Research Articles (Companion Animal Clinical Studies)

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Analytical and quality control validation of a novel symmetric dimethylarginine assay in dogs and cats
(Wiley, 2025-09) Mashego, Portia Tshidi; Hooijberg, Emma Henriette
BACKGROUND : An immunoturbidometric assay for symmetric dimethylarginine (SDMA) measurement on automated chemistry analyzers has recently become available. OBJECTIVE : To perform analytical validation of the EUROLyser SDMA assay in dogs and cats. METHODS : Method validation experiments were performed using stored canine and feline serum. Quality control validation was performed according to Westgard. Performance goals were derived from SDMA biological variation data for both species. RESULTS : Imprecision ranged from 3.7%-7.8% (dogs) to 6.0%-11.8% (cats) with a dispersion of ±35% for dogs and ±44% for cats. The assay showed linearity (up to 85 μg/dL [dogs], 75 μg/dL [cats]); the preliminary LoQ was 9.5 and 6.9 μg/dL, respectively. Recovery was 19.7% and 6.5%, respectively. Severe hemolysis resulted in a significant bias in both species. The EUROLyser method showed a significant negative proportional and constant bias in dogs and a significant positive proportional and negative constant bias in cats, compared to the comparative method. In dogs, the mean bias (-19.5%) and the bias at clinical decision limits exceeded the desirable bias; in cats, the mean bias (-4.0%) and the bias at clinical decision limits was < 8%. Because of high imprecision, the TEA that could be controlled for was 35%, with a 1-2.5 s rule using patient pools as quality control material. CONCLUSIONS : The novel SDMA assay showed acceptable analytical performance, but high dispersion has consequences for the interpretation of results at reference limits and serial measurements. Method-specific reference intervals and decision limits should be generated for both species, particularly for dogs, given the significant bias vs. the comparative method.
A single-centre retrospective study of surgical site infection following equine colic surgery (2013-2021)
(Wiley, 2025-05) Griessel, Theunis Steyn; Moran, Juan Alberto Munoz; Byaruhanga, Charles; Smit, Yolandi
BACKGROUND : Surgical site infection (SSI) is a significant cause of postoperative morbidity following equine laparotomy. Therefore, if risk factors for SSI can be identified, morbidity may consequently be reduced. The objectives of this study were to determine the prevalence of SSI in horses undergoing exploratory laparotomy at a single hospital over an 8-year period (2013‒2021), investigate the risk factors associated with SSI and report on the bacterial isolates identified. METHODS : The medical records of horses that had an exploratory laparotomy performed at the teaching hospital due to colic were retrospectively reviewed. SSI was defined as any purulent or serous discharge from the laparotomy incision for more than 24 hours duration during hospitalisation. Pre-, intra- and postoperative risk factors for SSI were identified using multivariable logistic regression analysis. RESULTS : A total of 143 horses met the criteria for inclusion in the study, of which 38 developed an SSI (26.6%, 95% confidence interval: 19.5–34.6%). Multivariable analysis revealed that the application of a postoperative abdominal bandage was significantly associated with a decreased likelihood of SSI (odds ratio = 0.29, p = 0.026). LIMITATIONS : As this was a retrospective study performed at a single hospital, the findings may have limited generalisability. CONCLUSIONS : The application of a postoperative abdominal bandage is protective against SSI in horses following exploratory laparotomy for colic.
