Small Animal Research Articles

Radiographic identification of challenging gastrointestinal tract foreign bodies: a descriptive study of how appearance varies in air versus water to aid interpretation.

To provide veterinarians with updated radiographic descriptions of select radiolucent foreign material in a simulated gastrointestinal environment. 368 veterinarian respondents from the US. An online survey was administered between June 18, 2023, and July 2, 2023, through a private veterinarian-based social media group. Representative commonly ingested foreign bodies were radiographed surrounded by air and water to simulate being within the gastrointestinal tract. Two examiners evaluated and qualified the opacity of the objects for each environment. The private social media group had a total of 3,900 members including veterinarians from all disciplines. A total of 362 small animal veterinarians (9.3% of the group) responded to the study reporting a total of 123 foreign objects that were not causing mechanical obstruction at the time of initial presentation. Sixty-eight foreign bodies were reported greater than or equal to 5 times and grouped as balls (n = 4), food (9), fabric (14), wood (3), soft plastic (14), hard plastic (18), or other (6). Most (98.5% [67/68]) objects were easily identifiable in air. In water, 23.5% (16/68) of the objects were obscured, and 39.7% (27/68) had inversion of the major opacity when compared to the opacity in air. The opacity of some ingested radiolucent material can invert relative to air or fluid, which may reflect substantial differences in detection following repositioning. When known dietary indiscretion occurs, radiographing a sample of the material in air and water will improve the accuracy of assessment.

In vivo engineering and transplantation of axially vascularized and epithelialized flaps in rats.

The arteriovenous loop (AVL) model allows the in vivo engineering of axially vascularized flaps, the so called AVL flaps. Although AVL flaps can be transplanted microsurgically to cover tissue defects, they lack an epithelial layer on the surface. Therefore, the objective of this study was to engineer axially vascularized AVL flaps with an accompanying epithelial layer for local defect reconstruction. In this study AVLs were established in 20 male Lewis rats. Minimally invasive injection of keratinocytes onto the surface of the AVL flaps was performed on postoperative day (POD) 21. AVL flaps were explanted from 12 rats on POD 24 or POD 30, then the epithelium formed by the keratinocytes on the surface of the flaps was evaluated using immunofluorescence staining. In six other rats, the AVL flap was locally transposed to cover a critical defect in the rats' leg on POD 30 and explanted for analysis on POD 40. In two control rats, sodium chloride was applied instead of keratinocytes. These control flaps were also transplanted on POD 30 and explanted on POD 40. Our results revealed that three days after keratinocyte application, a loose single-layered epithelium was observed histologically on the AVL flaps surface, whereas after nine days, a multilayered and structured epithelium had grown. The epithelium on the transplanted AVL flaps showed its physiological differentiation, when being exposed to an air-liquid interface. Histologically a layered epithelium identical to the rats' regular skin was formed. In the sodium chloride control group, no epithelium had been grown. This study clearly demonstrates that axially vascularized AVL flaps can be processed in the subcutaneous chamber by minimally invasive injection of keratinocytes. Thus, AVL flaps with an intact epithelial layer were engineered and could be successfully transplanted for local defect coverage in a small animal model.

Utility of immature platelet fraction in the Sysmex XN-1000V for the differential diagnosis of central and peripheral thrombocytopenia in dogs and cats.

The immature platelet fraction (IPF), a parameter obtained by the Sysmex XN-1000V analyzer, is used in humans to differentiate between central (CEN) and peripheral (PER) thrombocytopenia (TP) but has not been evaluated in small animals. Compare IPF between healthy, clinical non-TP and TP dogs and cats, study IPF in different causes of TP in dogs and cats and, establish IPF reference intervals (RIs), and study the effect of age and sex on IPF in healthy dogs and cats. A total of 3281 dogs and 726 cats. Retrospective review of medical records. Animals were classified as nonthrombocytopenic (healthy group and group of clinical patients without TP [NTP]) or TP. These latter animals were subclassified as pseudothrombocytopenia (PSE), CEN and PER, based on evaluation of platelet clumps, estimated platelet count in blood smears and final diagnosis. Blood samples were evaluated using a Sysmex XN-1000V with a specific platelet channel (PLT-F). The IPF was significantly different between each subtype of TP in both species. Immature platelet fractions <6.9% in dogs or 13.6% in cats, once PSE has been eliminated by review of blood smears, are indicative of CEN. Reference intervals for IPF were 0.5%-8% in healthy dogs and 1%-40.3% in healthy cats. We determined that IPF can differentiate between CEN and PER in dogs and cats, guiding additional testing and avoiding more invasive procedures (bone marrow sampling). A blood smear always should be evaluated to rule out platelet clumping.

