Clinical efficacy of recombinant canine interferon-gamma therapy in dogs with cutaneous epitheliotropic T-cell lymphoma.

BACKGROUND: The antitumour effects of interferon-gamma (IFN-γ) in humans with cutaneous epitheliotropic T-cell lymphoma (CETCL) have been described; however, the efficacy of IFN-γ in dogs has not been investigated. HYPOTHESIS/OBJECTIVES: The aim of this study was to evaluate the efficacy of recombinant canine IFN-γ (rCaIFN-γ) therapy in dogs with CETCL. ANIMALS: Twenty dogs with CETCL recruited from seven veterinary clinics were enrolled in the study. MATERIALS AND METHODS: Fifteen dogs were treated with rCaIFN-γ, and five control dogs were treated with prednisolone. We evaluated survival time, skin lesions (erythema, nodules, ulcers and bleeding), pruritus and general condition (sleep, appetite and body weight). In the rCaIFN-γ group, a questionnaire regarding the therapy was administered to owners after the dogs died. RESULTS: No significant differences existed in the median survival time between the rCaIFN-γ and control groups (log-rank test: p = 0.2761, Wilcoxon's rank sum test: p = 0.4444). However, there were significant differences in ulcer, bleeding, pruritus, sleep, appetite and body weight between the groups (Wilcoxon-Mann-Whitney U-test: p = 0.0023, p = 0.0058, p = 0.0005, p = 0.0191, p = 0.0306 and p = 0.0306, respectively). Two (40%) of five dogs were euthanised in the control group, compared with none in the rCaIFN-γ group. Fourteen questionnaires were collected, and owners reported that they were satisfied with the rCaIFN-γ treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Although the median survival time was not prolonged, rCaIFN-γ could be helpful in maintaining good quality of life for dogs with CETCL.

Long-term follow-up of a single dose of fluralaner in nine dogs with demodicosis.

BACKGROUND: Long-term follow-up of oral fluralaner for canine demodicosis has not been demonstrated. OBJECTIVES: A multicentre prospective open trial for the efficacy of oral fluralaner for the long-term (>12 month) management of canine demodicosis. ANIMALS: Client-owned dogs diagnosed with demodicosis at nine veterinary clinics. METHODS AND MATERIALS: A single fluralaner dose was administered orally. Although shampoo was allowed to treat secondary pyoderma, no other medication or shampoo was allowed, except for medication for possible underlying disorders. Each dog underwent a thorough parasitological and dermatological assessment monthly for three months and was followed up for >12 months. RESULTS: Twenty-six dogs were enrolled. Their ages ranged from three months to 16 years. The cases were nine juvenile and 17 adult onsets; and 18 generalised and eight localised forms. Fluralaner administration resulted in 100% eradication of mites and complete resolution of all skin lesions at three months. Seventeen dogs were excluded from the one year follow-up evaluation as they had required a second dose of isoxazoline or died from causes unrelated to the fluralaner treatment. In the remaining nine cases, no relapse was observed in any of the dogs (six adult and three juvenile onsets; six generalised and three localised forms). Four dogs were monitored for over one year, one dog for over two years, and four dogs for three years. CONCLUSIONS AND CLINICAL RELEVANCE: The results indicated that a single dose of fluralaner could effectively deliver a long-term cure when combined with managing underling conditions.

Narrow-band ultraviolet B therapy attenuates cutaneous T-cell responses in hapten-induced, experimental contact dermatitis in beagles.

