Development Of Canine Atopic Dermatitis Research Articles

Canine atopic dermatitis and recurrent otitis

The development of canine atopic dermatitis (CAD) and recurrent otitis are frequently interrelated conditions in dogs, representing a significant challenge in veterinary diagnosis and treatment. This case study details the experience of the dog crossbred (SRD), adopted with year of age, who suffers from CAD and frequent episodes of recurrent otitis caused by Malassezia sp. The objectives of this study were to investigate the relationship between CAD and recurrent otitis, as well as to develop an integrated approach for the effective management of these conditions. The dog underwent a comprehensive clinical evaluation, which included a detailed history, observation of symptoms, and allergy testing. Treatment consisted of the use of antihistamines, corticosteroids and immunosuppressants, in addition to the application of monoclonal antibodies every four weeks to control itching. Immunotherapy has been introduced to modulate the long-term immune response. Recurrent otitis was managed with regular cleaning and topical treatments with Chlorhexidine; miconazole and omega 3,6 and 9, applied three times a week, complemented by a restrictive diet to minimize food allergens. The results showed that the combination of these strategies provided significant relief from dog symptoms, improving their quality of life. The integrated approach, including environmental control, drug therapy and dietary management, proved effective in controlling CAD and recurrent otitis. This study highlights the importance of personalized and ongoing management, as well as suggesting the need for more research into new therapeutic approaches for these chronic conditions. It is concluded that coordination between veterinarians and owners is essential for the success of treatment and the well-being of affected dogs.

Identification of modifiable pre- and postnatal dietary and environmental exposures associated with owner-reported canine atopic dermatitis in Finland using a web-based questionnaire.

A cross-sectional hypothesis generating study was performed to investigate modifiable exposures such as whether feeding pattern (a non-processed meat based diet, NPMD, or an ultra-processed carbohydrate based diet, UPCD), certain environmental factors and their timing of exposure might be associated with the development of canine atopic dermatitis (CAD). Also, genetic and demographic factors were tested for associations with CAD. The data was collected from the validated internet-based DogRisk food frequency questionnaire in Finland. A total of 2236 dogs were eligible for the study (the owners reported 406 cases and 1830 controls). Our main interest was to analyze modifiable early risk factors of CAD, focusing on nutritional and environmental factors. We tested four early life periods; prenatal, neonatal, early postnatal and late postnatal periods. Twenty-two variables were tested for associations with CAD using logistic regression analysis. From the final models we identified novel dietary associations with CAD: the NPMD during the prenatal and early postnatal periods had a significant negative association with the incidence of CAD in adult dogs (age above 1 year). Oppositely, UPCD was associated with a significantly higher risk for CAD incidence. Other variables that were associated with a significantly lower risk for CAD were maternal deworming during pregnancy, sunlight exposure during early postnatal period, normal body condition score during the early postnatal period, the puppy being born within the same family that it would stay in, and spending time on a dirt or grass surface from 2 to 6 months. Also, the genetic factors regarding maternal history of CAD, allergy-prone breeds and more than 50% white-colored coat all showed a significant positive association with CAD incidence in agreement with previous findings. Although no causality can be established, feeding NPMD early in life seemed to be protective against CAD, while UPCD could be considered a risk factor. Prospective intervention studies are needed to establish the causal effects of the protective role of NPMD on prevalence of CAD during the fetal and early postnatal life.

Impact of the early-life skin microbiota on the development of canine atopic dermatitis in a high-risk breed birth cohort

Canine atopic dermatitis (CAD) is a prevalent inflammatory skin disease of dogs worldwide. Certain breeds such as the West Highland White Terriers (WHWT) are predisposed to suffer from CAD. Microbial dysbiosis is known to play a significant role in the pathogenesis of the disease, which is similar to its human counterpart, atopic dermatitis (AD). To date, no large cohort-study has been conducted in a predisposed dog breed to study the impact of the early-life microbiota on the development of CAD, as well as the possible implication of factors such as hygiene and access to the outdoors. In this study skin samples of 143 WHWT, including 109 puppies up to three weeks old and 34 parent dogs, from 17 breeders, were subjected to 16S rRNA gene and ITS2 amplicon sequencing to disclose the bacterial and fungal oral and skin microbiota, respectively. The oral samples served as a control group to confirm differences between haired and mucosal surfaces. The cutaneous microbiota differed between sample sites and age of the dogs. The season of sampling, geographical origin as well as hygiene status of the household and the access to the outdoors shaped the skin microbiota of the puppies significantly. However, we found that the individual early-life microbiota did not predispose for the later development of CAD.

