Clinical features and outcome of dogs and cats with gastrointestinal pneumatosis: 30 cases (2010-2021).

OBJECTIVES: To describe the presentation, etiology, and outcome of dogs and cats diagnosed with gastrointestinal pneumatosis (GP). DESIGN: Retrospective study. SETTING: Three referral institutions. ANIMALS: Twenty-six dogs and 4 cats. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The most common sites of GP were the stomach (n = 19), followed by the colon (n = 8) and small intestine (n = 2). One case had pneumatosis of both the stomach and the colon. GP was most commonly associated with gastrointestinal disease in dogs (18/26 [69%]) and cats (3/4 [75%]), with common diagnoses including gastric dilatation and volvulus (n = 5), acute hemorrhagic diarrhea syndrome (n = 4), and gastrointestinal ulceration (n = 4). Of the 4 cases of gastrointestinal ulceration, 3 were dogs with a history of glucocorticosteroid or nonsteroidal anti-inflammatory drug administration and vomiting and diarrhea. Six of 30 cases (20%), all of which were dogs, were determined to have a surgical indication for exploratory celiotomy, although not solely on the basis of diagnosis of GP. Five cases underwent exploratory celiotomy, of which 1 (20%) survived to hospital discharge. Of the medically managed cases, 13 of 24 (54%) survived to hospital discharge. Overall, 14 of 30 cases (47%) survived to hospital discharge. CONCLUSIONS: GP is an uncommon diagnostic imaging finding that is associated with a variety of disease processes. Its development is often related to primary gastrointestinal diseases. In the absence of other surgical disease, exploratory celiotomy based solely on the diagnosis of GP is unlikely to be indicated.

Causes and consequences of feline haemothorax: A retrospective case series.

BACKGROUND: The objective of this study was to describe the causes of haemothorax in cats, patient presentation and outcome. METHODS: This was a retrospective study based in a university teaching hospital. The electronic case records of cats presenting with a haemothorax between January 2005 and January 2023 were searched. Cases were categorised into 'trauma', 'neoplasia', 'coagulopathy' or 'other'. Signalment, physical examination, clinical pathology findings, concurrent injuries and diagnostic imaging findings were recorded. The median hospitalisation time was calculated, and survival to discharge was noted. RESULTS: Twenty-five cats were eligible for inclusion. Twenty cases of haemothorax were traumatic in origin, two were neoplastic, two were 'other' and one was coagulopathic. Increased respiratory rate (n = 22) and effort (n = 20) were common, and most patients were anaemic at presentation (n = 16). Common concurrent injuries included pulmonary contusions (n = 15) and pneumothorax (n = 11). The median hospitalisation time for the trauma cats was 5 days (range 1‒15). Overall, 83.3% of the cases survived to discharge. LIMITATIONS: The limitations of this study are related to its retrospective nature and the relatively small number of cats in the study population. CONCLUSION: Haemothorax requiring a thoracocentesis in cats is rare, with trauma being the most likely cause. These patients tend to have concurrent injuries and require ongoing hospitalisation. Owners can be advised that the short-term outcome is generally favourable.

Why some canine and feline blood donors do not make the cut: A cohort study.

BACKGROUND: While there has been extensive investigation into the selection and retention of human blood donors, veterinary research in this area is limited. This study aimed to identify the reasons for the rejection and withdrawal of canine and feline blood donors from a blood donation programme. METHODS: Records of cats and dogs presenting as prospective blood donors and/or donating between 2014 and 2019 were analysed. Reasons for rejection at sign-up were categorised into medical and temperament. Reasons why animals left before retirement age were categorised into medical, temperament and owner related. RESULTS: Data from 362 dogs and 134 cats were analysed. Cats (20.8%) were more likely to be rejected than dogs (5.2%) at sign-up, mostly due to medical reasons. Both species often left the blood donor service early due to temperament reasons. Owner and medical reasons for leaving early were also common. LIMITATION: This was a retrospective study with subjective assessment of temperament. CONCLUSIONS: Inability to donate due to temperament and medical reasons is common. When recruiting blood donors, it should be recognised that a fairly high proportion will not be successful. Owner understanding and motivation are essential to ensure successful selection and retention of donors, which allows amortisation of recruitment costs.