BACKGROUND: In human medicine, narrow-band ultraviolet B (NB-UVB) phototherapy has been used to treat various T-cell-mediated skin diseases. However, the effect of NB-UVB on inflamed canine skin remains uncertain. OBJECTIVES: To investigate the effect of NB-UVB phototherapy on the skin of dogs with hapten-induced contact dermatitis. ANIMALS: Seven healthy beagles without skin problems. METHODS AND MATERIALS: Dogs were irradiated with varying doses of NB-UVB to determine the minimal erythema dose (MED). After determining the MEDs of six dogs (excluding one of the seven whose skin did not show a visible reaction), we investigated the effect of NB-UVB on their inflamed skin by topically applying 2,4-dinitrochlorobenzene (DNCB), which causes type 1 helper T cell (Th1)- and cytotoxic T-cell (Tc)1-induced skin inflammation. We then irradiated the skin with NB-UVB. We analysed the treated skin samples via histopathological and immunohistochemical methods, and TdT-mediated dUTP nick-end labelling (TUNEL) to demonstrate apoptotic cells. We also analysed the cytokine gene transcription via real-time quantitative reverse transcription PCR. RESULTS: The NB-UVB MEDs caused mild inflammatory changes yet no severe epidermal exfoliations in the irradiated skin. In DNCB-treated skin irradiated by the NB-UVB MEDs, TUNEL-positive dermal apoptotic cells were increased significantly compared with those of DNCB-treated, nonirradiated skin. INF-γ and TNF-α transcription levels in DNCB-treated, irradiated skin were significantly lower than those in the DNCB-treated, nonirradiated skin. CONCLUSION AND CLINICAL RELEVANCE: Phototherapy using NB-UVB MEDs attenuated cutaneous Th1 and Tc1 cytokine responses with minimal skin damage in a canine model of hapten-induced contact dermatitis.

Serum canine thymus and activation-regulated chemokine (TARC/CCL17) concentrations correlate with disease severity and therapeutic responses in dogs with atopic dermatitis.

BACKGROUND: Thymus and activation-regulated chemokine (TARC/CCL17) has been implicated in the pathogenesis of canine atopic dermatitis (cAD). Serum TARC concentrations are a reliable biomarker for human atopic dermatitis; however, their potential as a biomarker for cAD has not been investigated. HYPOTHESIS/OBJECTIVES: To investigate whether serum TARC concentrations correlate with disease severity and therapeutic responses for cAD. ANIMALS: Thirty-nine dogs with cAD and 42 healthy dogs were recruited. METHODS AND MATERIALS: Serum TARC concentrations in dogs with cAD and healthy dogs were measured by sandwich ELISA with anti-canine TARC antibodies. The clinical severity of cAD was scored using the validated Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-04). Serum TARC concentrations were compared between dogs with cAD and healthy controls, and their relationship with CADESI-04 was examined. Serum TARC concentrations also were measured in 20 dogs with cAD treated with prednisolone or oclacitinib for four weeks. RESULTS: Serum TARC concentrations were significantly higher in dogs with cAD than in healthy dogs (P < 0.001). In dogs with cAD, serum TARC concentrations correlated with CADESI-04 scores (ρ = 0.457, P < 0.01). Furthermore, serum TARC concentrations significantly decreased in treated dogs with the attenuation of clinical signs (P < 0.001). Changes in serum TARC concentrations before and after treatment correlated with those in CADESI-04 scores (ρ = 0.746, P < 0.001). CONCLUSIONS AND CLINICAL RELEVANCE: Serum TARC concentrations have potential as a clinical and research tool for the objective evaluation of disease severity and therapeutic responses for cAD.

Clinical analysis and nonsurgical management of 11 dogs with aural cholesteatoma.

BACKGROUND: Aural cholesteatomas, also called tympanokeratomas, are destructive and expansile growths of keratinizing epithelium that develop in the middle ear. They have been reported sporadically in dogs, and surgery is usually the recommended treatment. OBJECTIVES: To describe the common clinical, radiological and histological findings of cholesteatoma; to report on the outcome of conservative management. ANIMALS: Eleven dogs (13 ears) with cholesteatomas. METHODS AND MATERIALS: Medical records were reviewed for dogs diagnosed with cholesteatoma between 2012 and 2018. All dogs had computed tomography (CT) and/or magnetic resonance imaging (MRI) followed by trans-canal endoscopic procedure (TEP) for removal and biopsy of middle ear lesions. Dogs were then treated with in-clinic flushing initially weekly tapered to monthly, as well as at-home ear cleaning and application of topical otic steroid medication, initially daily then tapered to once or twice weekly. RESULTS: Nine dogs had a history of chronic otitis externa; head tilt or facial paralysis was present in seven and four cases, respectively. Otic examination identified a protruding nodule in seven ears. CT demonstrated soft tissue-like material in 12 bullae and expansion in seven bullae. MRI revealed minimally contrast-enhancing bulla contents in 12 ears. Post-TEP and with maintenance medical treatment, nine ears had no further signs of middle ear disease during a mean follow-up of 27.9 months. CONCLUSIONS AND CLINICAL IMPORTANCE: The results suggest that otitis externa may not necessarily precede cholesteatoma in all dogs. MRI appears to be more sensitive than CT for identifying cholesteatomas. Conservative treatment of cholesteatomas could be useful before or as an alternative to surgery.