Effects of Partial-Body, Continuous/Pulse Irradiation at Dose Rates from Flash to Conventional Rates on the Level of Surviving Blood Lymphocytes: Modeling Approach. I. Continuous Irradiation.

A mathematical model developed by Cucinotta and Smirnova is extended to describe effects of continuous, partial-body irradiation at high doses D and at dose N rates from FLASH to conventional rates on the level of surviving blood lymphocytes in humans and small laboratory animals (mice). Specifically, whereas the applicability of the model is limited to the exposure times shorter than a single cardiac cycle T0, the extended model is capable of describing such effects for the aforementioned and longer exposure times. The extended model is implemented as the algebraic equations. It predicts that the level of surviving blood lymphocytes in humans and mice increases with increasing the dose rate from N = D / T0 to FLASH rates and approaches the upper limiting level of 1 - v R where v R is the fraction of blood volume in the irradiated part of the blood circulatory system. Levels of surviving blood lymphocytes computed at doses from 10 Gy to 40 Gy and at dose rates N, which equal or exceed 40 Gy/s for humans and 400 Gy/s for mice, are nearly indistinguishable from the upper limiting level. In turn, the level of surviving blood lymphocytes in humans and mice decreases with decreasing the dose rate from N = D / T0 to conventional rates and approaches a lower limiting level. This level strongly depends on the dose D (it is smaller at larger values of D) with a slight dependence on the dose rate N. The model with the parameters specified for mice (together with the model of the dynamics of lymphopoietic system in mice after partial-body irradiation) reproduce, on a quantitative level, the experimental data, according to which the concentration of blood lymphocytes measured in mice in one day after continuous, partial-body irradiation at a high dose and conventional dose rate is smaller at the larger value of vR. Additionally, the model predicts at the same high dose (>10 Gy) a faster restoration of the blood lymphocyte population in humans exposed to continuous, partial-body irradiation at a FLASH dose rate compared to a conventional dose rate.

A Mitochondrial DNA-based Molecular Phylogenetics Study of the Mahalli Goat as a New Animal Genetic Resource in Southern Anatolia in Turkey

Background: The Karacadağ Mountains are of extinct volcanic origin and cover a large area in the triangle between Diyarbakır (Center, Nar and Ergani districts), Şanlılurfa (Siverek and Viranşehir districts) and Mardin (Derik district). Agricultural activities are limited due to the stony structure of the region; therefore, small animal husbandry is intensively practiced in the villages of the region. Mahalli goats, which are morphologically new domestic goats, are distinguished from other domestic goats by their spiral horn structure. They are not only resistant to cold weather conditions, but also resistant to diseases. Therefore, present study aimed to determine the genetic diversity and phylogenetic relationships of Mahalli goats in Diyarbakır region. Methods: The study was carried out at Şanlıurfa, Harran University of Agricultural Faculty, Laboratory of Animal Biotechnology and Molecular Genetics, in 2019-2020. Out of 24 Mahalli goats, forward and reverse primers were used to amplify the 598 bp region over the mtDNA D-loop region encompassing the 481 bp most variable region (HVR1). Analysis of goat D-loop sequences revealed 481 regions of 0.378 G+C, 97 polymorphic regions and 19 haplotypes. The phylogenetic analysis of Mahalli goats was carried out using molecular genetic techniques. Result: As a result of data analysis, both haplotype diversity (HD) and nucleotide diversity (ND) were calculated to be 1.000±0.0039 and 0.0375±0.00209, respectively. The genetic distance between the haplotypes of Mahalli goat ranged from 0.003 to 0.087 and the genetic distance between the haplotypes of Mahalli goat and other domestic goat breeds in Turkey ranged from 0.016 to 0.027. All 19 haplotypes used in this study were represented in the lineage A phylogenetic tree.

