Dermatophagoides farinae-specific immunotherapy in atopic dogs with hypersensitivity to multiple allergens: a randomised, double blind, placebo-controlled study

A randomised, placebo-controlled, double blind study was conducted on 25 dogs that had atopic dermatitis, together with skin test reactivity and elevated serum IgE to Dermatophagoides farinae (Df) and at least one additional allergen. Dogs were treated with either a Df-restricted immunotherapy solution (n = 14) or a placebo (n = 11) and evaluated 6 weeks and 3, 5, 7 and 9 months after the initiation of treatment using a clinical scoring system (SASSAD) and pruritus analogue scale scores. The Df-restricted solution and the placebo had an equal effect on both pruritus and the skin manifestations (P > 0.05). The results of this study indicate that in dogs with atopic dermatitis based on hypersensitivity to environmental allergens in addition to D. farinae, Df-restricted immunotherapy is insufficient to control the disease. Consequently, a solution for allergen-specific immunotherapy should remain customised.     

Intradermal injection of heat-killed Mycobacterium vaccae in dogs with atopic dermatitis: a multicentre pilot study

Canine atopic dermatitis (cAD) is a common disease with a multifactorial aetiology associated with impaired immunoregulation. The immunopathogenesis has similarities to that of human atopic dermatitis. Clinical signs of allergic disease in humans and mice are reduced by administration of saprophytic mycobacteria that amplify regulatory cytokines and hence the effect of Mycobacterium vaccae on the clinical severity of cAD was investigated. Sixty-two dogs with cAD, selected according to strict criteria, were treated with a single intradermal injection and evaluated monthly for 3 months in a placebo-controlled double-blind clinical trial. Clinical severity was quantified using standardized scores and by owner assessment of pruritus. A single injection of a heat-killed suspension of M. vaccae was found to be well tolerated and effective in treating mild to moderate cases of cAD demonstrable for 3 months, but was insignificant in more severely affected dogs.     

Evaluation of the bacterial microflora of the conjunctival sac of healthy dogs and dogs with atopic dermatitis

The aim of this case–control study was to evaluate and compare the bacterial microflora from the conjunctival sac of dogs with atopic dermatitis and healthy dogs. Twenty‐one atopic dogs without clinical and/or cytopathological signs of bacterial blepharoconjunctivitis and 21 breed‐matched healthy dogs were enrolled. Under topical anaesthesia, the inferior conjunctival sac of one eye was scraped twice. Material was collected with a Kimura spatula, spread over a slide and stained with a Diff Quick^®‐type stain (Medion Diagnostics GmbH, Düdingen, Switzerland) for cytological examination. An area of 0.5 cm² was examined at ×1000 magnification, and the types and numbers of cells and bacteria were recorded. A bacterial swab was collected and inoculated into culture media for the growth of aerobic bacteria. Before sampling, each atopic dog was evaluated for severity of cutaneous lesions, pruritus and conjunctival inflammation. Significant differences were observed between atopic and healthy dogs for the presence of bacteria on cytology (P = 0.015), keratinized (P = 0.001) and nonkeratinized epithelial cells (P = 0.013), eosinophils (P = 0.019) and lymphocytes (P = 0.008). Bacteria were recovered from 12 atopic dogs and three healthy dogs (P = 0.004). Staphylococcus pseudintermedius was the most commonly isolated species in atopic dogs (seven of 12). In atopic dogs, no significant relation was found between conjunctival bacterial colonization (on cytology and culture) and the severity of any of the clinical parameters. This study suggests differences in conjunctival bacterial colonization and cytological features between atopic and healthy dogs.     

Preliminary investigations into the use of allergy skin testing solutions and desensitizing vaccines in dogs

Dogs suffering from chronic pruritus of unknown aetiology are a persistent problem for small animal practitioners. Many cases are classified as ‘allergic’ or ‘atopic’ even though little work has been carried out on the incidence or diagnosis of these conditions in Britain. Skin testing has been attempted but few published reports are available. Practitioners were supplied with skin testing kits containing a range of allergens to which dogs may be exposed and were asked to test clinical cases of pruritus which they considered might be of allergic aetiology. Positive reactions were obtained most commonly to house dust and house dust mite (Dermatophagoides pteronyssinus) antigens. In several cases the skin test results correlated with the symptoms and case history. Results suggest that in certain cases skin testing may be beneficial in diagnosis, although further immunological experimental work is necessary to evaluate more fully the technique. Desensitization therapy was attempted in several cases with fairly successful clinical results.     

