Mortality related to general anaesthesia and sedation in dogs under UK primary veterinary care

Risk factors associated with increased mortality within 14 days of general anesthesia in specialty veterinary dentistry and oral surgery practices

OBJECTIVE

To investigate the overall mortality rate and risk factors associated with mortality in dogs within 2 weeks of general anesthesia in a specialty veterinary dentistry and oral surgery practice.

STUDY DESIGN

Retrospective cohort study.

ANIMALS

A total of 3210 dogs were anesthetized for advanced imaging and/or oral surgery.

METHODS

Electronic medical records of four clinics were examined for dogs that had undergone advanced imaging and/or oral surgery requiring general anesthesia over a 2 year period (2021-2023). Data were collected on patient demographics, procedural and anesthetic details, and mortality status 2 weeks after anesthesia. Univariate analyses and multivariable logistic regression were used to identify risk factors associated with anesthetic death.

RESULTS

The mortality rate of the study population of dogs was 0.37%. Median age at death was statistically higher than that of dogs alive 2 weeks after anesthesia following univariate analysis (12 and 7 years, respectively). Median anesthetic duration was statistically longer in dogs that died than those that were alive following univariate analysis (177.5 minutes and 141 minutes, respectively). Following multivariate analysis, however, only older age remained a significant risk factor (odds ratio 1.364). Weight, sex, and American Society of Anesthesiologists physical status classification were not statistically significant risk factors for anesthetic death.

CONCLUSIONS AND CLINICAL RELEVANCE

Data from this study may facilitate risk discussions with clients, especially owners of older dogs undergoing anesthesia in veterinary dental practices.

Data-driven safety limits for assessing perianesthetic mortality risk in dogs and cats undergoing elective procedures

OBJECTIVE

To create data-driven clinical pathology thresholds for routine blood tests to assess perianesthetic mortality risk in dogs and cats undergoing elective procedures.

STUDY DESIGN

Retrospective analysis.

ANIMALS

Data from dogs and cats visiting Banfield hospitals between January 2019 and March 2023.

METHODS

Using routinely collected veterinary data from dogs and cats undergoing elective procedures at primary care veterinary practices, data-driven clinical pathology thresholds were calculated to identify perianesthetic mortality risk. This process involved simulation from a generalized additive model that estimated perianesthetic mortality risk, based on signalment data, procedure type, physical status classification and blood analyte values, with data collected between January 2019 and March 2023. The simulated data was used to test 400 potential thresholds. Optimal thresholds were chosen to maximize sensitivity (proportion of deaths correctly predicted) subject to limits on false positive rate (number of non-deaths incorrectly identified). These optimal limits were evaluated on observed data.

RESULTS

Two levels of data-driven clinical pathology thresholds were determined, 'stop' and 'critical stop', with the latter more stringent. For the 'stop' limits, the overall median sensitivity on observed data was 7.16% (interquartile range 4.29%-9.88%) and 11.80% (11.00%-14.60%) for dogs and cats, respectively, and the overall median false positive rate was 2.65% (2.40%-3.31%) and 8.25% (6.86%-9.66%) for dogs and cats, respectively. Albumin, hematocrit, neutrophils and white blood cells were identified as having strong evidence for their utility in creating thresholds for dogs. Neutrophils showed strong evidence for thresholds for cats. These new data-driven thresholds offer more consistent and quantifiable false positive rates and increased sensitivities compared with existing limits. However, weaker evidence resulted in fewer useful thresholds for cats owing to lower data availability.

CONCLUSIONS AND CLINICAL RELEVANCE

It is possible to use routinely collected data to create data-driven clinical pathology thresholds for blood tests to identify animals at increased risk of perianesthetic mortality.

