Three cases of feline exudative dermatitis associated with lymphangiosarcoma are described. The animals, an 11-year-old, neutered male and two 10-year-old, neutered female short hair European cats, presented with a 2-month history of transparent liquid oozing from the skin of the groin and caudal abdomen. On physical examination the neutered male cat and one of the females were slightly depressed and showed loss of weight. Skin lesions were similar in all cats and characterized by the presence of alopecia and moist dermatitis in the ventral abdomen, groin and inner thigh. The hair at the periphery appeared matted by the fluid. In all three cases, histopathological examination of skin biopsies from the abdomen identified poorly defined neoplasia involving dermis and subcutis, characterized by proliferation of spindle cells aligned along pre-existing collagen bundles. The dissection of collagen bundles gave rise to irregular shaped anastomosing, often blind-ending vascular channels and trabeculae. Vascular spaces were mostly optically empty. These histological features were strongly suggestive of lymphangiosarcoma. Neoplastic cells were positive for the blood vascular marker Von Willebrand factor, and a lymphatic vascular marker LYVE-1 (Lymphatic Vessel Endothelial receptor - 1), demonstrating the mixed vascular origin of the tumour. Ultrastructural findings confirmed the final diagnosis of lymphangiosarcoma.

A series of 18 allergic cats with multifocal Malassezia spp. overgrowth is reported: atopic dermatitis was diagnosed in 16, an adverse food reaction in another and one was euthanized 2 months after diagnosis of Malassezia overgrowth. All the cats were otherwise healthy and those tested (16 out of 18) for feline leukaemia or feline immunodeficiency virus infections were all negative. At dermatological examination, multifocal alopecia, erythema, crusting and greasy adherent brownish scales were variably distributed on all cats. Cytological examination revealed Malassezia spp. overgrowth with/without bacterial infection in facial skin (n = 11), ventral neck (n = 6), abdomen (n = 6), ear canal (n = 4), chin (n = 2), ear pinnae (n = 2), interdigital (n = 1) and claw folds skin (n = 1). Moreover, in two cats Malassezia pachydermatis was isolated in fungal cultures from lesional skin. Azoles therapy alone was prescribed in seven, azoles and antibacterial therapy in eight and azoles with both antibacterial and anti-inflammatory therapy in three of the cats. After 3-4 weeks of treatment, substantial reduction of pruritus and skin lesions was observed in all 11 cats treated with a combined therapy and in five of seven treated solely with azoles. Malassezia spp. overgrowth may represent a secondary cutaneous problem in allergic cats particularly in those presented for dermatological examination displaying greasy adherent brownish scales. The favourable response to treatment with antifungal treatments alone suggests that, as in dogs, Malassezia spp. may be partly responsible for both pruritus and cutaneous lesions in allergic cats.

BackgroundFeline nonflea hypersensitivity dermatitis (NFHD) is a frequent cause of over‐grooming, scratching and skin lesions. Multimodal therapy often is necessary.Hypothesis/ObjectivesTo investigate the efficacy of ultramicronized palmitoylethanolamide (PEA‐um) in maintaining methylprednisolone‐induced remission in NFHD cats.AnimalsFifty‐seven NFHD cats with nonseasonal pruritus were enrolled originally, of which 25 completed all study requirements to be eligible for analysis.Methods and materialsCats were randomly assigned to PEA‐um (15 mg/kg per os, once daily; n = 29) or placebo (n = 28) while receiving a 28 day tapering methylprednisolone course. Cats responding favourably to methylprednisolone were then administered only PEA‐um (n = 21) or placebo (n = 23) for another eight weeks, followed by a four week long treatment‐free period. Cats were maintained in the study until relapse or study end, whichever came first. Primary outcome was time to relapse. Secondary outcomes were pruritus Visual Analog Scale (pVAS), SCORing Feline Allergic Dermatitis scale (SCORFAD) and owner Global Assessment Score (GAS).ResultsMean relapse time was 40.5 days (±7.8 SE) in PEA‐um treated cats (n = 13) and 22.2 days (±3.7 SE) for placebo (n = 12; P = 0.04). On Day 28, the severity of pruritus was lower in the PEA‐um treated cats compared to placebo (P = 0.03). Mean worsening of pruritus at the final study day was lower in the PEA‐um group compared to placebo (P = 0.04), whereas SCORFAD was not different between groups. Mean owner GAS at the final study day was better in the PEA‐um than the placebo‐treated group (P = 0.05).Conclusion and clinical importanceUltramicronized palmitoylethanolamide could represent an effective and safe option to delay relapse in NFHD cats.

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM Objectives Trichophyton mentagrophytes is a zoophilic dermatophyte that recognizes lagomorphs and rodents as primary hosts. The fungus can also infect other animals, such as dogs and cats. While T. mentagrophytes is a polymorphic sexual species, T. interdigitale is recognized as its clonal offshoot. This delineation is meaningful from a clinical point of view in human patients. Trichophyton interdigitale is exclusively anthropophilic and mainly causes non-inflammatory chronic tinea pedis or onychomycosis. Trichophyton mentagrophytes is predominantly of animal origin and often leads to the development of inflammatory lesions. These two dermatophytes form a species complex and have several ribosomal internal transcribed spacer (ITS) region genotypes. Identifying the ITS type allows species attribution and simultaneously strain typing. Many studies have been dedicated to this argument concerning human infections, while scarce information is available regarding animals. This study aimed to gain insights into the current epidemiology of T. mentagrophytes genotypes in animals. Methods The fungal isolates included in the study regarded cases involving various animal species seen at multiple veterinary clinics in Italy (n = 39) and France (n = 1) between 2005 and 2021. DNA was extracted from isolates cultured on Sabouraud dextrose agar using a commercially available kit (NucleoSpin® Tissue, Macherey-Nagel, Düren, Germany). PCR was performed with the primer pair V9G and LR3. PCR products were sequenced using ITS5 and ITS4 primers through a commercial service (Macrogen Europe). Using MEGA11 software (https://www.megasoftware.net/), ITS sequences were aligned with the currently recognized genotypes (6 and 22 for T. interdigitale and T. mentagrophytes, respectively). Results Figure 1 shows the ITS Type attribution for our isolates within a phylogenetic tree that includes the currently recognized genotypes. A new genotype (that, following the nomenclature, we called XXVII) was found in two isolates coming from a dog and a cat living in the same city. Figure 2 shows the distribution of the genotypes according to the animal host. A total of 23 samples out of 40 (57.5%) belonged to the ITS Type III*. It was the lone found in rabbits and the most prevalent in cats. This finding agrees with past literature, which reported a wide distribution of this ITS type in European animals. Of note is the high number of isolates with ITS Type II* found in dogs. ITS Type II* differs only by one nucleotide substitution from T. interdigitale and is considered an ‘intermediate’ entity between it and T. mentagrophytes. Clinical pictures, as well as molecular data, would suggest attributing this genotype to T. interdigitale. On the other hand, it has been detected from animal sources (chinchilla, guinea pig, and brown rat) which would justify its interpretation as T. mentagrophytes. Our data support the latter possibility. Though we could not have a detailed description of all the dogs harboring ITS Type II*, it is noteworthy that many showed the same clinical presentation, i.e., exfoliative chronic disseminated alopecia. Moreover, in most cases, despite the extensive lesions, the infection was not transmitted to the owners. Conclusions: This study adds information on the molecular epidemiology of T. mentagrophytes infections in animals.