Clinical and clinicopathological features and outcomes of cats with suspected dietary induced pancytopenia.

BACKGROUND: After a strong epidemiological link to diet was established in an outbreak of pancytopenia in cats in spring 2021 in the United Kingdom, 3 dry diets were recalled. Concentrations of the hemato- and myelotoxic mycotoxins T-2, HT-2 and diacetoxyscirpenol (DAS) greater than the European Commission guidance for dry cat foods were detected in the recalled diets. OBJECTIVES: To describe clinical and clinicopathological findings in cats diagnosed with suspected diet induced pancytopenia. ANIMALS: Fifty cats presenting with pancytopenia after exposure to a recalled diet. METHODS: Multicenter retrospective case series study. Cats with known exposure to 1 of the recalled diets were included if presented with bi- or pancytopenia and underwent bone marrow examination. RESULTS: Case fatality rate was 78%. Bone marrow aspirates and biopsy examination results were available in 23 cats; 19 cats had a bone marrow aspirate, and 8 cats had a biopsy core, available for examination. Bone marrow hypo to aplasia-often affecting all cell lines-was the main feature in all 31 available core specimens. A disproportionately pronounced effect on myeloid and megakaryocytic cells was observed in 19 cats. Myelofibrosis or bone marrow necrosis was not a feature. CONCLUSION AND CLINICAL IMPORTANCE: Mycotoxin induced pancytopenia should be considered as differential diagnosis in otherwise healthy cats presenting with bi- or pancytopenia and bone marrow hypo- to aplasia.

An investigation into an outbreak of pancytopenia in cats in the United Kingdom.

BACKGROUND: In spring 2021 increasing numbers of cats presenting with severe pancytopenia were noted in United Kingdom (UK). OBJECTIVE: To describe process and outcome of the investigation performed into the outbreak of pancytopenia in cats. ANIMALS: Five hundred and eighty client owned cats that presented with severe bi- or pancytopenia of unknown cause. METHODS: Real-time data collection was performed by an online registration forum available to all veterinary surgeons in UK. Data collected included demographics, clinicopathological findings, diagnostic testing, dietary and drug history, outcome and COVID household status. Mycotoxicological feed analysis was performed on feed samples of 3 diets frequently mentioned in the database and 3 control diets. RESULTS: Five hundred and eighty cats presented to 378 veterinary practices were included for analysis. Case fatality rate was 63.3%. Dietary history was available for 544 (93.8%) cats, of which 500 (86%) were fed 1 of 3 diets (which were recalled midinvestigation). 54 (9.3%) cats were not fed a recalled product, with diet information unknown in 26 (4.5%) cats. Analysis of feed samples revealed concentrations of hematotoxic trichothecene T-2/HT-2 mycotoxins greater than recommended by the European Commission in 5/7 recalled diet samples but in none of control diet samples. The trichothecene mycotoxin diacetoxyscirpenol (DAS) was detectable in all recalled diet samples but not in any of control samples. CONCLUSION AND CLINICAL IMPORTANCE: Contaminated-feed induced trichothecene mycotoxicosis should be considered as a differential diagnosis for pancytopenia in cats.

Retrospective evaluation of the use of small-bore wire-guided catheters for the management of peritoneal effusion in cats and dogs.

OBJECTIVE: To describe the use of small-bore wire-guided catheters in the management of peritoneal effusion in cats and dogs and to detail any associated adverse events. DESIGN: Retrospective study. SETTING: University teaching hospital ANIMALS: Forty-five client-owned animals that had peritoneal catheters placed for management of peritoneal effusion between July 2010 and June 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Forty-five cases were included (25 dogs and 20 cats). Twenty-eight animals had the catheter placed to aid management of a uroabdomen, 8 of which recovered without surgical management, 11 had the catheter placed to allow autotransfusion of hemoabdomen, 3 had peritonitis, and 3 had ascites secondary to cardiac disease. Twenty-seven cases (15 dogs and 12 cats) received sedation (n = 24) or local anesthesia alone (n = 3) to facilitate catheter placement, and 6 cases had the catheter placed while under general anesthesia. Median length of catheter persistence was 24 hours (range: 2-144 h). The most common adverse events reported were impaired drainage (n = 7) and leakage at the insertion site (n = 4). CONCLUSIONS: Peritoneal catheters can be inserted percutaneously for management of peritoneal effusion. Indications include stabilization and conservative management of uroabdomen, and autotransfusion. They can often be placed with minimal or no sedation and adverse events appear infrequent in occurrence.

