Blood Neutrophil-to-Lymphocyte Ratio as a Potential Prognostic Marker in Dogs ≤10 kg With Multicentric Lymphoma.

Canine lymphoma, the most prevalent haematopoietic tumour in dogs, presents significant challenges in veterinary oncology. This study investigates the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in small-sized dogs (≤10 kg) with multicentric lymphoma. In this retrospective study, we examined medical records and haematological data from 35 dogs to assess the association between NLR and two key outcomes: time-to-progression (TTP) and lymphoma-specific survival (LSS) using Cox proportional hazards models. Our findings revealed a significant correlation between elevated NLR and a worse prognosis, as evidenced by TTP (p = 0.005) and LSS (p = 0.001). NLR is linked to increased hazard ratios (HRs) for the time-to-progression rate (TTPR) at 180, 360 and 540 days (p = 0.001, p = 0.003 and p = 0.005, respectively) and the lymphoma-specific survival rate (LSSR) at the same intervals (p = 0.016, p = 0.001 and p = 0.001, respectively). Cutoff value of 3.764 for NLR was established, above which there is a significantly increased risk of early disease progression and decreased survival. Additionally, our analysis indicates that dogs with substage b exhibited earlier progression than those with substage a, evident in overall (p = 0.026) and TTPR at 180 days (p = 0.004), 360 days (p = 0.018), 540 days (p = 0.026) and LSSR at 180 days (p = 0.033). The results underscore the potential of NLR as a prognostic marker in cases of dogs ≤10 kg with multicentric lymphoma, suggesting that higher NLR is associated with a poorer prognosis.

Successful use of ultrasound guided pecto-intercostal fascial plane block to provide intraoperative analgesia in four dogs undergoing median sternotomy.

OBJECTIVE: To evaluate the impact of pecto-intercostal fascial plane block on providing intraoperative analgesia in dogs undergoing median sternotomy. ANIMALS: 4 dogs. CLINICAL PRESENTATION: The dogs were presented with a history of inappetence, lethargy and respiratory distress. Thoracic radiographs, point of care ultrasound, thoracocentesis, bronchoscopy and computed tomography was performed to characterize the disease. RESULTS: 4 male castrated, 5.3 ± 3 years old dogs weighing 19.7 ± 13.5 kg and belonging to Dalmatian, Beagle, Siberian Husky and Rottweiler breeds were included. Three dogs were diagnosed with suppurative pleural effusions because of pulmonary abscesses and one dog with spontaneous pneumothorax due to the presence of pulmonary bullae. All dogs underwent median sternotomy under general anesthesia to explore the thorax. A pecto-intercostal fascial plane block was performed by injecting local anesthetic bupivacaine in the parasternal fascial plane between the deep pectoral and external intercostal muscles to provide antinociception by anesthetizing ventral cutaneous branches of intercostal nerves second through sixth. Analgesia from the block resulted in reduced requirement of inhalant anesthesia and minimal requirement for opioid to augment analgesia intraoperatively. CLINICAL RELEVANCE: Median sternotomy is required to perform thoracic surgery in dogs with various thoracic pathologies. Pecto-intercostal fascial plane block is a locoregional technique that can blunt nociception arising from the ventral thorax and can significantly improve perioperative patient care in dogs undergoing median sternotomy by providing effective intraoperative and potentially postoperative analgesia.

Exploring Montelukast in Dogs: A Preliminary Pharmacokinetic Study Following Oral Administration under Fasted and Fed Conditions.

