Cat Skin Research Articles

Molecular and genetic characterization of sex-linked orange coat color in the domestic cat.

The Sex-linked orange mutation in domestic cats causes variegated patches of reddish/yellow hair and is a defining signature of random X-inactivation in female tortoiseshell and calico cats. Unlike the situation for most coat color genes, there is no apparent homolog for Sex-linked orange in other mammals. We show that the Sex-linked orange is caused by a 5 kb deletion that leads to ectopic and melanocyte-specific expression of the Rho GTPase Activating Protein 36 ( Arhgap36 ) gene. Single cell RNA-seq studies from fetal cat skin reveal that red/yellow hair color is caused by reduced expression of melanogenic genes that are normally activated by the Melanocortin 1 receptor (Mc1r)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, but the Mc1r gene and its ability to stimulate cAMP accumulation is intact. Instead, we show that increased expression of Arhgap36 in melanocytes leads to reduced levels of the PKA catalytic subunit (PKA C ); thus, Sex-linked orange is genetically and biochemically downstream of Mc1r . Our findings solve a comparative genomic conundrum, provide in vivo evidence for the ability of Arhgap36 to inhibit PKA, and reveal a molecular explanation for a charismatic color pattern with a rich genetic history.

Mammary gland, skin and soft tissue tumors in pet cats: findings of the feline tumors collected from 2002 to 2022.

Cancer is a leading cause of death in cats, and the rate of such disease has been increasing recently. Nonetheless, feline oncology represents an important area of study not only for the health and wellbeing of cats but also for human health since various types of cancer in cats share similarities to those found in humans. Therefore, epidemiological studies on feline oncology may suggest environmental and genetic factors contributing to cancer in cats, which can eventually be translated to improve human cancer care. To provide an initial understanding of the epidemiology of feline neoplasms, a descriptive study was undertaken using a dataset documenting cases of feline cancer gathered from the Liguria region (northwest Italy) spanning from 2002 to 2022. The database includes tumor location, morphological codes of the International Classification of Diseases for Oncology, 3rd Edition (ICD-O-3), feline's breed, sex, neuter status, date of birth, date of diagnosis, national territorial unit code of the town of the owner's residence, and an alphanumeric string uniquely identifying the owner's surname. The dataset involves a population of 4,399 cats, including 3,195 females (1,425 neutered) and 1,204 males (750 neutered). Our results indicate that mammary gland tumors are the most represented tumors in the female population, while soft tissue and skin cancers appear to have a higher abundance in the male population during the periods investigated (2002-2022). Moreover, Poisson regression analysis showed that not neutered female cats have a significantly increased risk of developing mammary gland tumors compared to the neutered female population [proportional morbidity ratio (PMR) neutered vs. not neutered = 0.58, 95% CI: 0.47-0.72]; meanwhile, for both sexes, for soft tissue and skin tumors, being neutered appears to be a risk factor (PMR neutered vs. not neutered = 2.26, 95% CI: 1.86-2.73; PMR neutered vs. not neutered = 1.16, 95% CI: 0.89-1.51). Finally, the evaluation of the Ligurian municipalities pollution, based on wild boars data (i.e., biomonitors), which coexisted with cats, was correlated to cancer development for all the tumors investigated (in polluted areas, estimated PMRs ranged from 42.61 to 80.13, 95% CI: 29.94-105.11). Overall, the data presented here suggest the use of the feline population as a possible animal model for human health, i.e., sentinel.

A Mouse Model for Conditional Expression of Activated β-Catenin in Epidermal Keratinocytes

We report the generation and characterization of the K5: CAT bigenic mouse in which the constitutively activated form of β-catenin (ΔN89 β-catenin) is conditionally expressed in cytokeratin-5 (K5) positive epidermal keratinocytes. Following short-term doxycycline intake during the telogen resting phase, the adult K5: CAT bigenic develops enlarged pilosebaceous units that expand deep into the dermis, an expansion usually observed during the anagen growth phase. Prolonged doxycycline treatment results in significant thickening and folding of the K5: CAT epidermis. During this persistent induction period, there is clear evidence of increased keratinocyte proliferation, particularly in the epidermal basal cell layer and the outer root sheath of the hair follicle. This unscheduled increase in cellular proliferation likely explains the decrease in hair density observed in the K5: CAT mouse following persistent doxycycline intake. Numerous hyperplastic endometrioid cysts, which display cornification toward their lumens, are also observed during this treatment period. Remarkably, de-induction of ΔN89 β-catenin expression through doxycycline withdrawal results in a marked reversal of the skin phenotype, suggesting that these morphological changes are dependent on continued signaling by β-catenin and/or its downstream molecular mediators. Joining a small group of mouse models for conditional β-catenin signaling, our K5: CAT mouse model will be particularly useful in identifying those molecular mediators of β-catenin that are responsible for initiating and maintaining these phenotypic responses in the K5: CAT skin. Such studies are predicted to shed more light on β-catenin signaling in epidermal epithelial morphogenesis, hair follicle cycling, and hair growth pathologies.