FC‐30 Presence of dust mites in the environment of dust mite‐sensitized atopic dogs

Dust mites (DM) are the most common offending aeroallergens in atopic dogs. The aim of this study was to compare the DM load of households with atopic dogs (Group A, n = 8) that had positive intradermal test reactions to Dermatophagoides farinae, D. pteronyssinus, Acarus siro, Lepidoglyphus destructor and/or Tyrophagus putrescentiae to the DM load of households with nonatopic dogs (Group B, n = 4) and of nonpet households (Group C, n = 8). Group A dogs presented with perennial pruritus, were free of pathogenic mites and fleas, did not respond to an elimination diet, and fulfilled the diagnostic criteria of atopic dermatitis. All Group B dogs tested intradermally negative and had no dermatological problems. Dust samples were vacuum collected in a standardized fashion from the human (all groups) and dog mattresses (Groups A and B) or from the couch (Group C) four times, once for each season of the year. The presence of DM was assessed with a commercial test (Acarex test) and stereoscopically. At least one DM was found in all Group A houses. The DM load was not significantly different between the seasons or the three animal groups. The sensitivity of the Acarex test was significantly lower than that of stereoscopic examination (P < 0.001). In conclusion, the environmental DM load was similar between atopic and nonatopic dogs, the presence of dogs in a household didn't increase DM numbers, and stereoscopy was more sensitive than the Acarex test for the detection of DM. Funding: Self‐funded.     

Patch test reactions to house dust mites in dogs with atopic dermatitis

The purpose of this study was to determine the percentage of dogs with spontaneous atopic dermatitis that show a positive patch test reaction to a commercially available 20% house dust mites mixture containing equal parts of Dermatophagoides farinae and Dermatophagoides pteronyssinus in white petrolatum. In addition, we evaluated whether skin reactions induced after the epicutaneous application of house dust mites were clinically and histologically similar to naturally developed skin lesions of dogs with atopic dermatitis. Furthermore, we investigated if the reactions induced by house dust mites were true allergic reactions by comparing them to atopic lesional skin and to patch test reactions induced by an irritant substance (sodium lauryl sulphate). White petrolatum alone and nonlesional skin sites were used as negative controls. Macroscopic and microscopic evaluations of the patch test and control sites were performed in a blinded fashion at 48 and 72 h after patch test application. Microscopic results were evaluated in a qualitative and quantitative manner. A chi‐square test for homogenicity was used for the quantitative analysis to compare the proportion of each dermal inflammatory cell type among positive histopathological tested sites. P values ≤ 0.05 were considered significant. The study included 12 healthy nonatopic dogs and 13 dogs with nonseasonal atopic dermatitis. None of the nonatopic dogs reacted to house dust mites and white petrolatum. Ten (77%) of the 13 atopic dogs reacted macroscopically and histopathologically to house dust mites. Macroscopic reactions induced by house dust mites were characterized by erythema, oedema and papules. The macroscopic reactions induced by house dust mites were identical to lesional skin in 20% of the dogs and identical to reactions induced by sodium lauryl sulphate in 40% of the dogs. Qualitative histopathological findings showed that the reactions induced by house dust mites were similar to atopic lesional skin in 80% of the dogs and were similar to sodium lauryl sulphate in 20% of the dogs. Quantitative analyses showed that the proportion of neutrophils in reactions induced by sodium lauryl sulphate was significantly higher (P < 0.05) compared to house dust mites reactions, which could be a differentiator factor between an allergic and an irritant reaction. These results showed that the epicutaneous application of house dust mites in dogs with atopic dermatitis induced histopathological lesions similar to spontaneous atopic lesions in dogs. Therefore, this study demonstrated that house dust mites penetrated the skin of dogs with atopic dermatitis and induced an inflammatory response that resembled a true allergic reaction. Funding: Small Companion Animal Grant, University of Minnesota.     