Household hostilities : a descriptive study of inter-dog aggression requiring veterinary treatment of dog bite wounds in Pretoria, South Africa
(Elsevier, 2025-11) Hanekom, Josef Derek; Thompson, P.N. (Peter N.); Schoeman, Johan P.; Van Vollenhoven, Elize; joe.hanekom@up.ac.za
Inter-dog aggression (IDA) places a high burden on the dogs involved, their owners and their households. Treating dog bite wounds (DBW) accounts for a substantial proportion of small animal veterinary practice caseload. This study aimed to identify potential risk factors of IDA in dogs presented for the treatment of DBW at a veterinary teaching hospital in Pretoria, South Africa. Veterinary staff completed a survey regarding wound severity, distribution, treatment, and outcome of 126 dogs treated for DBW. A separate, but related survey was completed by 124 owners of dogs presenting for DBW, describing the fighting event, dogs involved, and the household context where these fighting dogs lived. Control household data was collected from surveys completed by 71 owners of dogs being treated for alternative conditions, where no household dogs had been treated for DBW by a veterinarian. Most fighting between dogs occurred on the owner’s property (85.4 %) and between household dogs (68.5 %). From the 83 household pairs where the sex and sterilisation status were known, fighting was more common between dogs of the same sex (71 %) and sterilisation status (53 %). Fighting pairs were most frequently both intact male (25 %) or both sterilised female dogs (16 %). Compared to control households, dog bite households kept on average significantly more dogs (4.14 compared to 3.44 dogs, p = 0.029) and significantly more male intact dogs (1.04 compared to 0.66 dogs, (p = 0.043). Breeds over-represented in dog bite households were Boerboels (p = 0.043), German Shepherd dogs (p = 0.034) and Pitbull Terriers (p = 0.002) compared to control household. Breeds under-represented in dog bite households were Dachshunds (p = 0.046), Labrador Retrievers (p = 0.026), Miniature Poodles (p = 0.016) and Schnauzers (p = 0.032) compared to control households. Few biting incidents occurred during supervised walks (4 %), which differs substantially from previous studies, which reported that most fights between dogs occurred in public spaces involving unleashed dogs. Based on our study findings, the following locally relevant IDA prevention measures are indicated: limiting the number of household dogs to three or fewer, reducing the number of male intact dogs, mixing sexes, and avoiding Boerboels, German Shepherds and Pitbull Terriers breeds in multidog households. HIGHLIGHTS • Most dog fights occurred on the owners’ property between household dogs. • Dog bite households owned more male intact dogs and more dogs than control households. • The majority of fights were between dogs of the same sex and sterilisation status. • Breeds over-represented in fighting were Pitbull terriers, Boerboels and German Shepherd dogs. • Several factors influencing fighting between South African dogs varied from Western studies.
Genome assembly and annotation of Babesia rossi, a protozoan parasite for canine babesiosis
(BioMed Central, 2025-07) Redekar, Neelam; Wang, Xu; Neves, Luís C.B.G.; Brooks, Steven; Lack, Justin; Leisewitz, Andrew L.; Ackerman, Hans
BACKGROUND : Apicomplexan parasite, Babesia rossi, is an Ixodid tick-transmitted pathogen that causes the most severe form of canine babesiosis disease. Compared to other Babesia pathogens of dogs, B. rossi exhibits unique pathophysiology, virulence, and a responsiveness to drugs that differs from the small Babesia parasites. RESULTS : Here we report the first near-complete chromosome-level assembly of Babesia rossi strain PMB – isolated from a sick dog from Pietermaritzburg, South Africa. Assembly with long-read HiFi data yielded 21.06 Mbp genome size, spanning across five gene-dense chromosome-level scaffolds, a single apicoplast scaffold, and a remaining 54 unplaced low gene density scaffolds with 1.32 Mb N50 and 96.6% BUSCO Apicomplexan completeness. The genome annotation identified a total of 3,098 protein-coding genes, 71 tRNA, and 16 rRNA genes. The mitochondrial genome (6.4 Kbp) was also identified. Genome assemblies of two additional field isolates of B. rossi were also reported. Comparative genomic analyses revealed four syntenic genomic inversions and multiple polymorphisms across three B. rossi isolates, although SNP and indel density was higher within the gene desserts of the genomes. Despite these differences, three B. rossi isolates’ genome assemblies showed 99% conserved orthologous gene sets. About 76% of protein-coding genes of Babesia rossi isolate PMB were shared with four other Babesia species. CONCLUSION : This report provides valuable genomic information that is crucial to comprehend B. rossi evolution, virulence, and potential drug targets for canine babesiosis.
Radiological landmarks as an aid in the interpretation of rodent skull extra-oral projections
(Wiley, 2025-05) Norval, Quintin; Tordiffe, Adrian Stephen Wolferstan; Steenkamp, Gerhardus
Knowledge of the radiographic anatomy of rodent skulls is essential for accurately interpreting extra-oral radiographs, a non-invasive diagnostic tool commonly used in veterinary practice. Due to the complexity of the skull and the potential for distortion in two-dimensional views, a systematic evaluation of anatomical structures is necessary. This study identifies the most clinically relevant anatomical landmarks on standard extra-oral radiographic views of the skull and mandible in various rodent species, including a cane rat, two woodchucks, and seven common mole rats. Specimens were evaluated with bone and soft tissue intact, as well as dried skulls, to identify key anatomical features. The findings highlight distinct species-specific variations despite general similarities in skull structure. These landmarks were catalogued to aid veterinary professionals in interpreting rodent radiographs. Improved recognition of these structures enhances diagnostic accuracy, enabling better assessment of normal anatomy and potential pathological conditions in rodent patients.