Total andToxocara canislarval excretory/secretory antigen‐ and allergen‐specific IgE in atopic and non‐atopic dogs

Total IgE concentrations are higher in dogs than in humans. Persistent Toxocara canis larval infection is prevalent in dogs and is associated with substantial specific antibody reactions. A correlation, however, between total IgE and T.canis-specific antibody levels in dogs has not been evaluated. To determine the relationship between total IgE, T.canis-specific IgG and IgE, and allergen-specific IgE levels in atopic and non-atopic dogs, and to evaluate possible confounding factors. Sera of 30 atopic and 30 non-atopic client-owned dogs. Total IgE, T.canis-specific antibody and allergen-specific IgE levels were evaluated by ELISA. Total IgE, T.canis-specific antibody and allergen-specific IgE levels were significantly higher in non-atopic compared to atopic dogs. A positive correlation was demonstrated between T.canis-specific IgG and T.canis-specific IgE; T.canis-specific IgG and total IgE; T.canis-specific IgE and total IgE; and allergen-specific IgE and total IgE. No differences were detected on the basis of age, gender, vaccination status; deworming or season between atopic and non-atopic dogs. Previous immunomodulatory treatment and cause of atopy did not influence antibody levels of atopic dogs. Toxocara canis-specific IgE appears to be a major component of total IgE in dogs. Total and T.canis-specific IgE levels are higher in non-atopic compared to atopic dogs. It is speculated that T.canis infection may have a protective effect against the development of canine atopic dermatitis and/or that elevations in total serum IgE level are often not associated with atopic dermatitis.

Importância da barreira epidérmica na dermatite atópica canina: Revisão

Canine Atopic Dermatitis (CAD) is an allergic, chronic and inflammatory skin disease which affects 10-15% of canine population. For several years, pathogenesis of the disease had been linked to hypersensitivity processes mediated by IgE, but during the last decade, researchers have led their efforts to demonstrate the importance of the skin barrier in the development of CAD, based most of the times on previous studies related with Human Atopic Dermatitis. Studies in dog sincluding transepidermal water loss, skin moisture levels and abnormalities in the stratum corneum lipids and in the superficial proteins of the epidermis, filaggrin mainly, have been very important to advance the understanding of this common and frequent disease in veterinary medicine.

Review: Lymphocytes, cytokines, chemokines and the T-helper1-T-helper2 balance in canine atopic dermatitis.

The development of atopic dermatitis (AD) and other cutaneous hypersensitivities involves the activation and differentiation of allergen-specific lymphocytes. Although hypersensitivity is often considered to be a 'T-helper2-polarized' lymphocyte response, recent evidence suggests that clinical disease is associated with the development of multiple lymphocyte phenotypes. The purpose of this paper is to review recent advances in the understanding of the roles of lymphocytes, cytokines and noncytokine factors in the pathogenesis of canine AD. Citation databases, abstracts and proceedings from international meetings published between 2001 and 2013 were reviewed in this update. Where necessary, older articles were included for background information. The development of canine AD is associated with changes in both cutaneous and circulating lymphocyte populations. These lymphocyte responses are characterized by the production of a complex variety of cytokines, including not only T-helper2 but also T-helper1, T-helper17 and regulatory T-cell responses. In addition, microarray gene expression analysis has enabled the identification of a number of noncytokine factors that appear to be associated with atopic inflammation. These include the calcium-binding protein S100A8, serum amyloidA and a number of protease inhibitors, as well as genes involved in epidermal barrier formation, innate immunity receptors, cell cycle proteins and apoptosis. The development of AD in dogs is characterized by the development of a delicate balance between a variety of T-cell phenotypes and inflammatory mediators, including cytokines, chemokines and noncytokine factors.

Role of the environment in the development of canine atopic dermatitis in Labrador and golden retrievers

Canine and human atopic dermatitis are multifaceted diseases whose clinical development may be influenced by several factors, such as genetic background, environment, secondary infections, food and psychological effects. The role of the environment has been extensively examined in humans but remains unclear in dogs. The aim of this study was to examine environmental factors in two genetically close breeds, Labrador and golden retrievers. Using standard criteria, atopic dogs in Switzerland and Germany were selected and compared with healthy individuals. Information on environmental factors was collected using a 46-question survey encompassing date and place of birth, way of life at the breeder's and owner's home, food and treatments. Univariate and multivariate logistic regression were used to assess the association between potential risk factors and disease status. The following parameters were associated with an increased risk of disease development: living in a shed during puppyhood, adoption at the age of 8-12 weeks and washing the dog regularly. In contrast, the following factors were associated with a lower risk: living in a rural environment, living in a household with other animals and walking in a forest. These associations do not prove causality but support the primary hypothesis that certain environmental factors may influence the development of canine atopic dermatitis. Further studies are warranted to confirm these results and conclusions.

Inverse association between endotoxin exposure and canine atopic dermatitis

The development of canine atopic dermatitis (CAD) may be related to exposure to mite allergens, bacterial endotoxin and/or fungal glucans. In this study, indoor exposure levels of house dust mite allergens, endotoxins and fungal glucans were measured to determine their possible association with CAD. A case-control study including adult Labrador retrievers with (n=28) and without (controls; n=65) CAD was conducted. Dust samples were collected from the living room floor and the bedding and coat of the dog and these were analyzed for house dust mite allergens Der p1 and Der f1, endotoxin and (1→3)-β-d-glucan levels. Dog owners were also required to return a questionnaire regarding their home characteristics. The endotoxin exposure level in the coats of dogs was significantly inversely associated with CAD (odds ratio 0.38; 95% confidence interval 0.15-0.97; P<0.05). No significant difference was found in exposure levels to house dust mite allergens and fungal glucans. The results indicated that endotoxin exposure is inversely associated with CAD, suggesting a protective effect of high indoor endotoxin exposure towards the development of the condition.

