Skin Of Dogs Research Articles

Pathological and Fungal Isolation study of dog skin disease in Iraq Governorates

Dogs are susceptible to several types of infectious diseases can be worrisome for their owner because some of them are fatal if not treated soon enough. Fungal infection can be contracted through different parts of body furthermore many of them are zoonotic infection among human and dogs the signs of any disease typical depend on location of infection either local or system infection. Local infection usually involves skin surface that look like wound the objective of this study was to briefly about the most common pathogenic fungal infection in dogs by describing information about the causative agent, clinical signs and grossly appearance with histopathological change skin examination current study were done on 200 dogs collected in Iraq governorates (Baghdad, Erbil, Anbar, Sulaymaniyah) during a period 6 months (January – June) 2023. 200 examined dogs with different age, breed and sex ( k9, ornamental and stray dogs ) were observed fungal isolation and pathological examination with clinical signs by using diagnostic tools for skin biopsies (biopsy punch) from suspected infected skin dogs. Results showed pathogenic fungi after collected on fungal culture for detection pathogenic fungal (Dermatophyte Test Agar) D.T.M Agar Base. Fungal isolation constitutes the following pathogenic fungi (100 infected samples from 200 suspected samples). 60% Aspergillus niger, 30% Trichophyton Verrucosum, 10% Alternaria spp. Clinical signs and grossly lesion showed complete skin ulcer, allopecia, odema, abscessation while microscopic appearance revealed skin ulcer, hyperkeratosis, folliculitis, necrosis, apoptosis, pyogranuloma and granulation tissue with septate hyphae in skin dermis and epidermis which infected with Aspergillus niger.

The Molecular Signature Related to Local Inflammatory and Immune Response in Canine Cutaneous Hypersensitivity Reactions: A Preliminary Study.

Cutaneous hypersensitivity reactions (CHRs) are complex inflammatory skin disorders that affect humans and dogs. This study examined the inflammatory and immune responses leading to skin damage, inflammation, and irritation by investigating gene expression through quantitative PCR (qPCR) and protein localization through the immunohistochemistry (IHC) of specific receptors and molecules involved in CHRs. Formalin-fixed paraffin-embedded (FFPE) samples from canine CHR skin (n = 20) and healthy dog skin (n = 3) were analyzed for expression levels of eight genes, including members of the pattern recognition receptor (PRR) family, CD209 and CLEC4G, the Regakine-1-like chemokine, and acute phase proteins (APPs), LBP-like and Hp-like genes. Additionally, we examined the local involvement of IL-6, Janus Kinase 1 (JAK1), and the signal transducer activator of transcription 3 (STAT3) in the CHR cases. The study demonstrated statistically significant increases in the expression levels of CD209, Hp-like (p < 0.01), LBP-like, Regakine-1-like, and CLEC4G (p < 0.05) genes in CHRs compared to healthy controls. Conversely, IL-6, JAK1, and STAT3 showed no significant difference between the two groups (p > 0.05). Protein analysis revealed JAK1 and STAT3 expression in CHR hyperplastic epithelial cells, dermal fibroblasts, and endothelial cells of small capillaries, indicating a possible involvement in the JAK/STAT pathway in local inflammatory response regulation. Our findings suggest that the skin plays a role in the development of CHRs.

Integrating multi-wet laboratory diagnostics to study staphylococci in animals in Uganda