This study investigates the pharmacokinetics (PK) of montelukast (MTK), a cysteinyl leukotriene receptor antagonist increasingly being considered in veterinary medicine. In dogs, MTK has found indications mainly for treating atopic dermatitis as an off-label use. Six male Labrador dogs underwent a single oral administration of MTK (40mg/dog) in both fasted and fed conditions according to an open, single-dose, two-treatment, two-phase, cross-over design, with a washout period of one week. Blood was withdrawn to heparinized tubes at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, and 24hr. MTK plasma concentrations were quantified using a validated HPLC method, and the data were analysed using PKanalixTM software with a non-compartmental approach. Concentrations remained quantifiable at 24hr after administration, under both conditions. No significant differences were observed in the PK parameters between the fasted and fed states. MTK was relatively eliminated slowly, with t1/2 values of 8.10 and 7.68hr after fasted and fed states, respectively. The attainment of maximum concentration (Cmax) occurred at a Tmax of 4hr, with mean values of 1.98µg/mL and 2.80µg/mL under fasted and fed conditions, respectively. Given the unknown therapeutic range of MTK in dogs and the absence of controlled studies proving its efficacy in this species, further dosing adjustments and refinements should be considered based on both the current PK data and the need to establish an effective therapeutic range, if present. Future research should focus on efficacy studies, multiple-dose investigations, and pharmacodynamic assessments to evaluate the suitability of MTK use in dogs.

Brain and heart activity during interactions with pet dogs: A portable electroencephalogram and heart rate variability study.

Dog ownership has been linked to numerous benefits to human health and wellbeing. However, due to the lack of previous research on changes to brain activity during interactions with pet dogs, the underlying psychophysiological mechanisms are still unclear. The aim of the present study was to examine changes in heart rate (HR), heart rate variability (HRV), and electroencephalogram (EEG) power during interactions between dog owners and their pet dog. Fifty healthy adult dog owners completed baseline psychological measures and pet attachment scales. Subjective units of relaxation (SUR) as well as continuous EEG, HR, and HRV via portable devices were measured during five experimental conditions (baseline resting, relaxation-induction exercise, patting a toy dog, real dog present, and patting a real dog) in participants' homes. SUR was higher in all experimental conditions than at baseline. SUR was also higher during dog interaction than when the dog was present with no interaction. However, SUR during dog interaction was not significantly different from the toy dog and relaxation induction condition. Higher delta, theta, alpha, beta power and HR were found during dog interaction than all other conditions. Higher HRV was found during dog interaction compared to baseline, patting a toy dog, and relaxation-induction exercise, but not significantly different from the real dog present only condition. Lastly, overall HR correlated with psychological measures. Overall, the results show that there are significant changes in brain and heart activity when humans interact with pet dogs, consistent with increases in relaxation and focussed attention. These findings are relevant to understanding the potential mechanisms for health benefits associated with pets.

A pilot study to detect the effects of a green-lipped mussel (Perna canaliculus) nutraceutical on working farm dogs with musculoskeletal abnormalities using accelerometry.

AIMS: To obtain preliminary data on changes in gait from the use of a green-lipped mussel (Perna canaliculus) extract product in working farm dogs with musculoskeletal abnormalities using accelerometry. METHODS: New Zealand working farm dogs (n = 32) with signs of musculoskeletal abnormalities were enrolled in a double-blinded, placebo-controlled cross-over study. Each dog was allocated to one of six groups to receive three trial substances (180 mg full fat green-lipped mussel extract (GLME180); 220 mg full fat green-lipped mussel extract (GLME220); placebo) in one of the six possible different orders. Each trial substance was administered orally once a day for an 8-week period, with a 4-week washout in between each. Dogs wore a collar-mounted triaxial accelerometer for the study duration. Diet and activity were not controlled. Accelerations were recorded continuously and analysed (n = 27) in 10-second activity epochs partitioned into daytime and night-time periods. Analysis of activity during the daytime period was limited to epochs when dogs were gaiting faster than a walk. The median and IQR of activity were determined for the daytime and night-time. Additionally, the 75th and 90th percentiles of daytime activity for each 24-hour period were determined. Mixed effects linear regression models were constructed to determine if each trial substance altered the response variables. RESULTS: During the daytime, the 90th percentile was higher when dogs were given GLME220 compared with the placebo (ß coefficient 2.6; 95% CI = 0.25-4.94; p = 0.03). Dogs that started the trial with the GLME products had a higher 90th percentile activity compared with dogs that began with the placebo (ß coefficient 26.26; 95% CI = 0.45-52.06; p = 0.046). The 75th percentile for activity was not affected by the GLME product. The daytime IQR was larger when dogs were given the GLME180 product compared with the placebo (ß coefficient 1.25; 95% CI = 0.12-2.37; p = 0.03). Night-time median activity and the IQR was greater in dogs that started the trial with the GLME products than in dogs that began with the placebo. The night-time IQR for activity was greater for GLME180 than for the placebo. CONCLUSIONS: Administration of a low dose of the GLME-containing product increased peak activity in working farm dogs with signs of musculoskeletal abnormalities and may improve their performance. CLINICAL RELEVANCE: Even mildly affected working farm dogs might benefit from support of their musculoskeletal abnormalities, and this particular GLME-based product shows promise as an adjunct to other management strategies.