Complementary effect of oral administration of Lactobacillus paracasei K71 on canine atopic dermatitis.

BACKGROUND: Atopic dermatitis is a common skin disease encountered in dogs. Glucocorticoids are commonly recommended for symptomatic therapy and well-tolerated adjunctive therapies may help to reduce the necessary dose and associated risks of chronic glucocorticoid use. HYPOTHESIS/OBJECTIVES: The purpose of this study was to evaluate the complementary efficacy of oral administration of Lactobacillus paracasei K71 in canine atopic dermatitis (cAD). ANIMALS: Forty one dogs with mild to moderate cAD were recruited by19 animal hospitals. METHODS: Dogs were assigned to receive either the investigational agent (K71 group; n = 20) or cetirizine hydrochloride (control group; n = 21). Previously prescribed medications were allowed to be continued during the 12 week trial. Dogs were assessed by the investigators using the cAD Extent and Severity Index (CADESI) and a medication scoring system. Pet owners assessed their dogs using a visual analog scale (VAS) and pruritus scores. RESULTS: The CADESI scores, VAS and pruritus scores in both groups at 12 weeks were improved compared with their baselines. The CADESI and pruritus scores in the K71 group were slightly lower than those in the control group and the reduction of medication scores in the K71 group was significantly lower compared with the control group (P < 0.05; Student's t-test). CONCLUSIONS AND CLINICAL IMPORTANCE: Oral administration of K71 can be useful in dogs with cAD as a complementary therapy, by providing a steroid-sparing effect.

In vitro antiseptic susceptibilities for Staphylococcus pseudintermedius isolated from canine superficial pyoderma in Japan.

BACKGROUND: Topical therapy, particularly with chlorhexidine, is becoming increasingly common as a treatment option for canine pyoderma; however, there are limited studies on the susceptibility of Staphylococcus pseudintermedius to chlorhexidine compounds. OBJECTIVES: To determine the in vitro susceptibility of both meticillin-resistant and meticillin-susceptible S. pseudintermedius isolates to chlorhexidine and other antiseptic agents and the presence of multidrug efflux pump genes. SAMPLES: One hundred S. pseudintermedius isolates from 23 initial and 77 recurrent cases of canine pyoderma. METHODS: After bacterial identification and mecA testing, minimal inhibitory concentrations (MICs) of antiseptic agents were determined. Multidrug efflux pump genes, including qacA, qacB and smr, were identified. RESULTS: Of the 100 isolates, 57 were identified as meticillin-resistant S. pseudintermedius. The MIC(90) of chlorhexidine acetate, chlorhexidine gluconate, acriflavine, ethidium bromide and benzalkonium chloride were 1, 1, 2, 0.5 and 2 µg/mL, respectively. Multidrug efflux pump genes qacA, qacB and smr were not detected in any of the isolates. CONCLUSIONS AND CLINICAL IMPORTANCE: The MICs for chlorhexidine and other antiseptics remain low, and multidrug efflux pump genes were not found in the tested isolates.

Transcription profile of chemokine receptors, cytokines and cytotoxic markers in peripheral blood of dogs with epitheliotropic cutaneous lymphoma.