BackgroundSeveral diagnostic environments in Uganda lack real-time, robust and high-throughput technologies for comprehensive typing of microbes, which is a setback to infectious disease surveillance. This study combined various wet laboratory diagnostics to understand the epidemiology of pathogenic staphylococci isolated from animals in Uganda and the implications for global health security priorities.MethodsA retrospective study was conducted employing records and pathogenic staphylococci (from animals) archived at the Central Diagnostic Laboratory (CDL), Makerere University, Uganda, between January 2012 and December 2019. The bacteria were speciated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and tested for virulence factors [beta lactamases, lecithinase, deoxyribonuclease (DNase), haemolysins] and resistance to ten antimicrobials of clinical and veterinary relevance. Tetracycline and methicillin resistance genes were also tested.ResultsThe prevalent diseases were mastitis in cattle and skin infections in dogs. Of the 111 staphylococci tested by MALDI-TOF MS, 79 (71.2%) were Staphylococcus aureus, 27 (24.3%) were Staphylococcus pseudintermedius and 5 (4.5%) were Staphylococcus schleiferi. All these strains expressed haemolysins. The prevalence of strains with lecithinase, penicillinase, cephalosporinase and DNase was 35.9% (14/39), 89.7% (35/39), 0.0% (0/39) and 87.2% (34/39), respectively. Staphylococci were primarily resistant to early penicillins (over 80%), tetracycline (57.7%), and chloramphenicol (46.2%). Minimal resistance was noted with cloxacillin (0.0%), ciprofloxacin (9.6%), and cefoxitin (3.8%). The prevalence of multidrug resistance (MDR) was 78.8% for general staphylococci, 82.2% for S. aureus, 73.1% for S. pseudintermedius, and 60.0% for S. schleiferi. Multidrug resistant staphylococci were significantly more prevalent in the cattle isolates than in the dog isolates (P < 0.05). The prevalence of methicillin-resistant staphylococci (MRS) tested by resistance to cefoxitin and mecA carriage was 3.8%. These four strains were all isolated from dog skin infections. The tetK gene was the most predominant (35.4%), followed by tetM (25.0%).ConclusionIn resource-constrained settings, the approach of integrated diagnostics promises sustainable disease surveillance and the addressing of current capacity gaps. The emergence of MRS (zoonotic bacteria) in companion animals creates a likelihood of reduced treatment options for related human infections, a threat to global health.

Histopathological and Ultrastructural Study of a Canine Langerhans Cell Tumour (Canine Cutaneous Histiocytoma).

Canine cutaneous histiocytoma (CCH) represents a significant proportion of dog skin tumours, often manifesting as the most common neoplastic skin condition in young animals. Predominantly affecting dogs under four, these tumours appear primarily as solitary lesions that may regress spontaneously. This study, conducted over five years at the University of Trás-os-Montes e Alto Douro, involved a detailed histopathological and ultrastructural examination of 93 CCH cases. Histologically, these tumours showed distinct patterns of lymphoid infiltration, which contributed to their classification into four groups based on the inflammatory response and histological architecture. Most tumours displayed signs of epidermal invasion and frequent mitotic figures, with necrosis present in over half of the cases. Ultrastructurally, the neoplastic cells were characterised by pleomorphism, abundant organelles, and adherens-type junctions. This study offers significant insights into the pathophysiology and morphological characteristics of CCH, underscoring the importance of detailed histological and ultrastructural analysis in accurately diagnosing and understanding this common canine tumour.

EXPERIMENTAL ASSESSMENT OF THE ACUTE TOXICITY OF "KUBAZOL" – SOLUTION FOR EXTERNAL APPLICATION BASED ON BIRCH TAR

Laboratory studies were conducted to determine the acute toxicity of the veterinary drug "Kubazol" on white rats. The drug "Kubazol" - a veterinary drug (spray for external use, solution) contains birch tar in its composition. Intended for the treatment and prevention of lesions of the skin (wounds, dermatitis, eczema), claws (injuries, superficial panaritium), hooves and hooves (foot rot, etc.) in dogs, wild pigs, wild birds and sports horses. According to the results of determining the parameters of the acute toxicity of the drug "Kubazol" (spray for external use, solution), in the case of a single intragastric administration, the LD50 for male rats is 7328.87±878.80 mg/kg of body weight, which allows us to classify it as toxic up to V class - practically non-toxic substances (LD50 5001-15000 mg/kg), and according to the degree of danger - up to IV class - low-hazard substances (LD50 &gt; 5000 mg/kg). According to the results of toxicological studies of the veterinary drug "Kubazol" (spray for external use, solution), the LD50 indicator could not be calculated, since the death of laboratory animals was not detected within 14 days after application to the skin of rats. At the same time, the maximum dose of the drug "Kubazol (spray for external use, solution) applied to the skin of rats (based on the absolute weight of the drug) was 15,000.0 mg/kg of body weight, which allows the drug to be classified according to the degree of danger to the IV class - low-hazardous substances (LD50Сut&gt;2500.0 mg/kg of body weight). Further studies will be the next stage of pre-registration tests aimed at studying the chronic toxicity of "Kubazol", which is mandatory material in the section "Studies on safety and residues" of the dossier for this drug.