Analysis of VEGFR-2 and PDGFR-ß expression in canine splenic hemangiosarcoma to identify drug repositioning candidates.

Splenic tumors are very common in dogs, and canine hemangiosarcoma (HSA) is one of the most important malignant splenic tumors. Surgery followed by chemotherapy (anthracycline-based protocols) is recommended for treating canine HSA; however, patients still do not achieve long-term survival. Therefore, this research aimed to assess vascular endothelial growth factor receptor-2 (VEGFR-2) and platelet-derived growth factor receptor-ß (PDGFR-ß) gene expression in formalin-fixed tissues, evaluate the quality of mRNA for quantitative polymerase chain reaction (qPCR) analysis and identify drug repositioning candidates based on VEGFR-2 and PDGFR-ß. qPCR analysis identified the relative expression of heterogeneous VEGFR-2 and PDGFR-ß, with samples showing no transcripts or very low expression and those with higher relative quantification for both genes. We then used immunohistochemistry to correlate the relative quantification of VEGFR-2 and PDGFR-ß transcripts with respective higher protein expression to validate our results. In the next step, we evaluated drug repositioning candidates and identified small molecule inhibitors (i.e. sorafenib) and natural compounds (curcumin and resveratrol) with the ability to block VEGFR-2 and PDGFR-ß genes. Overall, our results indicated that VEGFR-2 and PDGFR-ß expression is highly variable among canine HSA samples and different drugs can block the expression of both genes. Therefore, a personalized approach could be useful for selecting anti-VEGFR-2 and PDGFR-ß therapies and both genes are potential candidates for future oncological panels.

Os tumores esplênicos são muito comuns em cães, e o hemangiosarcoma (HSA) é um dos tumores esplênicos malignos mais importantes em cães. A cirurgia seguida de quimioterapia (protocolos baseados em antraciclinas) é a abordagem terapêutica mais recomendada para o tratamento da HSA canino; no entanto, os pacientes ainda não alcançam longa sobrevida após tratamento. Portanto, esta pesquisa teve como objetivo avaliar a expressão do receptor do fator de crescimento endotelial vascular-2 (VEGFR-2) e do receptor do fator de crescimento derivado de plaquetas-ß (PDGFR-ß) em tecidos fixados em formalina e identificar candidatos ao reposicionamento de medicamentos baseado na expressão desses genes. A análise qPCR identificou a expressão relativa heterogênea de VEGFR-2 e PDGFR-ß, com amostras sem transcritos ou com expressão muito baixa ou amostras com alta quantificação relativa para ambos os genes. Em seguida, foi realizada o exame imuno-histoquímico para correlacionar a quantificação relativa dos transcritos de VEGFR-2 e PDGFR-ß com a respectiva maior expressão proteica para validar nossos resultados. Na próxima etapa, avaliamos candidatos ao reposicionamento de medicamentos e identificamos inibidores de moléculas pequenas (ou seja, sorafenibe) e compostos naturais (curcumina e resveratrol) com capacidade de bloquear os genes VEGFR-2 e PDGFR-ß. No geral, nossos resultados indicaram que a expressão de VEGFR-2 e PDGFR-ß é altamente variável entre amostras caninas de HSA e diferentes drogas podem bloquear a expressão de ambos os genes. Portanto, uma abordagem personalizada poderia ser útil para selecionar terapias anti-VEGFR-2 e PDGFR-ß e ambos os genes são potenciais candidatos para futuros painéis oncológicos.