BACKGROUND: Mycosis fungoides (MF) is the most common form of canine epitheliotropic cutaneous lymphoma, which is characterized by the accumulation of neoplastic CD8(+) T cells. Given that multifocal skin lesions are commonly seen in MF, neoplastic lymphocytes may actively migrate into the blood circulation. HYPOTHESIS/OBJECTIVES: Cytotoxic T cells with a skin-homing phenotype could be increased in the blood circulation of dogs with MF. ANIMALS: Ten dogs with MF and 10 age-matched healthy dogs were included. METHODS: The transcription levels of chemokine receptors, cytokines and cytotoxic markers in peripheral blood of dogs with MF were quantified by real-time RT-PCR. RESULTS: The dogs with MF had lower transcription levels of chemokine receptors associated with skin homing (CCR4), epitheliotropism (CXCR3), lymph node homing (CCR7), a type-1 cytokine (LT-α) and cytotoxic markers (perforin and granzyme B) in the circulation than healthy control dogs (P < 0.05). CONCLUSIONS AND CLINICAL IMPORTANCE: The present results suggest that the number of peripheral cytotoxic T cells with a skin-homing phenotype could be decreased in the peripheral blood of dogs with MF, which might be due to the sequestration of cytotoxic T cells in the lesional skin.

Diode laser-assisted transcanal endoscopic removal of an aural polyp in the external auditory canal of a dog.

BACKGROUND: In humans, aural polyps comprise fibrovascular tissue covered by the respiratory epithelium. Aural polyps with ciliated epithelium are common in cats but are rarely reported in dogs. In a previous case, a mass filled the tympanic cavity alone, and it was surgically removed. OBJECTIVES: To report a case of a canine aural polyp with ciliated epithelium extending from the dorsal tympanic cavity to the external auditory canal with detailed otological features and to demonstrate the usefulness of the transcanal endoscopic procedure (TEP) with a diode laser as a less-invasive therapy. METHODS: A 12-year-old castrated male Cavalier King Charles Spaniel presented with a 6-month history of unilateral chronic otorrhoea. Video-otoscope examination revealed a protruding, reddish and soft-to-rubbery round mass in the right horizontal ear canal. Computed tomography and magnetic resonance imaging further revealed a smooth mass extending from the dorsal portion of the tympanic cavity into the horizontal part of the external auditory canal. However, it showed no lesions in the dorsal tympanic cavity. RESULTS: The mass was removed using aural forceps by a traction-torsion manoeuvre. The suspected base of the mass on the caudal side of the upper tympanic cavity was confirmed by a rigid scope, and it was completely vaporised with a diode laser. Histopathology revealed foci of columnar ciliated epithelium embedded in the connective tissue encapsulated by stratified squamous epithelium. No recurrence was observed at 3 years and 8 months. CONCLUSION: We describe a rare case of an aural polyp with ciliated epithelium extending from the upper-middle ear to the external auditory canal in a dog. The TEP using a diode laser may be a useful minimally invasive treatment option for managing external auditory canal polyps.

Focal cutaneous telangiectasia in a young dog of probable congenital origin.

BACKGROUND: Idiopathic cutaneous telangiectasia has been rarely described in the dog. OBJECTIVES: We present the first case of idiopathic focal cutaneous telangiectasia in a young dog of probable congenital origin. METHODS: An 18-month-old spayed female Maltese dog presented with demarcated erythema of the skin on the right thorax. The lesion consisted of scattered, florid, ramified macules with mild dermatrophia and desquamation. The lesion was examined with histopathology and immunohistochemistry using antibodies for alfa-SMA. RESULTS: Diascopy revealed a blanchable lesion. Tortuous capillary expansion was observed by dermoscopy. The histopathological examination revealed dilated but otherwise unremarkable capillaries in the superficial dermis compatible with cutaneous telangiectasia. The lesion was followed up over a 3-year period and had essentially remained stable. Other vascular anomalies displaying similarities with telangiectasia are discussed. CONCLUSIONS: In human vascular anomalies, this case would be presumably classified as 'telangiectasia' by the International Society for the Study of Vascular Anomalies. We propose that primary cutaneous telangiectasia should be included in the list of differential diagnoses for this type of lesions in dogs. We also suggest that dermoscopy would be a valuable tool for the identification of vascular anomalies in dogs.