DETERMINATION OF THE SENSITIVITY OF DERMATOMYCOSIS CAUSES TO FUNGICIDES

A microbiological study of the affected areas of the skin of dogs and cats was carried out for the detection of microscopic fungi. The following microscopic fungi were isolated from the pathological material: Candida spp., Aspergillus brasiliensis, Epidermophyton spp., Microsporum spp., Mucor spp., Trichophyton spp., Mallasseria spp., Sporotrich spp. Isolated microscopic fungi of the genus Malassezia spp. belong to the superficial mycoses (keratomycoses) and affect the surface layers of the skin and fur. Epidermatophytes: Trichophyton spp., Epidermophyton spp., Microsporum spp. affect the epidermis, skin, and coat. In addition, opportunistic fungi of the genus Aspergillus brasiliensis were found in the studied samples. It was established that the sensitivity of fungi isolated from the affected areas of the skin of dogs and cats to a 1% solution of ketonazole and clotrimazole is different. In particular, a 1% solution of ketonazole showed significantly higher activity compared to a 1% solution of clotrimazole. Thus, when determining the fungicidal effect of ketonazole, the growth retardation zone of the dermatophyte Trichophyton spp. was 34.3±0.6 mm, and the 1% clotrimazole solution was 21.3±0.3 mm. Ketonazol also showed higher fungicidal activity against the microscopic fungi Aspergillus brasiliensis and Candida spp., compared to clotrimazole. Thus, the activity of ketonazole was, respectively, 55.7 and 48.4% higher compared to clotrimazole. Clotrimazole showed the lowest fungicidal effect on Aspergillus brasiliensis, Mallasseria spp., Mucor spp., and Epidermophyton spp., the growth retardation zones of microscopic fungi were, respectively, 14.3±0.3, 14.3±0.6, 14.6± 0.6 and 16.6±0.3 mm.

Functions and Metabolism of Amino Acids in the Hair and Skin of Dogs and Cats.

The hair and skin of domesticcats or dogs account for 2% and 12-24% of their body weight, respectively, depending on breed and age. These connective tissues contain protein as the major constituent and provide the first line of defense against external pathogens and toxins. Maintenance of the skin and hair in smooth and elastic states requires special nutritional support, particularlyanadequate provision of amino acids (AAs). Keratin (rich in cysteine, serine and glycine) is the major protein bothin the epidermis of the skin andin the hair. Filaggrin [rich in some AAs (e.g., serine, glutamate, glutamine, glycine, arginine, and histidine)] is another physiologically important protein in the epidermisof the skin. Collagen and elastin (rich in glycine and proline plus 4-hydroxyproline) are the predominant proteins in the dermis and hypodermisof the skin. Taurine and 4-hydroxyproline are abundant free AAs in the skin of dogs and cats, and 4-hydroxyproline is also an abundant free AA in their hair. The epidermis of the skin synthesizes melanin (the pigment in the skin and hair) from tyrosine and produces trans-urocanate from histidine. Qualitative requirements for proteinogenic AAs are similar between cats and dogs but not identical. Both animal species require the same AAs to nourishthe hair and skin but the amounts differ. Other factors (e.g., breeds, coat color, and age) may affect the requirements of cats or dogs for nutrients. The development of a healthy coat, especially a black coat, as well as healthy skin critically depends on AAs [particularly arginine, glycine, histidine, proline, 4-hydroxyproline, and serine, sulfur AAs (methionine, cysteine, and taurine), phenylalanine, and tyrosine] and creatine. Although there are a myriad of studies on AA nutrition in cats and dogs, there is still much to learn about how each AA affects the growth, development and maintenance of the hair and skin. Animal-sourced foodstuffs (e.g., feather meal and poultry by-product meal) are excellent sources of the AAs that are crucial to maintain the normal structure and health of the skin and hair in dogs and cats.