Zoonoses-specific resources, collaborative networks, and enhanced communication can help US veterinarians tackle zoonotic diseases: results from a national survey.

Increased incidence of zoonoses, coupled with veterinarians' occupational exposure, led to this study examining the knowledge of licensed US veterinarians on zoonoses and their disease prevention practices. This online survey supported by the National Association of State Public Health Veterinarians received 466 responses from 36 US states; 67% of the respondents were female, and 72.5% were small animal medicine practitioners. The One Health concept was familiar among 82% of respondents, 51.3% knew of continuing education training on zoonoses, and 68% had attended such a training in the last 5 years. Respondents were unaware of which zoonoses to report to public health departments. For 3 out of 8 questions on standard operating procedures, statistically significant differences in protocols followed among small, large, and mixed animal medicine practitioners were observed. Most respondents believed they play a critical role in zoonoses prevention but would like more information on zoonotic diseases. Results indicate that assisting veterinarians with regularly updated information on zoonoses, providing targeted education and training to adhere to standardized infection control measures, and increasing communication with public health agencies and physicians may help prevent and reduce incidence of zoonoses.

Deep learning derived input function in dynamic [18F]FDG PET imaging of mice

Dynamic positron emission tomography and kinetic modeling play a critical role in tracer development research using small animals. Kinetic modeling from dynamic PET imaging requires accurate knowledge of an input function, ideally determined through arterial blood sampling. Arterial cannulation in mice, however, requires complex, time-consuming and terminal surgery, meaning that longitudinal studies are impossible. The aim of the current work was to develop and evaluate a non-invasive, deep learning based prediction model (DLIF), that directly takes the PET data as input to predict a usable input function. We first trained and evaluated the DLIF model on 68 [18F]Fluorodeoxyglucose mouse scans with image-derived targets using cross validation. Subsequently, we evaluated the performance of a trained DLIF model on an external dataset consisting of 8 mouse scans where the input function was measured by continuous arterial blood sampling. The results showed that the predicted DLIF and image-derived targets were similar, and the net influx rate constants following from Patlak modeling using DLIF as input function were strongly correlated to the corresponding values obtained using the image-derived input function. There were somewhat larger discrepancies when evaluating the model on the external dataset, which could be attributed to systematic differences in the experimental setup between the two datasets. In conclusion, our non-invasive DLIF prediction method may be a viable alternative to arterial blood sampling in small animal [18F]FDG imaging. With further validation, DLIF could overcome the need for arterial cannulation and allow fully quantitative and longitudinal experiments in PET imaging studies of mice.

Biphasic Calcium Phosphate and Activated Carbon Microparticles in a Plasma Clot for Bone Reconstruction and In Situ Drug Delivery: A Feasibility Study

The development of bone-filling biomaterials capable of delivering in situ bone growth promoters or therapeutic agents is a key area of research. We previously developed a biomaterial constituting biphasic calcium phosphate (BCP) microparticles embedded in an autologous blood or plasma clot, which induced bone-like tissue formation in ectopic sites and mature bone formation in orthotopic sites, in small and large animals. More recently, we showed that activated carbon (AC) fiber cloth is a biocompatible material that can be used, due to its multiscale porosity, as therapeutic drug delivery system. The present work aimed first to assess the feasibility of preparing calibrated AC microparticles, and second to investigate the properties of a BCP/AC microparticle combination embedded in a plasma clot. We show here, for the first time, after subcutaneous (SC) implantation in mice, that the addition of AC microparticles to a BCP/plasma clot does not impair bone-like tissue formation and has a beneficial effect on the vascularization of the newly formed tissue. Our results also confirm, in this SC model, the ability of AC in particle form to adsorb and deliver large molecules at an implantation site. Altogether, these results demonstrate the feasibility of using this BCP/AC/plasma clot composite for bone reconstruction and drug delivery.

