Identification of feline erythrocyte antigen 6 and lack of alloimmunization to feline erythrocyte antigen 4 in cats.

BACKGROUND: New feline erythrocyte antigens (FEAs) have been described based on the presence of naturally occurring alloantibodies (NOAb), but their immunogenicity and clinical relevance are poorly understood. HYPOTHESIS/OBJECTIVES: Describe the immunogenicity of FEA 4 after sensitizing FEA 4-negative cats lacking NOAb and characterize anti-FEA 4 alloantibodies produced, including their rate of appearance, agglutination titer, and immunoglobulin class. ANIMALS: Nineteen healthy type A cats were blood typed for FEAs 1 to 5 to identify suitable donor-recipient pairs for FEA 4 sensitization. METHODS: Four FEA 4-negative cats were transfused with FEA 4-positive red blood cells. Using a gel column technique, posttransfusion samples were screened daily for a week, weekly for a month, and monthly thereafter for anti-FEA 4 alloantibodies. RESULTS: Alloantibodies were not detected in the first 3 recipients despite repeated transfusions (1 and 3 additional transfusions for 2 and 1 recipients, respectively). In the 4th recipient, alloantibodies against its donor red blood cells were detected 21 days postsensitization. However, they were not directed against FEA 4, but rather against a novel FEA not yet described. The alloantibodies, named anti-FEA 6, remained detectable for >4 months after sensitization and were determined to be mostly immunoglobulin M based on sulfhydryl treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Feline erythrocyte antigen 4 does not appear to be immunogenic because repeated sensitization of 4 cats failed to produce detectable anti-FEA 4 alloantibodies. A new immunogenic antigen, named FEA 6, has been discovered, but additional studies are needed to document its clinical importance.

Dynamics of Feline Sporotrichosis in Espírito Santo, Brazil: Impact of Urbanisation.

INTRODUCTION: Sporotrichosis is a chronic infectious mycosis caused by traumatic implantation of Sporothrix spp., which poses a significant challenge to public health because of its zoonotic nature. It affects humans and other animals, particularly cats. This study investigated epidemiological trends and spatial distribution of feline sporotrichosis in Espírito Santo between 2017 and 2022. METHODS: This study collected diagnostic data on sporotrichosis from the Veterinary Pathology Laboratory and Center for Infectious Diseases in Espírito Santo from 2017 to 2022. Statistical analyses were performed using STATA and spatial analyses were performed using ArcGIS software to create maps and identify hotspots. Kernel density estimation and directional mean statistics were applied to visualise the disease concentration and transmission trends. RESULTS: The results showed a significant increase in feline sporotrichosis cases in Espírito Santo from 2017 to 2022, with hotspots identified in urban and densely populated areas. Anchieta, Aracruz and Vila Velha reported the highest numbers of cases. Spatial analysis indicated a spread towards the central and northern coastal regions. CONCLUSION: This study highlights the growing threat of feline sporotrichosis in Espírito Santo, Brazil, particularly in densely populated urban areas. This underscores the urgent need for comprehensive public health strategies that address urbanisation, human-animal interactions and managing stray cat populations. Effective control measures and enhanced surveillance are crucial to mitigate the spread of this zoonotic disease. Importantly, this study provides valuable insights into the epidemiology of sporotrichosis in Brazil and offers a framework for other regions identified as emerging hotspots that face similar challenges.

The influence and mechanism of fish collagen peptide and egg yolk lecithin on proliferation and lipid composition in feline adipocytes.

