Scoping review of the use of mesenchymal stem and stromal cell products in cats, Part 1: current logistics and safety.

Despite a pressing need for new therapies to address unmet veterinary medical need, no approved stem cell products are available for use in cats in the US. To evaluate the current state of mesenchymal stem or stromal cell (MSC) research in cats, a scoping review of published literature was performed, which identified 108 publications related to feline MSCs. Twenty-six of the articles described administration of MSC products to a total of 215 cats. Twelve of the studies included a control group. These experimental and clinical trials used 7 cell sources, 9 administration routes, 12 delivery vehicles, and a 300-fold range in dosages for initial studies in healthy cats and cats with 12 naturally occurring and induced diseases. The majority of studies administered 2 doses of allogeneic, adipose-derived MSC IV and monitored a median of 6.5 treated cats for a median of 90 days. The majority (150/215 [69.8%]) of cats had no reported adverse events associated with treatment. Although an increase in feline MSC publications in the past 10 years indicates progress, the wide variety and small number of studies using MSCs and MSC products in cats demonstrates that current evaluations are mostly still in the discovery phase, and several issues remain related to larger scale trials using MSC products in cats. The current available publications provide information to direct further clinical study development and informed owner consent for study enrollment.

Scoping review of the use of mesenchymal stem and stromal cell products in cats, Part 2: current scope and efficacy.

A scoping review of published literature found 108 articles related to mesenchymal stem or stromal cell (MSC) use in cats. Twenty-four of the publications summarized the treatment of 192 cats with MSC products for 12 naturally occurring and induced diseases. These trials used a variety of cell sources, administration routes, delivery vehicles, and dosages. The majority of studies did not have a control group. The disease with the largest number of cats administered MSCs thus far is chronic kidney disease (n = 59 cats). The majority of cats had no adverse events associated with treatment, which supports continued interest in the potential use of MSC products to address unmet medical needs. Treatment outcomes of the 192 cats have ranged from no response to long-term cure, depending on the disease being treated and the particular study. Some of these early studies show promise and provide significant information to direct both the design and focus of larger clinical trials investigating the safety and efficacy of MSC treatment for veterinary and human applications.

Anatomical classification of feline congenital extrahepatic portosystemic shunts based on CT angiography: A SVSTS and VIRIES multi-institutional study in 231 cats.

The prevalence of anatomical-based subtypes of feline congenital extrahepatic portosystemic shunts (EHPSS) has not been completely elucidated. The goal of this study was to use CT angiography to create an anatomical-based nomenclature system for feline congenital EHPSS. Additionally, subjective portal perfusion scores were generated to determine if intrinsic portal vein development was associated with different shunt conformations or patient age at the time of CT. The SVSTS and VIRIES list services were used to recruit cases. Data collected included patient DOB, gender, breed, weight, CT date, and reported diagnosis. Shunts were classified based upon (1) the shunt portal vessel(s) of origin, (2) the shunt systemic vessel(s) of insertion, and (3) any substantial portal vessels contributing to the shunt. Additionally, hepatic portal perfusion was subjectively scored between 1 (poor/none) and 5 (good/normal) based on the caliber of the intrahepatic PVs. A total of 264 CT scans were submitted from 29 institutions. Due to exclusion criteria, 33 (13%) were removed, leaving 231 CT scans to be included. Twenty-five different EHPSS anatomies were identified with five classifications accounting for 78% of all shunts (LGP [53%], LGC-post [11%], LCG [7%], LGC-pre [4%], and PC [4%]). Shunt origin involved the left gastric vein in 75% of the described classifications. Significant differences were identified among the five most common shunt types with respect to age at the time of CT scan (P = .002), breed (P < .001), and subjective portal perfusion score (P < .001). This refined anatomical classification system for feline EHPSS may enable improved understanding, treatment comparisons, and outcome prediction for cats with these anomalies.

Pharmacokinetic of two oral doses of a 1:20 THC:CBD cannabis herbal extract in cats.