The feasibility of K XRF bone lead measurements in mice assessed using 3D-printed phantoms

This article describes the development of a system for in vivo measurements of lead body burden in mice using 109Cd K x-ray fluorescence (XRF). This K XRF system could facilitate early-stage studies on interventions that ameliorate or reverse organ tissue damage from lead poisoning by reducing animal numbers through a cross-sectional study approach. A novel mouse phantom was developed based on a mouse atlas and 3D-printed using PLA plastic with plaster of Paris ’bone’ inserts. PLA plastic was found to be a good surrogate for soft tissue in XRF measurements and the phantoms were found to be good models of mice. As expected, lead detection limits varied with mouse size, mouse orientation, and mouse position with respect to the source and detector. The work suggests that detection limits of 10 to 20 μg Pb per g bone mineral may be possible for a 2 to 3 hour XRF measurement in a single animal, an adequate limit for some pre-clinical studies. The 109Cd K XRF mouse measurement system was also modeled using the Monte Carlo code MCNP. The combination of experiment and modeling found that contrary to expectation, accurate measurements of lead levels in mice required calibration using mouse-specific calibration standards due to the coherent scatter peak normalization failing when small animals are measured. MCNP modeling determined that this was because the coherent scatter signal from soft tissue, which until now has been assumed negligible, becomes significant when compared to the coherent scatter signal in bone in small animals. This may have implications for some human measurements. This work suggests that 109Cd K x-ray fluorescence measurements of lead body burden are precise enough to make the system feasible for small animals if appropriately calibrated. Further work to validate the technology’s measurement accuracy and performance in vivo will be required.

Investigating eukaryotic and prokaryotic diversity and functional potential in the cold and alkaline ikaite columns in Greenland

The ikaite columns in the Ikka Fjord, SW Greenland, represent a permanently cold and alkaline environment known to contain a rich bacterial diversity. 16S and 18S rRNA gene amplicon and metagenomic sequencing was used to investigate the microbial diversity in the columns and for the first time, the eukaryotic and archaeal diversity in ikaite columns were analyzed. The results showed a rich prokaryotic diversity that varied across columns as well as within each column. Seven different archaeal phyla were documented in multiple locations inside the columns. The columns also contained a rich eukaryotic diversity with 27 phyla representing microalgae, protists, fungi, and small animals. Based on metagenomic sequencing, 25 high-quality MAGs were assembled and analyzed for the presence of genes involved in cycling of nitrogen, sulfur, and phosphorous as well as genes encoding carbohydrate-active enzymes (CAZymes), showing a potentially very bioactive microbial community.

Scaling of buccal mass growth and muscle activation determine the duration of feeding behaviours in the marine mollusc Aplysia californica.

The mechanical forces experienced during movement and the time constants of muscle activation are important determinants of the durations of behaviours, which may both be affected by size-dependent scaling. The mechanics of slow movements in small animals are dominated by elastic forces and are thus quasistatic (i.e. always near mechanical equilibrium). Muscular forces producing movement and elastic forces resisting movement should scale identically (proportional to mass2/3), leaving the scaling of the time constant of muscle activation to play a critical role in determining behavioural duration. We tested this hypothesis by measuring the duration of feeding behaviours in the marine mollusc Aplysia californica whose body sizes spanned three orders of magnitude. The duration of muscle activation was determined by measuring the time it took for muscles to produce maximum force as A. californica attempted to feed on tethered inedible seaweed, which provided an in vivo approximation of an isometric contraction. The timing of muscle activation scaled with mass0.3. The total duration of biting behaviours scaled identically, with mass0.3, indicating a lack of additional mechanical effects. The duration of swallowing behaviour, however, exhibited a shallower scaling of mass0.17. We suggest that this was due to the allometric growth of the anterior retractor muscle during development, as measured by micro-computed tomography (micro-CT) scans of buccal masses. Consequently, larger A. californica did not need to activate their muscles as fully to produce equivalent forces. These results indicate that muscle activation may be an important determinant of the scaling of behavioural durations in quasistatic systems.

