Intradermal reactivity to two concentrations of pollen extracts in atopic dogs.

BACKGROUND: Intradermal test (IDT) is used widely for determination of allergens to include in allergen-specific immunotherapy (AIT). The optimal concentration of allergen solutions used for testing has not been established in atopic dogs. Inadequate concentrations could lead to falsely negative test results and lack of inclusion of important allergens in AIT. HYPOTHESIS/OBJECTIVES: To compare IDT reactivity to two concentrations of five pollen extracts and determine the effect on ASIT prescription. ANIMALS: Atopic dogs (n = 67) had IDT results including all of the allergens of interest. METHODS AND MATERIALS: Medical records from a veterinary teaching hospital were reviewed for all atopic dogs undergoing IDT over a three year period. In addition to the hospital's standard IDT concentration of 1,000 PNU/mL for pollen allergens, five pollen allergens of higher concentration (3,000-8,000 PNU/mL) had been added at the beginning of that period. The IDT scores for the standard test concentration of each of the five allergens were compared to the scores for the higher concentration. RESULTS: Positive reactions occurred much more commonly to the higher test concentration for each of the paired allergens (P < 0.05, chi-square). The AIT formulation was different in 58% of the dogs from what it would have been without the higher concentration allergens. CONCLUSIONS AND CLINICAL IMPORTANCE: The current standard IDT concentration of 1,000 PNU/mL for pollen allergens is likely too low, possibly resulting in inaccurate AIT formulations. This might explain treatment failures and the incorrect diagnosis of atopic-like dermatitis. Further work is needed to establish optimal allergen test concentrations.

Clinical techniques in Veterinary Dermatology: Regional anaesthesia of the canine ear.

BACKGROUND: Video otoscopy is a valuable tool for the diagnosis and treatment of otitis externa (OE) and otitis media (OM) in dogs. Procedures performed by video otoscopy often are painful and it can be challenging to maintain steady anaesthetic depth and provide smooth anaesthetic recovery. A multimodal approach to analgesia and anaesthesia is ideal to minimize complications associated with high doses of anaesthetic drugs while providing the patient with adequate analgesia. HYPOTHESIS/OBJECTIVE: To describe a technique for regional anaesthesia of the canine ear. ANIMALS: One canine cadaver, obtained as part of a teaching laboratory class for other clinical techniques, with institutional approval, was used for illustration purposes. RESULTS: Clinical technique for regional anaesthesia of the canine ear. CONCLUSIONS AND CLINICAL IMPORTANCE: Nerve blocks for regional anaesthesia are an important aspect of a multimodal anaesthetic approach. A technique for blocking the two major sensory nerves to the canine ear is described.

Deslorelin Implant Treatment for Hair Cycle Arrest (Alopecia X) in Two Intact Male Keeshonden.

Alopecia in dogs occurs secondary to a variety of underlying inflammatory and noninflammatory conditions. Hair cycle arrest (alopecia X) is a noninflammatory alopecia that is frustrating to diagnose and treat due to lack of understanding of disease pathogenesis. A variety of therapies for hair cycle arrest have been described with inconsistent efficacy in different dog breeds and sexes; no definitive treatment is available. This report describes the use of a deslorelin acetate implant in two sexually intact adult male keeshonden, both diagnosed with hair cycle arrest. The dogs had progressive alopecia of the trunk that spared the head and distal limbs present for at least 2 yr. Diagnosis of hair cycle arrest was made based on clinical features, dermatohistopathology, and lack of systemic abnormalities. Treatment with a single subcutaneous 4.7 mg deslorelin acetate implant resulted in profuse hair regrowth within 3.5 mo that endured for at least 14 mo. Deslorelin implantation is a management option that is safe, affordable, and appears effective for sexually intact male keeshonden with hair cycle arrest.

Impression Smear Agreement with Acetate Tape Preparation for Cytologic Sampling.

Cutaneous cytologic sampling techniques are used to detect bacteria, yeast, and inflammatory cells for diagnosis and therapeutic monitoring. Studies have examined slide evaluation techniques, ear swab cytology staining methods, and observer variations; few studies compare common clinical sampling techniques. The primary aim of this study was to measure detection of microorganisms and neutrophils by impression smear compared to acetate tape preparation; comparison of agreement between two acetate tape staining methods was a secondary aim. Thirty lesions consistent with superficial pyoderma were sampled via impression smear and acetate tape preparation. Acetate tape preparations were either stained with modified Romanowksy stain solutions two and three or solution three alone. Impression smears were stained in the standard manner. Bacteria, yeast, and neutrophils were evaluated using a semi-quantitative scale [0-4]. Quantities were aggregated and compared using Cohen's kappa to measure agreement between methods. When impression smears were compared to acetate tape, the lowest agreement occurred for neutrophils, with impression smears detecting more neutrophils. Comparison of acetate tape staining methods had the highest agreement for yeast detection. Sampling technique and staining method did not differ for detection of bacteria. Impression smears detected more neutrophils, and yeast detection appeared equivalent for acetate tape staining methods.

Serum Malassezia-specific IgE in dogs with recurrent Malassezia otitis externa without concurrent skin disease.

Immediate-type hypersensitivity (ITH), mediated by IgE, to Malassezia pachydermatis is recognized in atopic dogs with recurrent yeast dermatitis and otitis externa (OE). Malassezia-associated OE commonly occurs in dogs without other signs of atopic dermatitis (AD). The aim of this study was to detect Malassezia-specific IgE in the sera of dogs with recurrent Malassezia OE without concurrent skin disease. Sera from healthy dogs were used for comparison. An FcεRIα-based ELISA was used to measure Malassezia-specific IgE. There was no significant difference between number of positive affected dogs (6/21, 29%) and number of positive unaffected dogs (15/86, 17%) (P=0.36). There was also no significant difference in the concentrations of Malassezia-specific IgE between the two groups (P=0.97). Malassezia-specific IgE did not distinguish between patient groups so, as with other canine allergens, serum IgE reactivity for Malassezia could not be used to differentiate between diseased and healthy patients. The presence of Malassezia-specific IgE in some of the affected dogs might indicate ITH to Malassezia in those dogs. Evaluation of ITH via intradermal test reactivity and response to allergen-specific immunotherapy might clarify the role of Malassezia-associated ITH in similarly affected dogs.

Cutaneous squamous cell carcinoma manifesting as follicular isthmus cysts in a cat.

CASE SUMMARY: A 9-year-old spayed female domestic shorthair cat was examined for swelling of the right upper lip. The cat had been receiving oral ciclosporin A for eosinophilic plaques. The swelling appeared clinically and cytologically consistent with an abscess; exudate was cultured and treatment consisted of antibiotic therapy and surgical curettage. Five months of antibiotic therapy with three separate surgical treatments resulted in minimal improvement; three separate biopsy samples demonstrated epithelial cysts with severe dermal inflammation. Swelling and drainage of purulent material from the affected lip persisted and progressed to involve the left upper lip. Euthanasia was elected 13 months after initial examination due to disease progression. On necropsy, histopathology demonstrated multiple isthmus cysts intermixed with squamous cell carcinoma (SCC). RELEVANCE AND NOVEL INFORMATION: The clinical and histopathologic features were unusual for feline cutaneous SCC. The cystic nature and lack of epidermal involvement suggest the tumor arose from non-epidermal squamous cells such as follicular isthmus or ductal epithelium. There is a pattern of SCC recognized in human renal transplant patients with features of epidermal inclusion cysts. These features have not been previously reported in SCC from a cat.