Objective: To determine the pharmacokinetics (PK) of two oral doses of a Cannabis herbal extract (CHE) containing 1:20 THC:CBD in 12 healthy Domestic Shorthair cats. Methods: Single-dose PK were assessed after oral administration of CHE at low or high dose (2 mg CBD + 0.1 mg THC, or 5 mg CBD + 0.25 mg THC per kg bw, respectively; n = 6 per group) in fasting cats. Blood samples were drawn up to 48 h following CHE administration. Plasma samples were analyzed for CBD, THC, and metabolites 6-OH-CBD, 7-OH-CBD, 11-OH-THC, and THC-COOH using a previously validated LC-MS/MS method. Results: CBD and THC were quickly absorbed (mean Tmax of 2.4-2.9 h). Maximum plasma concentrations (Cmax) ranged from 36-511 ng/mL and 6.8-61 ng/mL for CBD and THC, respectively. Elimination was initially rapid for both CBD and THC, though a prolonged elimination phase was noted for CBD in some cats (T1/2 λ up to 26 h). Dose-adjusted Cmax and AUC0-last values were not statistically significantly different (p > 0.05) between dose groups indicating CBD and THC concentrations increased in a manner proportional (linear) to the dose. Dose-adjusted THC Cmax and AUC0-last were significantly higher than the corresponding dose-adjusted CBD parameters (p < 0.01). Low concentrations of the metabolite 6-OH-CBD were quantified but metabolites 7-OH-CBD, 11-OH-THC, and THC-COOH were not detected in any plasma samples. Inter-individual variance was notable. Salivation shortly after dosing was observed in two cats in the high dose group; these animals had substantially lower cannabinoid concentrations than other cats in this group. No adverse clinical signs (including vomiting, change in mentation or other neurological signs) were noted. Clinical significance: Although cats did not display adverse effects after administration of a single oral dose of 1:20 THC:CBD CHE formulation at 2 or 5 mg CBD/kg bw, observed plasma concentrations were highly variable but generally lower than in dogs receiving the same dose and formulation. Administration of CHE in the fasting state may not optimize CBD absorption, and oral dosing may be challenging when administering an oil-based CHE in some cats.

Identification and genomic characterization of feline calicivirus from a leopard cat (Prionailurus bengalensis) in Taiwan.

The leopard cat (Prionailurus bengalensis) is an endangered wildlife that is protected under Taiwan's regulations. The body of a road-killed leopard cat was found to contain sequences of feline calicivirus (FCV), designated W109-1443. Analysis of the complete genomic sequence revealed that it shared approximately 81% similarity with a Chinese strain of FCV found in a domestic cat. Phylogenetic analysis of the VP1 gene indicated that the W109-1443 isolate belonged to genogroup II. Recombination analysis revealed that the W109-1443 isolate may have resulted from recombination between two FCV strains. Given the potential impact of FCV on the health and survival of wild felids, further investigation is necessary to assess its pathogenicity in the leopard cat population.

A PAX3 insertion in the Celestial breed and certain feline breeding lines with dominant blue eyes.

During the last 60 years many inherited traits in domestic outbred cats were selected and retained giving birth to new breeds characterised by singular coat or morphological phenotypes. Among them, minimal white spotting associated with blue eyes was selected by feline breeders to create the Altai, Topaz, and Celestial breeds. Various established breeds also introduced this trait in their lineages. The trait, that was confirmed as autosomal dominant by breeding data, was first described in domestic cats from Kazakhstan and Russia, in British shorthair and British longhair from Russia, and in Maine Coon cats from the Netherlands, suggesting different founding effects. Using a genome-wide association study we identified a single region on chromosome C1 that was associated with the minimal white spotting and blue eyes phenotype (also called DBE by breeders for dominant blue eyes) in the French Celestial breed. Within that region we identified Paired Box 3 (PAX3) as the strongest candidate gene, since PAX3 is a key regulator of MITF (Melanocyte-Inducing Transcription Factor) and PAX3 variants have been previously identified in various species showing white spotting with or without blue eyes including the mouse and the horse. Whole genome sequencing of a Celestial cat revealed an endogenous retrovirus LTR (long terminal repeat) insertion within PAX3 intron 4 known to contain regulatory sequences (conserved non-coding element [CNE]) involved in PAX3 expression. The insertion is in the vicinity of CNE2 and CNE3. All 52 Celestial and Celestial-mixed cats with a DBE phenotype presented the insertion, that was absent in their 22 non-DBE littermates and in 87 non-DBE cats from various breeds. The outbred Celestial founder was also heterozygous for the insertion. Additionally, the variant was found in nine DBE Maine Coon cats related to the Celestial founder and four DBE Siberian cats with an uncertain origin. Segregation of the variant in the Celestial breed is consistent with dominant inheritance and does not appear to be associated with deafness. We propose that this NC_018730.3:g.206974029_206974030insN[395] variant represents the DBECEL (Celestial Dominant Blue Eyes) allele in the domestic cat.