First detection of Leishmania major in dogs living in an endemic area of zoonotic cutaneous leishmaniasis in Tunisia.

BACKGROUND: Dogs are considered the main domestic animals that may be a reservoir for Leishmania infantum, the agent of zoonotic visceral leishmaniasis (ZVL) in several countries of the world. The dog may host other Leishmania species, but its epidemiological role in the maintenance and spreading of these parasites is not completely elucidated. Zoonotic cutaneous leishmaniasis (ZCL), caused by Leishmania major, affects thousands of people every year and is particularly diffused in many countries of North Africa and Middle East Asia. In ZCL endemic countries, few reports of L. major-positive dogs have been reported, probably because most human cases occur in poor rural areas where the social role of the dog and its medical management is not well considered. The aim of the present study is to better understand the possible involvement of domestic dogs in the epidemiology of ZCL. METHODS: Our research focused on a well-established endemic focus of ZCL, in the area of Echrarda, Kairouan Governorate, central Tunisia. A total of 51 dogs with no or mild clinical signs of vector borne diseases were selected in small villages where human cases of ZCL are yearly present. All dogs were sampled for the Leishmania spp. diagnosis, by using the following procedures: blood sample for serology and buffy coat quantitative polymerase chain reaction (qPCR), popliteal fine needle aspiration, and cutaneous biopsy punch for lymph node and skin qPCR. RESULTS: The results demonstrated a high percentage (21.6%) of dogs positive at least at one or more test; the most sensitive technique was the lymph node qPCR that detected 8/11 positive dogs. Nine, out of the eleven positive dogs, resulted as infected by Leishmania infantum; ITS1-PCR-sequencing allowed Leishmania major identification in the remaining two cases, both from the popliteal lymph node samples, which can suggest a possible visceral spread of a cutaneous Leishmania species in the dog. Interestingly, one of the two L. major-positive dogs was living in the same house where 6-year-old children showed cutaneous lesions referred to as ZCL. CONCLUSIONS: To our knowledge, this is the first report of L. major-positive dogs in Tunisia, the  epidemiological role of which remains under investigation.

Investigating the Life Expectancy at Birth of Companion Dogs in Portugal Using Official National Registry Data.

This study aimed to provide a comprehensive picture of the life expectancy of dogs in Portugal, focusing on the impact of diverse factors including breed, sex, size, and skull shape. The final dataset, gathering data from the national registry database, consisted of 278,116 dogs with confirmed deaths. The mean lifespan at birth for all the dogs was around 8.91 years, with the female dogs tended to have a similar lifespan to male dogs. The analysis of life expectancy at birth for the 20 most common non-Portuguese breeds and 10 Portuguese breeds revealed that Yorkshire Terriers had the highest life expectancy (10.89 years) and French Bulldogs the lowest (6.27 years). Size and cephalic index were found to be influential factors, with large brachycephalic breeds exhibiting shorter life expectancies and smaller, mesocephalic breeds experiencing longer lifespans. Additionally, the cephalic index had a more substantial impact on life expectancy compared to body size. These findings enhance the understanding of the factors influencing canine longevity and aid in developing strategies to improve the health and lifespan of companion dogs.

Effects of a Nutraceutical Treatment on the Intestinal Microbiota of Sled Dogs.

Dog sledding is the main discipline of working dogs on snow, consisting of a team of dogs pulling a sled under the guidance of the owner. To carry out this sport, dogs must have adequate nutrition and vitamin and antioxidant supplementation to ensure that the physical effort is optimal. The present study evaluated the effect that sporting activity and stress have on the canine intestinal microbiota by dividing the dogs into two groups: a control group that did not take any nutraceutical products and the treated group to which a nutraceutical product was administered. The nutraceutical administered in this study is used in all cases of canine intestinal dysbiosis in which it is essential to quickly restore a balanced intestinal microbiota. The results obtained show that in dogs not taking the nutraceutical, there is an increase in bacteria, such as Streptococcus spp. and E. coli, considered enteropathogenic to the detriment of beneficial bacterial species such as Faecalibacterium spp., Turicibacter spp., Blautia spp., Fusobacterium spp., and Clostridium hiranonis. Instead, the group of dogs treated with nutraceutical displays a lower amount of enteropathogenic bacteria and a great increase in the other bacterial species considered beneficial for the animal's health. The results obtained in the present study show that Microbiotal cane® can be used in dogs subject to intense sporting activity by preventing severe alterations at intestinal ecosystem levels by maintaining intestinal bacterial composition as balanced as possible.