Incidence of acute haemolysis in cats receiving canine packed red blood cells (xenotransfusions).

OBJECTIVES: The aim of this study was to report the incidence of transfusion reactions in cats, including acute haemolysis (AH), occurring within 24 h of receiving a xenotransfusion. An additional aim was to determine whether cases with AH could be classified as having an acute haemolytic transfusion reaction (AHTR) as per the definition provided by the Association of Veterinary Haematology and Transfusion Medicine's Transfusion Reaction Small Animal Consensus Statement. METHODS: Medical records of cats that received canine packed red blood cells (PRBCs) between July 2018 and September 2020 at a veterinary hospital were reviewed. The incidence of AH, AHTRs, febrile non-haemolytic transfusion reactions (FNHTRs), transfusion-associated circulatory overload and septic transfusion reactions were recorded. RESULTS: The medical records of 53 cats were retrospectively evaluated. Twenty-three (43%) cats had transfusion reactions. Thirteen (25%) cats had AH; however, only four (8%) met the definition of an AHTR. Ten (19%) cats were determined to have FNHTRs. Survival to discharge of cats affected by AH was 50% (25% for cases that met the definition of an AHTR). Survival to discharge of cats not suffering from AHTR was 40%. CONCLUSIONS AND RELEVANCE: This report indicates that a higher proportion of cats undergo AH (25%) when administered canine PRBCs than previously reported, although many could not be classed as having an AHTR due to an apparently adequate packed cell volume rise. Challenges with sourcing feline blood in emergency situations occasionally necessitates the use of xenotransfusion in transfusion medicine. Clinicians should be aware that haemolysis after xenotransfusion can occur within 24 h and that a repeat feline transfusion may be required sooner than anticipated in some cases.

The effects of leukoreduction on canine blood unit weight and processing time.

BACKGROUND: Despite a lack of strong evidence of benefit, leukoreduction is employed to decrease the risk of leukocyte-induced transfusion reactions. However, the impact of leukoreduction on blood bank costs and inventory management is not well understood. The purpose of this study was to determine whether leukoreduction of whole blood increases total processing time and weight loss from packed red blood cells (PRBCs) and plasma relative to bags created from nonleukoreduced whole blood. KEY FINDINGS: A total of 68 canine whole blood collections were divided equally into leukoreduced and nonleukoreduced groups (N = 34 in each). There was no significant difference between groups in mean PRBC or plasma unit weights or processing times. Leukoreduced PRBC bags lost a significantly greater proportion of weight during processing than did nonleukoreduced PRBC bags (P < 0.01), which is attributed to red and white blood cells lost in the filtration process. SIGNIFICANCE: Leukoreduction did not lead to a significant increase in processing times or smaller PRBCs or plasma bags compared to nonleukoreduced bags. The blood remaining in the leukoreduction filter following filtration is primarily composed of red blood cells, with minimal plasma retained.

Occurrence and clinical management of urethral obstruction in male cats under primary veterinary care in the United Kingdom in 2016.

BACKGROUND: Urethral obstruction (UO) has a negative effect on welfare of cats. OBJECTIVES: This study aimed to determine incidence, case management, and outcomes of UO in cats in primary-care practice in the United Kingdom. ANIMALS: All male cats under veterinary care within the VetCompass database in 2016. METHODS: A retrospective cohort study was performed. The electronic records of all male cats with a clinical note during the study period were searched for UO cases and were manually reviewed for inclusion. Additional demographic and clinical information were extracted on cases. RESULTS: From the study cohort of 237 825 male cats, there were 1293 incident cases. The estimated UO incidence risk during 2016 was 0.54 (95% CI: 0.51-0.57). Demographic and clinical data were available for 1108 cases. Antibiotics were administered to 641/1108 (57.9%) cases. Overall repeat catheterization rate was 253/854 (29.6%). Repeat catheterization at 48 hours was less frequent in patients with indwelling catheters (10.1%) vs those that had a catheter placed and then immediately removed (14.8%; P = .04). Death during a UO episode was 329/1108 (29.6%), and 285/329 (88.0%) deaths involved euthanasia. CONCLUSIONS AND CLINICAL IMPORTANCE: Antibiotics were commonly prescribed in cats for treatment of UO despite minimal evidence in the clinical records of bacterial cystitis. Repeat catheterization was common and case fatality rate during a UO episode was high. Repeat catheterization within 48 hours of elective removal of a urethral catheter was less common in cats that had previously had indwelling catheters. The majority of cats requiring repeat catheterization survived until the end of the study.