Isolation and characterization of feline endometrial mesenchymal stem cells.

BACKGROUND: Recently, there has been a growing interest in stem cells for human medicine. Limited feline endometrial mesenchymal stem cell (fEM-MSC) research in veterinary medicine necessitates reporting for future feline disease research and therapy. OBJECTIVES: This study aimed to isolate fEM-MSCs from feline endometrial tissues and evaluate their morphology, proliferative ability, differentiation ability, and immunophenotype. METHODS: Feline endometrial tissues were obtained from the ovariohysterectomies of healthy cats and isolated using an enzymatic method. The morphology and proliferative ability of the isolated cells were assessed using a doubling time (DT) assay from passages 3 to 6 (P3 - P6). We measured pluripotency gene expressions of cells in P2 using quantitative real-time polymerase chain reaction (qRT-PCR). To investigate MSC characteristics, a trilineage differentiation assay was conducted in P4, and cells in P4 were immunophenotyped using flow cytometry. RESULTS: fEM-MSCs showed a typical spindle-shaped morphology under a microscope, and the DT was maintained from P3 to P6. fEM-MSCs could differentiate into adipocytes, osteoblasts, and chondrocytes, and expressed three pluripotency markers (OCT4, SOX2, and NANOG) by qRT-PCR. Immunophenotypic analysis showed that the fEM-MSCs were CD14 -, CD34 -, CD45 -, CD9+, and CD44+. CONCLUSIONS: In this study, the feline endometrium was a novel source of MSCs, and to the best of our knowledge, this is the first report on the isolation method and characteristics of fEM-MSCs.

Oscillometric and Doppler techniques can provide continuous noninvasive blood pressure readings in cats and dogs: an instructional video.

OBJECTIVE: To provide a video tutorial detailing how to perform continuous noninvasive blood pressure monitoring in dogs and cats. ANIMALS: Any size dog or cat. METHODS: To measure blood pressure noninvasively, a blood pressure cuff is selected on the basis of the circumference of the limb and placed at the level of the right atrium. For oscillometric blood pressure measurement, the cuff is connected to an oscillometric unit that will automatically inflate and deflate the cuff in order to measure the patient's blood pressure using an internal algorithm. For Doppler blood pressure measurement, a sphygmomanometer is used to manually inflate the pressure cuff 30 to 40 mm Hg above the point where the audible arterial sounds disappear. Then, the cuff is gradually deflated until the audible arterial sounds return; the pressure at the first sound is recorded as the blood pressure. To generate continuous readings, the oscillometric machine is set to measure blood pressure as often as every minute. Alternatively, the Doppler crystal is taped to the patient's leg to facilitate repeated cuff inflation/deflation and collection of blood pressure values as often as every minute. RESULTS: Continuous blood pressure readings can be obtained by both the oscillometric and Doppler techniques. CLINICAL RELEVANCE: Continuous blood pressure readings identify trends in a patient's cardiovascular status. The most reliable oscillometric blood pressure reading is the mean arterial pressure. Doppler blood pressure values are considered systolic in dogs. Doppler values in cats underestimate systolic and overestimate mean blood pressure.

Exploring the Tumor-Associated Risk of Mesenchymal Stem Cell Therapy in Veterinary Medicine.

Mesenchymal stem cell (MSC) therapy has been actively applied in veterinary regenerative medicine to treat various canine and feline diseases. With increasing emphasis on safe cell-based therapies, evaluations of their tumorigenic potential are in great demand. However, a direct confirmation of whether tumors originate from stem cells or host cells is not easily achievable. Additionally, previous studies evaluating injections of high doses of MSCs into nude mice did not demonstrate tumor formation. Recent research focused on optimizing MSC-based therapies for veterinary patients, such as MSC-derived extracellular vesicles in treating different diseases. This progress also signifies a broader shift towards personalized veterinary medicine, where treatments can be tailored to individual pets based on their unique genetic profiles. These findings related to different treatments using MSCs emphasize their future potential for veterinary clinical applications. In summary, because of lower tumor-associated risk of MSCs as compared to embryonic and induced pluripotent stem cells, MSCs are considered a suitable source for treating various canine and feline diseases.