The association between taurine concentrations and dog characteristics, clinical variables, and diet in English cocker spaniels: The Canine taURinE (CURE) project.

BACKGROUND: Occurrence of low blood taurine concentrations (B-TauC) and predisposing factors to taurine deficiency in English Cocker Spaniels (ECS) are incompletely understood. OBJECTIVES: Investigate the occurrence of low B-TauC in a Swedish population of ECS and evaluate the association between B-TauC and dog characteristics, clinical variables, and diet composition. ANIMALS: One-hundred eighty privately owned ECS. METHODS: Dogs were prospectively recruited and underwent physical examination, blood analyses, and echocardiographic and ophthalmic examinations. Dogs with clinical signs of congestive heart failure (CHF) also underwent thoracic radiography. Taurine concentrations were analyzed in plasma (EDTA and heparin) and whole blood. Diets consumed by the dogs at the time of the examination were analyzed for dietary taurine- (D-TauC), cysteine- (D-CysC), and methionine concentrations (D-MetC). RESULTS: Fifty-three of 180 dogs (29%) had low B-TauC, of which 13 (25%) dogs had clinical and radiographic signs of CHF, increased echocardiographic left ventricular (LV) dimensions and volumes, and impaired LV systolic function. Five (9%) dogs with low B-TauC had retinal abnormalities. Dietary MetC, dietary animal protein source (red/white meat), and age were associated with B-TauC in the final multivariable regression model (P < .001, R2 adj = .39). CONCLUSIONS AND CLINICAL IMPORTANCE: Low B-TauC suggests that taurine deficiency may play a role in the development of myocardial failure and CHF in ECS. Low D-MetC and diets with red meat as the animal protein source were associated with low B-TauC. Dogs with B-TauC below the normal reference range were older than dogs with normal concentrations.

Significance of scattered small echogenic foci floating in urinary bladder as ultrasonography finding in dogs.

BACKGROUND: Despite the prevalence of echogenic foci floating in the urinary bladder seen in ultrasonography in dogs, surprisingly little has been written on its significance, including its potential association with urinalysis. The objective of the study was to determine the diagnostic value of the echogenic foci floating in urinary bladders in dogs. RESULTS: - Cystosonography was performed on 45 dogs. Bladder contents were examined and divided into positive (containing echogenic particles) and negative (absent echogenic particles) groups according to the presence and absence of floating echogenic particles. Five mL of urine was collected via cystocentesis. Urine analysis and culture were done and the relationship between ultrasound evaluation and urinalysis results was investigated. In dogs with bladder echogenic particles in ultrasonography, the prevalence of hematuria, pyuria, bacteriuria, and lipiduria were 88.9%, 92.6%, 29.6%, and 70.3%, respectively. However, in dogs in which echogenic particles were not observed in their bladders, the prevalence of hematuria, pyuria, bacteriuria, and lipiduria was 77%, 50%, 5.5%, and 77%, respectively. There was a significant association between bladder debris and positive urine culture, with an odds ratio of 7.15 (95% confidence interval: 0.81-63.28) compared with matched controls. Furthermore, there was a significant relationship between the presence of floating echogenic particles with pyuria, and urine color ( p ≤ 0.05). CONCLUSION: In conclusion, the present results showed the detection of bladder debris on ultrasound can be a predictor for pyuria and positive urine culture in dogs.

Immunohistochemistry Screening of Different Tyrosine Kinase Receptors in Canine Solid Tumors-Part I: Proposal of a Receptor Panel to Predict Therapies.