Double‐blinded cross‐over study on the efficacy of pentoxifylline for canine atopy

The pathogenesis of canine atopy has not been established completely. Recent studies have shown that tumour necrosis factor alpha and Interleukin‐6 play a role in allergic reactions in humans and mice. Pentoxifylline (PTX) suppresses synthesis of these cytokines and may be a useful therapy for modulating the symptoms of canine atopy. The objectives of this study were to investigate the effects of PTX (10mg kg^?1 twice daily for 4 weeks) on clinical signs (erythema and pruritus) and intradermal skin test reactivity in atopic dogs (n = 10). The study was a double‐blinded, placebo controlled, crossover clinical trial with a washout period of 2 weeks between treatments. Clinical signs were evaluated and scored by the investigator and owners. During PTX treatment, scores of pruritus and erythema decreased significantly. PTX did not affect intradermal skin test reactivity to house dust mite at 15 min (allergen of reference for this study).     

Subconjunctival Dirofilaria repens infection in a dog resident in the UK

Dirofilaria repens infection was diagnosed in a 5‐year‐old female German shepherd crossbreed, originally from Romania but brought into the UK in February 2014. The dog presented with conjunctivitis in March 2014 and then again 2 months later with additional ocular and nasal mucopurulent discharge. Bacterial cultures from the nasolacrimal duct were negative for bacterial growth. The case was referred in August 2014 for ophthalmic examination, which revealed abnormalities in both eyes, especially the left. They included mild palpebral conjunctival hyperaemia and marked follicular conjunctivitis, as well as a dorsonasal bulbar conjunctival mass. Serum biochemistry was unremarkable and a conjunctival biopsy taken from the dorsonasal bulbar conjunctival mass revealed eosinophilic/lymphoplasmacytic conjunctivitis. At re‐examination, nematodes were found in the area of the previous biopsy site and in the ventral palpebral conjunctival fornix. Polymerase chain reaction and sequencing confirmed these to be D. repens. Treatment with 10% imidacloprid and 2·5% moxidectin (Advocate Spot‐On) was successful, and clinical signs resolved over a 6‐week period. This case report indicates that D. repens infection should be considered as a possible aetiological cause of ocular lesions in dogs in the UK, especially those with a history of foreign travel. Implications for establishment and spread of D. repens in the UK are discussed.     

Pilot investigation of a model for canine atopic dermatitis: environmental house dust mite challenge of high-IgE-producing beagles, mite hypersensitive dogs with atopic dermatitis and normal dogs

Although canine atopic dermatitis (cAD) is common, few models are available. The aim of this study was to evaluate high-IgE beagles epicutaneously sensitized to house dust mite (HDM) as a possible model for cAD. Six high-IgE beagles were environmentally challenged with HDM using various doses and protocols. Similar challenge protocols were used in positive and negative control dogs: three dogs with naturally occurring cAD and positive intradermal skin test (IDT) to HDM and three normal dogs without history of skin disease and negative IDT to HDM. All high-IgE beagles and all atopic dogs developed severe cutaneous lesions and pruritus after challenge. Lesions were erythematous papules and macules in contact areas such as face, ears, ventral abdomen, groin, axillae and feet. They were first visible after 6 h and increased in severity over time. No normal dog developed pruritus or lesions. Biopsies of representative lesions in the high-IgE beagles were taken for histopathology and immunohistochemistry. There was superficial perivascular dermatitis with mononuclear infiltrates and spongiosis. Lymphocytes and eosinophils accumulated in small epidermal micro-abscesses with hyperplasia of epidermal IgE-bearing dendritic cells. These findings suggest that this colony of high-IgE beagles develops a dermatitis that clinically, histopathologically and immunologically resembles the naturally occurring canine disease. It is also concluded that this modality of challenge is not irritating to normal dogs but induces flare-ups in hypersensitive atopic dogs.     