Outcomes and prognostic factors in canine epitheliotropic and nonepitheliotropic cutaneous T-cell lymphomas.

Canine cutaneous lymphoma is an uncommon lymphoma in dogs. Most canine cutaneous lymphoma cases have a T-cell origin. Canine cutaneous T-cell lymphoma (CTCL) is classified into epitheliotropic and nonepitheliotropic cutaneous lymphomas, and each type of lymphoma is subclassified into several histological subtypes. Limited information is available regarding the prognostic significance of clinical variables and histopathological subtypes in dogs with CTCL. This retrospective study aimed to investigate the influence of clinical variables and histopathological subtypes on the prognosis of dogs with CTCL. Forty-six dogs diagnosed with CTCL by histopathological examination were included. Histopathological specimens were reexamined and classified into CTCL subtypes. The influence of the type of skin lesion, histopathological subtype, haematological examination results and treatment response on the overall survival time (OS) was examined. Thirty-one dogs were diagnosed with epitheliotropic CTCL (mycosis fungoides in 28 dogs; pagetoid reticulosis in 3 dogs) and 15 dogs were diagnosed with nonepitheliotropic CTCL (anaplastic large T-cell lymphoma in 6 dogs; peripheral T-cell lymphoma, not otherwise specified, in 9 dogs). The OS of dogs diagnosed with epitheliotropic CTCL (141 days) was significantly shorter than that of dogs diagnosed with nonepitheliotropic CTCL (374 days). As clinical variables, the presence of neoplastic lymphocytes in peripheral blood, thrombocytopenia and initial chemotherapeutic response was related to prognosis. Our results demonstrated that histopathological subtype and several clinical variables were found to influence the prognosis of dogs with CTCL.

Dose assessment of 2% chlorhexidine acetate for canine superficial pyoderma.

The dose of 2% chlorhexidine acetate (2CA; Nolvasan(®) Surgical Scrub; Fort Dodge Animal Health, Fort Dodge, IA, USA) for canine superficial pyoderma was evaluated. The first trial compared three doses (group 1, 57 mL/m(2) body surface area; group 2, 29 mL/m(2) body surface area; and group 3, 19 mL/m(2) body surface area) in a randomized, double-blind, controlled fashion. Twenty-seven dogs with superficial pyoderma were treated with 2CA at the allocated doses every 2 days for 1 week. The owners and investigators subjectively evaluated the dogs, and investigators scored skin lesions, including erythema, papules/pustules, alopecia and scales, on a 0-4 scale. There were no significant differences in response between the treatment groups. The second trial established a practical dose-measuring method for 2CA. Sixty-eight owners were asked to apply 2CA on their palm in an amount corresponding to a Japanese ¥500 coin, 26.5 mm in diameter. This yielded an average dose of 0.90±0.40 mL. Mathematically, the doses used in groups 1, 2 and 3 can be represented as one coin per approximately one-, two- and three-hand-sized lesions, respectively. The results therefore suggest that owners instructed to apply one coin of the product per two-hand-sized areas of superficial pyoderma would use the range of doses evaluated in this trial.

Genotyping of Malassezia pachydermatis isolates from canine healthy skin and atopic dermatitis by internal spacer 1 (IGS1) region analysis.

Isolates of Malassezia pachydermatis from healthy dog skin and from dogs with atopic dermatitis were molecularly characterized using internal spacer 1 (IGS1) region analyses, and their phospholipase A2 activity and pH growth profiles were then characterized in vitro. The percentage of isolates from healthy dogs that had the following IGS1 subtypes (isotype, %) were as follows: 1A, 6%; 1B, 27%; 1C, 11%; 2A, 6%; 2B, 6%; 3A, 11%; 3C, 3%; and 3D, 24%. In contrast, 9% of isolates from dogs with atopic dermatitis were isotype IB and 91% were isotype 3D, indicating that isolates of subtype 3D were the most prevalent in dogs with atopic dermatitis. Production of phospholipase A2 was statistically higher in isolates of subtype 3D than in the other subtypes. The subtype 3D isolates showed enhanced growth on alkaline medium compared with non-3D subtype isolates. The main clinical sign of canine Malassezia dermatitis is waxy exudates on the skin, which predispose the patient to development of a yeast overgrowth of the subtype 3D. Increased phospholipase A2 production may be involved in the inflammatory process associated with Malassezia dermatitis.