The use of tyrosine kinase inhibitors (TKI) has been growing in veterinary oncology and in the past few years several TKI have been tested in dogs. However, different from human medicine, we lack strategies to select patients to be treated with each TKI. Therefore, this study aimed to screen different tumor subtypes regarding TKI target immunoexpression as a predictor strategy to personalize the canine cancer treatment. It included 18 prostatic carcinomas, 36 soft tissue sarcomas, 20 mammary gland tumors, 6 urothelial bladder carcinomas, and 7 tumors from the endocrine system. A total of 87 patients with paraffin blocks were used to perform immunohistochemistry (IHC) of human epidermal growth factor receptor 2 (HER-2), epidermal growth factor receptors 1 (EGFR1), vascular endothelial growth factor receptor 2 (VEGFR-2), platelet derived growth factor receptor beta (PDGFR-ß), c-KIT, and extracellular signal-regulated kinase 1/2 (ERK1/ERK2). The immunohistochemical screening revealed a heterogeneous protein expression among histological types with mesenchymal tumors showing the lowest expression level and carcinomas the highest expression. We have demonstrated by IHC screening that HER2, EGFR1, VEGFR-2, PDGFR-ß and ERK1/ERK2 are commonly overexpressed in dogs with different carcinomas, and KIT expression is considered relatively low in the analyzed samples.

Neurological manifestations in dogs with acute leukemia.

Canine acute leukemia is a rare hematopoietic neoplasm. Neurological abnormalities have been frequently reported in dogs with acute leukemia (AL). However, the description of the presentation and findings are limited. This study aimed to describe the clinical findings in dogs with acute leukemia presenting with neurological signs as their primary complaint. The database of a private referral hospital was searched for cases that presented to the neurological department with neurological deficits and were subsequently diagnosed with acute leukemia. Six cases were included; all had neurological clinical signs and an abnormal neurological examination. All cases had a focal neuroanatomical localisation on neurological examination (brain n = 4; spinal = 2). Out of the four dogs with a complete magnetic resonance imaging (MRI) study, there was an ill-defined infiltrative pattern with abnormal signal intensity in the central nervous system (CNS) in three dogs and the loss of grey and white matter differentiation in the brain (n = 2) and/or spinal cord (n = 2). Other MRI findings included abnormal meningeal enhancement (n = 3), changes affecting spinal nerves and epaxial muscles (n = 2), and lymphadenopathy in the field of view (n = 2). The bone marrow assessment on MRI showed evidence of signal change (n = 3), characterized by a loss of normal fat opacity and an abnormal degree of contrast enhancement. The cerebrospinal fluid (CSF) analysis of the four dogs showed an increased protein level with non-specific pleocytosis and without evidence of malignant cells. Treatment with cytotoxic medication was implemented in two dogs. The dogs diagnosed with acute leukemia had focal neuroanatomical localisation, an infiltrative CNS pattern, and bone marrow remodulation on MRI with an increase in CSF protein and negative cytology analysis.

Predicting dog tracheal diameter and length: A tool for improved intubation.

Objective: This study aims to develop formulas for estimating tracheal diameter and length in dogs using easily measurable anatomical parameters. Materials and Methods: The samples consisted of 20 dogs of various breeds, comprising 10 males and 10 females, sourced from cadavers. The measured parameters included occipital tuberosity to tail base (OT), eye angle to ear tragus, nose to ear tragus, inner vertical diameters (IVD), and tracheal length (TL). The study conducted correlation and linear regression analyses, and subsequently, the formulated models underwent validation using 16 live dogs. The results were compared to radiographic measurements. Results: Linear regression recommended formulas based on OT, resulting in IVD (mm) = 0.203 × OT - 3.724 (r2 = 0.608, p < 0.001) and TL (cm) = 0.346 × OT-3.773 (r2 = 0.837, p < 0.001). The predicted tracheal diameter and length from formulas were slightly smaller than radiographic measurements (IVD = 2.76 ± 1.85 mm, p < 0.0001 and TL = 2.07 ± 1.81 cm, p < 0.0001). Conclusion: These formulas offer a practical way to estimate tracheal dimensions in live dogs, facilitating the selection of suitable endotracheal tube sizes and insertion depth. Further studies with larger sample sizes and consistent measurement methods can enhance the accuracy of these findings.