Respiratory complications in dogs with tetanus: A retrospective study of 53 cases.

Tetanus can lead to respiratory complications, and the outcome of dogs affected by this disease is still largely unknown. This retrospective study aimed to evaluate the frequency and outcome of 53 dogs with tetanus and respiratory complications between February 2006 and January 2019. Medical records from dogs diagnosed with tetanus admitted to a referral teaching hospital were reviewed. Fifty-three dogs were diagnosed with tetanus and respiratory complications were observed in 26.4% (14/53) of dogs; 8 developed aspiration pneumonia (AP), 5 developed upper airway obstruction (UAO) and 1 dog developed both. A total of 5 AP dogs were mechanically ventilated. Three dogs with UAO had tracheostomy tubes placed. Dogs with respiratory complications had a poorer outcome, with only 14.3% (2/14) surviving to discharge, compared to 94.8% (37/39) for dogs with no respiratory complications. Respiratory complications such as AP and UAO were common in dogs with tetanus, and this was associated with a poorer outcome.

Complications respiratoires chez des chiens affectés par le tétanos : une étude rétrospective de 53 cas. Le tétanos peut entrainer des complications respiratoires et les conséquences de celles-ci sur le pronostic vital du patient sont souvent inconnues. Cette étude rétrospective d'observation a pour but d'évaluer l'incidence et les conséquences de complications respiratoires chez 53 chiens affectés par le tétanos entre février 2006 et janvier 2019.Les dossiers médicaux de chiens ayant le tétanos et admis dans un hôpital de référence furent analysés. Cinquantetrois chiens furent diagnostiqués du tétanos et des complications respiratoires ont été observé dans 26,4 % (14/53) des cas; huit développèrent une pneumonie par aspiration (AP), 5 développèrent une obstruction des voies aériennes supérieures (UAO), un patient eut les deux. Trois patients avec une UAO reçurent une trachéostomie. Les patients avec des complications respiratoires avaient une évolution plus néfaste, avec seulement 14,3 % (2/14) qui survécurent jusqu'à la sortie de l'hôpital, comparativement à 94,8 % (37/39) pour les patients sans complications respiratoires. Les complications respiratoires chez les chiens souffrant du tétanos sont courantes et ces patients ont un pronostic vital plus mitigé.(Traduit par les auteurs).

Focused Ultrasound Examination of Canine and Feline Emergency Urinary Tract Disorders.

This article discusses the usefulness of ultrasound examinations in the management of the patient with an emergency urinary tract disorder. It discusses the use of previously described point-of-care ultrasound protocols such as the abdominal focused assessment with sonography for trauma, triage, and tracking protocol in the unstable azotemic patient. Point-of-care ultrasound examination can help direct investigations and expedite the diagnosis of specific causes of azotemia. The limitations of point-of-care ultrasound assessment of the kidneys, ureter, bladder, and urethra are also addressed, emphasizing that point-of-care ultrasound examination should complement and not replace a complete urinary tract ultrasound examination.

Randomized double-blinded clinical trial on acute transfusion reactions in dogs receiving leukoreduced versus nonleukoreduced packed red blood cells.