HISTOPATHOLOGICAL FEATURES OF DOGS SKIN WITH ATOPIC DERMATITIS AFTER TREATMENT USING ECO ENZYME

Atopic dermatitis is one of the most common diseases in dogs that is multifactorial and usually attacks dogs aged between 6-36 months. This study was aimed to determine the histopathological appearance of the skin of dogs suffering from atopic dermatitis after treated with eco enzyme. Eco enzyme is a liquid product resulting from the fermentation of organic kitchen waste product such as fruit and vegetable dregs, molasses, and water. This study used five dogs suffering from atopic dermatitis which were divided into two groups. Group A: three dogs samples were bathed with 10% eco enzyme liquid every three days for 28 days. In Group B: two samples of dogs were bathed with 10% eco enzyme every three days until the 9th day, followed by a 2% eco enzyme bath once a week (13th, 20th, 27th day). Both treatment groups started from day 0 until day 28. Skin samples were taken using the biopsy method and histopathological changes were observed by making histopathological skin preparations stained with Hematoxylin and Eosin. Observations of the preparations were carried out using a light microscope. Data were analyzed using the Analysis of Variance test followed by the Duncan multiple range test and the Kruskall Wallis test followed by the Mann-Whitney test, then the data was explained descriptively. The results of the Anova test showed that the thickness of the dogs epidermis treated with 2% and 10% eco enzyme was significantly different (P&lt;0.05). The Kruskall Wallis test for scoring inflammatory cell infiltration and degeneration showed that there was a significant difference (P&lt;0.05) in the administration of 2% and 10% eco enzyme. Eco enzyme liquid is able to reduce atopic dermatitis lesions in dogs. Giving eco enzyme at a concentration of 10% and followed by a concentration of 2% with an extended application time can return the histological structure of the dog’s skin to normal, especially the thickness of the epidermis, reduce inflammatory cell infiltration, and reduce degeneration.

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.

Cellular profile of the skin and ocular surface in healthy shih-tzu dogs

Cytology involves analyzing individual cells and is crucial for diagnosing skin and ocular surface diseases. The skin acts as a barrier against various threats and communicates with the immune system via receptors. The conjunctiva also provides protection to the eyes. This study aimed to describe the cytological profiles of healthy Shih-Tzu dogs' skin and ocular surfaces, assessing how age impacts these profiles. Materials for cytological analysis were collected using a nylon microbrush and evaluated with the Schirmer test. Results showed lymphocytes were predominant in ocular cytology (RE - 47%, LE - 41.93%), while polymorphonuclear cells dominated in nasal fold (62%) and palmar pad cytologies (100%). Superficial cells were prevalent in all regions (RE 83.11%, LE 90.52%, palmar pads 100%, nasal fold 96.91%). Malassezia spp was detected in all areas. This research underscores the cellular variations across different anatomical sites and provides insights into normal cytological patterns in these dogs.

Prevalence and genetic diversity of azole-resistant Malassezia pachydermatis isolates from canine otitis and dermatitis: A 2-year study.

Despite previous reports on the emergence of Malassezia pachydermatis strains with decreased susceptibility to azoles, there is limited information on the actual prevalence and genetic diversity of azole-resistant isolates of this yeast species. We assessed the prevalence of azole resistance in M. pachydermatis isolates from cases of dog otitis or skin disease attended in a veterinary teaching hospital during a 2-year period and analyzed the ERG11 (encoding a lanosterol 14-α demethylase, the primary target of azoles) and whole genome sequence diversity of a group of isolates that displayed reduced azole susceptibility. Susceptibility testing of 89M. pachydermatis isolates from 54 clinical episodes (1-6 isolates/episode) revealed low minimum inhibitory concentrations (MICs) to most azoles and other antifungals, but 11 isolates from six different episodes (i.e., 12.4% of isolates and 11.1% of episodes) had decreased susceptibility to multiple azoles (fluconazole, itraconazole, ketoconazole, posaconazole, ravuconazole, and/or voriconazole). ERG11 sequencing of these 11 azole-resistant isolates identified eight DNA sequence profiles, most of which contained amino acid substitutions also found in some azole-susceptible isolates. Analysis of whole genome sequencing (WGS) results revealed that the azole-resistant isolates from the same episode of otitis, or even different episodes affecting the same animal, were more genetically related to each other than to isolates from other dogs. In conclusion, our results confirmed the remarkable ERG11 sequence variability in M. pachydermatis isolates of animal origin observed in previous studies and demonstrated the value of WGS for disentangling the epidemiology of this yeast species.