Feline Facial Spindle Cell Tumors in 29 Cats: Histomorphological and Immunohistochemical Characterization.

Soft tissue tumors/sarcomas (STSs) in felines, encompassing a variety of mesenchymal tumors with similar histomorphological features, present diagnostic challenges due to their diverse cellular origins and the overlap with other tumor types such as feline sarcoid. This study aimed to delineate the clinical, histomorphological, and immunohistochemical characteristics of 34 feline facial spindle cell tumors affecting 29 cats, including testing for bovine papillomavirus type 14 (BPV14), the virus causing feline sarcoids. Only five out of 12 tumors previously diagnosed as feline sarcoids based on histomorphology were confirmed by PCR for BPV14, underscoring the importance of comprehensive diagnostic approaches to accurately distinguish between STSs and feline sarcoids. This study shows that most facial spindle cell tumors were compatible with peripheral nerve sheath tumors (PNSTs) based on positive immunohistochemical staining for Sox10 and other immunohistochemical markers such as GFAP, NSE, and S100. Some of these tumors displayed as multiple independent masses on the face or as erosive and ulcerative lesions without obvious mass formation, an atypical presentation and an important highlight for general practitioners, dermatologists, and oncologists. This study also describes periadnexal whorling of neoplastic cells as a novel histomorphologic finding in feline facial PNSTs and emphasizes Sox10 as a useful complementary immunohistochemical marker for the diagnosis of facial PNST in cats, providing valuable insights for veterinary pathologists.

A case of severe benzalkonium chloride intoxication in a cat.

BACKGROUND: Benzalkonium chloride (BAC) is a quaternary ammonium compound (QAC), that can be found in a wide variety of household products-from disinfectants to medicaments and home fragrances-but also professional products. In pets, cats have long been reported as more sensitive than dogs to QACs; in fact, signs of irritation such as oral ulcerations, stomatitis and pharyngitis can be observed after contact with concentrations of 2% or lower. In a review of 245 cases of BAC exposure in cats, reported by the Veterinary Poisons Information Service (United Kingdom) only 1.2% of the cases died or were euthanized. Nevertheless, BAC toxidromes in cats can result in transitory CNS and respiratory distress, as well as severe mucosal and cutaneous lesions. Currently, only a few reports are available concerning BAC poisoning in this species. CASE PRESENTATION: A 4 month-old kitten presented with severe glossitis, lameness in the hindlimbs and episodes of vomiting and diarrhoea. The cause was unknown until the owners reported use of a BAC-containing mould remover (5%) 4 days later. The patient developed severe oral burns requiring a pharyngeal tube for feeding and severe cutaneous chemical burns. The kitten was managed with supportive therapy and required hospitalization for 10 days. The symptoms disappeared completely 3 weeks after exposure. CONCLUSIONS: BAC is a very common compound contained in several household and professional products but, to the best of our knowledge, no previous case had been reported in Italy. We hope that this report will help raise awareness on the hazards of BAC products for cats in both domestic and work contexts.

Treatment success in cats with chronic enteropathy is associated with a decrease in fecal calprotectin concentrations.