Avaliação do uso de nanoemulsão de clorexidina a 0,25% na antissepsia da pele de gatos

ABSTRACT: This study evaluated the antiseptic effect of 0.25% chlorhexidine nanoemulsion (NM-Cl) on cat skin and compare its effect with that of 2.0% chlorhexidine digluconate (CS-Cl). NM-Cl was synthesized using the spontaneous emulsification method, and physical and chemical properties were analyzed. The antiseptic effects of NM-Cl and CS-Cl were randomly tested on the thoracic limbs of 10 healthy male cats. After a wide trichotomy of the thoracic limbs, NM-Cl was randomly applied to the trichotomy area of the right (n = 5) or left (n = 5) thoracic limbs. Then, a catheter was inserted aseptically in the cephalic vein. Subsequently, the same procedure was performed using CS-Cl on the contralateral limb. Cutaneous microbiota swab samples were obtained before antisepsis (Tpre); immediately after antisepsis (Tpost); and 4, 8, and 24 h after antisepsis. The collected samples were immediately inoculated on blood agar plates and incubated at 35 ºC ± 2 ºC in aerobiosis. Colony-forming units (CFUs) were manually counted after 24 h of inoculation. The Kruskal-Wallis and Mann-Whitney U tests were performed between groups and within the same group at different sample times, respectively. The NM-Cl and CS-Cl groups showed a reduction in CFUs between Tpre and Tpost in all animals (P < 0.001). Both formulations presented an antiseptic effect 24 h of antisepsis (P < 0.05), and no difference was observed between formulations at different times (P < 0.05). With a lower concentration of chlorhexidine than CS-Cl, NM-Cl presents effective antiseptic action and prolonged residual effect in antisepsis for cat venipuncture.

Seasonal and age dynamics of infection of cats with ectoparasites in the Moscow metropolis

The purpose of the research is to study the epizootic situation of ectoparasitosis of cats in the Moscow metropolis, taking into account the season and the age of the animals.Materials and methods. The study of the seasonal and age dynamics of infection of cats with ectoparasites in the Moscow metropolis was carried out on the basis of the All-Russian Scientific Research Institute of Infectious Diseases (VNIIP), a branch of the Federal State Budgetary Institution FSC VIEV RAS, as well as the veterinary clinic GLOBALVET CLINIC LLC (Moscow) in 2020–2022. We examined 85 cats in different seasons. When examining the animals, attention was paid to damage to the skin and hair. At the same time, the gender, age, condition of the skin and hair of the animals were taken into account; the ears were examined and the hair was combed using a magnifying glass; Microscopic examination of the ear contents, as well as scrapings of the superficial and deep layers of the skin. The number of ectoparasites was determined according to the method of M. V. Arisov, I. A. Arkhipov (2018). The results obtained were processed statistically using Microsoft Excel.Results and discussion. Infection of cats with Demodex cati was maximum in Spring and Summer (5.9%), and decreased to 3.5% in Autumn and Winter. Ixodes ricinus mites were found on the skin and hair of cats (15%) only in the warm season. We noted an increase in the infection of cats with Otodectes cynotis and Notoedres cati in Spring and Summer. The seasonal dynamics of infection of cats by insects of different species differed. Fleas were found in 4.7% of cats in Winter, and in 8.5 and 10.6% of cats in Spring and Summer, respectively. The infection of cats with lice eaters was low.

Osteoinductive squamous cell carcinoma associated with a putative novel papillomavirus on the digit of a cat