Development of populational female thorax sizes and body habitus categories using computed tomography (CT) images
(Elsevier, 2025-08) Pape, R.; Xie, G.; Zheng, X.; Carstens, Ann; West, C.; Cowling, C.
INTRODUCTION: Positioning of the breast during mammography examination is critical to producing optimum quality images. However, the variation in female thorax and body habitus may affect mammography positioning for best image quality. This study aims to establish populational female thoracic (rib cage) sizes and quantify female body habitus categories. METHODS: A retrospective analysis of 347 female computed tomography (CT) chest axial scans was retrieved from an open access database to establish female rib cage sizes. Dimensions of the rib cage were measured digitally across six cross sections with six anterior rib landmark points and recorded in millimetres (mm). A Bayesian Network (BN) model was developed to establish the relationships of information extracted from the rib cage image data to quantify and categorise female body habitus. RESULTS: Female body habitus (thoracic size) were classified into three cohort categories: lean (20.5 %),norm (55.6 %) and curvaceous (23.9 %). The mean values (115–126 mm) and the corresponding 80 %prediction interval ranges for the healthy female rib cage size were obtained through the BN scenario analysis. CONCLUSION: The significance of this study is that it categorised 55.6 % of female thoracic sizes as being normal on a larger group of female population. This study contributed to a good understanding of the range of female body habitus (thoracic size) to improve positioning practice and maximize image quality. IMPLICATIONS FOR PRACTICE: This study used a BN model to establish a range of female thorax sizes using CT chest images to support improved positioning practices. These ranges of thorax sizes should be integrated as a body habitus criterion in the current image evaluation system to maximise image quality and subsequent breast cancer diagnosis.
Evaluation of subjective assessment of right heart size and function using standard 2D-echocardiographic recordings in horses with and without pulmonary hypertension
(Wiley, 2025-07) Van Spijk, Julia N.; Junge, Hannah K.; Eberhardt, Christina; Wolf, Natalie; Vogt, Debora; Zscherpe, Paula; Herger, Elena; Straub, Manon; Schwarzwald, Colin C.
BACKGROUND : Echocardiographic evaluation of right heart (RH) size and function in horses is challenging and relies on subjective assessment. OBJECTIVES : Evaluate inter- and intra-rater agreement of subjective assessment of RH size, RH function, and the presence of pulmonary hypertension (PHT) in horses. Assess subjective RH changes with and without PHT and the influence of observer experience. ANIMALS : Healthy horses (n = 30) and horses with Doppler measurements suggesting the presence or absence of PHT (n = 30 each). METHODS : Nine standard echocardiographic recordings were analyzed by experienced (n = 4) and inexperienced (n = 5) observers. RH size, RH function, pulmonary artery (PA) size and distensibility, and the presence of PHT were subjectively assessed as normal, mildly, moderately, or severely changed. Inter- and intra-rater agreement was calculated using percentual agreement (% agree) and kappa (k). Sensitivity and specificity to detect PHT were calculated. RESULTS : Overall inter-rater agreement in all observers was low with 61% perfect agreement and k of 0.21; it was higher in experienced observers (k = 0.34, 77% agree) than in beginners (k = 0.18, 52% agree). Intra-rater agreement showed % agree > 80% in experienced observers (k = 0.35–0.76) and < 80% in beginners (k = 0.33–0.54). RH size and function were more commonly abnormal in the PHT group, with high specificity but low sensitivity to detect PHT. CONCLUSIONS AND CLINICAL IMPORTANCE : Rater agreement of subjective RH assessment was low and influenced by observer experience. Subjective absence of RH changes does not allow ruling out PHT, while the presence of characteristic RH changes suggests PHT.
A multi-modal investigation into the prevalence and diagnostic evaluation of vector-borne pathogens and retroviruses in domestic cats throughout Namibia
(Elsevier, 2025-08) De Villiers, Lourens; Penzhorn, Barend Louis; Schoeman, Johan P.; Molini, Umberto; De Villiers, Mari; Byaruhanga, Charles; Makgabo, Sekgota Marcus; Collins, Nicola E.; Zealand, Samantha; Baines, Ian J.M.; Stoltsz, Wilhelm Heinrich; Thompson, P.N. (Peter N.); Oosthuizen, Marinda C.