Molecular Prevalence of MecA and MecC Genеs in Coagulasе-Positive Staphylococci Isolated From Dogs with Dermatitis and Otitis in Belgrade, Serbia: A One Year Study

Abstract The escalating global concern of antimicrobial resistance in human and veterinary medicine is exacerbated by the inappropriate prescription of antibiotics for bacterial infections in companion animals. This study aimed to determine the distribution of coagulase-positive staphylococci causing clinical skin and ear infections in dogs and to determine methicillin-resistant isolates. A total of 78 staphylococcal strains were isolated from clinical samples taken from patients at the Dermatology Clinic at the Faculty of Veterinary Medicine in Belgrade, Serbia. Multiplex PCR was used for species-specific identification, and mecA and mecC genes were used to determine methicillin resistance, in addition to phenotypic determination, MIC values and detection of PBP2a. Out of the 78 samples analyzed, 65.8% were identified as Staphylococcus pseudintermedius, 22.4% as S. aureus, 7.9% as S. coagulans, and 3.9% as S. intermedius. Four S. aureus isolates exhibited methicillin resistance confirmed by cefoxitin disk diffusion, while five were confirmed with MIC testing and latex agglutination. MecA gene was detected in 29.4% of S. aureus and 30% of S. pseudintermedius isolates. These isolates were classified as methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. pseudintermedius (MRSP), respectively. No isolates carried the mecC gene. This study provides insights into the prevalence of CoPS species and methicillin resistance in isolates from dogs. Continued surveillance is essential to monitor and understand the emergence and dissemination of antimicrobial resistance in veterinary medicine and the results of this study accent the need for establishment of a continuous antimicrobial resistance surveillance program in the Republic of Serbia.

Functional properties of Ganoderma lucidum supplementation in canine nutrition.

Ganoderma lucidum (GL) is a mushroom that has been widely used in Asia for its immunostimulatory and anti-inflammatory capacity, which has been hypothesized to be attributed mainly to the recognition of its cell-surface patterns by cells of the immune system present in the gastrointestinal tract, resulting in a cascade of modulatory events. However, the nutraceutical properties of GL have not been tested in dogs. Forty adult beagles were used in a completely randomized design. The objective of the present study was to evaluate the effects of dietary inclusion of GL on peripheral blood mononuclear cells (PBMC; T cells, B cells, monocytes, and natural killers), vaccine response, nutrient digestibility, fecal fermentative end-products, and skin and coat quality of adult dogs. Dogs were fed a commercial dry extruded complete and balanced diet plus GL top-dressed daily upon feeding time. Four experimental treatments were used: 0% GL supplementation (control), 5mg/kg BW of GL, 10mg/kg BW of GL, or 15mg/kg BW of GL. Following a 7d adaptation to the control diet, dogs were fed their respective treatment diets for 28d. They were challenged with vaccination of a modified live virus Canine Distemper, Adenovirus Type 1 (Hepatitis), Adenovirus Type 2, Parainfluenza, and Parvovirus and killed Rabies Virus on day 7 with blood collections on days 0, 14, and 28. The inclusion of GL in all dosages was well-accepted by all dogs, with no detrimental effect on macronutrient apparent total tract digestibility. There was a trend that the percentage of major histocompatibility II (MHC-II) from B cells was greater in dogs fed 15mg/kg of GL (41.91%) compared to the control group (34.63%). The phagocytosis response tended to have treatment-by-time interaction among treatments; dogs fed 15mg/kg of GL tended to have greater phagocytosis activity on day 28 than dogs from the control group and dogs fed 5mg/kg of GL. The vaccine-specific serum immunoglobulin G (IgG) concentrations were higher in the group supplemented with 15mg/kg of GL compared to treatment control 7d after the vaccination for rabies. These data suggest that the inclusion of GL had no detrimental effects on any analyzed PBMC. Due to changes in immune parameters among treatments, GL may also exert beneficial immunostimulatory effects in healthy adult dogs when provided at a daily dose of 15mg/ kg BW.