Inter-observer agreement in classifying anesthetic deaths in cats and dogs

Determining the cause of death in studies assessing mortality during small animal anesthesia poses challenges due to varying definitions of anesthetic death, limited information, and differences in evaluators' interpretations. This study aims to establish the interobserver agreement in classifying the cause of death in anesthetized animals. The observational, retrospective, multicenter study analyzed 432 deaths (83 cats and 349 dogs). Data were collected from a database of 55,022 anesthetized dogs and 14,962 anesthetized cats, created to investigate anesthetic-related mortality in these species. Three highly qualified veterinary anesthesiologists independently assessed whether the deaths were related to anesthesia, using their professional judgment. Data were collected from questionnaires that included the animal's signalment, reason for anesthesia, ASA status, drugs, anesthetic procedures, and comments from the submitting veterinarian. Light's Kappa and the intraclass correlation coefficient (ICC) measured interrater agreement among the three evaluators, while Cohen's Kappa assessed interrater reliability between pairs of observers (p < 0.05). Evaluators A, B, and C classified 296/432 (68.5%), 264/432 (61.1%), and 54/432 (12.5%) of the cases as anesthesia-related deaths, respectively. Agreement among the three evaluators was 128/432 (29.6%) [Light's Kappa: 0.17, p = 0.00026; ICC: 0.06, p-value = 0.0167]. The three evaluators agreed on classifying a death as anesthetic-related in 14.1% of cases (50 out of 354 cases where at least one evaluator classified the death as anesthetic-related). Similarly, for non-anesthetic-related deaths, the three evaluators reached an agreement in 20.4% of cases (78 out of 382 cases where at least one evaluator classified the death as non-anesthetic-related). Overall, agreement between two out of three evaluators was 304/432 (70.4%). Evaluators A and B had a 65.7% agreement [Cohen's Kappa: 0.25, p < 0.00001], A and C had a 46.6% agreement [Cohen's Kappa: 0.10, p < 0.00001], and B and C had a 50.9% agreement [Cohen's Kappa: 0.16, p < 0.00001]. In conclusion, the evaluators' agreement was weak, highlighting the need for a consensus on defining anesthetic mortality in dogs and cats.

High-field MRI findings in epileptic dogs with a normal inter-ictal neurological examination

Introduction

Epilepsy is one of the most common chronic neurological conditions affecting dogs. Previous research exploring the likelihood of a structural cause of epilepsy specifically in dogs with a normal inter-ictal examination is limited to a small population of dogs using low-field MRI. The aims of this study were to establish high-field (1.0T and 1.5T) MRI findings in dogs presenting with epileptic seizures and a normal inter-ictal examination.

Methods

Medical records were retrospectively searched for dogs presenting with at least two epileptic seizure events more than 24 h apart. To be included in the study, patients had to have a normal neurological examination, high-field MRI of the brain and have had metabolic and toxic causes excluded.

Results

Four hundred and twelve dogs were eligible for inclusion. Crossbreeds were most commonly affected (n = 63, 15.3%) followed by Border collies (n = 39, 9.5%) and Labrador retrievers (n = 26, 6.3%). Seventy-six dogs (18.5%) had abnormalities detected on MRI, 60 (78.9%) of which were considered to be incidental. Overall, 16 dogs (3.9%) had a structural cause of their epileptic seizures including neoplasia (n = 13, 81.3%), anomalous (n = 2, 12.5%) and meningoencephalitis of unknown origin (MUO) (n = 1, 6.3%). When split into age group at first epileptic seizure structural lesions were documented in 0/66 dogs aged <1 year, 4/256 (1.6%) dogs aged ≥1 year ≤6 years (three neoplastic and one anomalous), 3/51 (5.9%) aged >6 years ≤8 years (two neoplastic and one MUO), and 9/39 (23.1%) dogs aged >8 years (eight neoplastic, one anomalous). Multivariate analysis identified two risk factors for structural disease: increasing age at first epileptic seizure (p < 0.001, OR = 4.390, CI 2.338-8.072) and a history of status epilepticus (p = 0.049, OR = 4.389, CI 1.010-19.078).

Discussion

Structural lesions are an uncommon cause of epilepsy at any age in dogs with a normal inter-ictal examination.