Neglected, but economically significant, tropical diseases may be prevalent in domestic cats of Namibia. A multi-centre prevalence field study was conducted across Namibia to assess the distribution of vector-borne pathogens and retroviruses from domestic cats. Samples of blood and serum from 280 cats in 15 towns across eight regions (22–51 cats per region) were analysed. Screening for Ehrlichia, Anaplasma, Babesia, and Hepatozoon species, as well as feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV), was conducted using light microscopy, point-of-care serology, and quantitative real-time polymerase chain reaction (qPCR) assays. Haematology and serum biochemistry analyses were also performed. Several pathogens were identified in Namibian cats using these diagnostic tools. Comparatively, pathogen detection rates varied by modality, namely light microscopy (5 %), serology (42 %), and qPCR (27 %). More specifically, microscopy revealed an overall prevalence (3 %) for inclusions resembling large Babesia parasites, serology indicated a seroprevalence for FIV antibodies (4 %) and FeLV antigen (40 %), and an overall prevalence determined by qPCR for E. canis (2 %) and H. canis (26 %). The investigation also demonstrated the associations between tick presence, pathogen infection, and disease manifestations in Namibian cats. A particular significant positive association was found between H. canis infection and FeLV antigen seroprevalence (P = 0.005). Overall, the study highlighted the difference of various diagnostic tools for detecting pathogen prevalence in cats. Appropriate diagnostic testing - informed by known associations with disease manifestation - should be key in guiding responsible treatment strategies and evaluating potential zoonotic risks linked to domestic cats of Namibia. HIGHLIGHTS • First comprehensive survey of vector-borne diseases and retroviruses in domestic cats across several Namibian regions. • First confirmed detection of Ehrlichia canis and Hepatozoon canis in domestic feline blood across several regions of Namibia. • Demonstrated significant associations between pathogen infection, tick presence, and disease manifestation.
A persistent hymen resulting in an open cervix but closed pyometra and pyocolpos in a mixed-breed female domestic dog
(Wiley, 2025) Kruger, Taylor June; Kitshoff, Adriaan Mynhardt; Schoeman, Johan P.; Hoepner, Sara Nicolene; Hanekom, Josef Derek
A rescued mixed-breed (Africanis type), entire, female dog, approximately 2 years old, with an unknown history, presented with a prominent perineal swelling between the anus and vulva. Ultrasound identified it as a fluid-filled structure, and an aspirate revealed an exudate consisting of degenerate neutrophils, bacterial cocci and rods. A vaginal exam showed a persistent hymen, while an abdominal ultrasound revealed distended, fluid-filled uterine loops consistent with a pyometra. Under general anaesthesia, an ovariohysterectomy was performed, and the persistent hymen was resected via an episiotomy to allow drainage of the purulent material. The surgery and recovery were without complications. This report describes an unusual presentation of a pyocolpos and ‘closed’ pyometra because of a persistent hymen.
Editorial : Comparative cranial morpho-physiology applied to domestic and wild animals
(Frontiers Media, 2024-06-24) Magalhaes , Henrique Inhauser Riceti; De Assis Ribeiro, Lucas; Steenkamp, Gerhardus; Verstraete, Frank J.M.
No abstract available.
Effects of haemorrhage and lactated Ringer's solution or tetrastarch 130/0.4 resuscitation on colloidal osmotic pressure and osmolality in cats
(Sage, 2025-04) Michaletos, Anthea; Breytenbach, Marinell; Zeiler, Gareth Edward; gareth.zeiler@up.ac.za
OBJECTIVES : To determine the effects of haemorrhage and fluid over-resuscitation on colloidal osmotic pressure of albumin (COP albumin), plasma (Posm) and effective (Eosm) osmolality in anaesthetised cats. METHODS : A total of six cats were given three treatments once, at 2-month intervals, in a randomised, crossover haemorrhage-resuscitation study. The treatments were divided into two phases, a controlled haemorrhage phase and a fluid resuscitation phase, as follows: (1) NoHR = no controlled haemorrhage and no resuscitation; (2) LRS = controlled haemorrhage followed by lactated Ringer’s solution infusion (60 ml/kg/h); and (3) TS = controlled haemorrhage followed by 6% tetrastarch 130/0.4 suspended in 0.9% saline infusion (20 ml/kg/h). The resuscitation fluids were administered for 120 mins. Data were collected before haemorrhage, before resuscitation and at 30 min intervals until 120 mins. Variables were calculated at each time point as follows: COP albumin = albumin concentration (g/l) × 0.57; Posm = (2 × sodium) + glucose + blood urea nitrogen; and Eosm = (2 × sodium) + glucose. All Posm and Eosm concentrations were measured as mmol/l. Data were compared using a general linear mixed model (significance: P <0.05). RESULTS : Mean ± SD total haemorrhage volumes for NoHR, LRS and TS were 10.2 ± 2.3, 29.3 ± 9.0 and 29.1 ± 6.3 ml/kg, respectively. The COP albumin decreased over time in all treatments regardless of volumes of blood lost and fluid administered. The decrease in COP albumin was profound and clinically relevant in LRS and TS (both P <0.001). There were no statistical differences in Posm and Eosm over time except in LRS at 90 (P = 0.004) and 120 ml/kg (P <0.001). CONCLUSIONS AND RELEVANCE : The COP albumin decreased in all treatments but to low and clinically relevant concentrations in LRS and TS, putting the cats at risk of fluid overload. There were no clinically relevant derangements in Posm and Eosm.
