Clinical Guidelines for the Use of Antipruritic Drugs in the Control of the Most Frequent Pruritic Skin Diseases in Dogs.

Pruritus is a common clinical sign in many skin disorders and is currently the main complaint in canine dermatology. Pruritic skin diseases can affect the quality of life of dogs and their owners. Several families of antipruritic drugs are available to help control pruritus in dogs. The aim of this review is to help practitioners select the most appropriate symptomatic treatment in the most frequent situations of dermatological pruritus in dogs. The molecules reviewed here are systemic and topical glucocorticoids, antihistamines, ciclosporin, oclacitinib and lokivetmab. A level of evidence (1, 2 or 3) has been established according to a detailed algorithm for each individual study in the literature published between 1990 and March 2021. The guidelines result from evidence grading using the strength of recommendation taxonomy (SoRT) and clinical recommendations using a thorough methodology.

Comparison of three methods for the diagnosis of otoacariasis due to Otodectes cynotis in dogs and cats.

BACKGROUND: The diagnosis of otoacariasis due to Otodectes cynotis is based on the visualization of the parasite, either directly by otoscopy or indirectly after microscopic examination of cerumen collected by several methods. OBJECTIVES: To compare the sensitivity of three techniques: conventional handheld otoscopy, Volkmann's curette sampling and cotton-tipped swabbing. ANIMALS: Five dogs and 12 cats (30 naturally infested ears). METHODS AND MATERIALS: For each case, following otoscopy, the order of examinations (swab or curette) was chosen randomly and the samples were observed on a slide mixed with lactophenol and covered with a coverslip. Parasite detection was noted as positive or negative and parasitic stages were counted separately. RESULTS: The diagnostic sensitivity of otoscopy alone was 67% (positive in 20 of 30 cases), using the curette sampling it was 93% (28/30) and 57% (17/30) for the swabbing. The curette technique had a significantly higher sensitivity than classic ear-swabbing (P = 0.001) or otoscopy alone (P = 0.02). Combining otoscopy and the curette, we obtained a sensitivity of 100% compared to 86% when otoscopy and swabbing were combined. Moreover, the parasite count in the curette samples (average 25 ± 30 SD) was significantly higher than the swab samples (4.5 ± 11) (P < 0.001). CONCLUSIONS AND CLINICAL IMPORTANCE: When suspecting O. cynotis infestation, otoscopic examination should be performed. To confirm the nature of the parasites observed or whenever this examination result is negative, doubtful or cannot be performed, the curettage sampling method for microscopic cerumen examination is recommended.

Reliability of different sets of criteria in diagnosing canine atopic dermatitis applied to a population of 250 dogs seen in a veterinary teaching hospital.

BACKGROUND: Different sets of criteria are available in veterinary dermatology for the diagnosis of canine atopic dermatitis (cAD); there are limited data to assess their reliability. HYPOTHESIS/OBJECTIVES: The aim of this study was to assess the discriminative and predictive ability of four sets in diagnosing cAD in a population of dogs with different skin diseases. ANIMALS: Two hundred and fifty dogs examined in the dermatology unit of a veterinary teaching hospital. METHODS AND MATERIALS: Dogs were diagnosed with cAD, flea infestation (FI), flea bite hypersensitivity (FBH), sarcoptic mange (SM) and other skin diseases (OD). FI, FBH and SM were pooled in one group of dermatoses mimicking cAD (MD). All nonatopic dogs were grouped as a "global population" (GP). Four criteria sets were applied to all dogs. For each set of criteria, sensitivity, specificity, positive and negative predictive values (PPV, NPV), likelihood ratios (LR) and diagnostic odds ratio (DOR) were calculated. RESULTS: When applied to the GP, sensitivities ranged from 54 to 83%, specificities from 68 to 75% and PPVs from 35 to 43%. NPVs ranged from 87 to 94%. LRs and DORs were poor. When applied to MD, sensitivities remained unchanged, specificities and PPV were mildly higher, whereas NPVs were mildly lower and LRs and DORs were comparable. CONCLUSIONS AND CLINICAL IMPORTANCE: This study showed that each set of criteria had a low diagnostic reliability when used alone. The use of more discriminant criteria integrated into a thorough clinical approach excluding MDs should be considered.