Radiographs are of limited use and low cost-effectiveness when combined with ultrasound for abdominal restaging in dogs with solid, soft tissue tumours

OBJECTIVE

The purposes of this study were to assess the frequency of detection of clinically relevant findings by abdominal radiographs and abdominal ultrasound during restaging of solid, soft tissue tumours in dogs and to determine the cost per clinically relevant finding for both modalities.

MATERIALS AND METHODS

The medical records of 159 dogs which underwent a total of 223 restaging episodes following a diagnosis of a solid, soft tissue tumour within, or with potential for metastasis to, the abdomen were reviewed. Data collected from the sample dogs were reviewed for clinically relevant findings, including local recurrence, lymph node or intra-abdominal metastasis, and other changes that would influence prognosis or management. The clinically relevant findings were compared between abdominal radiographs and abdominal ultrasound. The cost per clinically relevant finding was calculated per modality based on current hospital costs.

RESULTS

Clinically relevant findings were observed in 158 restaging episodes. Ninety-two clinically relevant findings were detected with ultrasound alone, and 65 clinically relevant findings were detected with a combination of both modalities. Only one dog had a clinically relevant finding detected with radiographs alone. Findings were identified significantly more frequently with ultrasound than radiographs. Cost per clinically relevant finding was 495 USD (approx. 373 GBP/448 EUR) for abdominal radiographs and 323 USD (approx. 242 GBP/292 EUR) for abdominal ultrasound.

CLINICAL SIGNIFICANCE

Abdominal radiographs were of minimal use beyond abdominal ultrasound for restaging in this study, despite a higher cost per clinically relevant finding than abdominal ultrasound. This study does not support routine use of abdominal radiographs during routine restaging of solid, soft tissue tumours.

Evaluation of Recovery Time and Quality After Two Different Post-Operative Doses of Medetomidine in Spanish Purebred Horses Anaesthetized with Medetomidine-Isoflurane Partial Intravenous Anaesthesia

Recovery from general anaesthesia is risky in horses. Alpha2-agonist administration after anaesthesia enhances the quality of recovery but may prolong this phase. Recovery time and quality were investigated after medetomidine administration at the end of general anaesthesia in a prospective, randomised, masked and clinical study. Horses underwent medetomidine-isoflurane partial intravenous anaesthesia. Medetomidine (0.5 or 1 µg/kg) IV was administered just after isoflurane was discontinued. The duration of different recovery phases and the number of attempts were recorded. A composite scale (from 1-excellent to 6-accident) was used for quality assessment. Mann-Whitney U-test was performed (p < 0.05). Twenty-seven horses per group were included. Results for 0.5 and 1 µg/kg groups were as follows: lateral recumbency time: 35 (24-45) and 43 (35-55) minutes; sternal recumbency time: 6 (3-15) and 5 (2-15) minutes; total recovery time: 47 (40-59) and 49 (42-62) minutes; number of attempts to sternal: 1 (1-1) and 1 (1-2) and to standing: 1 (1-3) and 1 (1-2); and, quality: 2 (1-2) and 2 (1-2), respectively. No significant differences between the groups were found. Medetomidine 0.5 µg/kg dose did not decrease the recovery time but maintained the recovery quality.

Gut feelings: gastrointestinal signs in French bulldogs undergoing spinal surgery

Introduction

The French bulldog (FBD) is a brachycephalic breed prone to several neurological conditions, of which intervertebral disc herniation (IVDH) is considerably prevalent. Gastrointestinal (GI) disease is a reported complication in dogs surgically treated for IVDH. The objective of this study was to describe GI signs and their outcome in FBDs surgically treated for IVDH.

Materials and methods

Data regarding the GI signs (vomiting, diarrhoea and regurgitation), their frequency and short-term outcome in FBDs surgically treated for IVDH (cervical, thoracolumbar or lumbar) between January 2017 and April 2023 were obtained from medical records at one institution. Categorical variables were compared using Fisher exact tests, and ordinal/continuous data between categorical groups using Kruskal-Wallis or Mann-Whitney tests.