The influences of fish collagen peptide (FCP) and egg yolk lecithin (EYL) on the proliferation, fat accumulation and triglyceride content in feline adipocytes were investigated in this work, aiming at unveiling the mechanism of fat accumulation for cheek of feline animals. The lipogenic changes of adipocytes in the presence of FCP and EYL were determined by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The results demonstrated that FCP of 10 mg/mL had the strongest cell activity, with a relative increment rate of 156 ± 0.23%, and the triglyceride content reached 215.9 ± 3.86 mmol/L. By comparison, it was observed that an EYL concentration of 5 mg/mL elicited the highest cell activity, exhibiting a relative increment rate of 152 ± 0.60%, and the level of triglyceride content was noted to reached 256.56 ± 25.68 mmol/L. After the feline adipocytes were treated with different concentrations of two active substances, fat formation and lipid droplets were found by oil red O staining. Liposome analyses confirmed that the formation of lipid compounds was regulated by FCP and EYL through pathways involved in lipid metabolism, notably including inositol phosphate insulin resistance, and phosphatidylinositol signaling pathways. This regulation was found to enhance cell vitality and facilitate fat accumulation. These findings provide a new strategy for the development of nutritional and healthy products or foods that promote feline cheek.

Case report: Diffuse large B-cell lymphoma presenting as congestive heart failure in a cat.

Cardiac lymphoma is uncommon in cats and is rarely considered as a differential diagnosis for congestive heart failure. A 10-year-old neutered male domestic short-haired cat with clinical histories of feline immunodeficiency virus, diabetes mellitus, and congestive heart failure was humanely euthanized. Post-mortem evaluation demonstrated a massively infiltrative round cell neoplasm of the heart, resulting in CHF. Immunohistochemistry of neoplastic tissue was consistent with diffuse large B-cell lymphoma. This case demonstrates a peculiar presentation of cardiac diffuse large B-cell lymphoma, with chronic feline lentiviral infection possibly contributing to disease initiation and progression.

Short QT intervals in African lions.

The cardiac conduction system in large carnivores, such as the African lion (Panthera leo), represents a significant knowledge gap in both veterinary science and in cardiac electrophysiology. Short QT intervals have been reported from zoo-kept, anaesthetized lions, and our goal was to record the first ECGs from wild, conscious lions roaming freely, and compare them to zoo-kept lions under the hypothesis that short QT is unique to zoo-kept lions. Macroscopic and histological examinations were performed on heart tissue removed from nine healthy zoo lions. ECGs were recorded from the nine anaesthetized zoo-kept lions, and from 15 anaesthetized and conscious wild lions in Africa. Our histological and topographical description of the lion's heart matched what has previously been published. In conscious lions, the ECG recordings revealed a mean heart rate of 70 ± 4 beats/min, with faster heart rates during the night. PQ and QT intervals were heart rate dependent in the conscious lions. Interestingly, QT intervals recorded in wild lions were markedly longer than QT intervals from zoo lions (398 ± 40 vs. 297 ± 9 ms, respectively; P < 0.0001). Anaesthesia or heart rate did not account for this difference. We provide a comprehensive description of the cardiac anatomy and electrophysiology of wild and zoo-kept lions. QT intervals were significantly shorter in zoo lions, suggesting functional disparities in cardiac electrophysiology between wild and zoo-kept lions, potentially related to physical fitness. These findings underscore the plasticity of cardiac electrophysiology and may be of value when reintroducing endangered species into the wild and when managing lions in human care.

Retrospective analysis of dual-energy x-ray absorptiometry data demonstrates body composition changes with age in dogs and cats.

OBJECTIVE: Use 18 years of dual-energy x-ray absorptiometry (DEXA) scan data to characterize how body composition changes with age in dogs and cats. METHODS: This was a retrospective observational study using data obtained from DEXA scans performed between 2006 and 2023. A total of 6,973 observations from 1,273 colony-housed dogs ≤ 1 to 16.1 years old and 6,593 observations from 1,096 colony-housed cats ≤ 1 to 16.9 years old were obtained. Animal ages were rounded to the nearest 1/10-year intervals. Means for each interval were calculated and quadratic, cubic, and quartic polynomial models were fit to assess trends over age. RESULTS: Age had an effect on all DEXA measurements. In dogs, lean mass increased early in life before slowing to a peak at age 6.3 and then declined gradually. Fat mass also increased until slowing to a peak at age 9.3 and then decreased. In cats, lean mass increased before slowing to a peak at age 4.5, decreased gradually until age 12.5, and then sharply declined. Fat mass increased until slowing to a peak at age 7.5 and then decreased gradually. CONCLUSIONS: This retrospective study provides a baseline for how body composition changes with age. Results suggest that lean mass loss may begin earlier than previously reported in dogs and cats. CLINICAL RELEVANCE: Sarcopenia and obesity are common conditions in aging pets. Results can be used to improve body composition assessment of patients and investigate the efficacy of nutritional interventions.