TREATMENT OF BABESIOSIS AND ECTOPARASITIC INFESTATION IN TERRIER CROSSBREED DOG

Babesiosis is an infectious disease caused by Babesia sp. distributed in the circulatory system. A 5-month-old male Terrier mix with a body weight of 6.20 kg had complaints of weakness and many ticks all over the dog's body. The results of the physical examination found ticks almost all over the body, pale eye mucosa, erythema on the right ear, and the inside of the ear was dirty. Laboratory examination results include routine haematological examination showing hypochromic normocytic anaemia followed by leucocytosis and lymphocytosis; blood smear examination showing Babesia sp erythoparasites; microscopic examination found Rhipicephalus sanguineus ticks and Ctenocephalides canis larvae on the skin and nails of dogs and the results of earwax swabs found Otodectes cynotis. Based on the results of history taking, physical examination, and laboratory examination, the case dog was diagnosed with babesiosis with a prognosis of fausta. The therapy given was imidocarb dipropionate 6.6mg/kg BW every 2 weeks for 3 repetitions; doxycycline 10 mg/kg BW twice a day for 21 days; and ivermectin 0.2 mg/kg BW given once a week for 3 repetitions; and herbal oabat Fufang E'jiao Jiang 1 ml/kg given once a day for 7 days. Observation on the 14th day of therapy showed clinical improvement such as lethargy that disappeared, decreased intensity of nausea, and reduced tick infestation.

Mastocytosis in the skin in dogs: A multicentric case series.

Canine cutaneous mastocytosis (CM) is rare in contrast to canine mast cell tumours. In humans, CM commonly affects children and is usually indolent with possible spontaneous resolution. Systemic mastocytosis (SM) with bone marrow involvement typically affects adults, can have a poor outcome, and often includes skin lesions. 'Mastocytosis in the skin' (MIS) is the preferred term of skin lesions, if bone marrow evaluations are not available, which is often the cases in dogs. In human SM and CM, KIT mutations are often detected. The veterinary literature suggests clinical resemblances between human and canine MIS, but data is limited, and KIT mutations are rarely assessed. This retrospective study describes clinicopathological findings, treatment and outcome of 11 dogs with suspected MIS. Dogs with multiple mast cell tumours were excluded. Histopathology reports (n = 5) or slides (n = 6) were reviewed. KIT mutation analysis including exons 8, 9, 11, 14 and 17 were analysed in eight dogs. Median age at diagnosis was 4 years (range, 1-12). Typical clinical signs included multifocal to generalised nodules and papules. Histologically, skin lesions were characterised by dermal infiltration of well-differentiated mast cells. KIT mutations were detected in 3/8 dogs (exon 9: n = 2; exon 11: n = 1). One dog had mastocytaemia suggesting possible SM. Glucocorticoids were mostly successful with lesion improvement in all treated dogs (n = 8). This cohort highlights resemblances between human and canine MIS. Further studies are required to confirm these findings and establish diagnostic criteria for CM and MIS associated with SM in dogs.

Erythritol alters phosphotransferase gene expression and inhibits the in vitro growth of Staphylococcus coagulans isolated from canines with pyoderma.

Staphylococcus coagulans (SC) belongs to a group of coagulase-positive staphylococci occasionally isolated from the skin lesions of dogs with pyoderma. We recently revealed that erythritol, a sugar alcohol, inhibited the growth of SC strain JCM7470. This study investigated the molecular mechanisms involved in this growth inhibition of JCM7470 by erythritol, and determine whether erythritol inhibits the growth of SC isolated from the skin of dogs with pyoderma. Comprehensive analysis of the gene expression of JCM7470 in the presence of erythritol revealed that erythritol upregulated the expression of glcB and ptsG genes, both of which encode phosphotransferase system (PTS) glucoside- and glucose-specific permease C, B, and A domains (EIICBA), respectively, associated with sugar uptake. Moreover, erythritol suppressed in vitro growth of all 27 SC strains isolated from the skin lesions of canine pyoderma, including 13 mecA gene-positive and 14 mecA gene-negative strains. Finally, the growth inhibition of the SC clinical isolates by erythritol was restored by the addition of glucose. In summary, we revealed that erythritol promotes PTS gene expression and suppresses the in vitro growth of SC clinical isolates from dogs with pyoderma. Restoration of the erythritol-induced growth inhibition by glucose suggested that glucose starvation may contribute to the growth inhibition of SC.

The effects of hydrolyzed protein on macronutrient digestibility, fecal metabolites and microbiota, oxidative stress and inflammatory biomarkers, and skin and coat quality in adult dogs.