Results

Ninety-seven FBDs were included for analysis. GI signs occurred in 74/97 (76.3%) FBDs while hospitalised, with 33.8% and 66.2% developing GI signs pre- and post-operatively, respectively. FBDs that developed GI signs had a mean of 4.9 episodes. Diarrhoea was the most common GI sign encountered (51/74) compared to regurgitation (38/74) and vomiting (22/74). Resolution of GI signs occurred within a mean of 2.2 days. Mean duration of hospitalisation post-surgery was 4.6 days in FBDs that developed GI signs versus 3.7 days in FBDs that did not (p = 0.033). Anaesthesia length was associated with developing GI signs (p=0.037). Neurological severity, neuroanatomical localisation and surgical procedure were not associated with development of GI signs (p = 0.42, p = 0.794 and p = 1, respectively).

Conclusion

GI signs were commonly encountered in FBDs surgically treated for IVDH and associated with length of anaesthesia and prolonged hospitalisation.

Anaesthetic practices and attitudes to patient safety in a sample of Australian veterinary practices

OBJECTIVE

To survey anaesthetic practices and attitudes towards veterinary patient safety in Australia.

STUDY DESIGN

This was a cross-sectional sample population from Australian veterinary practices, including first opinion small animal, mixed animal and referral small animal practices. The survey included practices' anaesthetic management, monitoring equipment and topics regarding patient safety.

RESULTS

Responses were obtained from 310/1700 (18%) veterinary practices, with 208 respondents from small animal practices (67%), 71 mixed animal practices (23%) and 31 referral small animal centres (10%). Overall, 61% of respondents reported always having a dedicated staff member monitoring the anaesthetic, who was most commonly a certified veterinary nurse (89%). In 22% of the practices, some of the staff monitoring an anaesthetic did not have any qualification. Completion of anaesthetic plans for each animal prior to an anaesthetic was reported by 24.5% of respondents and labelling of syringes was completed in 80% of practices. Pulse oximetry (98%) and temperature (88%) were the most common clinical variables monitored. The use of capnography (46%) or an electrocardiogram (48%) was also reported by the respondents. Emergency drugs, airway and ventilation equipment are available in 96%, 88% and 59% of practices, respectively. A defibrillator was available in 11% of practices with only 54% respondents being confident in using it. Of the respondents 60% were aware of anaesthesia safety interventions and clinical guidelines regarding patient safety during anaesthesia.

CONCLUSIONS AND CLINICAL RELEVANCE

Despite practices showing a relative improvement over the years in the standard of anaesthesia care, most of them are still not meeting international guidelines. Areas where changes could lead to improved safety practices could include: a trained person dedicated to monitor anaesthesia, pain scoring evaluation in patients recovering from anaesthesia, an increased use of standardised handover checklists, record keeping and an increase in open discussion of adverse events by the veterinary team.

Technique description and outcome evaluation of Thoroughbred racehorses following soft palate thermocautery performed under standing sedation

BACKGROUND

Palatal dysfunction (PD), which encompasses palatal instability (PI) and intermittent dorsal displacement of the soft palate, is the most common performance-limiting upper respiratory tract obstruction in young Thoroughbred racehorses. Soft palate thermocautery (SPT) performed under general anaesthesia is a routinely performed procedure for PD in some countries, but the procedure for and outcome of SPT performed under standing sedation has not been published.

OBJECTIVES

(1) To describe a technique for SPT performed under standing sedation; and (2) to assess post-operative performance in horses compared to controls using the Racing Post rating (RPR), British Horseracing Authority official rating (OR), Performance Index and Earnings.

STUDY DESIGN

Retrospective case series.