ABSTRACT Case history and clinical findings An approximately 10-year-old, castrated male domestic short-haired cat developed swelling and ulceration of the second digit of the right front paw. Radiographs revealed a spherical soft tissue swelling with irregular distal margins that contained multiple lacy mineral opacities. The digit was amputated and submitted for histology. No recurrence has been observed 7 months after amputation. Pathological and molecular findings Histology revealed a moderately well-circumscribed proliferation of well-differentiated squamous cells arranged in trabeculae and nests. Numerous thin spicules of osseous metaplasia were visible throughout the neoplasm. Around 70% of the neoplastic cells contained papillomavirus-induced cell changes including large amphophilic cytoplasmic bodies and cells with shrunken nuclei surrounded by a clear halo. Intense p16CDKN2A protein immunostaining was visible within the neoplastic cells, suggesting papillomavirus-induced changes in cell regulation. A DNA sequence from a putative novel Taupapillomavirus type was amplified from the neoplasm. Diagnosis Osteoinductive squamous cell carcinoma associated with a putative novel papillomavirus type. Clinical relevance The findings in this case increase the number of papillomavirus types known to infect cats, and the squamous cell carcinoma had histological features that have not been previously reported. The neoplasm was not as invasive as is typical for a squamous cell carcinoma and excision appeared curative. This is the first report of an osteoinductive squamous cell carcinoma of the skin of cats and the neoplasm had a unique radiographic appearance.

Cat Scabies Prevalence at Animal Health Center Pemalang

Scabies in cats is an infectious skin disease caused by the mite Sarcoptes scabiei that attacks the stratum corneum layer of the cat's skin at all ages and is zoonotic. The purpose of this study is to determine the prevalence of scabies using cat patient data from the Pemalang Animal Health Center from May 13th to July 15th, 2022, as well as morphological information of S. scabiei. The scabies diagnosis method employs two stages, namely the examination of clinical and laboratory symptoms. Purposive sampling was used to select laboratory examination samples. Cats with clinical scabies use the skin scraping technique, which involves scraping the skin in the area around the lesion, placing it on an object glass, dripping with 10% KOH, covering it with a cover glass, and examining it under a 400x microscope. The prevalence of scabies in cat patients at the Pemalang Health Center was 33.19%, and S. scabiei was found on the legs of cat patients.

Possibilities of skin coat color-dependent risks and risk factors of squamous cell carcinoma and deafness of domestic cats inferred via RNA-seq data.

The transcriptome data of skin cells from domestic cats with brown, orange, and white coats were analyzed using a public database to investigate the possible relationship between coat color-related gene expression and squamous cell carcinoma risk, as well as the mechanism of deafness in white cats. We found that the ratio of the expression level of genes suppressing squamous cell carcinoma to that of genes promoting squamous cell carcinoma might be considerably lower than the theoretical estimation in skin cells with orange and white coats in white-spotted cat. We also found the possibility of the frequent production of KIT lacking the first exon (d1KIT) in skin cells with white coats, and d1KIT production exhibited a substantial negative correlation with the expression of SOX10, which is essential for melanocyte formation and adjustment of hearing function. Additionally, the production of d1KIT was expected to be due to the insulating activity of the feline endogenous retrovirus 1 (FERV1) LTR in the first intron of KIT byits CTCF binding sequence repeat. These results contribute to basic veterinary research to understand the relationship between cat skin coat and disease risk, as well as the underlying mechanism.

Rapid and visual RPA-CRISPR/Cas12a detection for Staphylococcus pseudintermedius and methicillin-resistant S. pseudintermedius in clinical samples of dogs and cats

Staphylococcus pseudintermedius can cause severe infections of the skin, ear and other tissues in dogs and cats. Methicillin-resistant S. pseudintermedius (MRSP) has recently become more prevalent, posing a severe threat to companion animals and public health. Therefore, rapid and accurate diagnosis of S. pseudintermedius and MRSP infections in dogs and cats is essential for timely controlling infections. The development of CRISPR/Cas technology offers an innovative solution for rapid diagnosis. Here, we established an assay combining recombinant polymerase amplification (RPA) and CRISPR/Cas12a. By separately detecting the spsJ gene, the specific gene of S. pseudintermedius, and the mecA gene, the methicillin resistance gene, this method allows for the direct detection of methicillin-susceptible S. pseudintermedius (MSSP) and MRSP in clinical samples at 37 °C for a total of 40 min, The results can be directly visualized by the naked eye under blue light. The limits of detection of the RPA-CRISPR/Cas12a assay were 103 copies per reaction for the spsJ gene and 104 copies per reaction for the mecA gene. The RPA-CRISPR/Cas12a detection successfully detected and differentiated clinical isolates of MSSP and MRSP without cross-reactivity with other tested bacteria species. The evaluation of the detection performance of RPA-CRISPR/Cas12a with 47 clinical samples (without culture) from dogs and cats showed that the results of detection were 100% consistent with those of clinical culture and colony sequencing, which was more sensitive than PCR. RPA-CRISPR/Cas12a assay can quickly and sensitively detect S. pseudintermedius and MRSP in clinical samples without expensive instruments, making it suitable for small veterinary clinics.