Isolation of Trichophyton rubrum var. raubitschekii from a dog.

A rare anthropophilic dermatophyte, Trichophyton rubrum var. raubitschekii, was isolated for the first time from a case of animal dermatophytosis. We morphologically and physiologically identified the isolate from a case of canine dermatophytosis. Molecular typing of chitin synthase 1 (CHS1) and ITS1-5.8S-ITS2 sequences suggest that human and canine isolates of T. rubrum and T. rubrum var. raubitschekii are genetically identical. Therefore, T. rubrum, including T. rubrum var. raubitschekii, might be pathogenic to humans and dogs.

Antimicrobial susceptibility and methicillin resistance in Staphylococcus pseudintermedius and Staphylococcus schleiferi subsp. coagulans isolated from dogs with pyoderma in Japan.

To understand species distribution, trends of antimicrobial susceptibility and prevalence of methicillin resistance in canine staphylococci in Japan, 190 coagulase-positive staphylococci (CoPS) were isolated from dogs with pyoderma in 2 Japanese veterinary referral hospitals. Using a multiplex polymerase chain reaction (M-PCR) method, two CoPS species were identified: 170 Staphylococcus pseudintermedius (89.5%) and 20 S. schleiferi subsp. coagulans isolates (10.5%). In these isolates, susceptibility to 7 antimicrobial agents was determined. Overall, the levels of susceptibility to cefalexin (CEX), amoxicillin/clavulanic acid (CVA/AMPC), minocycline (MINO), ofloxacin (OFLX), norfloxacin (NFLX), lincomycin (LCM) and clindamycin (CLDM) in S. pseudintermedius isolates were 38.2, 52.4, 34.7, 31.2, 34.1, 1.2 and 11.2%, respectively. In S. schleiferi subsp. coagulans isolates, 55% demonstrated susceptibility to CEX, 80% to CVA/AMPC, 70% to MINO, 45% to OFLX or NFLX and 30% to CLDM. None of S. schleiferi subsp. coagulans isolates was susceptible to LCM. To determine the prevalence of methicillin-resistant strains, we used a PCR method, which enabled detection of the fragment of mecA gene in 66.5% (113 of 170) in S. pseudintermedius and 30.0% (6 of 20) in S. schleiferi subsp. coagulans isolates. The frequencies of susceptibility to CEX, CVA/AMPC, OFLX, NFLX and CLDM were significantly lower in methicillin-resistant CoPS than in methicillin-susceptible CoPS isolates. These data suggest a high level of methicillin resistance in staphylococci isolated from dogs with pyoderma in Japan.

A case of canine lymphomatoid granulomatosis with cutaneous lesions.

A 10-year-old, castrated, mixed-breed dog presented with a 1.5-month history of scattered, crateriform ulcers on the trunk and extremities. Some skin lesions appeared to regress spontaneously, but new lesions developed. Thoracic radiography revealed pulmonary consolidated lesions suggestive of tumor. A skin biopsy was performed for histopathological, immunohistochemical and clonality analyses. Histopathological examination of the cutaneous lesion revealed an intense infiltration of atypical lymphoid cells with some other cell populations around the blood vessels in the dermis. Atypical lymphoid cells were shown to be CD3-positive in the immunohistochemical analysis. The presence of clonally expanded T-cells was revealed by the clonal rearrangement of T-cell receptor gamma-chain gene. From the above findings, the dog was diagnosed with lymphomatoid granulomatosis.

Cultivation and characterization of canine skin-derived mast cells.