Case report: Intracranial epidermoid cyst in a cat.

A 9-year-old American Shorthair, castrated male, weighing 4.3 kg was presented to our hospital because of intermittent ataxia and tetraparesis for 6 weeks. On presentation, the cat was in a stupor and on recumbency, and had vertical nystagmus in both eyes. These clinical signs suggested a brainstem disorder. MRI showed a mass lesion in the caudal aspect of the fourth ventricle with hyperintensity on T2-weighted and FLAIR imaging, low-intensity on T1-weighted imaging, and enhanced margins on post-contrast T1-weighted imaging. The mass compressed the fourth ventricle, causing obstructive hydrocephalus. A second cystic lesion was found rostral to the cerebellum. After MRI, the cat experienced respiratory difficulties and the mass was removed by emergency craniectomy. Although the mass including the cyst wall was successfully removed, the cat was euthanized because spontaneous breathing did not return. The mass was histopathologically diagnosed as epidermoid cyst. A biopsy to the rostral cystic lesion had not been performed and therefore the etiology of this lesion remained unclear. This is the first case of feline intracranial epidermoid cyst in which MRI and surgical excision were performed. MRI findings were similar to those in humans and dogs, suggesting that imaging studies are useful in cats for the diagnosis of intercranial epidermoid cyst.

Ultraviolet (UV-C) Light Systems for the Inactivation of Feline Calicivirus and Tulane Virus in Model Fluid Foods.

Conventional UV-C (254 nm) inactivation technologies have limitations and potential operator-safety risk. To overcome these disadvantages, novel UV-C light-emitting diodes (LED) are developed and investigated for their performance. This study aimed to determine the inactivation of human norovirus (HuNoV) surrogates, Tulane virus (TV), and feline calicivirus (FCV-F9), by UV-C (254 nm) in comparison to UV-C LED (279 nm) in phosphate-buffered saline (PBS) and coconut water (CW). Five-hundred microliters of FCV-F9 (~ 5 log plaque forming units (PFU)/mL) or TV (~ 6 log PFU/mL) were added to 4.5 mL PBS or CW in continuously stirred glass beakers and exposed to 254 nm UV-C for 0 up to 15 min (maximum dosage of 33.89 mJ/cm2) or 279 nm UV-C LED for 0 up to 2.5 min (maximum dosage of 7.03 mJ/cm2). Recovered viruses were assayed in duplicate from each treatment replicated thrice. Mixed model analysis of variance was used for data analysis. Significantly lower D10 values were obtained in PBS and CW (p ≤ 0.05) for both tested viruses using UV-C LED (279 nm) where FCV-F9 showed D10 values of 7.08 ± 1.75 mJ/cm2 and 3.75 ± 0.11 mJ/cm2, while using UV-C (254 nm) showed D10 values of 13.81 ± 0.40 mJ/cm2 and 6.43 ± 0.44 mJ/cm2 in PBS and CW, respectively. Similarly, lower D10 values were obtained for TV of 3.91 ± 1.03 mJ/cm2 and 4.26 ± 1.02 mJ/cm2 with 279 nm UV-C LED and were 18.76 ± 3.16 mJ/cm2 and 10.21 ± 1.48 mJ/cm2 with 254 nm UV-C in PBS and CW, respectively. Viral resistance to these treatments was fluid-matrix dependent. These findings indicate that use of 279 nm UV-C LED is more effective in inactivating HuNoV surrogates than conventional 254 nm UV-C in the tested fluids.

Clinical Utility of Circulating Cell-Free DNA as a Liquid Biopsy in Cats With Various Tumours.