BACKGROUND: Leukoreduction of blood products is commonly performed in human medicine, but its effect on outcome or incidence of transfusion reactions (TRs) in dogs is unknown. OBJECTIVES: To prospectively evaluate the incidence of acute TRs in, and the outcome of, dogs receiving either leukoreduced (LR) or nonleukoreduced (N-LR) packed red blood cells (PRBC). ANIMALS: Dogs (n = 194) administered PRBC between August 2017 and June 2020. METHODS: Prospective randomized double-blinded clinical trial. Dogs were randomized to receive either LR or N-LR PRBC and clinicians, nurses and investigators were blinded to the group allocations. The incidence of TRs, change in PCV, hospitalization duration, and survival to discharge were recorded. RESULTS: Out of the 194 dogs, 96 received LR and 98 received N-LR PRBCs. The mean 12-hour change in PCV value was +9.22% (SD 5.27%) for dogs that received N-LR and +10.69% (SD 6.44%) for dogs that received LR PRBC (effect size 0.26, 95% confidence interval [CI] -0.02 to 0.55), which was not significantly different (P = .08). TRs were documented in 16/194 (8.24%) dogs, with 1/194 (0.51%) being a mild allergic reaction, while 15/194 (7.73%) had suspected febrile nonhemolytic TRs (FNHTRs). FNHTR incidence was not significantly different between the LR (6/96, 6.25%, 95% CI 2.8-13.56) and N-LR (9/98, 9.18%, 95% CI 4.92-17.11) groups (P = .81). Of the 156 dogs that survived to discharge, 80/156 received N-LR PRBC and 76/156 received LR PRBC which was not significantly different (P = .66). CONCLUSIONS AND CLINICAL IMPORTANCE: A clinical advantage of using LR over N-LR PRBC in terms of TRs and increase in PCV after transfusion was not detected.

Retrospective evaluation of the seasonality of canine tetanus in England (2006-2017): 49 dogs.

OBJECTIVE:  To evaluate the seasonality of canine tetanus in England. METHODS:  Medical records of a single referral hospital in England were reviewed. Dogs diagnosed with localized or generalized tetanus between January 2006 and June 2017 were studied. RESULTS:  Forty-nine cases were included. The prevalence of tetanus in England was significantly higher in the winter when compared with the summer (P = 0.002) and autumn (P = 0.024), with the highest number of cases recorded in February. CONCLUSIONS:  The prevalence of canine tetanus in England was significantly higher in winter months, especially in February.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS). Part 1: Definitions and clinical signs.

OBJECTIVE: To use a systematic, evidence-based consensus process to develop definitions for transfusion reactions in dogs and cats. DESIGN: Evidence evaluation of the literature was carried out for identified transfusion reaction types in dogs and cats. Reaction definitions were generated based on synthesis of human and veterinary literature. Consensus on the definitions was achieved through Delphi-style surveys. Draft recommendations were made available through industry specialty listservs and comments were incorporated. RESULTS: Definitions with imputability criteria were developed for 14 types of transfusion reactions. CONCLUSIONS: The evidence review and consensus process resulted in definitions that can be used to facilitate future veterinary transfusion reaction research.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS) Part 2: Prevention and monitoring.

OBJECTIVE: To systematically review available evidence to develop guidelines for the prevention of transfusion reactions and monitoring of transfusion administration in dogs and cats. DESIGN: Evidence evaluation of the literature (identified through Medline searches through Pubmed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. Evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. Evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines for prevention and monitoring were generated based on the synthesis of the evidence. Consensus on the final recommendations and a proposed transfusion administration monitoring form was achieved through Delphi-style surveys. Draft recommendations and the monitoring form were made available through veterinary specialty listservs and comments were incorporated. RESULTS: Twenty-nine guidelines and a transfusion administration monitoring form were formulated from the evidence review with a high degree of consensus CONCLUSIONS: This systematic evidence evaluation process yielded recommended prevention and monitoring guidelines and a proposed transfusion administration form. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) transfusion reaction small animal consensus statement (TRACS). Part 3: Diagnosis and treatment.

OBJECTIVE: To systematically review available evidence to develop guidelines for diagnosis and treatment of transfusion-associated reactions in dogs and cats. DESIGN: Standardized and systemic evaluation of the literature (identified through Medline via PubMed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. The available evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. The evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines, diagnostic, and treatment algorithms were generated based on the evaluation of the evidence. Consensus on the final guidelines was achieved through Delphi-style surveys. Draft recommendations were disseminated through veterinary specialty listservs for review and comments, which were evaluated and integrated prior to final publication. RESULTS: Medline via PubMed and Google Scholar databases were searched. There were 14 Population Intervention Comparison Outcome questions identified and corresponding worksheets were developed focusing on the diagnosis and treatment of transfusion-associated reactions in dogs and cats. Fourteen guidelines and four algorithms were developed with a high degree of consensus. CONCLUSIONS: This systematic evidence evaluation process yielded recommended diagnostic and treatment algorithms for use in practice. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Left heart dimensions in anemic cats and dogs before and after blood transfusion.