Canine ocular thelaziosis caused by Thelazia callipaeda in Portugal

Ocular thelaziosis caused by Thelazia callipaeda is a vector‐borne disease affecting dogs and humans. We report a case of thelaziosis in a 10‐year‐old German Shepherd dog from Vila Real city (Portugal). Ophthalmological examination revealed bulbar and nictitating membrane conjunctival hyperemia with serous discharge noted at the left medial canthus and blepharitis. Schirmer tear test value and intraocular pressure were within the reference ranges in both eyes, and biomicroscopy showed a transparent cornea without lesions or edema and no inflammatory reaction in the anterior chamber. No funduscopic alterations were detected by direct and indirect ophthalmoscopic examination. When testing the nasolacrimal patency, two white worms were observed on the caruncle conjunctival surface with undulating movements that increased with light intensity. In total, eight worms were collected and morphologically identified as T. callipaeda (seven mature females and one male). PCR amplification of a 689 sequence of partial cytochrome c oxidase subunit 1 target gene confirmed the nematodes were T. callipaeda, haplotype 1. The dog was treated with a single subcutaneous injection of ivermectin combined with additional topical application of ophthalmic fusidic acid drops and oral milbemycin oxime. One week after treatment, no worms were detected and the ocular clinical signs resolved. The most recent reports of canine thelaziosis in the Iberian Peninsula should alert local health authorities to the zoonotic potential of infestation with T. callipaeda, which should be included in the differential diagnosis of conjunctivitis in dogs and humans.     

High allergen-specific serum immunoglobulin E levels in nonatopic West Highland white terriers

Human and canine atopic dermatitis (AD) share an association with IgE specific to environmental allergens, but few studies have evaluated serum allergen‐specific IgE in nonatopic dogs. This study compared serum allergen‐specific IgE levels in 30 atopic and 18 nonatopic West Highland white terriers. Atopic dermatitis was confirmed using standard criteria. Nonatopic dogs were over 5 years of age and had no clinical signs or history of AD. Serum allergen‐specific IgE levels were measured with Allercept^® IgE ELISAs using a 48‐allergen Australian panel. Positive reactions were defined as ≥150 ELISA absorbance units. Intradermal tests were performed in 16 atopic dogs, either at the time of or at various times prior to serum collection. In atopic dogs, the most common positive ELISA and intradermal test results were to Dermatophagoides farinae (11 of 30 dogs), but there were no statistically significant correlations between results from the two methods for any allergen. In nonatopic dogs, multiple high‐positive ELISA reactions were reported to 45 of 48 allergens, most commonly D. farinae and Tyrophagus putrescentiae (17 of 18 dogs each). Positive ELISA results in nonatopic dogs were statistically significantly higher than those in atopic dogs for 44 of 48 allergens, including two allergens (D. farinae and Dermatophagoides pteronyssinus) commonly regarded as significant in canine AD. In conclusion, positive allergen‐specific IgE ELISAs were not specific for canine AD, and high allergen‐specific IgE levels were seen in nonatopic dogs. The clinical significance of this and whether it characterizes a protective phenotype is unclear.     

FC‐36 The use of immunostimulatory bacterial DNA sequences in allergen‐specific immunotherapy of canine atopic dermatitis

The purpose of this study was to evaluate a combination of immunostimulatory bacterial DNA sequences and allergen‐specific immunotherapy for the treatment of canine atopic dermatitis. Seven dogs with nonseasonal atopic dermatitis diagnosed by history, clinical signs and exclusion of differential diagnoses were included. All dogs had been on allergen‐specific immunotherapy for at least 12 months with incomplete responses, were on additional antipruritic therapy and showed residual pruritus. Pruritus was marked by the owner on a visual analogue scale, lesions were determined by a clinician using the Canine Atopic Dermatitis Extent and Severity Index (CADESI), and concurrent medications were recorded before entering the study and after 14 weeks of treatment. Peripheral blood mononuclear cells were isolated and cultured; canine cytokine message for IFNγ, IL‐4, TNF and IL‐10 was quantitated using RT‐PCR. A mixture of allergen extract and liposome‐DNA complexes was injected intradermally at the beginning of the study and after 2, 4, 6, 10 and 14 weeks. CADESI, pruritus and medication scores, and cytokine messages at the beginning and end of the study were compared with a paired t‐test. There were significant improvements in pruritus scores (P = 0.0277). Reductions in medication scores and CADESI were not statistically significant. IL‐4 production decreased significantly (P = 0.0428); decreases in other cytokines were not significant. Although the number of dogs in this pilot study was small, the results warrant further investigation of a combination of immunostimulatory bacterial DNA sequences and allergen‐specific immunotherapy for the treatment of canine atopic dermatitis. Funding: Self‐funded.     