METHODS

Medical records were reviewed for all horses that had SPT performed under standing sedation following topical and local infusion of lidocaine hydrochloride into the rostral soft palate, and that were identified to have PI by overground endoscopy. Two matched controls were identified for each case. The median RPR, OR, Performance Index and Earnings for the three pre-operative and three post-operative races were compared.

RESULTS

No significant differences were identified between the SPT (n = 23) and Control groups (n = 46) for baseline characteristics or outcomes.

MAIN LIMITATIONS

Retrospective study design, small sample size.

CONCLUSIONS

No significant differences in racing performance were identified between horses that had SPT performed under standing sedation and controls.

Anaesthetic mortality in cats: A worldwide analysis and risk assessment

BACKGROUND

Patient safety is essential in small animal anaesthesia. This study aimed to assess anaesthesia-related deaths in cats worldwide, identify risk and protective factors and provide insights for clinical practice.

METHODS

A prospective multicentre cohort study of 14,962 cats from 198 veterinary centres across different countries was conducted. Data on anaesthesia-related deaths, from premedication up to 48 hours postextubation, were collected. Logistic regression was used to analyse patient demographics, American Society of Anesthesiologists (ASA) classification, procedure type and anaesthetic drugs.

RESULTS

The anaesthesia-related mortality was 0.63%, with 74.5% of deaths occurring postoperatively. Cats with cachexia, a higher ASA status or who underwent abdominal, orthopaedic/neurosurgical or thoracic procedures exhibited elevated mortality. Mechanical ventilation use was associated with increased mortality. Mortality odds were reduced by the use of alpha2-agonist sedatives, pure opioids in premedication and locoregional techniques.

LIMITATIONS

Limitations include non-randomised sampling, potential biases, unquantified response rates, subjective death cause classification and limited variable analysis.

CONCLUSIONS

Anaesthetic mortality in cats is significant, predominantly postoperative. Risk factors include cachexia, higher ASA status, specific procedures and mechanical ventilation. Protective factors include alpha2-agonist sedatives, pure opioids and locoregional techniques. These findings can help improve anaesthesia safety and outcomes. However, further research is required to improve protocols, enhance data quality and minimise risks.

Anaesthetic mortality in dogs: A worldwide analysis and risk assessment

BACKGROUND

Ensuring patient safety during small animal anaesthesia is crucial. This study aimed to assess anaesthetic-related deaths in dogs globally, identify risks and protective factors and inform clinical practice.

METHODS

This prospective cohort multicentric study involved 55,022 dogs from 405 veterinary centres across various countries. Data on anaesthesia-related deaths from premedication to 48 hours post-extubation were collected. Logistic regression was used to analyse patient demographics, American Society of Anesthesiologists (ASA) classification, procedure type and anaesthetic drugs used.

RESULTS

Anaesthetic-related mortality was 0.69%. Most deaths occurred postoperatively (81%). Age, obesity and a higher ASA classification score were associated with increased mortality. Urgent procedures, non-urgent but unscheduled anaesthesias and short procedures also had higher mortality. Some sedatives, systemic analgesics, hypnotics and the use of locoregional anaesthesia were linked to a decrease in mortality.

LIMITATIONS

The limitations of the study include the non-randomised sample, potential selection bias, lack of response rate quantification, variable data quality control, subjectivity in classifying causes of death and limited analysis of variables.

CONCLUSION

Careful patient evaluation, drug selection and monitoring can be associated with reduced mortality. These findings can be used to develop guidelines and strategies to improve patient safety and outcomes. Further research is needed to refine protocols, enhance data quality systems and explore additional risk mitigation measures.