Skin disease in donkeys (Equus asinus): a retrospective study from four veterinary schools.

BACKGROUND: Donkeys are important throughout the world as work animals and occasionally as pets or a meat source. Most descriptions of skin disease in donkeys are reported in small case series, textbooks or review articles. HYPOTHESIS/OBJECTIVES: To document skin diseases and their prevalence in donkeys and to investigate predilections for the most common conditions. ANIMALS: Case populations at four veterinary schools totalling 156 donkeys. METHODS AND MATERIALS: A retrospective study was performed by searching computerized medical records, using the key word "donkey", at the School of Veterinary Medicine, University of California, Davis (UCD). Records of donkeys from the veterinary schools in Nantes, France; Utrecht, Netherlands and Ghent, Belgium were searched in a similar manner. The time periods included in the searches varied by institution. RESULTS: At UCD, 83 of 346 (24%) of donkeys had skin disease noted in their records. The most common diagnoses were insect bite hypersensitivity, sarcoid and habronemiasis. At Nantes, 36 of 144 (25%) had skin disease and the most common diagnoses were sarcoid and superficial pyoderma. At Utrecht 23 of 143 (16%) had skin disease and the most common diagnosis was dermatophytosis. At Ghent, 14 of 320 (4%) had skin disease and the most common diagnosis was sarcoid. CONCLUSIONS AND CLINICAL IMPORTANCE: Cutaneous conditions in donkeys are common. Age, sex and breed predisposition and the most common diagnoses varied with geographical location. Clinicians should include a dermatological examination regardless of the reason for presentation.

Companion rats (Rattus norvegicus) with cutaneous lesions: a retrospective study of 470 cases at two university veterinary teaching hospitals (1985-2018).

BACKGROUND: Rats are popular companion animals that are often presented to veterinarians for treatment of skin diseases. However, descriptions of dermatoses in rats have primarily been limited to case reports and text books. HYPOTHESIS/OBJECTIVES: To document skin diseases and their prevalence in companion rats examined in northern California, USA and Nantes, France and to investigate predilections for the most common conditions over a 33 year or 15 year period, respectively. ANIMALS: Four hundred and seventy rats from two hospital populations met the inclusion criteria. METHODS AND MATERIALS: A retrospective study was performed by searching computerized medical records of rats seen at the School of Veterinary Medicine at University of California, Davis (UCD), USA from 1 January 1985 to 1 January 2018 using the key words "skin" and "dermatitis". The medical records of rats presenting to Ecole Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes-Atlantique (ONIRIS), France from 1995 to 2016 were reviewed for evidence of skin disease. The presence of lesions as noted in the key search words for the UCD records were used as the inclusion criteria for both institutions. RESULTS: Of 494 rats examined at UCD, 231 (47%) had skin disease, with neoplasia the most common diagnosis. Of the 619 rats examined at ONIRIS, 239 (39%) had skin disease, with ectoparasitism being the most common diagnosis. CONCLUSIONS AND CLINICAL IMPORTANCE: Cutaneous conditions in companion rats are common. Clinicians should include a dermatological examination when examining these rodents, especially in regard to neoplasia, ectoparasites and pyoderma.

Companion hamsters with cutaneous lesions; a retrospective study of 102 cases at two university veterinary teaching hospitals (1985-2018).

