Feline idiopathic head-and-neck dermatitis—also named feline idiopathic ulcerative dermatitis (IUD)—is considered as a rare skin disease of unknown origin. It is usually associated with a crusted, non-healing, self-induced ulcer occurring most commonly on the dorsal or lateral neck or between the scapula where self-grooming by scratching occurs. Usually, IUD is diagnosed after exclusion of other causes of pruritus. In feline medicine, self-induced alopecia is recognized as a behavioral disorder (abnormal repetitive behavior) due to excessive licking, which is an amplification of a normal maintenance behavior. Such repetitive behaviors, like self-induced alopecia or self-induced wounds, are named stereotypies and considered as indicators of poor welfare. The objectives of our study were to determine, first, if the repetitive behavior associated with self-induced wounds was related to a poor welfare, and, second, if improving the welfare in the cat’s environment would lead to healing, thanks to environmental enrichment. We recruited 13 cats diagnosed with IUD by a dermatologist. These cats were referred to a behaviorist for welfare evaluation. A welfare score was attributed using a new 21-point welfare scale. The median score of the 13 IUD cats was 16, while the median score of 35 healthy cats was 7 (significant difference, p < 0.001). Major modifications of the cat’s environment and the human–cat relationship were then recommended for IUD cats. Within 15 days after environment modifications, ulcerative lesions were healed and welfare scores improved significantly (median score of 6, significantly different from the score before environmental modifications), being similar to healthy cats (no significant differences). Only one cat was treated with a psychotropic drug, owners being reluctant to improve environmental modifications. These results suggest that feline IUD is a behavioral disorder indicative of poor welfare and that it requires management by behavior specialists, proposing environmental modifications. We hence propose to rename this affection to “behavioral ulcerative dermatitis,” given that welfare scores were significantly different from healthy cats, and that environmental modifications modified welfare scores and lead to successful healing in all cases.

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.

Background: Flea bite is considered to be the main cause of allergic dermatitis in cats. There is a need for treatments able to control clinical signs of allergic dermatitis associated with flea bite in cats. This was an open pre-treatment versus post-treatment clinical field study. All cats included in the study presented pruritus, skin lesions or other evidence compatible with flea infestation. Skin lesions were assessed (using SCORFAD) at days 0, 28, 56 and 84 whereas pruritus severity was assessed (using PVAS) at days 0, 15, 28, 56 and 84. On day 0, The fluralaner (280 mg/ml) product (Bravecto® spot-on for cats) was supplied in pipettes containing 0.4, 0.89 and 1.79 ml for cats of 1.2–2.8 kg, > 2.8–6.25 kg and > 6.25–12.5 kg body weight, respectively. The other animals living in the same household also received fluralaner. Based on cytological examination at day 0, oral amoxicillin and clavulanic acid was prescribed for 21 days if indicated. For cats presenting intense pruritus and discomfort at day 0, oral prednisolone at 0.5 mg/kg was prescribed for 3 days. Results: During the study all cats, except for one (cat number 10), improved significantly. Post-treatment median SCORFAD scores at all evaluations were significantly different from the pre-treatment score on day 0 (P values < 0.002 for all three post treatment examination days) with a score reduction of 49% on day 28, 79% on day 56 and 87% on day 84. The PVAS score decreased significantly over the study period for all cats but one (cat number 10). Post-treatment median PVAS scores at all evaluations were significantly different from the pre-treatment PVAS score on day 0 (P value < 0.002 for all four post-treatment days) with a reduction of 46% on day 15, 67% on day 28, 82% on day 56 and 92% on day 84. No adverse reaction or other health issue was reported during the study. Conclusions: A single topical treatment with fluralaner results in a significant reduction of flea bite allergic dermatitis clinical signs in cats over the subsequent 12 weeks without any additional environmental treatment.

Ichthyoses represent a heterogeneous group of hereditary cornification disorders characterized by generalized scaling of the skin. An autosomal recessive congenital ichthyosis (ARCI) has been described in American Bulldogs and is caused by a variant in the NIPAL4 gene encoding for the ICHTHYIN protein. So far, this variant has not been described in other breeds. A 1.5-year-old female pedigreed American Bully was referred for generalized scaling and bad coat quality since adoption at 8weeks of age. Clinical examination, cytological and histopathological examination, and DNA testing were performed. Clinical examination revealed a generalized scaling; cytological evaluation using impression with acetate tapes showed a secondary Malassezia dermatitis. Histopathological examination revealed a moderate to marked, diffuse, compact orthokeratotic hyperkeratosis with the formation of large scales. Few Malassezia were observed in the stratum corneum associated with minimal mixed perivascular inflammation and moderate epidermal hyperplasia. DNA testing of the dog revealed that he carries two defective alleles of the NIPAL4 gene previously described in the American Bulldog. We performed a commercially available breed detection test which, although not specifically testing for American Bully signatures, revealed a high probability of American Bulldog DNA signature within the past three generations. Topical treatment using a combination of keratolytic and keratomodulator shampoo, emollient and moisturizers spray and antimicrobial wipes achieved a marked clinical improvement after only 1month. Continuous topical treatment was necessary to maintain clinical improvement. To the authors' knowledge, this is the first description of the deleterious NIPAL4 variant in an American Bully as well as the first description of clinical management and follow-up of ARCI in this breed.

Ehlers-Danlos syndrome (EDS) is a group of heterogeneous, rare diseases affecting the connective tissues. The main clinical signs of EDS are skin hyperextensibility, joint hypermobility, and skin fragility. Currently, the classification of EDS in humans distinguishes 13 clinical subtypes associated with variants in 20 different genes, reflecting the heterogeneity of this set of diseases. At present, variants in three of these genes have also been identified in dogs affected by EDS. The purpose of this study was to characterize the clinical and histopathological phenotype of an EDS-affected Chihuahua and to identify the causative genetic variant for the disease. The clinical examination suggested a diagnosis of classical EDS. Skin histopathology revealed an abnormally thin dermis, which is compatible with classical EDS. Whole-genome sequencing identified a heterozygous de novo 27 bp deletion in the COL5A2 gene, COL5A2:c.3388_3414del. The in-frame deletion is predicted to remove 9 amino acids in the triple-helical region of COL5A2. The molecular analysis and identification of a likely pathogenic variant in COL5A2 confirmed the subtype as a form of classical EDS. This is the first report of a COL5A2-related EDS in a dog.

Dogs and cats may suffer from a variety of diseases, mainly immune mediated, that require the administration of immunosuppressive drugs. Such therapies can cause adverse effects either by the toxicity of the drugs or as a consequence of immune suppression and associated opportunistic infections. Here we present an, yet unknown, association of Toxoplasma gondii and Alternaria fungus, within cutaneous lesions in a dog under long-term immunosuppressive therapy. The diagnosis of such infections is laborious and not obvious at first glance, since the clinical signs of cutaneous toxoplasmosis, neosporosis or alternariosis are not specific. A further laboratory confirmation is needed. Therefore, we currently recommend that dogs and cats should undergo serologic testing for toxoplasmosis or neosporosis prior to immunosuppressive therapy and a regular dermatological evaluation during the immunosuppressive therapy.