Outcome of the Use of Clinical Reasoning Alone in Dogs with Acute Thoracolumbar Myelopathy and/or Pain

Acute thoracolumbar myelopathy is a common neurological presentation in dogs. Although certain spinal conditions present with characteristic clinical pictures, managing such cases with clinical reasoning alone (i.e., without cross-sectional imaging) has never been explored. The aim of this study was to define the outcome of patients with suspected intervertebral disc extrusion (IVDE), ischaemic myelopathy (IM) or acute non-compressive nucleus pulposus extrusion (ANNPE) that were managed with clinical reasoning alone. The database of the Queen's Veterinary School Hospital (Cambridge) was searched for paraparetic or paraplegic dogs with suspected IVDE or IM/ANNPE that were initially managed medically without undergoing imaging. Clinical presentation and outcome were recorded. If cross-sectional imaging was subsequently performed, information about the final diagnosis was collected and compared with the initially suspected diagnosis. A total of 123 IVDE cases were collected: 81% had a successful outcome with no imaging performed; 16% had IVDE confirmed with imaging and successful outcome with surgery or medical management; and just 3% were found to have an alternative diagnosis or were euthanised without imaging. A total of 16 IM/ANNPE cases were collected: 94% had a successful outcome, and one dog was euthanised. Successful outcomes can be obtained by using clinical reasoning alone in most dogs with suspected IVDE or IM/ANNPE.

Quantifying refractive error in companion dogs with and without nuclear sclerosis: 229 eyes from 118 dogs

OBJECTIVE

To evaluate the relationship between nuclear sclerosis (NS) and refractive error in companion dogs.

ANIMALS STUDIED

One hundred and eighteen companion dogs.

PROCEDURES

Dogs were examined and found to be free of significant ocular abnormalities aside from NS. NS was graded from 0 (absent) to 3 (severe) using a scale developed by the investigators. Manual refraction was performed. The effect of NS grade on refractive error was measured using a linear mixed effects analysis adjusted for age. The proportion of eyes with >1.5 D myopia in each NS grade was evaluated using a chi-square test. Visual impairment score (VIS) was obtained for a subset of dogs and compared against age, refractive error, and NS grade.

RESULTS

Age was strongly correlated with NS grade (p < .0001). Age-adjusted analysis of NS grade relative to refraction showed a mild but not statistically significant increase in myopia with increasing NS grade, with eyes with grade 3 NS averaging 0.58-0.88 D greater myopia than eyes without NS. However, the myopia of >1.5 D was documented in 4/58 (6.9%) eyes with grade 0 NS, 12/91 (13.2%) eyes with grade 1 NS, 13/57 (22.8%) eyes with grade 2 NS, and 7/23 (30.4%) eyes with grade 3 NS. Risk of myopia >1.5 D was significantly associated with increasing NS grade (p = .02). VIS was associated weakly with refractive error, moderately with age, and significantly with NS grade.

CONCLUSIONS

NS is associated with visual deficits in some dogs but is only weakly associated with myopia. More work is needed to characterize vision in aging dogs.

A Retrospective Study on Canine and Feline Mortality during Anaesthesia at a University Clinic in Greece

This retrospective cohort study investigated the mortality rate during anaesthesia and possible contributing factors in canine and feline population in an academic institution in Greece. Data on 1187 dogs and 250 cats which underwent general anaesthesia from 1 January 2018 to 31 December 2019 at the Veterinary Faculty of the Aristotle University of Thessaloniki were analysed regarding cardiac arrest and mortality. In dogs, the rate of cardiac arrest was 1.1% and the rate of death was 0.6%. In cats, these rates were 2.8% and 0.8%, respectively. The mortality rate in healthy/mild disease (ASA I-II) dogs was 0.1% and in cats was 0.5%. Sick (ASA III-V) dogs exhibited a death rate of 2.6%, while sick cats had a rate of 2.2%. In dogs, ASA status had a positive association with cardiac arrest and mortality, with sick dogs being 23 times more likely to suffer cardiac arrest and 24.5 times more likely to die than healthy/mild disease ones. Other factors associated with cardiac arrest and mortality were the anaesthetic protocol and the use of inotropes. In cats, premedication and inotropic support were related to cardiac arrest and death. Feline anaesthesia involves higher risk, and requires greater vigilance in peri-anaesthetic management than dogs.