Survey on the therapeutic use of Canabidiol by veterinary in the metropolitan region of Belém do Pará

The present study aimed to analyze the knowledge of veterinarians in the metropolitan region of Belém do Pará about the use of Cannabis sativa for medicinal purposes in veterinary medicine. To this end, structured questionnaires were applied through the google forms platform. The data obtained were presented in percentages, in order to collect information on this subject, which is of fundamental importance for the creation of dissemination strategies regarding the medicinal use of Cannabis, making their knowledge evident when more than 40% of respondents claim to have knowledge through scientific articles and understand its importance of integration into the clinical routine, and more than 90% believe that research on the use of medicinal Cannabis needs to be stimulated and have greater dissemination. It is clear in a common opinion of the interviewees the affirmation of the need, not only for more studies on the use of cannabidiol in small animals, but also for the use of tools such as social media to bring this knowledge to people who can be both professionals in the area, as well as tutors who are interested in the subject.

Antibacterial therapy for kidney pathology of small pets

The article considers etiological factors, clinical manifestations, laboratory and instrumental methods for diagnosing kidney pathology, which requires the use of antibacterial drugs – pyelonephritis. However, this pathology can be difficult to diagnose and not every antibacterial drug is suitable for its treatment. The main ways of kidney damage by bacterial infection in small domestic animals are ascending infection and hematogenous introduction, when pathogenic microorganisms enter the kidneys along with the bloodstream. The article provides predisposing factors leading to the development of pyelonephritis. Pyelonephritis has several types of course. The acute form of the disease is most easily diagnosed due to the vivid clinical signs and pronounced changes in blood, urine, and kidney sonography tests. Whereas the chronic form and latent course may be overlooked due to the nonspecific clinical picture. In the treatment of pyelonephritis, the occurrence of antibiotic resistance in bacteria can be fatal for the patient, because if it is impossible to eliminate infection in the kidneys, the development of renal failure is inevitable, leading to all manifestations of uremia, anemia and other changes that occur with impaired renal function. To prevent the development of antibiotic resistance, it is extremely important to make a final diagnosis through bacteriological urine culture, but pyelonephritis is a pathology that requires a comprehensive diagnostic approach and, if suspected, it is advisable to start etiological treatment immediately, correctly choosing an antibiotic. Not every antibacterial drug is suitable for the treatment of pyelonephritis. For example, one of the first-line drugs of choice in the treatment of urinary tract infection (UTI), amoxicillin with clavulanic acid does not penetrate the renal parenchyma. The group of choice for the treatment of bacterial inflammation of the kidneys are fluoroquinolones, but not every drug from this group is suitable for treatment in animals and there are certain restrictions in their use in the case of puppies, kittens, as well as in cats as a species, therefore, the selection of an antibiotic should be carried out individually in each clinical case, taking into account the pharmacokinetics and pharmacodynamics of the drug, the result of urine sampling and other studies, as well as the physiological characteristics of the patient.

The effects of gastrointestinal diet therapy for chronic pathologies of the digestive system in cats

Gastroeintestinal diseases are one of the most common groups of diseases among small domestic animals. The gastro-intestinal tract includes the oral cavity, pharynx, esophagus, stomach, pancreas, small intestine and large intestine. General signs of digestive system disorders in cats with diseases of the digestive tract are vomiting, regurgitation, capricious appetite, as well as various defecation disorders: diarrhea, coprostasis, various inclusions in feces (blood, mucus). Diseases of the gastrointestinal tract of a chronic nature often involve the manifestation of symptoms on an ongoing basis or are recur-rent in nature. Chronic gastritis, enteropathy, pancreatitis require specialized diets that normalize the functioning of the digestive tract and help improve digestive function. These therapeutic complete diets are presented in ready-made feeds in dry (pellets) and wet (pates, pouches) variations from many manufacturers of industrial feeds. Dietary therapy is required long-term or lifelong; during remission it is the basis in the treatment of chronic patients. The compositions of these diets take into account the physiological and specific needs of the animal, and are also developed on the basis of easily digestible ingredients and a reduced amount of fat, but completely replenishing the required amount of calories.