Dust mite species in the households of mite-sensitive dogs with atopic dermatitis

Background – The presence of important house dust and storage mite species in the microenvironment of atopic dogs has not been thoroughly investigated. Objectives – To compare the presence and population of five dust mite species (Dermatophagoides farinae, Dermatophagoides pteronyssinus, Acarus siro, Tyrophagus putrescentiae and Lepidoglyphus destructor) among households with mite‐sensitive atopic dogs (Group A), households with clinically healthy dogs (Group B) and households without pets (Group C, n = 25) in Greece. Animals – Twenty mite‐sensitive atopic dogs and 20 clinically healthy dogs. Methods – Dust samples were collected with a vacuum cleaner from owners’ mattresses (all groups) and from dogs’ sleeping areas (Groups A and B) or living room couch (Group C), once every season of the year. Following dust flotation, mites were counted and identified. Results – Dermatophagoides farinae was the most prevalent (60, 40 and 64% in Groups A, B and C, respectively), followed by D. pteronyssinus (45, 35 and 48%, respectively), whereas the three storage mites were found in fewer households. No major differences could be found between Groups A and B or between households with (Groups A and B) and without dogs (Group C) regarding the presence or numbers of the five dust mite species. Conclusions and clinical importance – The presence and population of five common house dust and storage mite species does not differ among Greek households with mite‐sensitive atopic dogs, households with healthy dogs and households without pets.     

FC-31 Prevalence and characterization of house dust mites and house dust mite allergens collected from the bedding, skin and hair coat of dogs in southwest England

Dust mites (DM) are the most common offending aeroallergens in atopic dogs. The aim of this study was to compare the DM load of households with atopic dogs (Group A, n  = 8) that had positive intradermal test reactions to Dermatophagoides farinae , D. pteronyssinus, Acarus siro, Lepidoglyphus destructor and/or Tyrophagus putrescentiae to the DM load of households with nonatopic dogs (Group B, n  = 4) and of nonpet households (Group C,  n  = 8). Group A dogs presented with perennial pruritus, were free of pathogenic mites and fleas, did not respond to an elimination diet, and fulfilled the diagnostic criteria of atopic dermatitis. All Group B dogs tested intradermally negative and had no dermatological problems. Dust samples were vacuum collected in a standardized fashion from the human (all groups) and dog mattresses (Groups A and B) or from the couch (Group C) four times, once for each season of the year. The presence of DM was assessed with a commercial test (Acarex test) and stereoscopically. At least one DM was found in all Group A houses. The DM load was not significantly different between the seasons or the three animal groups. The sensitivity of the Acarex test was significantly lower than that of stereoscopic examination ( P  < 0.001). In conclusion, the environmental DM load was similar between atopic and nonatopic dogs, the presence of dogs in a household didn't increase DM numbers, and stereoscopy was more sensitive than the Acarex test for the detection of DM.
Funding: Self-funded.     

Commercial dry dog food in the north central United States is not contaminated by Dermatophagoides house dust mites

Contamination of home-stored cereal grain food products with Dermatophagoides spp. house dust mites (HDM) was reported recently, along with anaphylaxis after consumption of these foods by dust mite-allergic people. We hypothesized that commercial dry dog food could become similarly contaminated, particularly if stored improperly, and could eventually contribute to allergic signs in dogs. Newly purchased bags of dry dog food (n = 30), from a variety of sources and manufacturers, and client samples of dry dog food (n = 50), stored under a variety of conditions, were obtained. Food samples were extracted in aqueous buffer, and extracts were assayed using ELISA for Dermatophagoides group II (Der II) allergen, as a marker for the presence of HDM. Der II allergen was not detected in any of the 30 newly purchased or 50 stored samples tested. Positive control samples consisting of house dust or dog food mixed with house dust, similarly extracted, and Dermatophagoides commercial allergen extract were positive for Der II in the same assay. We could find no evidence of HDM contamination in newly purchased or stored commercial dry dog food in the north central United States.     

