monitor - DVM
  • SEARCH:
News Center
DVM Featuring Information from:

ADVERTISEMENT

Feline uveitis:aqueous flare intensity excellent clinical monitor


DVM360 MAGAZINE


Uveitis of undetermined origin is a cause for uveitis that can often not be found by routine hematologic or serologic tests, especially in older cats in which the uveitis had been present chronically. The typical clinical signs of this idiopathic uveitis are mild to moderate aqueous flare, keratic precipitates, iris color change and iridal nodules representing mono-nuclear inflammatory cell infiltrates (lymphocytes and plasma cells). The uveitis is either unilateral or bilateral, and secondary glaucoma seems to be an inevitable sequelae. Recently, serologic evidence has suggested feline herpesvirus-1 and Bartonella species may be causes of chronic uveitis in cats.

Treatment

Corticosteroids remain the primary treatment of uveal inflammation. Topical therapy is the route of choice in most cases, as effective anterior uveal concentrations are easily achieved. It is imperative that uveitis be treated with cortico-steroids with the ability to penetrate the epithelial barrier of the cornea. 1 percent prednisolone acetate suspension or 0.1 percent dexamethasone is an excellent topical steroid choice. The routine initial frequency in moderately severe cases is four-times daily and then reduced to a maintenance frequency of one to two times daily after the clinical signs have subsided or resolved (usually within two to three weeks). In acute severe anterior uveal inflammation topical therapy as frequent as every one to two hours is sometimes necessary. The intensity of aqueous flare is an excellent clinical monitor of the effectiveness of therapy. Subconjunctival corticosteroids (1-2 mg betamethasone) are also highly effective but are generally reserved for cases in which the uveitis is unusually severe, or when owner compliance with topical therapy cannot be expected. Needless to say, subconjunctival therapy must be used with caution in the face of systemic infectious diseases, particularly mycoses. Systemic corticosteroids are usually not indicated unless the posterior segment is involved, and the cause is non-infectious in nature.

Specific antimicrobial therapy is a critical adjunct to palliative anti-inflammatory therapy in cases in which the uveitis can be attributed to a susceptible organism. For toxoplasmosis, clindamycin hydro-chloride (25 mg/kg daily in divided oral doses) may be beneficial; however, the use of antimicrobial therapy for Toxoplasma-associated uveitis remains controversial. The prognosis for uveitis secondary to systemic mycoses is generally poor. Cures from histoplasmosis and cryptococcosis have been noted with imidazole therapy. Effective specific therapy for FIP and FIV infection has not been reported. On the basis of the serologic information suggesting a role for Bartonella species as a cause of uveitis in cats, azithromycin therapy (10 mg/kg PO daily for 21 days) has been advocated for treating cats with this uveitis.

Cycloplegic therapy is not routinely indicated in feline uveitis because the disease is rarely associated with significant miosis. Atropine solution should be avoided in cats because it invariably travels the short nasolacrimal duct to induce copious salivation. n

Dr. Hoskins is owner of DocuTech Services. He is a diplomate of the American College of Veterinary Internal Medicine with specialities in small animal pediatrics. He can be reached at (225) 955-3252, fax: (214) 242-2200, or e-mail:


ADVERTISEMENT

Source: DVM360 MAGAZINE,
Click here