BACKGROUND: Hamsters are popular companion animals which may present to veterinarians for treatment of skin diseases. Most descriptions of dermatoses in hamsters have primarily been in case reports and in text books. HYPOTHESIS/OBJECTIVES: To document skin diseases and their prevalence in companion hamsters examined in northern California, USA, and Nantes, France, and to investigate predilections for the most common conditions documented in medical records over a 33 year or 15 year period, respectively. ANIMALS: One hundred and one hamsters from two hospital populations. METHODS AND MATERIAL: A computerized search of medical records of all hamsters seen at the School of Veterinary Medicine at UC-Davis in California, USA, from 1 January 1985 to 1 January 2018, was performed using the key search words "skin" and "dermatitis". The medical records of all hamsters presenting to the Ecole Nationale Vétérinaire, Nantes, from 1 September 1998 to 1 December 2013, were reviewed for skin diseases. The presence of lesions noted in key search words for the California records were used as inclusion guidelines for both institutions. Cases of suspected mammary neoplasia were excluded. RESULTS: Of the 65 hamsters seen in California, 34 (54%) had skin disease; of a total of 164 hamsters in Nantes, 67 (41%) had skin disease. Nodules were the most common lesions noted by both institutions. CONCLUSIONS AND CLINICAL IMPORTANCE: Cutaneous conditions in companion hamsters are common. Clinicians should include a dermatological examination when examining these rodents.

Efficacy of two formulations of afoxolaner (NexGard® and NexGard Spectra®) for the treatment of generalised demodicosis in dogs, in veterinary dermatology referral centers in Europe.

BACKGROUND: A multi-centre field trial was conducted to evaluate the efficacy of afoxolaner based chewables (NexGard® or NexGard Spectra®) for the treatment of generalised demodicosis caused by Demodex canis in dogs under field conditions in France, Italy and Poland. METHODS: Client-owned dogs, diagnosed positive for Demodex mites by pre-treatment skin scrapings and presenting clinical signs of generalised demodicosis were included. Dogs were orally treated with afoxolaner three times at monthly intervals. Of the 50 dogs enrolled, 48 completed the whole study. Efficacy of the treatments was assessed monthly by Demodex mite counts and physical examination with special regard to the severity and extension of skin lesions. RESULTS: Treatments were well tolerated in all dogs and resulted in a rapid reduction of mites, with all post-treatment mite counts significantly lower than baseline. The number of mites was reduced by 87.6%, 96.5% and 98.1% on Days 28, 56 and 84, respectively. In addition, the skin lesion severity and extent scores as well as the pruritus were all significantly lower at all post-treatment visits compared to the pre-treatment assessment. CONCLUSIONS: This clinical field study demonstrated that monthly administrations of afoxolaner in NexGard® or NexGard Spectra®, offered a convenient and reliable solution for the treatment of canine generalised demodicosis.

Prospective pilot study to detect dogs with non food-induced canine atopic dermatitis using Fourier transform infrared spectroscopy.

BACKGROUND: The diagnosis of canine atopic dermatitis (CAD) remains challenging due to the lack of a simple biomarker or metabolic profile. In human medicine, Fourier transform infrared spectroscopy (FTIR) is an analytical technique used for several diseases. It requires a small amount of sample and allows the identification of structural moieties of biomolecules on the basis of their infrared absorption, with limited sample pretreatment. HYPOTHESIS/OBJECTIVES: The aim of the study was to evaluate the diagnostic value of FTIR. ANIMALS: Three groups were tested: 21 dogs with non food-induced CAD (NFICAD), 16 dogs with inflammatory conditions of various origins but without allergic dermatoses (OD) and 10 healthy dogs (H). METHODS: Peripheral blood was collected and spectra were acquired with a FTIR spectrophotometer. A principal component analysis (PCA) was performed on the full wavenumber spectra (4000-600/cm), followed by a Fisher discriminant analysis (DA) to assess the differences between the three groups. RESULTS: The PCA followed by the DA of whole spectra showed significant differences between the three groups. These results suggest that by using the FTIR method, dogs with NFICAD can be differentiated from healthy dogs and dogs with nonallergic inflammation. There was no overlap between the spectral data of the three groups indicating that NFICAD dogs were correctly segregated from the H and OD groups. CONCLUSIONS: A study on a larger cohort including common pruritic skin diseases is necessary to confirm these initial results and the relevance of this diagnostic technique.