Sensitisation to the House Dust Mite, Dermatophagoides farinae, in Dogs with Sarcoptic Mange

Abstract— Sensitisation to the house dust mite, Dermatophagoides farinae , was demonstrated by skin testing and allergen-specific IgG determination in 15 out of 20 dogs in which a definitive diagnosis of sarcoptic mange was made following recovery of Sarcoptes scabiei mites on skin scrapings. After therapy, no dogs exhibited clinical signs of atopic dermatitis. Intradermal skin testing and 40 per cent of specific IgG assays for Dermatophagoides farinae were negative 90–180 DAys after the original diagnosis.
Résumé— Une sensibilisation a l'acarien de la poussière de maison, Dermatophagoides farinae , est demontrée par tests cutanés et dosage d'immunoglobulines IgG specifiques d'allergenes sur 15/20 chiens atteints de gale sarcoptique prouvée par la presence de nombreux sarcoptes aux raclages cutanés. Après traitement, aucun chien n'a présenté des signes cliniques de dermatite atopique. Les tests cutanés intradermiques et 40 plus des posages IgG pour Dermatophagoides farinae sont negatifs 90 à 180 jours après le diagnostic initial. [Prélaud, P., Guaguère, E. Sensitisation to the house dust mite, Dermatophagoides farinae , in dogs with sarcoptic mange (Une sensitisation à l'acarien de la poussière de maison sur les chiens atteints de gale sarcoptique).     

Late-phase reactions to intradermal testing with Dermatophagoides farinae in healthy dogs and dogs with house dust mite-induced atopic dermatitis

OBJECTIVE: To determine the prevalence of late-phase reactions to intradermal testing with Dermatophagoides farinae in healthy dogs and dogs with atopic dermatitis and an immediate reaction to D farinae. ANIMALS: 6 healthy dogs and 20 dogs with atopic dermatitis and immediate reactions to D farinae. PROCEDURE: ntradermal tests were performed with D farinae at 1:1,000 wt/vol and 1:50,000 wt/vol concentrations, and skin reactivity was evaluated after 0.25, 6, and 24 hours. Serum D farinae-specific IgE antibodies were assayed. Extent of lesions (atopy index) and pruritus (visual analogue scale) were evaluated in dogs with atopic dermatitis. RESULTS: Late-phase reactions were observed in healthy dogs at 6 hours (n = 2 dogs) and 24 hours (1) with the 1:1,000 wt/vol concentration, and at 6 hours (1) and 24 hours (1) with the 1:50,000 wt/vol concentration of allergen. Late-phase reactions in healthy dogs were only observed in dogs with an immediate reaction to D farinae. Late-phase reactions were observed in 11 of 20 dogs with atopic dermatitis at 6 and 24 hours with the 1:1,000 wt/vol concentration and in 10 of 20 at 6 and 24 hours with the 1:50,000 wt/vol concentration of allergen. There was no difference in mean atopy index, mean visual analogue scale of pruritus, or mean serum D farinae-specific IgE concentration of dogs with a late-phase reaction, compared to dogs without a late-phase reaction. CONCLUSIONS AND CLINICAL RELEVANCE: Late-phase reactions may be observed after an immediate reaction to intradermal skin testing in healthy and allergic dogs but are more commonly observed in dogs with atopic dermatitis.     

Canine atopic dermatitis in Greece: clinical observations and the prevalence of positive intradermal test reactions in 91 spontaneous cases.