Feline chronic enteropathies (FCE) are challenging to diagnose and monitor for progression and response to treatment. Fecal calprotectin might be a useful non-invasive marker to evaluate clinical endpoints of therapeutic monitoring in FCE. We evaluated fecal calprotectin concentrations in cats with FCE before and after initiation of treatment comprised of immunomodulation and/or dietary intervention. Included were 17 cats with FCE and 18 healthy controls. Clinical investigation of FCE cases included clinical severity grading (feline chronic enteropathy activity index, FCEAI) in all cats, abdominal ultrasonography in 15 cats, and gastrointestinal biopsies in 6 cats. Fecal calprotectin was measured in samples from 12 cats with FCE before treatment, all 17 FCE cats ≥6 weeks after treatment initiation, and all healthy controls. Fecal calprotectin concentrations in FCE cases before treatment (median: 61 µg/g) were significantly higher than after treatment initiation (median: 15 µg/g; p = 0.0098) and compared to controls (median: 6 µg/g; p = 0.0235) and correlated with the FCEAI scores (ρ = 0.54, p = 0.0316). Fecal calprotectin concentrations after treatment initiation were higher with more severe duodenal/proximal jejunal pathology (ρ = 0.83, p = 0.0427) and shorter intervals between sampling time points (ρ = -0.54, p = 0.0250). Relevant decreases in initially increased fecal calprotectin concentrations are seen in cats with FCE on varying treatment strategies that significantly improve or have remission of clinical signs. This supports the utility of fecal calprotectin as a surrogate biomarker to assess disease severity in FCE cases. Further studies need to evaluate fecal calprotectin concentrations longitudinally in relation to mucosal healing vs. clinical response.

Cabot rings in a cat with myeloproliferative disease.

A 6-year-old spayed female Scottish Fold cat presented with lethargy and anorexia. A complete blood cell count indicated severe anemia and mild thrombocytopenia. Examination of peripheral blood smears revealed marked changes in the erythroid lineage, including the presence of basophilic stippling and Howell-Jolly bodies as well as an increase in nucleated erythrocytes, polychromatophils, ovalocytes, and schistocytes. Additionally, some erythrocytes contained a ring or figure-eight shaped structure known as a Cabot ring, which were especially observed in polychromatophilic erythrocytes. Hemolytic diseases (Mycoplasma infection and IMHA) were diagnostically excluded, and the cat was treated through prednisolone administration, whole blood transfusion, and administration of vitamins (K2 and B12); however, the anemia progressively worsened. Cabot rings were observed until Day 22 and subsequently disappeared as the number of nucleated RBCs increased, and the erythrocyte lineage shifted to immature population. On Day 42, peripheral blood examination revealed further left shifting and appearance of many rubriblasts. The patient died at home on Day 43. Necropsy revealed neoplastic cells infiltrating the bone marrow and other organs, which were immunopositive to CD71 which is an erythroid lineage marker. In humans, Cabot rings have been observed in megaloblastic anemia, lead poisoning, myelodysplastic syndrome, and myelofibrosis; further, they are thought to be related to stressed bone marrow and dyserythropoiesis. This is the first case report of a cat with Cabot rings, which are suggestive of defects in erythroid lineage production.

Novel mutation N588 residue in the NS1 protein of feline parvovirus greatly augments viral replication.

Feline parvovirus (FPV) infection is highly fatal in felines. NS1, which is a key nonstructural protein of FPV, can inhibit host innate immunity and promote viral replication, which is the main reason for the severe pathogenicity of FPV. However, the mechanism by which the NS1 protein disrupts host immunity and regulates viral replication is still unclear. Here, we identified an FPV M1 strain that is regulated by the NS1 protein and has more pronounced suppression of innate immunity, resulting in robust replication. We found that the neutralization titer of the FPV M1 strain was significantly lower than that of the other strains. Moreover, FPV M1 had powerful replication ability, and the FPV M1-NS1 protein had heightened efficacy in repressing interferon-stimulated genes (ISGs) expression. Subsequently, we constructed an FPV reverse genetic system, which confirmed that the N588 residue of FPV M1-NS1 protein is a key amino acid that bolsters viral proliferation. Recombinant virus containing N588 also had stronger ability to inhibit ISGs, and lower ISGs levels promoted viral replication and reduced the neutralization titer of the positive control serum. Finally, we confirmed that the difference in viral replication was abolished in type I IFN receptor knockout cell lines. In conclusion, our results demonstrate that the N588 residue of the NS1 protein is a critical amino acid that promotes viral proliferation by increasing the inhibition of ISGs expression. These insights provide a reference for studying the relationship between parvovirus-mediated inhibition of host innate immunity and viral replication while facilitating improved FPV vaccine production.IMPORTANCEFPV infection is a viral infectious disease with the highest mortality rate in felines. A universal feature of parvovirus is its ability to inhibit host innate immunity, and its ability to suppress innate immunity is mainly accomplished by the NS1 protein. In the present study, FPV was used as a viral model to explore the mechanism by which the NS1 protein inhibits innate immunity and regulates viral replication. Studies have shown that the FPV-NS1 protein containing the N588 residue strongly inhibits the expression of host ISGs, thereby increasing the viral proliferation titer. In addition, the presence of the N588 residue can increase the proliferation titer of the strain 5- to 10-fold without affecting its virulence and immunogenicity. In conclusion, our findings provide new insights and guidance for studying the mechanisms by which parvoviruses suppress innate immunity and for developing high-yielding FPV vaccines.