Development of solid microneedles for transdermal drug delivery in companion animals

The objective of this paper was to create an economical and abecedarian 3D printing method for the production of solid microneedles, as a more efficient transdermal drug delivery method, for day-to-day use in companion animals. The process of 3D printing was conducted using two types of 3D printers, utilizing the FDM and SLA printing techniques. Modulus of Elasticity was calculated for the determination of mechanical properties of the material, wherethe printed specimen was subjected to axial loading, and deformations were measured using an optical scanner. Post-processing was conducted by washing microneedles in isopropyl alcohol, followed by UV curing. The procedure of testing penetration capabilities was conducted at two sites of cat skin: Auris externa and the lateral part of the abdomen. The SLA printing method was more precise, resulting in higher quality microneedles for animal use compared to the FDM printing technique. Modulus of Elasticity was calculated and the value E=0.9 GPa can be used. Testing proved that the printed model was able to penetrate the skin at the tested sites. The use of microneedles is simple and economical, and therefore has wide applications in small animal practice. Veterinarians can access microneedle design repositories and print them for more effective transdermal drug delivery. The multifunctionality and transferability of the design in the present study ensure that it can be further modified to provide personalized therapy.

Genetic characterisation of Felis catus papillomavirus type 7, a rare infection of cats that may be associated with skin cancer

Six Felis catus papillomavirus (FcaPV) types have been fully sequenceed from domestic cats including some that have been associated with the development of neoplasia. A sequence from a novel FcaPV type was amplified from a basal cell carcinoma that contained unusual histological evidence of PV infection and intense p16CDKN2A protein (p16) immunostaining. The entire 7467 bp genome was amplified using ‘outward facing’ primers. The PV was designated FcaPV7 and contained putative coding regions that were predicted to produce five early proteins and two late ones. The ORF L1 showed 77% similarity to that of FcaPV6. As the novel PV also showed greater than 60% similarity to three other feline Tau-PV types, FcaPV7 is proposed to be classified within this genus. Specific primers were designed but did not amplify FcaPV7 DNA from any of 60 samples from the mouth and skin of cats. FcaPV7 appears to rarely infect cats. However, FcaPV7 may be associated with skin cancer in this species.

A theoretical liquid crystal elastomer model that mimics the elasticity of cat skin

A mathematical model for nematic liquid crystal elastomers is proposed that mimics the elastic response of cat skin where reorientation of dermal fibres produces an increase in the thickness direction under tensile stretch. To capture this unusual effect, the uniaxial order parameter in the nematic elastomer model is allowed to decrease then increase again, and the critical stretch at which this change of monotonicity occurs and where the director also rotates suddenly is predicted. In addition, the model parameters are described by probability density functions and their uncertainty is propagated numerically to the predicted mechanical results.

Molecular study of feline dermatophytosis and Toll-like receptor 2 and 4 gene expression in their lesions.

Pattern recognition receptors (PRRs) as the recognition of pathogenic fungal structures induce the secretion of cytokines by immune systems. Toll-like receptors (TLRs) 2 and 4 are the main PRRs that recognize fungal components. The present study aimed to assess the presence of dermatophyte species in symptomatic cats in a region of Iran and to investigate the expression of TLR-2 and 4 in cat lesions with dermatophytosis. A total of 105 cats suspected of dermatophytosis with skin lesions were examined. Samples were analysed by direct microscopy using potassium hydroxide (20%) and culture on Mycobiotic agar. Dermatophytes strains were confirmed by the polymerase chain reaction (PCR) amplification and then sequencing of the Internal Transcribed Spacer rDNA region. Also, for pathology and real-time PCR studies, skin biopsies were taken by sterile single-use biopsy punch from active ringworm lesions. Dermatophytes were found in 41 felines. Based on the sequencing of all strains, Microsporum canis (80.48%, p < 0.05), Microsporum gypseum (17.07%) and Trichophyton mentagrophytes (2.43%) were the dermatophytes isolated from cultures. Cats under 1 year (78.04%) revealed a statistically significantly higher prevalence of infection (p < 0.05). Gene expression by real-time PCR revealed the increased TLR-2 and 4 mRNA levels in skin biopsies of cats with dermatophytosis. M. canis is the most prevalent dermatophyte species isolated from feline dermatophytosis lesions. Increased expression of TLR-2 and TLR-4 mRNAs in cat skin biopsies suggests that these receptors are involved in the immune response by recognizing dermatophytosis.