Only a limited number of tumour biomarkers are currently available in veterinary medicine, particularly in cats. Cell-free DNA (cfDNA) is an extracellular DNA fragment released upon cell death and is considered a minimally invasive biomarker for the diagnosis and monitoring of various human malignancies. This study aimed to clarify the utility of circulating cfDNA as a liquid biopsy for various feline tumours. Plasma samples were collected from 44 cats with various tumours, 24 cats with other diseases and 10 healthy controls. A follow-up study was conducted in three tumour-bearing patients. All cfDNA concentrations were quantified via real-time polymerase chain reaction (PCR), which provided short and long fragments of a newly identified feline LINE-1 gene. We found that cfDNA levels were significantly higher in cats with various tumours than in those with other diseases or healthy controls. The cfDNA concentration was not correlated with serum amyloid A (SAA) levels. Cats with tumours exhibited elevated cfDNA levels that predicted tumour-bearing with a sensitivity and specificity of 50.5% and 91.2%, respectively (AUC 0.736; p < 0.001). In lymphoma cases, cats with high cfDNA levels had significantly shorter survival times than those with low cfDNA levels (median: 33 days vs. 178 days; p = 0.003). In addition, the cfDNA levels of the three patients correlated with clinical status during follow-up. Collectively, these findings indicate the potential of cfDNA as a useful biomarker for the diagnosis, therapeutic monitoring and prognostic assessment of tumours in cats.

Artificial intelligence-based quantification of lymphocytes in feline small intestinal biopsies.

Feline chronic enteropathy is a poorly defined condition of older cats that encompasses chronic enteritis to low-grade intestinal lymphoma. The histological evaluation of lymphocyte numbers and distribution in small intestinal biopsies is crucial for classification and grading. However, conventional histological methods for lymphocyte quantification have low interobserver agreement, resulting in low diagnostic reliability. This study aimed to develop and validate an artificial intelligence (AI) model to detect intraepithelial and lamina propria lymphocytes in hematoxylin and eosin-stained small intestinal biopsies from cats. The median sensitivity, positive predictive value, and F1 score of the AI model compared with the majority opinion of 11 veterinary anatomic pathologists, were 100% (interquartile range [IQR] 67%-100%), 57% (IQR 38%-83%), and 67% (IQR 43%-80%) for intraepithelial lymphocytes, and 89% (IQR 71%-100%), 67% (IQR 50%-82%), and 70% (IQR 43%-80%) for lamina propria lymphocytes, respectively. Errors included false negatives in whole-slide images with faded stain and false positives in misidentifying enterocyte nuclei. Semiquantitative grading at the whole-slide level showed low interobserver agreement among pathologists, underscoring the need for a reproducible quantitative approach. While semiquantitative grade and AI-derived lymphocyte counts correlated positively, the AI-derived lymphocyte counts overlapped between different grades. Our AI model, when supervised by a pathologist, offers a reproducible, objective, and quantitative assessment of feline intestinal lymphocytes at the whole-slide level, and has the potential to enhance diagnostic accuracy and consistency for feline chronic enteropathy.

Evaluation of gabapentin administration on neurologic examination in 2 different age groups of healthy cats.

BACKGROUND: Gabapentin is often administered PO for preappointment or in-hospital anxiolysis in cats. A previous study reported mild changes on the neurologic examination after administration. OBJECTIVES: Investigate the effects of gabapentin on anxiety, sedation, compliance, and neurologic examination in 2 age groups of cats. ANIMALS: Thirty-one young cats and 12 geriatric cats perceived by their owners to be healthy and neurologically normal. METHODS: Prospective double-blinded clinical crossover study. Assessment of baseline sedation and anxiety was performed before initial neurologic examinations and after gabapentin administration (100 mg/cat). Assessments were repeated 90 to 120 minutes after administration. Ease of handling pregabapentin and postgabapentin was assessed in the younger cats. All examinations were performed by a board-certified veterinary neurologist and scoring of examinations was performed by a different, masked board-certified neurologist. RESULTS: Sixteen cats (50%) in the younger cohort and 6 cats (50%) in the geriatric cohort exhibited an increase in their overall neurologic examination score postgabapentin administration, mainly through new or progressive postural reaction deficits and gait changes. Anxiety and sedation scores were significantly changed in the geriatric population (P < .01, P = .004, respectively); however, only sedation scores were significantly increased in the younger cats after gabapentin administration (P = .004). CONCLUSIONS AND CLINICAL IMPORTANCE: All study participants showed mild neurologic changes after gabapentin administration, most markedly noted in the geriatric population. Dose reduction of gabapentin for preappointment anxiolysis and neurologic examination in geriatric patients should be considered.