Human transmission and outbreaks of feline-like G6 rotavirus revealed with whole-genome analysis of G6P[9] feline rotavirus.

Group A rotaviruses (RVAs) are generally highly species-specific; however, some strains infect across species. Feline RVAs sporadically infect humans, causing gastroenteritis. In 2012 and 2013, rectal swab samples were collected from 61 asymptomatic shelter cats at a public health center in Mie Prefecture, Japan, to investigate the presence of RVA and any association with human infections. The analysis identified G6P[9] strains in three cats and G3P[9] strains in two cats, although no feline RVA sequence data were available for the former. A whole-genome analysis of these G6P[9] strains identified the genotype constellation G6-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3. The nucleotide identity among these G6P[9] strains exceeded 99.5% across all 11 gene segments, indicating the circulation of this G6P[9] strain among cats. Notably, strain RVA/Human-wt/JPN/KF17/2010/G6P[9], previously detected in a 3-year-old child with gastroenteritis, shares high nucleotide identity (>98%) with Mie20120017f, the representative G6P[9] strain in this study, across all 11 gene segments, confirming feline RVA infection and symptomatic presentation in this child. The VP7 gene of strain Mie20120017f also shares high nucleotide identity with other sporadically reported G6 RVA strains in humans. This suggests that feline-origin G6 strains as the probable source of these sporadic G6 RVA strains causing gastroenteritis in humans globally. Moreover, a feline-like human G6P[8] strain circulating in Brazil in 2022 was identified, emphasizing the importance of ongoing surveillance to monitor potential global human outbreaks of RVA.

Three-dimensional magnetic resonance cholangiography is superior to two-dimensional single-shot magnetic resonance cholangiography for visualization and image quality of the feline and canine biliary tract: A postmortem study.

Magnetic resonance cholangiography (MRC) is an established diagnostic tool for noninvasive assessment of the biliary tract in humans. It has also been found to be feasible in companion animals, but no published studies have compared MRC sequences in veterinary medicine. The present study is part of a prospective, observational, analytical investigation on MR cholangiopancreatography performed on the donated bodies of 12 cats and eight dogs. The main aim of this study was to compare the images of 2D-SSh-TSE-MRC and 3D-TSE-MRC sequences for visualization and image quality of the feline and canine biliary tract. Both sequences are T2-weighted and noncontrast. Three independent readers scored the visibility of four segments of the biliary tract, namely the gallbladder (GB), cystic duct, common bile duct (CBD), and extrahepatic ducts, and the image quality of the two MRC sequences using five-point Likert scales. Wilcoxon signed-rank test was used to compare the scores between the MRC sequences separately for cats and dogs. Inter- and intraobserver agreements were measured using Gwet's AC2 with linear weighting. The 3D-TSE-MRC images were scored significantly higher than the 2D-SSh-TSE-MRC for both visibility and image quality (P < .001-.016 for cats, P = .008-.031 for dogs); the only exception was GB in dogs. In both cats and dogs, interobserver agreement for segment visibility and image quality ranged from slight to substantial in 2D-SSh-TSE-MRC and from poor to almost perfect in 3D-TSE-MRC. Most of the assessments (73% for segment visibility and 66% for image quality) had substantial to almost perfect intraobserver agreement. Findings from the current study support the use of 3D-TSE-MRC over 2D-SSh-TSE-MRC for evaluation of the feline and canine biliary tract, but further studies on live animals are warranted.

SOX-10 and TRP-1 expression in feline ocular and nonocular melanomas.