Brachyspira in dogs: risk factors of shedding in central Germany and longitudinal study of an infected kennel

BackgroundBrachyspira (B.) pilosicoli is a zoonotic pathogen, able to infect different animal species such as pigs, poultry, and rodents, causing intestinal spirochetosis. An association of gastrointestinal clinical signs, such as diarrhea, with the isolation of B. pilosicoli from fecal samples or rectal swabs has not been proven in dogs. Other Brachyspira species commonly isolated from dogs, such as “B. canis” and “B. pulli”, are considered commensals. This study investigated the occurrence of different Brachyspira species in rectal swabs and fecal samples in an independent canine cohort in central Germany. These included samples from shelter dogs, hunting dogs, and dogs presenting at regional small animal practices with various clinical signs. Data about the dogs, including potential risk factors for Brachyspira isolation, were obtained using a standardized questionnaire. The study also longitudinally investigated a colony of Beagle dogs for Brachyspira over 5 years.ResultsThe rate of Brachyspira spp. isolation was 11% and included different Brachyspira species (“B. canis”, “B. pulli”, and B. pilosicoli). “B. canis” was detected in 18 dogs, whereas B. pilosicoli was only isolated from 1 dog in the independent cohort (not including the Beagle colony). Risk factors for shedding Brachyspira and “B. canis” were being less than 1 year of age and shelter origin. Gastrointestinal signs were not associated with the shedding of Brachyspira. B. pilosicoli and “B. canis” were isolated from several dogs of the same Beagle colony in 2017 and again in 2022, while Brachyspira was not isolated at multiple sampling time points in 2021.ConclusionsShedding of B. pilosicoli in dogs appears to be uncommon in central Germany, suggesting a low risk of zoonotic transmission from dogs. Commensal status of “B. canis” and “B. pulli” is supported by the results of this study. Findings from the longitudinal investigation of the Beagle colony agree with an asymptomatic long-term colonization of dogs with “B. canis” and B. pilosicoli and suggest that introducing new animals in a pack can trigger an increased shedding of B. pilosicoli.

Comparison of veterinarians and a deep learning tool in the diagnosis of equine ophthalmic diseases.

The aim was to compare ophthalmic diagnoses made by veterinarians to a deep learning (artificial intelligence) software tool which was developed to aid in the diagnosis of equine ophthalmic diseases. As equine ophthalmology is a very specialised field in equine medicine, the tool may be able to help in diagnosing equine ophthalmic emergencies such as uveitis. In silico tool development and assessment of diagnostic performance. A deep learning tool which was developed and trained for classification of equine ophthalmic diseases was tested with 40 photographs displaying various equine ophthalmic diseases. The same data set was shown to different groups of veterinarians (equine, small animal, mixed practice, other) using an opinion poll to compare the results and evaluate the performance of the programme. Convolutional Neural Networks (CNN) were trained on 2346 photographs of equine eyes, which were augmented to 9384 images. Two hundred and sixty-one separate unmodified images were used to evaluate the trained network. The trained deep learning tool was used on 40 photographs of equine eyes (10 healthy, 12 uveitis, 18 other diseases). An opinion poll was used to evaluate the diagnostic performance of 148 veterinarians in comparison to the software tool. The probability for the correct answer was 93% for the AI programme. Equine veterinarians answered correctly in 76%, whereas other veterinarians reached 67% probability for the correct diagnosis. Diagnosis was solely based on images of equine eyes without the possibility to evaluate the inner eye. The deep learning tool proved to be at least equivalent to veterinarians in assessing ophthalmic diseases in photographs. We therefore conclude that the software tool may be useful in detecting potential emergency cases. In this context, blindness in horses may be prevented as the horse can receive accurate treatment or can be sent to an equine hospital. Furthermore, the tool gives less experienced veterinarians the opportunity to differentiate between uveitis and other ocular anterior segment disease and to support them in their decision-making regarding treatment.