Odontogenic-like neoplasms of the rabbit cheek: pathological features and comparison to cutaneous trichoblastoma and jaw-associated ameloblastoma.

Odontogenic neoplasms demonstrate unique histopathological features and are thought to arise from the germinal tissues of the developing tooth germ, effectively restricting their anatomic origin to the tooth-bearing regions of the jaw and directly associated soft tissues of the oral cavity. Ectopic odontogenic-like neoplasms located in the skin of cats, rabbits, and human beings challenge these assumptions. Here we describe the clinical, pathological, and immunohistochemical features of 6 spontaneously occurring odontogenic-like neoplasms arising in the cutaneous tissue of the cheek in client-owned pet rabbits, including ameloblastoma-like (n = 3), ameloblastic fibroma-like (n = 2), and ameloblastic carcinoma-like neoplasms (n = 1). Microscopically, all the cheek tumors featured neoplastic epithelium exhibiting odontogenic architectural structures (plexiform ribbons, anastomosing trabeculae, follicles, cysts, and irregular structures with rounded botryoid protuberances) and 1 or more cardinal odontogenic epithelial features (basal palisading, antibasilar nuclei, and central stellate reticulum-like cells). The pancytokeratin, cytokeratin 5/6, cytokeratin 14, and vimentin immunohistochemical patterns of these odontogenic-like lesions were most similar to those of jaw-associated ameloblastoma and differed from those of cutaneous trichoblastoma. All neoplasms were narrowly excised, and for lesions with clinical follow-up information, none had evidence of recurrence 1-7 months after surgical removal. Although evidence suggests that these odontogenic-like tumors of the rabbit cheek may be derived from ectopic rests of transformed tooth germ, the histogenesis of these lesions remains unresolved.

Histiocytic Diseases.

Canine cutaneous histiocytomas originate from Langerhans cells. Multiple histiocytomas are referred to as cutaneous Langerhans cell histiocytosis. Feline pulmonary Langerhans cell histiocytosis causes respiratory failure owing to extensive lung infiltration. Localized and disseminated histiocytic sarcomas usually arise from interstitial dendritic cells. Primary sites include spleen, lung, skin, brain (meninges), lymph node, bone marrow, and synovial tissues of limbs. An initially indolent form of localized histiocytic sarcomas, progressive histiocytosis, originates in the skin of cats. Hemophagocytic histiocytic sarcomas originates in splenic red pulp macrophages. Canine reactive histiocytoses (systemic histiocytosis and cutaneous histiocytosis) are complex inflammatory diseases with underlying immune dysregulation.

Clinical, diagnostic and epidemiological implications of Hepatozoon spp., Babesia spp. and Leishmania infantum infection in cats and dogs in a Mediterranean periurban setting

Hepatozoon spp., Babesia spp. and Leishmania infantum are common parasites of dogs in Mediterranean countries and are less frequent in cats, particularly Babesia spp. and L. infantum. Moreover, there is limited information on coinfections between these parasites and on L. infantum’s distribution in blood, skin and lymphoid tissue in cats. We used PCR and DNA sequencing to investigate the prevalence of these parasites and the aetiology of Hepatozoon spp. and Babesia spp., in blood, skin, spleen and lymph node samples from up to 212 stray cats and 82 abandoned dogs in southeast Spain. All except 2 dogs were healthy; instead, 112 cats had clinical signs. The estimated PCR prevalences (95% confidence interval) were 25% (19–31%) Hepatozoon felis in cats, 13% (6–21%) Hepatozoon canis in dogs, 1% (0–4%) Babesia vogeli in dogs, 0% Babesia spp. in cats and 21% (15–26%) and 44% (33–55%) L. infantum in cats and dogs, respectively, and infections were not associated with each other. Leishmania infantum prevalence in lymphoid tissue was significantly higher in dogs than in cats (p < 0.001), and dogs had higher parasite loads than cats (p = 0.012). Moreover, L. infantum prevalence was significantly higher in the skin and lymphoid tissue compared to blood in infected, asymptomatic animals but it was similar in cats with clinical signs, which also had higher parasite loads compared to infected, asymptomatic cats (p < 0.05). The study highlights significant differences between sympatric dogs and cats with respect to the parasite infections investigated, as well as the need to examine both lymphoid tissue and skin samples to maximise the sensitivity of L. infantum infection diagnosis.