Relationships between arterial and central venous blood acid–base variables in anaesthetised cats during euvolaemic and hypovolaemic states
(Sage, 2025-03) Breytenbach, Marinell; Michaletos, Anthea; Zeiler, Gareth Edward; gareth.zeiler@up.ac.za
OBJECTIVES : The aim of the study was to determine differences, agreements and correlations of acid–base variables between arterial and venous blood gas in anaesthetised cats in a euvolaemic or hypovolaemic state. METHODS : A group of six cats was used in a prospective randomised crossover haemorrhage–resuscitation study. Anaesthetised cats underwent three treatments at intervals of 2 months. Each treatment had a controlled haemorrhage phase and a resuscitation phase. The haemorrhage phase is the focus of this study. Arterial (carotid artery) and central venous blood were drawn simultaneously from preplaced catheters before haemorrhage (euvolaemic state; mean ± SD blood loss 1.3 ± 0.3 ml/kg for pre-haemorrhage data collection) and soon after controlled haemorrhage (hypovolaemic state; mean ± SD blood loss 15.8 ± 9.9 ml/kg). Acid–base variables from arterial and venous blood were compared under euvolaemic and hypovolaemic states as follows: (1) a paired t-test to determine the differences between the two samples; (2) a Bland–Altman plot to evaluate agreement and establish maximum clinically acceptable differences (defined a priori); and (3) Pearson’s correlation with least squares linear regression to determine the strength of correlation between the variables. RESULTS : The differences in pH and partial pressure of carbon dioxide were statistically significant under euvolaemic and hypovolaemic states but would not alter clinical decision-making. Agreements were clinically acceptable for all acid–base variables, except for the bias observed in the partial pressure of carbon dioxide under a hypovolaemic state. Correlations for all variables were strong under a euvolaemic state but weakened under a hypovolaemic state. CONCLUSIONS AND RELEVANCE : Using central venous blood sampling for acid–base analysis was clinically acceptable compared with arterial blood in our haemorrhage–resuscitation cat model during early compensated hypovolaemia. However, the partial pressure of carbon dioxide should be interpreted with caution, especially during hypovolaemia. Further investigation is necessary to determine whether these findings can be translated to critically ill cats.
Exploring the impact of the female thoracic size, breast size and image receptor angles on the volume of missing breast tissue in mammographic imaging
(Elsevier, 2025-05) Pape, R.; Zheng, X.; Cowling, C.; West, C.; Carstens, Ann; Kostidis, M.; Bowmast, H.
INTRODUCTION : Optimal positioning in mammography and subsequent image quality can be impacted by thorax variability, breast size and the chosen image receptor (IR) angles. This study aims to explore the impact of the female thoracic size, breast size and IR angle on the volume of missing breast tissue (MBT) in mammographic imaging. METHODS : Sixty-three images were recorded: one craniocaudal (CC) at an IR angle of 0° for three sized breast phantoms attached to three sized thoracic models; and six mediolateral obliques (MLOs) at IR angles of 30°, 40°, 45°, 50°, 55°, 60° for three sized breast phantoms attached to three sized thorax models. Breast size was determined using the posterior nipple line (PNL) measurement and were recorded in millimetres. Breast volume was recorded in cubic centimetres. RESULTS : The breast size and breast tissue volume of a small thorax and large breasts was better visualised with increasing IR angles. Optimal MLO IR angles were determined for the combined average thorax with average breast at 55° and large thorax with large breast at 40° with minimum MBT values of 51.33 cm3 and 75.07 cm3, respectively. Female thoracic size, IR angle, and breast size are significant (p < 0.01) and have a positive impact on the volume of MBT. CONCLUSION : Optimal MLO IR angles were determined for the three breast phantoms attached to three thoracic models. Female thoracic size positively impacts the volume of MBT and in terms of clinical practice it is vital to adjust the MLO IR angle to ensure maximum breast tissue coverage. IMPLICATIONS FOR PRACTICE : These findings can be modelled in current clinical practice on women presented for mammography examinations with varying thorax and breast sizes, allowing optimal IR angle selection and therefore resulting in improved breast tissue inclusion and subsequently a more accurate breast cancer diagnosis.