Tight junction proteins in the canine epidermis: a pilot study on their distribution in normal and in high IgE-producing canines.

Epidermal tight junctions (TJ) have been well-described in human medicine and are involved in many skin diseases such as atopic dermatitis (AD). In dogs, there are no data regarding the implication of TJ in skin diseases including canine AD. The aim of this study was to compare the expression and the distribution of ZO-1, occludin and claudin-1 in the epidermis of healthy and atopic dogs. Skin biopsies from 6 high IgE-producing beagles sensitized to house dust mite (atopic group) were used. Skin specimens from nine healthy dogs without skin issues were sampled (healthy group). Immunoperoxydase staining was used to study the staining pattern of zonula occludens-1 (ZO-1), occludin and claudin-1 in the epidermis of healthy and atopic dogs. Positive controls were healthy human skin samples. Labeling patterns were assessed by 2 examiners blinded to the identities of the specimens. Comparisons between groups were performed using an exact Wilcoxon-Mann-Whitney test. The mean total expression score of claudin-1 was lower in atopic dogs as compared to healthy subjects. Occludin and ZO-1 expression remained unchanged within each group. These results suggest a defect in claudin-1 expression in the nonlesional epidermis of atopic dogs.

Les jonctions serrées (JS) épidermiques sont bien décrites en médecine humaine et sont impliquées dans de nombreuses affections cutanées telles que la dermatite atopique (DA). Dans l'espèce canine, il n'existe aucune donnée concernant l'implication des JS dans la DA canine ou dans d'autres affections dermatologiques.Le but de cette étude est de comparer l'expression et la distribution de ZO-1, de l'occludine et de la Claudine-1 dans l'épiderme de chiens atopiques et de chiens sains.Les biopsies cutanées de six chiens sensibilisés dans leur jeune âge aux acariens de poussière et produisant de forts taux d'IgE (groupe atopique) on été utilisées. Des échantillons de peau exempte de lésions cutanées ont été prélevés avant tout challenge allergique. Des échantillons de peau saine provenant de neuf chiens sans problème dermatologique ont été recueillis (groupe sain).Deux examinateurs ont évalué l'immunomarquage, en aveugle. Des comparaisons entre les différents groupes ont été réalisées à l'aide du test statistique de Wilcoxon-Mann-Whitney.L'expression de la claudine-1 était plus faible dans l'épiderme de chiens atopiques par comparaison aux sujets sains. L'expression de ZO-1 et de l'occludine était identique dans chaque groupe.Ces résultats suggèrent un défaut d'expression de la Claudine-1 dans l'épiderme non lésionnel des chiens atopiques.(Traduit par les auteurs).

Increased numbers of peripheral blood CD34+ cells in dogs with canine atopic dermatitis.

BACKGROUND: The bone marrow may be involved in human atopic diseases, as shown by the release of CD34+ cells into the peripheral blood. HYPOTHESIS/OBJECTIVES: The aim was to determine the numbers of CD34+ cells in atopic dogs. ANIMALS: The following three groups of dogs were studied: 27 dogs with nonfood-induced atopic dermatitis (NFICAD); 16 dogs with nonallergic inflammatory diseases; and 13 healthy control dogs. METHODS: Dogs with NFICAD were selected after fulfilment of Favrot's criteria and exclusion of other pruritic dermatoses, including flea infestation and adverse reaction to foods. The Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03 and a Visual Analog Scale (VAS) score for pruritus were used to quantify clinical signs. A phycoerythrin-conjugated anticanine CD34 antibody was used to stain peripheral blood CD34+ cells, and these were enumerated using a flow cytometer. The CD34+ cell counts were compared between groups and tested (in the NFICAD group) for correlation with the severity of clinical signs. RESULTS: The numbers of peripheral CD34+ cells in dogs with NFICAD (median 1.7) were statistically higher than in dogs with other nonallergic inflammatory diseases (median 1.0; P = 0.01) and healthy control dogs (median 0.9; P = 0.009). In dogs with NFICAD, there was no correlation between CD34+ cell numbers and CADESI-03 scores or owner-assessed pruritus (VAS score). CONCLUSIONS AND CLINICAL IMPORTANCE: The results of this study suggest the possible involvement of CD34+ cells in dogs with NFICAD. The role of CD34+ cells in the aetiopathogenesis of canine atopic dermatitis remains to be determined.