It is essential to develop a technique to culture purified skin-derived mast cells (SMCs) to facilitate immunological research on allergic diseases in dogs. This study was performed to develop an efficient culture system for canine SMCs and to characterize the cells in comparison to canine bone marrow-derived mast cells (BMMCs). Enzymatically digested skin biopsy samples were cultivated in serum-free AIM-V medium supplemented with recombinant canine stem cell factor. Three to five weeks after the initiation of culture, mast cells were collected by a magnetic activated cell separation system using anti-c-Kit antibody. The collected cells were composed of a uniform population showing morphological characteristics of mast cells with a round or oval nucleus and abundant toluidine blue-positive metachromatic granules in the cytoplasm. The results of flow cytometric analysis for the presence of cell membrane c-Kit and Fc epsilon receptor I (FcepsilonRI) indicated that approximately 90% of the cells were mast cells. The cytoplasmic granules were positive for both tryptase and chymase. Apparent dose-dependent degranulation was induced by antibody-mediated cross-linking of immunoglobulin E (IgE) bound to the cells. These cytological and immunological characteristics observed in SMCs were mostly similar to those observed in BMMCs; however, IgE-mediated degranulation was significantly lower in SMCs than BMMCs. The culture system for canine SMCs developed in this study would be useful in understanding the pathophysiology and developing anti-allergic therapeutics in canine allergic dermatitis.

Efficacy of a surgical scrub including 2% chlorhexidine acetate for canine superficial pyoderma.

The clinical efficacy of a surgical scrub containing 2% chlorhexidine acetate (2CA; Nolvasan® Surgical Scrub; Fort Dodge Animal Health, USA) was evaluated for the topical management of canine superficial pyoderma. The first study was a randomized, double-blind, controlled trial. The control was a shampoo containing 4% chlorhexidine gluconate (4CG; Skin Clinic Shampoo; CHD MEDICS, Goyang, Korea). Ten dogs with symmetrical lesions of canine superficial pyoderma were allocated to receive either 2CA or the control shampoo applied to either side of the body twice weekly for 1 week. Both the owners and the investigators subjectively scored skin lesions including pruritus, erythema, crusted papules and scales on a scale of 0-3. The 2CA and 4CG resulted in almost the same degree of improvement of skin lesions, and there were no significant differences between the two groups. The second study was an open trial of 2CA monotherapy in eight dogs with cefalexin-resistant Staphylococcus intermedius group-associated superficial pyoderma. The 2CA monotherapy was applied every 2 days for 2 weeks. Five dogs improved with 2CA monotherapy, one partially improved and two did not. No adverse reactions were seen in either trial. This suggests that a 2CA surgical scrub could be a useful and safe topical adjunct therapy for dogs with superficial pyoderma involving cefalexin-resistant Staphylococcus intermedius group.

Sarcoptes scabiei var. canis refractory to ivermectin treatment in two dogs.

A 10-year-old castrated male Shih Tzu presented with severe generalized pruritus. Skin scrapings revealed the presence of Sarcoptes scabiei var. canis. A Yorkshire terrier in the same household simultaneously developed pruritus due to scabies. Both dogs were treated with 300 µg/kg ivermectin, at first orally and then subcutaneously at 14 day intervals. However, live mites were still found on day 35, and the skin condition deteriorated in both dogs. These findings suggested that the S. scabiei in these dogs was clinically refractory to ivermectin. The pruritus in both dogs rapidly and completely disappeared following topical fipronil administration. This appears to be the first report of canine scabies refractory to ivermectin treatment.

Auricular chondritis associated with systemic joint and cartilage inflammation in a cat.

An adult, Japanese domestic cat presented with bilateral swelling, distortion, and erythema of ears and deformation of the limbs. Biopsy of the pinnae confirmed auricular chondritis. These lesions and the cat's general condition subsequently deteriorated, and the cat died. At necropsy, chondral changes were present in the pinnae, costae, larynx, trachea, and limbs. Histopathologically, these chondral tissues showed marked deformation with lymphocytic inflammation. The limb joint inflammation was associated with chondral erosion, deformation of subchondral bones with pannus, and thinning of cancellous bones. These lesions were consistent with the diagnostic criteria for human relapsing polychondritis. However, the cat had erosive arthritis, which appeared to be different from human relapsing polychondritis.