Research on protein hydrolysates has observed various properties and functionalities on ingredients depending on the type of hydrolysate. The objective of this study was to evaluate the effects of hydrolyzed chicken protein that was incorporated into diets on digestibility, gut health, skin and coat health, oxidative stress, and intestinal inflammation markers in healthy adult dogs. Five complete and balanced diets were manufactured: (1) CONd: 25% chicken meal diet; (2) 5% CLHd: 5% chicken liver and heart hydrolysate plus 20% chicken meal diet; (3) CLHd: 25% chicken liver and heart hydrolysate diet; (4) 5% CHd: 5% chicken hydrolysate plus 20% chicken meal diet; (5) CHd: 25% chicken hydrolysate diet. A replicated 5 × 5 Latin square design was used which included 10 neutered adult Beagles. Each of the 5 periods consisted of a 7-d washout time and a 28-d treatment period. All diets were well accepted by the dogs. Fecal butyrate concentration was higher while fecal isovalerate and total phenol/indole were lower in dogs fed CLHd than CONd (P < 0.05). Dogs fed CHd had higher fecal immunoglobulin A concentration when compared with CLHd (P < 0.05); however, both groups were comparable to the CONd. There was no difference among groups in serum cytokine concentrations, serum oxidative stress biomarkers, or skin and coat health analyses (P > 0.05). Fecal microbiota was shifted by CLHd with higher abundance in Ruminococcus gauvreauii group as well as lower Clostridium sensu stricto 1, Sutterella, Fusobacterium, and Bacteroides when compared with CONd (P < 0.05). There was also a difference in beta diversity of fecal microbiota between CLHd and CHd (P < 0.05). In conclusion, chicken protein hydrolysate could be incorporated into canine extruded diets as a comparable source of protein to traditional chicken meal. The test chicken protein hydrolysates showed the potential to support gut health by modulating immune response and microbiota; however, functional properties of protein hydrolysates are dependent on inclusion level and source.

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.

Comparative study of parasite load in the spleen, lymph node, and skin of dogs with visceral leishmaniasis

Canine visceral leishmaniasis (VL) is a zoonosis caused by the protozoan Leishmania infantum. The lymph nodes, spleen, and skin are essential organs in the immunopathogenesis of the disease. This study aimed to investigate the histomorphological alterations and parasite load in the popliteal lymph node, spleen, and skin of eleven VL-positive dogs in the fine needle aspiration (FNA), Dual-path Platform chromatographic immunoassay (DPP® CVL rapid test) and Enzyme-linked immunosorbent assay (ELISA). Histopathological and immunohistochemical methods were used to evaluate the samples, and the results showed variable histopathological changes and parasite load. The popliteal lymph nodes and spleen exhibited granulomatous reaction, lymphoid atrophy, presence of plasma cells, and disorganization of the architecture was marked. The skin showed multifocal to diffuse inflammation in the superficial dermis, composed of lymphoplasmacytic infiltrate and granulomatous reaction. Immunodetection of the parasite Leishmania sp. was observed in all organs. The intensity of histological changes was not associated with the higher number of parasitized macrophages. The popliteal lymph node had the highest median parasite load (11.2) compared to the skin and spleen. Statistically, the Pearson correlation test revealed a highly significant correlation in the parasite load between the popliteal lymph node and spleen (r=0.89081, p=0.0002) and between the popliteal lymph node and skin (r=0.71185, p=0.0140). The study concludes that VL-positive dogs’ lymph nodes, spleen, and skin suffer histomorphological alterations that could be one of the aspects that favor the maintenance of the infection.

Histomorphological changes in atheroma of the dog (morphological study on the example of 12 clinical cases)

Pathological processes in the skin of domestic animals are one of the most common diseases of domestic animals both in the Kyrgyz Republic and throughout the world. In connection with the complex differential diagnosis of oncological and non-neoplastic diseases in animals based only on clinical signs, the purpose of this work was to conduct a statistical and histomorphological analysis of cases of atheroma development in dogs. Clinical, histological and statistical methods were used during the research. The research was conducted on a controlled group of domestic dogs in the amount of 12 animals, which were followed for several years. When collecting the anamnesis, in addition to clinical signs, the breed, age and concomitant diseases of the dogs were recorded. During surgical removal of atheroma, histological preparations were prepared to clarify the diagnosis and study histomorphological changes in the tissues. Atheroma of the skin in dogs was most often registered in old animals, which were more than 9 years old at the time of diagnosis. At the same time, such pathology was most often localized in dogs in the area of the head and neck. Among the breeds, the Boxer turned out to be the most susceptible to the formation of sebaceous gland cysts. Also, the incidence among females was 75% of all cases of registered diseases. Histological studies revealed the prevalence of cases with the formation of multiple cysts – 67%, when a number of smaller formations are found near one huge atheroma, while cases of purulent inflammation were only 16%. Surgical removal of the atheroma was an effective method of treatment, while no cases of re-development of cysts were observed during the long postoperative follow-up. The obtained results make it possible to expand knowledge on the clinical manifestation, diagnosis and treatment of non-neoplastic skin diseases in domestic animals