The Effect of Early Diet on Canine Atopic Dermatitis (CAD) in Three High-Risk Breeds

The effect of diet on the occurrence of canine atopic dermatitis (CAD) in the high-risk breeds boxer, English bull terrier and West Highland white terrier was investigated as part of an extensive case-control study. In that study, a sparing association was seen for feeding the bitch a diet containing non-commercial ingredients during lactation and the subsequent development of CAD in the offspring. The purpose of this study was to further explore the role of diet of the bitch during lactation as well as early dietary exposure of puppies (up to six months of age) on the occurrence of CAD. Two factors were significant in a final logistic regression model: “not feeding non-commercial animal products (meat, egg or milk-products) to the bitch during lactation” (OR = 3.39, 95% CI 1.46-7.92) and “feeding non-commercial meat to the puppy between the age of 2-6 months” (OR = 2.97, 95% CI 1.27-6.93), and further analysis revealed that there was an interaction between these two factors.

Molecular Cloning of Canine Protease-Activated Receptor-2 and its Expression in Normal Dog Tissues and Atopic Skin Lesions

Protease-activated receptor-2 (PAR-2) belongs to a new G protein-coupled receptor subfamily and is activated by serine proteases. PAR-2 has been demonstrated to play an important role in inflammation and immune response in allergic diseases. In this study, we cloned canine PAR-2 cDNA from the canine kidney by RT-PCR. The canine PAR-2 clone contained a full-length open reading frame encoding 397 amino acids that had 84% and 80% homology with human and mouse homologues, respectively. Canine PAR-2 mRNA was detected in the heart, lung, liver, pancreas, stomach, small intestine, colon, kidney, adrenal gland, spleen, thyroid gland, thymus, skeletal muscle, lymph node, fat and skin of three healthy dogs. The expression pattern of PAR-2 mRNA in canine tissues was similar to that in humans. The expression level of PAR-2 mRNA in skin was not different between the atopic dermatitis (AD) and healthy dogs, suggesting that the level of PAR-2 mRNA transcription may not be associated with development of canine AD. The canine PAR-2 cDNA clone obtained in this study will be useful for further investigation of the immunopathogenesis of canine allergic diseases.

Prediction of future development of canine atopic dermatitis based on examination of clinical history

The aim of this study was to identify clinical features that could be used to identify individual dogs within the Guide Dogs for the Blind Association canine population at risk of being diagnosed as atopic in the future before they had fully developed the condition. Clinical histories of atopic and non-atopic dogs from the Guide Dogs for the Blind Association population were analysed and statistically significant differences identified between the two groups. Atopic dogs were consistently affected by skin disease at a younger age than non-atopic dogs and that there was a significant difference in event curves between atopic and non-atopic dogs at 10 months of age. From a predictive point of view, dogs that suffered from four or more episodes of atopic-type skin disease by the age of 15 months were at an increased risk of developing atopic dermatitis. It is suggested that the clinical history of all dogs from the Guide Dogs for the Blind Association about to undergo training should be examined for these factors to assess whether or not they should undergo training.

A case–control study of risk factors for canine atopic dermatitis among boxer, bullterrier and West Highland white terrier dogs in Sweden

Environmental and dietary risk factors for the development of canine atopic dermatitis (CAD) in the high-risk breeds of boxer, bullterrier and West Highland white terrier were assessed in a case-control study. A logistic regression model was developed to evaluate their relative importance in 58 cases from 12 practices in Sweden and 61 unaffected controls, matched to cases by breed and year of birth. The final model included a random error term for 'examining veterinarian', as dogs from the same practice were not considered independent. No effect of gender, season of birth, environment, vaccination or de-worming practices on the odds of developing CAD was detected. The main finding was that feeding a diet including noncommercial products to the bitch during lactation had a protective effect on the development of CAD in her offspring; the odds of developing CAD were twice as high among offspring from bitches that were not exposed to home-made/noncommercial diets [95% confidence interval (CI) of the odds ratio: 1.2-3.8]. The population attributable fraction for not feeding home-made diets to the lactating bitch was estimated as 0.4 (95% CI: 0.04-0.63). Randomized controlled clinical trials are needed to further support the finding of a potential protective role of diet in CAD development.

The ACVD task force on canine atopic dermatitis (XI): the relationship between arthropod hypersensitivity and atopic dermatitis in the dog

The relationship between arthropod allergen hypersensitivity and the development of canine atopic dermatitis (AD) is unclear. It has been shown that dogs with AD are more likely to exhibit positive intradermal reactivity to flea allergens than non-pruritic dogs from the same flea-endemic geographic region. Also, dogs in a flea endemic region are four times more likely to suffer from flea allergy dermatitis (FAD) and AD than from FAD alone. These results provide indirect evidence to support the hypothesis that, in the canine species, atopy predisposes to the development of hypersensitivity to flea allergens and eventually to FAD. A causal relationship between insects other than fleas and canine AD has not been identified with certainty.