In felines, ocular and nonocular melanomas are uncommon tumors that represent a diagnostic challenge for pathologists, especially when amelanotic. To date, the immunohistochemical diagnostic panel in cats is based on specific melanocytic markers (Melan-A and PNL2) and a nonspecific but sensitive marker (S100). In human medicine, SOX-10 is reported to be a sensitive antibody for the detection of melanoma micrometastasis in the lymph node. TRP-1, an enzyme involved in melanogenesis, has recently been used in humans and dogs as a specific melanocyte marker. The aim of this study was to evaluate the cross-reactivity and the expression of SOX-10 and TRP-1 antibodies in feline normal tissue and melanocytic tumors. Thirty-one cases of ocular, cutaneous, and oral melanomas were retrospectively evaluated and confirmed by histopathological examination and by immunolabeling with Melan-A and/or PNL2. SOX-10 nuclear expression in normal tissues was localized in epidermal, subepidermal, hair bulb, and iridal stromal melanocytes and dermal nerves. In melanomas, nuclear expression of SOX-10 was detected in ocular (11/12; 92%), oral (6/7; 86%), and cutaneous sites (12/12; 100%). TRP-1 cytoplasmic immunolabeling in normal tissue was observed in epidermal and bulbar melanocytes and in the lining pigmented epithelium of the iris and in its stroma. Its expression was positively correlated to the degree of pigmentation in the tumor and was observed in 75% of ocular (9/12), 43% of oral (3/7), and 33% of cutaneous melanomas (4/12). This study demonstrated the cross-reactivity of SOX-10 and TRP-1 antibodies in feline non-neoplastic melanocytes and their expression in ocular and nonocular melanomas.

Feline leishmaniasis in an animal shelter in northeastern Brazil: Clinical aspects, coinfections, molecular detection, and serological study of a new recombinant protein.

Infection and clinical cases of leishmaniasis caused by Leishmania infantum in cats have been increasingly reported in several countries, including Brazil. In this study, we used an enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic test (ICT) based on a recombinant antigen (rKDDR-plus) to detect anti-Leishmania antibodies in cats from an animal shelter in northeastern Brazil. We compared the results with an ELISA using L. infantum crude antigen (ELISA-CA). We also investigated the presence of Leishmania DNA in blood or ocular conjunctival samples as well as the association between Leishmania PCR positivity and serological positivity to feline immunodeficiency virus (FIV), feline leukemia virus (FeLV) and Toxoplasma gondii. Concerning serological assays, a higher positivity was detected using the ICT-rKDDR-plus (7.5%; 7/93) as compared to ELISA-rKDDR-plus (5.4%; 5/93) and ELISA-CA (4.3%; 4/93). Upon PCR testing, 52.7% (49/93) of the ocular conjunctival swabs and 48.3% (44/91) of the blood samples were positive. Together, PCR and serological testing revealed overall positivities of 73.1% (68/93) and 12.9% (12/93), respectively. Among PCR-positive samples, 45.5% (31/68) showed co-infection with FIV, 17.6% (12/68) with FeLV, and 82.3% (56/68) with T. gondii. More than half of the PCR-positive cats showed at least one clinical sign suggestive of leishmaniasis (58.8%; 40/68) and dermatological signs were the most frequent ones (45.5%; 31/68). Both tests employing the recombinant antigen rKDDR-plus (i.e., ICT-rKDDR-plus and ELISA-rKDDR-plus) detected more positive cats than the ELISA-CA but presented low overall accuracy. PCR testing using either blood or ocular conjunctival samples detected much more positive cats than serological tests.

Characterization of feline-originated probiotics Lactobacillus rhamnosus CACC612 and Bifidobacterium animalis subsp. lactis CACC789 and and evaluation of their host response.