The use of fully threaded headless cannulated screws for femoral neck fracture fixation in small-breed dogs show promise in cadaveric study.

OBJECTIVE: To biomechanically evaluate the stability of internal fixation methods for femoral neck fractures in small-breed dogs. Furthermore, the possibility of replacing the headed screw with fully threaded headless cannulated screws in the fixation method was assessed. METHODS: The study was conducted from December 12, 2023, to February 7, 2024. A total of 18 femurs from 9 canine cadavers were used in this study. After a simple neck fracture was created, in group A (n = 6), the fracture was stabilized with three 1.1-mm parallel Kirschner wires (K-wires). In group B (n = 6), a 3.0-mm partially threaded cannulated screw and an antirotation pin were used. In group C (n = 6), a 2.5-mm fully threaded headless cannulated screw and an antirotation pin were used. A mechanical test was conducted to apply a single axial compressive load to the femoral head. RESULTS: 9 adult small-breed dogs weighing 3.6 to 8.3 kg (mean ± SD; 5.9 ± 1.6). The mean maximum failure load was highest in group C (495 ± 81 N), followed by group B (454 ± 50.4 N), and then group A (222 ± 21.6 N). Significant differences in maximum failure load were observed between groups A and B as well as groups A and C but not between groups B and C. CONCLUSION: The use of fully threaded headless cannulated screws presents a promising method for internal fixation of canine femoral neck fractures. CLINICAL RELEVANCE: To demonstrate the potential stability and reliability of fully threaded headless cannulated screws.

Incorporation of Biologic Variables Into the Staging for Canine Cutaneous and Subcutaneous Mast Cell Tumours: Proposal of the UBo pTNM System.

Canine cutaneous mast cell tumours (MCTs) are currently staged based on the World Health Organization (WHO) classification, which has remained unchanged since its initial formulation. Our study aimed to assess the reliability of a novel pTNM staging system, which incorporates tumour extent (T), lymph node involvement (N), presence of distant metastases (M) and the two-tier histologic grade. We analysed medical records of dogs with one or more cutaneous/subcutaneous completely staged MCT, undergoing tumour excision with lymphadenectomy, unless distant metastases were present, in which cases, medical therapy was administered. Dogs were categorized into three stages: I (T1-2N0M0), II (T1-2N1M0) and III (distant metastases). Stages I and II were further divided based on histologic grade into 'low' and 'high'. Substage b was defined as the presence of tumour diameter of ≥3 cm and/or ulceration. Of 226 dogs, 87 (38.5%) were in Stage I (I-low, n = 75; I-high, n = 12), 107 (47.3%) in Stage II (II-low, n = 59; II-high, n = 48), and 32 (14.2%) in Stage III. The newly proposed staging system was able to significantly stratify the population for both time to progression and tumour-specific survival. Compared to Stage I-low, the risk of progression increased significantly for Stage I-high (18.3 times), Stage II-low (8.5 times), Stage II-high (41.5 times) and Stage III (110.3 times). The staging system was highly prognostic for both cutaneous and subcutaneous MCTs. Prospective validation studies are essential to compare this new system with the current WHO staging and further validate its accuracy and clinical utility.

Imaging of experimental venous thrombus by means of Doppler and CEUS techniques in dogs.