A qualitative study of mammography best practice positioning for female body habitus and breast tissue inclusion in Australia
(Elsevier, 2025-05) Pape, R.; West, C.; Zheng, X.; Carstens, Ann; Cowling, C.
INTRODUCTION : Optimal positioning in mammography is key to maximise the inclusion of breast tissue on the image. This study aimed to explore the top performing Australian radiographers' mammography best positioning techniques for patients with various body habitus and their perspective on optimised breast tissue inclusion. METHODS : Twelve qualified Australian female radiographers with an age range of 20–70 years with equal representation from screening and diagnostic mammography settings were invited through Volpara® Health to participate in an online individual semi structured interview. Audio-recorded data was transcribed and analysed thematically. Key demographics of the participants include age, education, and mammographic experience. RESULTS : Three key themes emerged for the craniocaudal (CC) view and the mediolateral oblique (MLO) view: good communication, CC detector height and MLO image receptor (IR) angle. Responses to each theme were categorised under six female body habitus for both the CC and MLO views: small, average, large, rib hump, pectus excavatum and pectus carinatum. Effective communication was demonstrated as critical by radiographers during positioning for varied body habitus. A 45° angle was commonly used for an average, small and large body habitus. CONCLUSION : Appropriate and customised positioning and effective communication is important during mammography positioning to maximise breast tissue inclusion on the image. Routine CC and MLO positioning techniques cannot be applied for patients with extreme curvature of the thorax or protruding sternum and ribs. IMPLICATIONS FOR PRACTICE : It is critical for mammography screening programs to include a language interpretation service that targets patients from multiple cultural backgrounds to enhance effective communication during positioning. This study highlights best positioning technique by radiographers that may impact women with extreme thorax curvature or protruding ribs, and subsequent obstruction in optimal positioning.
Butorphanol–azaperone–medetomidine and ketamine–butorphanol–azaperone–medetomidine chemical immobilization in habituated subadult female giraffe (Giraffa camelopardalis)
(Elsevier, 2025-07) Pfitzer, Silke; Laubscher, Liesel L.; Raath, Jacobus P.; Semjonov, Aleksandr; Basson, Etienne P.; Wolfe, Lisa L.; Miller, Michael W.; Zeiler, Gareth Edward
Please read abstract in the article.
Two point-of-care cardiac Troponin I immunoassays have acceptable analytical performance for the detection of measurands of cardiac Troponin I cardiac muscle homogenates from southern-central black rhinoceros (Diceros bicornis minor) and southern white Rhinoceros (Ceratotherium simum simum)
(Wiley, 2025-06) Rautenbach, Yolandi; Meyer, Leith Carl Rodney; Goddard, Amelia; Buss, Peter Erik; Hooijberg, Emma Henriette
BACKGROUND : Skeletal and possible cardiac muscle damage has been reported in chemically immobilized and transported African rhinoceros during conservation-related activities. The extent of cardiac muscle injury in these rhinoceros is unknown due to a lack of validated cardiac troponin I (cTnI) assays. However, recently, five human cTnI assays were deemed suitable for analytical validation in African rhinoceros based on cTnI sequencing results. OBJECTIVES : The first objective was to validate two cTnI immunoassay point-of-care analyzers (POCAs) in African rhinoceros and, secondly, to perform quality control (QC) validation for the POCAs. METHODS : Analytical validation of the Stratus CS Acute Care Troponin I cTnI immunoassay and Atellica VTLi high sensitivity cTnI (hs-cTnI) assay was performed using rhinoceros serum samples and species-specific cardiac muscle homogenate. Experiments included precision studies, reportable range, hemoglobin interference studies, recovery studies, and detection limit studies, with results assessed against prescribed total allowable error (TEa) performance goals. Commercial quality control material (QCM) data were used to calculate bias and imprecision for QC validation. RESULTS : Imprecision was acceptable (1.9%-10.3%) and met low cTnI concentration performance goals. Reportable ranges were similar to the manufacturer's specifications. High hemoglobin concentrations in white rhinoceros resulted in a positive bias in the Stratus CS. A simple 13s QC rule using two levels of QCM and a TEa of 70% could be used in both analyzers, except at very low cTnI concentrations in the Atellica VTLi. CONCLUSIONS : Both cTnI POCAs are suitable for use in African rhinoceros, and analytical performance goals for low cTnI concentrations in hs-cTnI assays were met.