BACKGROUND: Whether anemic cats and dogs with increased left heart dimensions are at higher risk of transfusion-associated circulatory overload, and the effect of blood transfusion on left heart dimensions in naturally occurring anemia is unknown. HYPOTHESIS/OBJECTIVES: To evaluate the effect of blood transfusion on left heart dimensions in clinically relevant anemia. ANIMALS: Twenty dogs and 20 cats presenting to a university veterinary teaching hospital. METHODS: In this prospective observational study, anemic dogs and cats requiring blood transfusion were included. Packed cell volume (PCV), total solids, and echocardiography were performed before and within 24 hours of blood transfusion. Signalment, bodyweight, disease process, transfusion duration and volume, and prior treatments were recorded. Nonparametric statistics were reported as median [range]. Post hoc Bonferroni correction set significance at P < .006. RESULTS: After transfusion, PCV increased in cats (12% [6-16] to 18% [10-33], P = .001) and dogs (14% [7-24] to 25% [9-37], P = .001), heart rate decreased in dogs (104 bpm [86-166] to 87 bpm [56-138], P < .001), and fractional shortening decreased in cats (57.1% [36.0-84.7] to 41.0% [28.1-69.6], P = .002) and dogs (33.79% [19.33-62.79] to 31.89% [19.06-51.47], P = .006). Left ventricular internal diameter in systole increased in cats (6.5 mm [2.7-9.8] to 7.9 mm [5.3-11.1], P = .001). Normalized left ventricular internal diameter in diastole (1.48 [1.25-1.79] to 1.57 [1.33-2.00], P = .001) and systole (0.87 [0.58-1.19] to 1.00 [0.74-1.36], P = .001) increased in dogs. Incidence of volume overload did not differ before (14/20 cats, 70%; 9/20 dogs, 45%) or after (12/20 cats, 60%; 11/20 dogs, 55%) transfusion (P = .64). CONCLUSIONS AND CLINICAL IMPORTANCE: Blood transfusion is well tolerated when signs of volume overload are present before transfusion.

Prospective evaluation of pericardial catheter placement versus needle pericardiocentesis in the management of canine pericardial effusion.

OBJECTIVE: To compare the safety and efficacy of pericardial catheter placement with needle pericardiocentesis in dogs with pericardial effusion (PE) DESIGN: Prospective, randomized clinical trial. SETTING: University teaching hospital. ANIMALS: Thirty client-owned dogs requiring pericardiocentesis between January 2017 and August 2019. INTERVENTIONS: Dogs were randomized to undergo PE drainage via indwelling pericardial catheter placement (catheter group) followed by elective drainage every 4-6 hours or needle pericardiocentesis (needle group) repeated as necessary. MEASUREMENTS AND MAIN RESULTS: Fifteen dogs were allocated to the catheter group and 15 to the needle group. Data collected included signalment, cause of effusion, occurrence of arrhythmias pre-, during, and post-pericardiocentesis, procedural length, and details of repeated drainages. There was no significant difference between mean procedural times for pericardial catheter placement (17.7 min [±11.8]) and needle pericardiocentesis (12.1 min [±8.6]) (P = 0.192) or the rate of new arrhythmias in the catheter (36%) and needle (64%) groups (P = 0.24). Pericardial catheters were kept in situ for a median of 21 hours (range, 14-85). Three of 15 (20%) dogs in the needle group required repeated pericardiocentesis within 24 hours of initial pericardiocentesis. Pericardial catheters enabled repeated large volume PE drainage in 4 cases (median, 10.6 mL/kg; range, 8-5-10.6). CONCLUSIONS: Pericardial catheters appear to offer a safe alternative to needle pericardiocentesis. Minimal sedation is required for placement, and they can be placed quickly. Their indwelling nature and use was not associated with a higher rate of arrhythmia compared to that of needle pericardiocentesis alone, and may be beneficial in the event that clinically significant PE recurs.