Venous thrombosis has been widely studied in humans, but not in dogs. This study was designed to evaluate a venous thrombus in dogs, from creation to solution, by means of various ultrasonographic techniques. Nine healthy Beagle dogs were included in the study. The venous thrombus was formatted by puncturing the lumen of the external jugular veins and then, the veins were examined with B-mode, color Doppler, pulsed-wave Doppler, and contrast-enhanced ultrasound (CEUS) techniques, at regular intervals, within 210-270 min after venipuncture. Haemodynamic parameters were calculated at two different locations, before and after the site of the thrombus formation. The existence of a thrombus was confirmed by CEUS technique. Thrombus volume and echogenicity were evaluated. The results showed that the visualization of the venous thrombus by color Doppler modality was not feasible in some veins. The blood volume was the parameter that could more precisely indicate the presence or absence of a thrombus. In cases where thrombus volume was less than 0.001 cm3, it was impossible to detect its presence using haemodynamic parameters. The CEUS imaging depicted accurately the size and shape of an anechoic venous thrombus, even when its volume was 0.001cm3.

Characterizing dog cognitive aging using spontaneous problem-solving measures: development of a battery of tests from the Dog Aging Project.

Companion dogs are a valuable model for aging research, including studies of cognitive decline and dementia. With advanced age, some dogs spontaneously develop cognitive impairments and neuropathology resembling features of Alzheimer's disease. These processes have been studied extensively in laboratory beagles, but the cognitive assays used in that context-which rely on time-consuming operant procedures-are not easily scalable to large samples of community-dwelling companion dogs. We developed a battery of five short-form tasks targeting three aspects of cognition that are impaired in Alzheimer's disease: spatial memory, executive functions, and social cognition. In Experiment 1, we tested a cross-sectional sample of dogs (N = 123) and estimated associations between age and task performance. Older dogs scored lower on measures of spatial learning, memory, and response flexibility, and spent less time near, but more time gazing at, the experimenter. We found no differences in associations between age and performance across dogs of different body masses, a proxy for expected lifespan. In Experiment 2, we demonstrated the feasibility of these measures in clinical settings (N = 35). Dogs meeting clinical criteria for moderate or severe cognitive impairment scored lower, on average, than dogs characterized as mildly impaired and healthy agers, although these distributions overlapped. However, few dogs in our study cohort met the criteria for moderate or severe impairment. The measures presented here show promise for deployment in large-scale longitudinal studies of companion dogs, such as the Dog Aging Project.

The reduction in relative brain size in the domesticated dog is not an evolutionary singularity among the canids.

Domestication has long been considered the most powerful evolutionary engine behind dramatic reductions in brain size in several taxa, and the dog (Canis familiaris) is considered as a typical example that shows a substantial decrease in brain size relative to its ancestor, the grey wolf (Canis lupus). However, to make the case for exceptional evolution of reduced brain size under domestication requires an interspecific approach in a phylogenetic context that can quantify the extent by which domestication reduces brain size in comparison to closely related non-domesticated species responding to different selection factors in the wild. Here, we used a phylogenetic method to identify evolutionary singularities to test if the domesticated dog stands out in terms of relative brain size from other species of canids. We found that the dog does not present unambiguous signature of evolutionary singularity with regard to its small brain size, as the results were sensitive to the considerations about the ancestral trait values upon domestication. However, we obtained strong evidence for the hibernating common raccoon dog (Nyctereutes procyonoides) being an evolutionary outlier for its brain size. Therefore, domestication is not necessarily an exceptional case concerning evolutionary reductions in brain size in an interspecific perspective.

One Health Investigation into Mpox and Pets, United States.

Monkeypox virus (MPXV) is zoonotic and capable of infecting many mammal species. However, whether common companion animals are susceptible to MPXV infection is unclear. During July 2022-March 2023, we collected animal and environmental swab samples within homes of confirmed human mpox case-patients and tested for MPXV and human DNA by PCR. We also used ELISA for orthopoxvirus antibody detection. Overall, 12% (22/191) of animal and 25% (14/56) of environmental swab samples from 4 households, including samples from 4 dogs and 1 cat, were positive for MPXV DNA, but we did not detect viable MPXV or orthopoxvirus antibodies. Among MPXV PCR-positive swab samples, 82% from animals and 93% the environment amplified human DNA with a statistically significant correlation in observed cycle threshold values. Our findings demonstrate likely DNA contamination from the human mpox cases. Despite the high likelihood for exposure, however, we found no indications that companion animals were infected with MPXV.