Use of a point prevalence survey to measure antimicrobial use and antimicrobial resistance in equine veterinary hospitals
(Wiley, 2025) Leus, E.K.; Collins, N.; Gruyaert, M.; Kennedy, R.N.; McConnell, E.; McGorum, B.C.; Luethy, D.; Sanz, M.; Versporten, A.; Viljoen, Adrienne; Lyle, C.H.
BACKGROUND : Antimicrobial resistance (AMR) is increasingly recognised in equine medicine. Antimicrobial use (AMU) is a key driver of AMR. OBJECTIVES : To pilot a point prevalence survey (PPS), based on the Global-PPS used in human hospitals, to obtain data on antibiotic prescribing and AMR in equine hospitals and to identify targets for improvement in AMU. STUDY DESIGN : Point prevalence survey. METHODS : Eight equine hospitals located in Australia, Belgium, South Africa, the United Kingdom and the United States were recruited. Data on AMU were collected from all in-patients on antibiotic treatment at 08h00 on four selected study days throughout the study year (2022). RESULTS : In total, 742 patients, 310 (41.8%) surgical and 432 (58.2%) nonsurgical cases, were evaluated and 58.7% (182/310) surgical and 25.9% (112/432) nonsurgical patients were on antibiotics. The most prescribed antibiotics were penicillin, gentamicin and trimethoprim sulfonamides. In 45.2% (215/476) of prescriptions, use was prophylactic. Therapeutic use was based on a biomarker in 48.8% (127/260) of treatments. A sample was submitted for culture in 56.9% (148/260) of therapeutic treatments. A positive culture result was reported from 49.3% (73/148) of samples, with an antibiogram available for 90.4% (66/73) of the positive cultures. An antibiotic use stop/review date was not recorded in 59.5% (283/476) of uses. MAIN LIMITATIONS : This PPS was a pilot study with a relatively small sample size and likely does not reflect AMU in all types of equine hospitals in all geographic locations. CONCLUSIONS AND CLINICAL RELEVANCE : The PPS identified multiple ways in which antibiotic prescribing could be improved. Targets identified for stewardship interventions included empiric use of European Medicines Agency Category A and B antibiotics, the high prevalence of prophylaxis and the lack of use of a stop/review date. The survey could be used as a repeatable tool to assess stewardship interventions in equine hospitals.
Equine colic outcomes and prognostic factors at a South African academic hospital (2019–2021)
(Medpharm Publications, 2025) Van der Merwe, L.M.; Schliewert, Eva-Christina
BACKGROUND : Colic is a common equine emergency requiring medical or surgical intervention. These interventions can be costly, making outcomes data and prognostic indicators essential for guiding referral and treatment decisions. OBJECTIVES : To determine survival rates to hospital discharge and evaluate prognostic indicators in equine colic cases treated at a referral hospital (Onderstepoort Veterinary Academic Hospital [OVAH], South Africa). METHODS : This retrospective observational cohort study analysed records from horses with colic that were presented to the OVAH from January 2019 to August 2021. Data included signalment, admission heart rate (HR) and packed cell volume (PCV), treatment type (medical vs. surgical), surgical diagnosis, postoperative complications, and survival to discharge. RESULTS : Of 415 cases, 375 were treated (292 medically, 83 surgically). 91% of medically, 77% of surgically treated, and 88% overall survived. Compared to a previous study, overall survival to discharge improved by 5% (p = 0.025), mainly due to improved surgical outcomes. Survival was associated with treatment type and surgical lesion site (lower for small intestinal than large intestinal lesions). Medically treated cases with an increased HR and surgical cases with a high PCV had lower survival rates. Signalment showed no association with outcomes. CONCLUSION : Survival rates to discharge were comparable to previously published international reports and showed significant improvement to previous results from the same institution, due to improved surgical outcomes. These findings can assist veterinarians in referral and treatment decisions. Further research on long-term survival and additional prognostic indicators is required to improve outcome predictions for equine colic treatment.
