Idiopathic periadnexal multinodular granulomatous dermatitis in twenty-two dogs.

A distinctive periadnexal multinodular granulomatous dermatitis of unknown cause was diagnosed over a 6-year period in 22 dogs (13 males and nine females) aged 8 months to 10 years, purebred as well as mixed-breed. Nodules, usually more than two, started on the face and were often unaccompanied by signs of irritation. All dogs were otherwise healthy except a Viszla with bilateral anterior uveitis and a Basset hound with nasal congestion and sneezing. Microscopically, cutaneous lesions occurred in a periadnexal pattern, replaced sebaceous glands, coalesced, and extended into the subcutis and in more advanced cases through the panniculus carnosus. Infectious agents were not demonstrated by aerobic, anaerobic, or fungus cultures or by light or electron microscopy, nor were ectoparasites seen. Immunofluorescence and peroxidase-antiperoxidase techniques gave negative results for intraepidermal and basement membrane deposits of IgA, IgG, IgM, and C3. Lesions were unresponsive to a variety of antibiotics; they regressed spontaneously in two untreated dogs and rapidly in dogs given only corticosteroid therapy. Continuous low-dose corticosteroids were necessary in a few dogs to prevent recurrence.

Telangiectasia of Pembroke Welsh Corgi dogs.

Multiple vascular lesions involving kidneys and various other organs consisting of cavernous, blood-filled spaces lined by endothelial cells with various amounts of mural collagen are described in eight Pembroke Welsh Corgi dogs. The most common clinical sign associated with this condition is hematuria.

Nosocomial transmission of Serratia marcescens in a veterinary hospital due to contamination by benzalkonium chloride.

During a 1-year period, Serratia marcescens was isolated from 50% of all contaminate intravenous catheters from dogs and cats in a large veterinary hospital. S. marcescens was also isolated from respiratory tracts, genitourinary tracts, skin, and other sites in hospitalized animals. A total of 55% of the clinical isolates and 66% of the intravenous catheter isolates had the same API biochemical profile. The source of the S. marcescens was determined to be aqueous benzalkonium chloride (0.025%) sponge pots located in the intensive care unit, surgery rooms, and outpatient clinic areas of the hospital. Of the 11 S. marcescens isolates submitted to the Centers for Disease Control for serotyping (6 from aqueous benzalkonium chloride sponge pots, 5 from intravenous catheters), 8 were identified as serotype O10:H11. All S. marcescens isolates tested for antibiotic susceptibilities were multiply resistant; isolates were most frequently resistant to streptomycin, cephalothin, and ampicillin. This study demonstrates that improper use of disinfectants plays an important role in the nosocomial transmission of S. marcescens.