Transcriptome analysis of selected cytokine and chemokines in the eosinophilic plaques of cats with atopic skin syndrome.

Previous evaluations of cytokine and chemokine gene expressions [messenger (m)RNA] in the skin of allergic cats were mostly unsuccessful in detecting the T-helper 2 (Th2) pathway, which is associated with the major effector cytokines interleukin (IL)-4, IL-5 and IL-13. To evaluate differences in the mRNA expression in eosinophilic plaques of cats diagnosed with feline atopic skin syndrome (FASS) compared to healthy controls. Four client-owned cats with FASS with eosinophilic plaques and five healthy control cats. Gene expressions (mRNA) of 14 cytokines and chemokines from eosinophilic plaque skin of cats with FASS and site-matched skin samples from healthy controls were analysed using quantitative reverse-transcription PCR analysis. Eosinophilic plaques were characterized by upregulation of Th2 cytokines IL-4 (p≤ 0.01), IL-5 (p≤ 0.01) and IL-13 (p≤ 0.01) and Th2-attracting chemokine CCL17 (p≤ 0.05). Moreover, there was higher expression of S100 calcium-binding protein A 8 (p≤ 0.01) as well as C-X-C Motif chemokine ligand 10 (CXCL10; p≤ 0.01), IL-10 (p≤ 0.05) and the Th17 cytokine IL-17A (p≤ 0.01) in lesional skin compared to healthy samples. There was no difference in gene expressions of IL-12A, IL-31, IL-33, thymic stromal lymphopoietin (TSLP), tumour necrosis factor-α (TNF-α) or CCL5. Results demonstrate that eosinophilic plaques feature dominant Th2 and IL-17A inflammatory responses in the skin. Further larger-sample transcriptome studies are needed to advance our understanding of the pathogenesis of different skin lesions in FASS.

Effect of serum starvation and contact inhibition on dermal fibroblast cell cycle synchronization in two species of wild felids and domestic cat

Abstract Cell cycle synchronization of donor cells is an important step in mammalian somatic cell nuclear transfer (SCNT). This study was designed to compare the efficiency of serum starvation (Ss) and contact inhibition (cI) on cell cycle synchronization of jaguarundi, manul, and domestic cat skin fibroblasts, in the production of G0/G1 cells suitable for SCNT in felids. Ss was performed after the growing (G) cells reached 40–50% (G50+Ss), 60–70% (G70+Ss) and full confluency (Fc), i.e. in association with cI (cI+Ss). Frozen-thawed cells were cultured to the given state of confluency (d0; controls), and subjected to Ss or cI for 1, 3, and 5 days (d). In manul, the effect of Ss on arresting fibroblasts in the G0/G1 phase was noted after just 1d of culture at G70 confluence, while G50+Ss and cI+Ss were effective after 5d of treatment. In jaguarundi, 1–5d of G50+Ss and 5d of G70+Ss increased the percentage of G0/G1 cells versus d0 (P&lt;0.01), with 5d of G70+Ss producing more (P&lt;0.05) quiescent cells than after the same period of G50+Ss, cI+Ss and cI. In the domestic cat, Ss was efficient only after 3 and 5d of G50+Ss. In all species, cI alone failed to increase the proportion of G0/G1 cells compared to d0, however in the domestic cat, 5d of cI was more efficient than the same period of G50+Ss. In jaguarundi, &gt;93% of cells were already in G0/G1 phase at d0 of Fc, suggesting that culture to Fc could be also a valuable method for fibroblast cell cycle synchronization in this species. In contrast to cI, prolonged Ss generated cell loss and could induce apoptosis and/or necrosis. In conclusion, Ss was the more efficient method for skin fibroblast cell cycle synchronization at the G0/G1 phase in manul, jaguarundi and the domestic cat. The response of cells to the treatments was species-specific, depending on cell confluence and duration of culture. This research may find application in preparing donor karyoplasts for SCNT in felids.