Retroperitoneal granuloma in a cat caused by Nocardia brasiliensis resulting in bilateral ureteral entrapment and unilateral hydronephrosis.

Nocardia infections in cats most commonly present as subcutaneous wounds, or less commonly, as pneumonia, purulent pleurisy and disseminated disease. Abdominal involvement is rarely reported, and to date, localised retroperitoneal infection has only been reported in people. This report describes a five-year-old domestic shorthair cat living in Canberra, Australia, that presented with a two-month history of pyrexia and inappetence progressing to anorexia. Ultrasonography showed a large retroperitoneal mass incorporating both ureters. Euthanasia was elected because of the guarded prognosis. Necropsy examination revealed the mass to be comprised of extensive pyogranulomatous inflammation with fibrosis, Splendore-Hoeppli phenomenon and filamentous Gram-positive bacteria. Culture and MALDI-TOF mass spectrometry identified the causative agent as Nocardia brasiliensis. N. brasiliensis is commonly diagnosed as a cause of cutaneous nocardiosis in Australian human patients, but to date has only been reported in one cat from the United States and one dog from Australia. A treatment approach that might have been used in such a case is provided even though the cat's owners elected not to proceed with surgical intervention.

Evaluation of potential novel biomarkers for feline hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common cardiomyopathy in cats. The diagnosis can be difficult, requiring advanced echocardiographic skills. Additionally, circulating biomarkers (N-terminal pro-B type natriuretic peptide and cardiac troponin I) have several limitations when used for HCM screening. In previous work, we identified interleukin 18 (IL-18), insulin-like growth factor binding protein 2 (IGFBP-2), brain-type glycogen phosphorylase B (PYGB), and WNT Family Member 5 A (WNT5A) as myocardial genes that show significant differential expression between cats with HCM and healthy cats. The products of these genes are released into the circulation, and we hypothesized that IL-18, IGFBP-2, PYGB, and WNT5A serum RNA and protein concentrations differ between healthy cats, cats with subclinical HCM, and those with HCM and congestive heart failure (HCM + CHF). Reverse transcriptase quantitative polymerase chain reaction (RTqPCR) and enzyme-linked immunosorbent assay (ELISA) were applied to evaluate gene and protein expression, respectively, in the serum of eight healthy controls, eight cats with subclinical HCM, and six cats with HCM + CHF. Serum IGFBP-2 RNA concentrations were significantly different among groups and were highest in cats with subclinical HCM. Compared to healthy controls, serum IL-18 and WNT5A gene expression were significantly higher in cats with HCM + CHF, and WNT5A was higher in cats with subclinical HCM. No differences were observed for PYGB. These results indicate that further investigation via large scale clinical studies for IGFBP-2, WNT5A, and IL-18 may be valuable in diagnosing and staging feline HCM.

Domestic cat hepadnavirus genotype B is present in Southern Brazil.

Domestic cat hepadnavirus (DCH) (Orthohepadnavirus felisdomestici) is an emerging virus related to the hepatitis B virus (HBV) already reported in many countries. The molecular prevalence of DCH varies widely in the regions investigated so far. In the present work, we reported the presence of DCH in Brazil. Sixty cat serum samples tested by DCH presence using PCR and 1.67% (1/60) were positive, similar to the low positive molecular rates reported in United States and Japan. The DCH full-length genome was classified in genotype B, which is uncommon since this genotype was only reported once in Japan. The DCH-positive sample was obtained in a stray cat female apparently healthy, presenting ALT, AST, and ALKP normal values, and negative for FIV and FeLV. Due the low positivity rate detected, some factors as alteration in hepatic enzymes and FIV/FeLV infection could not be evaluated. Other works are necessary to statistically validate these observations in Brazil.