Influence of carcinoma and sarcoma on neutrophil gelatinase-associated lipocalin and symmetric dimethylarginine concentrations in dogs
(Wiley, 2025-03) Rixon, Anouska J.; Meyer, Evelyne; Daminet, Sylvie; Goddard, Amelia; Kongtasai, Thirawut; Pazzi, Paolo
BACKGROUND : It is unknown if tumors or concomitant renal disease influence neutrophil gelatinase–associated lipocalin (NGAL) and symmetric dimethylarginine (SDMA) concentrations in tumor-bearing dogs. OBJECTIVES : Determine the effect of tumor presence, tumor type, and metastasis on concentrations of serum NGAL (sNGAL), SDMA, urinary NGAL (uNGAL), and uNGAL-to-creatinine ratio (uNGAL/Cr) in dogs with carcinoma or sarcoma without clinically relevant renal disease. ANIMALS : Twenty-one dogs with carcinoma, 18 with sarcoma, and 20 healthy age-controlled dogs. METHODS : Concentrations of sNGAL, SDMA, and uNGAL, and uNGAL/Cr ratio were measured from banked samples collected during a previous prospective study. Patient clinicopathological and histopathology records were reviewed, and those with renal azotemia or moderate to severe histopathological renal abnormalities were classified as having clinically relevant renal disease. Biomarker concentrations were compared between tumor-bearing dogs without clinically relevant renal disease and healthy age-controlled dogs. Additionally, comparisons were made between dogs with carcinoma and sarcoma, as well as between dogs with and without metastasis. Correlations between uNGAL and sNGAL concentrations, along with acute phase protein (APP) concentrations, were also analyzed. RESULTS : Tumor-bearing dogs without clinically relevant renal disease had increased uNGAL/Cr (p < 0.001), but not sNGAL, compared with healthy controls. Although median SDMA concentrations did not significantly differ between groups, increased concentrations were found in 32% of dogs with carcinoma and 20% of dogs with sarcoma. No differences were found between dogs with carcinoma and those with sarcoma, or between dogs with metastasis and those without. Urinary and serum NGAL concentrations were moderately correlated, while weak to no correlations were observed with APPs. CONCLUSION : Carcinomas and sarcomas, but not metastasis, influence uNGAL/Cr and SDMA concentrations in dogs.
Influence of tibial plateau angle in cranial cruciate ligament-deficient stifle on patellar ligament strain : an ex vivo study
(American Veterinary Medical Association, 2025-02) Bester, Elizabeth G.; Zeiler, Gareth Edward; Stoltz, George G.; Oberholster, Abraham Johannes (Abrie); Kitshoff, Adriaan Mynhardt; elge.bester@up.ac.za
OBJECTIVE : The aim was to investigate the patellar ligament strain with varying degrees of tibial plateau angles (TPAs) after tibial plateau leveling osteotomy (TPLO) in a cranial cruciate ligament (CrCL)-deficient stifle during the stance phase. METHODS : 12 pelvic cadaver limbs were secured to a custom-built jig to mimic a loadbearing stance after which an axial load of 120 N was applied. Patellar ligament strain, change in strain, and percent change in strain were calculated on pre-TPLO (intact and transected CrCL) and post-TPLO tibial TPAs of −5°, 0°, 5°, 10°, and 15°. Strain was measured using a 3-D digital image correlation to calculate Green-Lagrange strain (E33). Data were compared using a linear mixed model and applying the Dunnett method of multiple comparisons (control was pre-TPLO intact CrCL). RESULTS : The post-TPLO TPAs of 0° and 5° increased in patellar strain compared to pre-TPLO intact CrCL constructs, whereas no significant changes were seen at a TPA of −5°, 10°, and 15°. Significant changes in patellar ligament strain were noted at a TPA of 0° and 5°. The percent change in strain differed at −5°, 0°, and 5° TPAs. The median magnitude of percent change in strain was 35.1%, 37.0%, 79.0%, −7.1%, and −21.1% for −5°, 0°, 5°, 10°, and 15°, respectively. CONCLUSIONS : Significant increases in patellar ligament strain (CrCL-deficient stifle) during the stance phase were observed at TPAs of 0° and 5°. CLINICAL RELEVANCE : A TPA post-TPLO > 5° and < 15° is less likely to cause an increase in patellar ligament strain; however, further research is needed to investigate the clinical relevance of these findings.

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