A prospective cohort study investigating the peri- and postoperative outcomes following ovariohysterectomy in bitches neutered prepubertally or post-pubertally

The aim of this prospective cohort study was to investigate perioperative and postoperative outcomes for bitches that were neutered at different times in relation to puberty (rather than age). Three hundred and six Labrador and Golden Retriever crossbreed bitches were neutered before (prepubertal neuter [PPN], n = 155) or after puberty (Control, n = 151) by experienced veterinarians at one of four veterinary practices (VP1-4). Data were gathered from veterinarians at the time of neutering and from bitch caregivers for the 14-day period after neutering using purpose-designed questionnaires. PPN bitches had shorter surgery durations than Control bitches (OR = 0.877, 91% CI = 0.800 to 0.961, P = 0.015). Longer surgery durations were reported for bitches that had intraoperative complications (OR = 1.620, 91% CI = 1.397 to 1.879, P < 0.001). Shorter surgery durations were reported for VP1 compared to all other veterinary practices (OR = 1.189 to 1.534, P < 0.001). There was no difference in the number of PPN or Control bitches that had perioperative complications (PPN: 3.9%, n = 6; Control: 7.7%, n = 11) and no bitch had more than one perioperative complication reported. For the 14-day postoperative period, fewer PPN (1.3%, n = 2) compared to Control bitches (8.9%, n = 13) had wound discharge (Chi-square = 11.151, D.F = 1, P = 0.001) or showed inappetence (PPN: 2.9%, n = 4; Control: 17.3%, n = 19, Chi-square = 14.884, D.F. = 1, P < 0.001). There was no difference in the number of PPN and Control bitches that had redness or swelling of the wound (52 PPN, 48 Control), showed attention to the wound (6 PPN, 6 Control), required veterinary attention (25 PPN, 23 Control), or that showed any other unusual behaviours: discomfort (27 PPN, 16 Control), uncharacteristic irritability (2 PPN, 4 Control), or uncharacteristic licking or chewing of parts of the body (15 PPN, 6 Control). Bitches neutered at VP2-4 were more likely to have wound redness or swelling reported than those neutered at VP1 (OR = 3.109 to 4.076, P = 0.003). Future studies should consider the impact of veterinary practice on results. These results for peri and postoperative complications could suggest that prepubertal ovariohysterectomy may be a suitable option for neutering bitches. However, it is recommended that they be interpreted together with evidence relating to the impacts on other factors including behaviour and longer-term health in order to make fully informed decisions.

Risk factors for unilateral cranial cruciate ligament rupture diagnosis and for clinical management in dogs under primary veterinary care in the UK

This study aimed to evaluate demographic risk factors associated with unilateral cranial cruciate ligament (CCL) rupture diagnosis and to explore demographic and clinical risk factors associated with management of unilateral CCL rupture in dogs under primary veterinary care in the UK. A retrospective cohort study design was used. Clinical records were automatically searched and manually verified for incident cases of unilateral CCL rupture during 2019 and additional clinical management information extracted. Multivariable logistic regression modelling was used to evaluate associations between risk factors and: (1) CCL rupture diagnosis; and (2) clinical management (surgical or non-surgical). The analysis included 1000 unilateral CCL rupture cases and a random selection of 500,000 non-cases. After accounting for confounding factors, dogs aged 6 to < 9 years, male neutered and female neutered dogs, insured dogs, and Rottweiler, Bichon Frise, and West Highland White terrier breeds, in particular, had increased odds of unilateral CCL rupture diagnosis. Insured dogs and dogs ≥ 20 kg had increased odds of surgical management, while dogs ≥ 9 years and dogs with one non-orthopaedic comorbidity at diagnosis with CCL rupture had reduced odds. These findings inform identification of at-risk dogs, with Rottweilers and Bichon Frise particularly predisposed. Additionally, they contribute to a greater understanding of the clinical rationales used in primary-care veterinary practices to decide between surgical or non-surgical management of unilateral CCL rupture.