Atopic dermatitis was diagnosed in a total of 91 dogs by combining the compatible historical evidence and clinical signs with the presence of one or more positive intradermal test reactions well correlated with the exposure to the aeroallergens and the seasonality of the clinical signs. Compared to the general hospital population Yorkshire terriers, Chinese Shar-Peis and cocker spaniels showed a strong predilection. No such predilection was found regarding the sex of the animals. The age of the dogs at the onset of the clinical signs ranged from 2 months to 8 years (median: 2.5 years). Moderate to severe pruritus, noticed in all the 91 dogs, was either localized (29/91) or generalized (64/91) and non-seasonal (43/91), seasonal (19/91) or of unknown seasonality (29/91). The most common cutaneous lesions included erythema, hyperpigmentation, hypotrichosis and crusts; their body distribution was generalized (64%) or localized (36%) with the feet as the most common site of involvement. Five dogs that had unlesional skin were significantly younger and had been pruritic for a shorter period of time compared to the majority of our study population. Otitis externa (43/91) and bacterial pyoderma (30/91) were the most common conditions associated with atopic dermatitis, while the prevalence of Malassezia dermatitis was very low (2/91). Of the other allergic skin diseases flea allergic dermatitis was the most common (29/91) followed by food hypersensitivity (2 out of the 15 dogs tested). The majority of the dogs demonstrated multiple sensitivities to the 50 aeroallergens tested, while domestic mites (77/91), and particularly Dermatophagoides farinae (64/91), were the most commonly implicated. The total number of the positive intradermal test reactions was increasing parallel to the age of the dogs but it was negatively associated with the presence of skin lesions on the carpal and tarsal joints.     

Evaluation of fungal flora in normal and diseased canine ears

This study was undertaken to characterize otic fungal flora encountered in normal dogs, atopic dogs with no clinical or cytological evidence of otitis and dogs with otitis externa. Forty‐two normal dogs, 23 atopic dogs and 32 dogs with otitis were included in the study. Samples for otic fungal culture and cytology were obtained from all animals, for a total of 194 ears. Sixty‐seven ear samples (34%) were culture positive for saprophytic fungal organisms, as follows: 43 (64%) Penicillium species, 13 (19%) Aspergillus species and the remaining 17% comprised of various other saprophytic fungal organisms. Cytological evidence of saprophytic fungal colonization or infection was not found in any animal. There was no relationship between positive saprophytic fungal culture and any study group. Thirty‐three ear samples (17%) were positive for Malassezia pachydermatis. Cytological findings of Malassezia were significantly associated with positive culture for Malassezia (P = 0.006 left ear; P = 0.019 right ear). Furthermore, increased numbers of Malassezia led to a higher chance of positive culture (P = 0.003 left ear; P = 0.008 right ear; McNemar’s test). Malassezia pachydermatis was more likely to be cultured from ears with increased cerumen. Ear type (erect or pendulous) was not significantly associated with positive culture for Malassezia or saprophytic fungal organisms. There was no relationship between positive Malassezia culture and any study group; however, Malassezia was more likely to be cultured from individual dogs in the atopic or otitis groups that also had other dermatological signs consistent with allergic dermatitis and/or pyoderma (P = 0.031 left ear; P = 0.005 right ear).     

A double-blinded placebo-controlled evaluation of adipose-derived mesenchymal stem cells in treatment of canine atopic dermatitis

Mesenchymal stem cells (MSCs) have emerged as a new therapy for various immune-mediated inflammatory diseases. In this study we perform the first double-blinded, placebo-controlled evaluation of the efficacy of adipose-derived allogenic canine MSCs for the treatment of canine atopic dermatitis (cAD). Enrolled canine patients were randomly divided into placebo (PBS saline), low-dose (5?×?10⁵ cells/kg), and high-dose (5?×?10⁶ cells/kg) treatment groups. Each patient received three subcutaneous MSCs treatments or PBS saline at four-week intervals with injections at five sites. Patients were monitored by physical exams, pruritus visual analog scales (PVAS) signed by the primary caretaker, canine atopic dermatitis extent and severity index-4 (CADESI-4) scores by two veterinarians, and complete blood count and serum chemistry analysis along with laboratory analysis for potential biomarkers. Patients were kept off any immune-modulating drugs during the study period, and oral antibiotics and topicals were used for managing pruritus and secondary infections. The PVAS scores and the serum miR-483 levels were significantly lower in the high dose group compared to the placebo group at day90 post first-treatment. The CADESI-4 scores of the high dose group also showed downward trends. No severe adverse effects were observed in any patient in this study. The high dose MSC treatment is efficacious in alleviating the clinical signs of cAD until 30 days after the last subcutaneous administration of MSCs, and miRNA-483 may be a reliable prognostic biomarker for cAD. The MSCs efficacy and potential biomarkers should be further explored by a larger scale clinical trial.