Immunoreactivity of p21, MMP-1 and CB2 receptor proteins in cutaneous canine mast cell tumours: an association with the three-tier grading system.

Mast cell tumours (MCTs) arise in the dermis and subcutaneous tissues in animals and humans and are one of the most common neoplasms of the skin in dogs. Cannabinoid type 2 receptor (CB2R), cyclin-dependent kinase inhibitor (p21) and matrix metalloproteinase 1 (MMP-1) are potential targets for novel anti-tumour therapeutic strategies. This study evaluated by immunohistochemical means the reactivity of p21, MMP-1 and CB2R proteins in association with a three-tier grading system in cutaneous canine MCTs. Formalin-fixed, paraffin-embedded canine MCTs were processed for histochemical analysis and immunohistochemical staining using antibodies against p21, MMP-1 and CB2R. The results were analysed statistically. The strongest p21 immunolabelling was detected in grade 3 MCTs, while grade 1 tumours showed mild or no detectable p21 immunoreactivity (P-value < 0.001). Strong immunolabelling of MMP-1 was the most common in grade 1 tumours (P-value < 0.001) and CB2R was significantly less frequent in grade 3 tumours than in grade 1 (P-value < 0.001) and grade 2 (P-value < 0.001). High immunoreactivity of MMP-1 can be a marker of grade 1 MCTs in dogs, whereas p21 protein overexpression can be a marker of grade 3 canine MCTs. Strong CB2R immunoreactivity with simultaneous underexpression of p21 and high immunoreactivity of MMP-1 proteins may indicate that the use of cannabinoids in grade 1 MCTs in dogs is practicable.

PSIX-6 The Effects of Hydrolyzed Protein on Macronutrient Digestibility, Fecal Metabolites, Oxidative Stress and Inflammatory Biomarkers, and Skin and Coat Quality in Adult Dogs

Abstract Research on protein hydrolysates has observed various properties and functionalities of these ingredients depending on the type of hydrolysate. The objective of this study was to evaluate the effects of hydrolyzed chicken protein that was incorporated into diets on digestibility, gut health, skin and coat health, oxidative stress, and inflammation in healthy adult dogs. Five complete and balanced treatment diets were manufactured: 1) CONd: chicken meal diet; 2) 5% CLHd: 5% substitution of chicken liver hydrolysate of chicken meal diet; 3) CLHd: chicken liver hydrolysate diet; 4) 5% CHd: 5% substitution of chicken hydrolysate of chicken meal diet; and 5) CHd: chicken hydrolysate diet. A 5×5 Latin square design was used which included 10 neutered adult beagles. Each of the 5 periods consisted of a 7-d washout time and a 28-d treatment period. All diets were well accepted by the dogs. There was greater (P &amp;lt; 0.05) fecal butyrate (226.8 μmol/g DMB) concentration as well as decreasedr isovalerate (6.8 μmol/g DMB), 4-ethylphenol (1.4 μmol/g DMB), and indole (0.7 μmol/g DMB) in dogs fed CLHd than CONd (149.3, 10.8, 2.5, and 1.5 μmol/g DMB, respectively). Doges fed CHd had greater (P &amp;lt; 0.05) fecal immunoglobulin A concentration (2.86 mg/g) when compared with CLHd (0.91 mg/g); however, both groups were comparable to the control. There was no difference among groups in serum cytokine concentrations, serum oxidative stress biomarkers, or skin and coat health analyses (P &amp;gt; 0.05). In conclusion, chicken protein hydrolysate could be incorporated into canine extruded diets as a comparable source of protein to traditional chicken meal. The test chicken protein hydrolysates may have potential to support gut health by modulating immune response and fermentative activity; however, more research is needed to confirm the effect.