2024 guidelines for the vaccination of dogs and cats - compiled by the Vaccination Guidelines Group (VGG) of the World Small Animal Veterinary Association (WSAVA).

2024 guidelines for the vaccination of dogs and cats - compiled by the Vaccination Guidelines Group (VGG) of the World Small Animal Veterinary Association (WSAVA).

Environmental and behavioral variables associated with lower urinary tract diseases in domestic cats

Objectives: Feline lower urinary tract disease (LUTD) is a frequently seen disease with multiple etiologies. Since it is a complex condition, the aim of this study is to evaluate the factors that may affect the development of the disease.&#x0D; Materials and Methods: Demographic, clinical, behavioral and environmental parameters of 30 cats diagnosed with lower urinary tract disease and 15 aged-matched healthy cats presented to Ankara University Small Animal Hospital were evaluated. &#x0D; Results: In the diseased group, the male population was higher and the cats were overweight. The number of food, water and litter boxes and litter material were found to differ significantly between groups. Daily habits such as playing with a scratching board and self-grooming differed between the groups. Inappropriate behaviors observed by the owners of the cats in the first group were listed as urinating/defecating outside the litter box and showing aggression towards the owner, guests, and/or other animals. &#x0D; Conclusions: The results of this study show that the detailed evaluation and regulation of the daily needs of cats is important for the emergence or recurrence of the disease and therefore may contribute to the correct management of the treatment process in cats with lower urinary tract disease.

Active surveillance of antimicrobial resistance in companion animals: A pilot study in a Spanish Veterinary Teaching Hospital

The role of small animal veterinary hospitals in the onset and dissemination of antimicrobial-resistant organisms (AMROs) is still not clear, and the implementation of an internal surveillance systems is a cost-effective tool to better understand their impact. The aim of this study was to describe a pilot program of active surveillance in a Spanish Veterinary Teaching Hospital, developed to estimate the detection frequency of AMROs in the commensal flora of patients and in the environment. Surveillance was focused on Methicillin-resistant Staphylococci (MRS), third generation cephalosporins resistant gram-negative bacteria (3GCR-GNB), and carbapenems-resistant gram-negative bacteria (CR-GNB). Oral and perirectal swabs were collected in the same dogs and cats hospitalized > 48 h, at their admission and before their discharge. Out of 50 patients sampled, 24% (12/50) were carriers at admission of at least one of the three investigated AMROs. Twenty-eight percent of patients (14/50) acquired at least one AMRO during the hospital stay. MRS detection frequency at admission was 12% (6/50), while acquisition was 6% (3/50). 3GCR-GNB detection frequency was 14% at admission (7/50) and acquisition 22% (11/50), while CR-GNB detection frequency was 2% at admission (1/50) and acquisition 2% (1/50). Environmental surveillance (98 samples) showed a total detection frequency of 22.4% for MRS (22/98), 2% for 3GCR-GNB and CR-GNB (2/98). Clinical staff’ shoe soles showed high detection frequency for MRS (50%). 3GCR Escherichia coli was the most isolated species in patients (n = 17). The results show how active surveillance can be used as a tool to assess the impact of AMROs in veterinary hospitals to subsequently build up tailored control plans based on specific issues.

Longitudinal imaging of vitreal hyperreflective foci in mice with acute optic nerve damage using visible-light optical coherence tomography.

Hyperreflective foci (HRFs) appear in optical coherence tomography (OCT) images of the retina and vitreous of patients with various ocular diseases. HRFs are hypothesized to be immune cells that appear in response to ischemia or tissue damage. To accurately identify HRFs and establish their clinical significance, it is necessary to replicate the detection of similar patterns in vivo in a small animal model. We combined visible-light OCT with temporal speckle averaging (TSA) to visualize and track vitreal HRFs (VHRFs) densities for three days after an optic nerve crush (ONC) injury. Resulting vis-OCT images revealed that VHRF density significantly increased approximately 10-fold at 12 h after ONC and returned to baseline three days after ONC. Additional immunohistochemistry results confirmed these VHRFs as inflammatory cells induced from optic nerve damage.