Replication kinetics and cytopathic effect of feline calicivirus in feline corneal epithelial cells.

OBJECTIVE: To determine the replication kinetics and cytopathic effect (CPE) of feline calicivirus (FCV) in feline corneal epithelial cells (FCEC). ANIMALS STUDIED: Seven archived FCV isolates and one archived feline herpesvirus type 1 (FHV-1) isolate, previously obtained from eight domestic short hair cats. PROCEDURES: FCV RNA was extracted for sequencing using Illumina MiSeq, to identify three genomically diverse isolates for further testing. Following reference-based assembly, viral genomes were annotated and assessed. Superficial keratectomies were performed to isolate the corneal epithelium of cats and the cells were cultured in vitro. FCEC were infected with the three chosen FCV isolates and one FHV-1 isolate at two different multiplicity of infection ratios (MOIs, 0.1 and 0.01 PFU/cell) and virus titration was assessed at 0, 2, 6, 12, 24, and 48 h post-infection (hpi). Viral identity was confirmed by RT-qPCR. RESULTS: Three genomically diverse FCV isolates were chosen for further assessment in the FCEC model. All infections of FCEC with FCV led to visible CPE, characterized by epithelial cell rounding and detachment from the plate by 24 hpi, while FHV-1 led to visible CPE within 48 hpi. All three of the FCV isolates replicated effectively in FCEC at both 0.1 and 0.01 MOI, with a peak increase in titer approximately 12-24 hpi. CONCLUSIONS: The results support the possible role of FCV as a primary pathogen of the feline ocular surface. FCV replicates in FCEC in vitro, leading to profound CPE.

Enhancing felid conservation: Exploring the impact of in vitro culture media on domestic cat blastocyst production.

This study investigated the optimization of assisted reproductive techniques for wild felid conservation, focusing on in vitro procedures using the domestic cat as a model species. The research evaluated the impact of three different in vitro culture media on blastocyst formation. Oocytes and spermatozoa were collected and processed, followed by in vitro fertilization and culture. Results returned a similar blastocyst rate (ANOVA, p > .05), over 16% across all groups. While demonstrating the potential of these techniques, further investigations are warranted to evaluate embryo quality to refine optimal protocols and their applicability in felid conservation efforts.

Comparison between a Flash Glucose Monitoring System and a Portable Blood Glucose Meter for Monitoring of Cats with Diabetic Ketosis or Ketoacidosis.

Cats with diabetic ketosis or ketoacidosis DK(A) require intensive glucose monitoring. The aim of this study was to assess the agreement between a portable blood glucose meter (PBGM) and a flash glucose monitoring system (FGMS; FreeStyle Libre 2.0 Abbott®) measuring interstitial glucose in cats with DK(A). Ten client-owned cats with naturally occurring DK(A) were prospectively enrolled. Glucose concentrations were assessed with both methods every 1-3 h until resolution of DK(A), and every 4-8 h thereafter. While the median FGMS measured glucose concentration (14.3 mmol/L) was significantly lower than the median PBGM measured glucose concentration (19 mmol/L) (p < 0.001), the overall correlation between the FGMS and PBGM was high (r = 0.88; p < 0.001). In the Parkes error grid analysis, 98.3% of measurements fell in zones A and B. Bland-Altman plot analysis demonstrated that in the low glycaemic range (BG < 5.5 mmol/L), 50% of FGMS measurements deviated more than ±0.83 mmol/L, and in the high glycaemic range (BG > 5.5 mmol/L), 81% of results deviated >15% from the PBGM measurements. There was significant inter-individual variation in the difference between glucose concentrations measured by the FGMS and PBGM (p < 0.001). In spite of being more easily tolerated and easier to use, currently this method cannot be recommended for routine monitoring of cats with DK(A).

Situational Analysis of Cat Ownership and Cat Caring Behaviors in a Community with High Shelter Admissions of Cats.