BACKGROUND: Probiotics are beneficial for animal health and new potential probiotics need to be characterized for their prospective use in improving animal health. In this study, 32 bacterial strains were isolated from a Norwegian forest cat (castrated, 12 years old) and a Persian cat (castrated, 10 years old), which were privately owned and had indoor access. RESULTS: Lactobacillus rhamnosus CACC612 (CACC612) and Bifidobacterium animalis subsp. lactis CACC789 (CACC789) were selected as potential probiotics; characterization of the two strains showed equivalent acid tolerance, similar cell adhesion rates on the HT-29 monolayer cell line, and superior bile tolerance compared to Lactobacillus rhamnosus GG (LGG). Subsequently, they exhibited inhibitory effects against a broad spectrum of pathogenic bacteria, including E. coli (KCTC 2617), Salmonella Derby (NCCP 12,238), Salmonella Enteritidis (NCCP 14,546), Salmonella Typhimurium (NCCP 10,328), Clostridium difficile JCM 1296T. From evaluating host effects, the viability of the feline macrophage cell line (Fcwf-4) increased with the treatment of CACC612 or CACC789 (P < 0.05). The induced expression of immune-related genes such as IFN-γ, IL1ß, IL2, IL4, and TNF-α by immune stimulation was significantly attenuated by the treatment of CACC612 or CACC789 (P < 0.05). When 52 clinical factors of sera from 21 healthy cats were analyzed using partial least squares discriminant analysis (PLS-DA), the animals were obviously clustered before and after feeding with CACC612 or CACC789. In addition, hemoglobin and mean corpuscular hemoglobin concentration (MCHC) significantly increased after CACC612 feeding (P < 0.05). CONCLUSIONS: In this study, feline-originated probiotics were newly characterized and their potentially probiotic effects were evaluated. These results contribute to our understanding of the functional effects of feline-derived probiotics and support their industrial applications.

Efficacy of Bravecto® Plus spot-on solution for cats (280 mg/ml fluralaner and 14 mg/ml moxidectin) in the prevention of feline Aelurostrongylus abstrusus infection evaluated in a multi-diagnostic approach.

BACKGROUND: Aelurostrongylus abstrusus is one of the most important respiratory nematodes of felines. Infections may lead to respiratory clinical signs with varying severity or even death, emphasizing the need for preventive treatment of cats with outdoor access to circumvent patent infections. METHODS: Therefore, the preventive efficacy of a spot-on formulation of 280 mg/ml fluralaner and 14 mg/ml moxidectin (Bravecto® Plus spot-on solution for cats, MSD) against A. abstrusus was evaluated in a negative controlled, randomized and partially blinded efficacy study with 28 purpose-bred cats in a non-terminal design. In three different treatment regimes, the minimum recommended dose of 40 mg fluralaner and 2.0 mg moxidectin/kg bodyweight (BW) was administered once at 12, 8 or 4 weeks (study group G1, G2 and G3, respectively) prior to experimental infection with 300 third-stage A. abstrusus larvae, while G4 served as placebo-treated control. RESULTS: From 30 to 46 days post infection (dpi; SD 114 to 130), faeces were sampled to monitor first-stage larvae (L1) excretion for efficacy determination. Secondary efficacy criteria, including respiratory parameters, serological antibody levels and computed tomography (CT) findings, were assessed once before enrolment (SD -7 to -1) and before infection (SD 75 to 83). After infection, CT evaluation was performed once at 47-50 dpi (SD 131 to 134), and respiratory parameters and antibody levels were regularly assessed twice or once a week, respectively (1 up to 78 dpi, SD 85 up to 162). All animals in the control group excreted L1 by 33-37 dpi and remained positive throughout the study period from 41 to 46 dpi (SD 125 to 130). In the treatment groups, only one animal each of G1 and G2 excreted L1 at two consecutive days, and four cats of G1, two of G2 and three of G3 were positive on single occasions. While the geometric mean (GM) of the maximum number of excreted L1 per 5 g of faeces was 7380.89 in the control group (G4), GMs were significantly lower in the treatment groups with 1.63 in G1, 1.37 in G2 and 0.79 in G3. Thus, based on GMs, the reduction in excreted L1 exceeded 99.9% in all three treatment groups. Based on CT severity scores, all lungs of the animals of the control group showed severe pulmonary changes post infection, whereas lungs of the cats of the treatment groups were either unaltered (4 animals), mildly (11 animals), or moderately altered (5 animals). Moreover, seroconversion was observed in all cats of the control group, but not in those of the treatment groups. CONCLUSIONS: The combination of diagnostic methods used in this non-terminal study yielded coherent and reliable results. A single administration of Bravecto® Plus spot-on solution for cats was well tolerated and effective in the prevention of aelurostrongylosis for at least 12 weeks.