Characterization of pruritus in canine atopic dermatitis, flea bite hypersensitivity and flea infestation and its role in diagnosis.

BACKGROUND: In dogs, flea infestation (FI), flea bite hypersensitivity (FBH) and canine atopic dermatitis (CAD) have been mainly characterized by their lesions but never by their pruritus. In clinical practice, many of these dogs exhibit only pruritus. HYPOTHESIS/OBJECTIVES: The purpose of this study was to evaluate the characteristics of pruritus in these dermatoses and their potential usefulness for diagnosis. ANIMALS: Dogs included were selected from the Oniris clinical data. Cases were selected in which the dogs had only one of the three dermatoses diagnosed. The diagnosis of CAD was based on Prélaud's criteria and positive intradermal tests except flea; for FBH by compatible clinical signs and a response to an intradermal test with flea allergen; and for FI by the presence of fleas. Moreover, in each group, other primary pruritic skin diseases were excluded. METHODS: Location, behavioural manifestations, seasonality and quantification of the pruritus were evaluated. The statistical analysis used chi-squared test with a P-value <0.05. RESULTS: Three hundred and forty-six dogs were analysed, 91 with CAD, 110 FI and 145 FBH. The period (season) of onset was not statistically different either for each dermatosis or among the three dermatoses. Some locations were highly specific for one dermatosis as follows: ventral abdomen/medial surface of thigh (chewing) and radius/carpus/tibia/tarsus (chewing) in FI; back/dorsolumbar area (chewing) and tail (chewing) in FBH; and paws (chewing/licking) and face/neck (rubbing) in CAD. CONCLUSIONS AND CLINICAL IMPORTANCE: Some features of pruritus could be suggestive of the causal disease, with possible diagnostic value in pruritic dogs.

Reptiles with dermatological lesions: a retrospective study of 301 cases at two university veterinary teaching hospitals (1992-2008).

This retrospective study reviews the medical records of 301 reptiles with dermatological lesions that were examined at the Veterinary Medical Teaching Hospital, University of California at Davis (VMTH-UCD) and the Unité de Dermatologie-Parasitologie-Mycologie, Ecole Nationale Vétérinaire de Nantes (UDPM-ENVN) from 1 January 1992 to 1 July 2008. The most common reptile groups differed between the two hospitals, with lizards being the most common at the VMTH-UCD and chelonians at the UDPM-ENVN. At the VMTH-UCD, boa constrictors (Boa constrictor), ball pythons (Python regius) and other Python species were over-represented, and box turtles (Terrapene carolina) were under-represented in the dermatological lesion caseload. When institutional data were combined, 47% of all reptiles at both institutions with confirmed or suspected cases of sepsis had petechiae, with the highest association seen in chelonians at 82%. Dependent on institution and reptile group, from 29% to 64% of the cases had underlying husbandry issues. Sixty-two per cent of all cases were alive at final status. Veterinarians treating reptiles with skin disease should be aware of the following: (i) that boa constrictors and Python species may be predisposed to dermatological lesions; (ii) that client education is important for proper husbandry; and (iii) that there is a possible association between petechiae and sepsis, especially in chelonians. The conjectural association between certain skin lesions and sepsis remains to be confirmed by systematically derived data that demonstrate a causal relationship between the two.