Managing stray cats in urban areas is an ongoing challenge, and in Australia, many are euthanized. Most stray cats are from disadvantaged areas and are under 1 year of age. The Australian Pet Welfare Foundation intended to assess the impact of a free cat sterilization program in an area with high shelter intake of cats in the city of Ipswich, Queensland. The aims of this pre-intervention study were to undertake a situational analysis of cat ownership, semi-ownership and cat caring behaviours, and compare those in the same demographic with dog ownership and caring behaviours relating to sterilization rates, to provide a basis against which to assess the program's effectiveness. In a sample of 343 participants from that area, 35% owned cats and 3% fed stray cats. Cats were predominantly obtained from family or friends (31%) and shelters (20%). More respondents owned dogs (53%), which were most often sourced from breeders (36%) and family acquaintances (24%). More owned cats than owned dogs were sterilized (91% versus 78%). However, only 74% of cats aged 4 to <12 months were sterilized. Cat containment practices varied, with 51% of owners containing their cat(s) at all times, and a further 18% doing so at night. These results suggest the need for community-based programs that focus on sterilizing owned and semi-owned cats, and assisting semi-owners in becoming full owners to reduce stray cat populations and associated negative impacts. This includes assistance with cat containment where vulnerable native species are present. Public understanding of the causes and effective solutions for free-roaming cats, alongside legislative changes, are required to facilitate these efforts. Assistive programs aligned with One Welfare principles are expected to benefit the wellbeing of animals, humans and their environments.

Ultrasound-guided trigeminal nerve approach at the level of the pterygopalatine fossa in cat cadavers.

OBJECTIVE: To describe an ultrasound-guided suprazygomatic approach to the trigeminal nerve block in cat cadavers. STUDY DESIGN: Prospective descriptive study. ANIMALS: Ten feline cadaver heads. METHODS: A 25:75 methylene blue-iopamidol mixture (0.1 mL cm-1 cranium length) was injected into 10 cadaver heads using an ultrasound-guided suprazygomatic approach. A computed tomography (CT) scan was performed to identify contrast presence at the orbital fissure, foramen rotundum and ovale, followed by anatomical dissection to identify staining of the pterygopalatine fossa (PPF), extraconal retrobulbar area, mandibular and maxillary nerves. Descriptive statistics were used to summarize results. RESULTS: A total of 20 injections were performed. Of these, 1/20 misinjection occurred and excluded from further reporting. The volume of injectate was 0.9 (0.9-1.1) mL [median (range)]. Staining of the PPF, extraconal space, maxillary and mandibular nerves over more than 6 mm was achieved in 19/19 (100%), 18/19 (95%), 17/19 (89%) and 19/19 (100%) of injections, respectively. CT showed presence of contrast within 5 mm of the orbital fissure, foramen rotundum and ovale in 18/19 (95%), 19/19 (100%) and 19/19 (100%) of the injections, respectively. No intracranial migration was observed. CONCLUSIONS AND CLINICAL RELEVANCE: This cadaver study illustrates that the suprazygomatic ultrasound-guided trigeminal nerve injection technique can successfully stain the PPF, retrobulbar cone extraconally, mandibular and maxillary nerves. Consequently, this technique has the potential to be used in vivo in cats to desensitize areas innervated by the trigeminal nerve.

The Feline calicivirus capsid protein VP1 is a client of the molecular chaperone Hsp90.

Feline calicivirus (FCV) icosahedral viral capsids are composed of dozens of structural subunits that rely on cellular chaperones to self-assemble in an orderly fashion. Here, we report that the heat shock protein 90 (Hsp90) inhibition significantly reduced FCV particle production, suggesting a role in the replicative cycle. We found that Hsp90 inhibition was not related to the synthesis or stability of the early proteins that translate from the gRNA nor to the minor capsid protein VP2 but with a reduction in the major capsid protein VP1 levels, both translated late in infection from the subgenomic RNAs. Reduction in VP1 levels was observed despite an augment of the leader of the capsid (LC)-VP1 precursor levels, from which the LC and VP1 proteins are produced after proteolytic processing by NS6/7. The direct interaction of VP1 with Hsp90 was observed in infected cells. These results suggest that upon release from the polyprotein precursor, VP1 becomes a client of Hsp90 and that this interaction is required for an efficient FCV replicative cycle.