Objective:Hyperkalemia is a frequent, life-threatening emergency in dogs and cats. It disrupts neuromuscular function and cardiac conduction. Clinicians need a clear physiologic framework to recognize risk and act quickly. Animals and procedure:Part 1 of this 2-part review explains potassium homeostasis and the main causes of hyperkalemia in small animals. The article draws on peer-reviewed veterinary studies and core physiology, with direct patient-side relevance. Results:Most body potassium is intracellular; small extracellular shifts alter membrane excitability and electrocardiogram patterns. Two systems control plasma potassium: transcellular control through insulin, β2-adrenergic tone, and acid-base effects; and renal control through filtration, distal sodium delivery, tubular flow, and mineralocorticoid effect. Common clinical causes include decreased renal excretion (feline urethral obstruction, oligoanuric acute kidney injury, canine hypoadrenocorticism); transcellular shifts from intracellular to extracellular spaces (diabetic ketoacidosis, mineral metabolic acidosis, extensive tissue injury); increased intake or iatrogenic load when excretion is limited (potassium chloride in IV fluids, older stored blood, drugs that reduce aldosterone effect or distal sodium delivery); and pseudohyperkalemia due to sample factors (hemolysis, marked thrombocytosis or leukocytosis, anticoagulant contamination). Conclusion and clinical relevance:Evaluate hyperkalemia in the full clinical context. In dogs, common causes include hypoadrenocorticism, acute kidney injury, and urinary tract obstruction or rupture. In cats, urethral obstruction and advanced renal failure predominate, whereas iatrogenic potassium load and severe metabolic acidosis are additional concerns. A firm grasp of both pathophysiology and etiology improves differential diagnosis and early decisions. Part 2 of this review will build on this foundation and outline diagnosis and treatment.

Objective:Hyperkalemia in dogs and cats can cause rapid cardiac and neuromuscular compromise. Fast recognition, ECG-guided stabilization, and cause-directed therapy improve survival. Animals and procedure:Part 2 of this 2-part review gives a patient-side approach for recognition, confirmation, and emergency treatment of hyperkalemia. It integrates current veterinary evidence and core physiology into step-by-step guidance for ECG interpretation, point-of-care testing, drug selection, and monitoring. It also maps 1st-hour priorities to common etiologies such as urethral obstruction and hypoadrenocorticism. Results:Immediate cardioprotection with intravenous calcium treats cardiotoxicity. Potassium decreases rapidly with regular insulin plus dextrose, β2 agonists serve as adjuncts, and bicarbonate is reserved for severe acidemia. Potassium elimination follows with balanced crystalloids and, when needed, renal replacement therapy. After initial stabilization, durable correction depends on identifying and treating the underlying cause and removing excess potassium from the body. Close glucose surveillance prevents late hypoglycemia after insulin. For urethral obstruction, prompt unblocking and fluids often normalize potassium with little need for repeat shifting drugs. For Addisonian crisis, fluids and glucocorticoids correct the driver while potassium decreases. Conclusion and clinical relevance:Use a consistent sequence: Verify true hyperkalemia, protect the heart, shift potassium, remove potassium, and fix the cause. Pair ECG findings with serum potassium concentrations to guide action, since ECG stages do not always match absolute potassium concentrations. This approach helps emergency clinicians stabilize patients quickly and avoid relapse. Part 1 of this review covered homeostasis and causes, whereas Part 2 delivers diagnostic and treatment approaches.

Objective:To establish the expected presenting blood lactate values in dogs with acute seizure activity. The secondary goal was to compare lactate values between dogs presenting for a single seizure (SSG) or cluster seizures (CSG) or in status epilepticus (SEG). Methods:In this retrospective observational study, the electronic medical record at a university small animal hospital was queried for dogs with acute seizures (within 24 hours of presentation) with a blood lactate measurement within 2 hours of presentation between January 1, 2014, and October 31, 2024. Data related to seizure type, lactate values, patient vital parameters, and other blood parameters (if available) were extracted. Dogs with incomplete medical records were excluded. Results:88 dogs were included in 95 presentation events. The median age was 6 years, 5 months; 52 events involved female dogs, and 43 events involved male dogs. Twenty-two dogs made up the SSG, 51 dogs made up the CSG, and 22 dogs made up the SEG. The majority (72.6%) of dogs had a high lactate value on presentation (median values: SSG, 2.7 mmol/L; CSG, 3.1 mmol/L; and SEG, 4.65 mmol/L). Status epilepticus dogs had a statistically significantly elevated body temperature (median, 39.4 °C) compared to the SSG (38.8 °C); there were no statistically significant differences in blood glucose, lactate, or blood pH between groups. Conclusions:Median lactate values were elevated in all groups at presentation, but there was no statistical difference between groups. The median temperature was elevated in the SEG. Clinical Relevance:This study provides expected lactate values in dogs with acute seizure activity.

Objective:To investigate the effects of high-dose IV vitamin C (HDIVC) on handheld portable blood glucose monitor (PBGM) and interstitial glucose monitor (IGM) readings in dogs. Methods:6 client-owned Border Collies with normal physical examinations and baseline bloodwork were enrolled in this prospective experimental study from November through December 2024. Glucose was measured via an IGM, PBGM, and laboratory blood glucose analyzer (LG) at time (T)-0, T1, T2, T3, T6, T12, T18, and T24 hours after HDIVC (200 mg/kg; ascorbic acid 500 mg/mL diluted 1:10 with sterile water, given over 30 minutes, IV). Results:The median PBGM (T1, 189 mg/dL; T2, 138 mg/dL) and IGM (T1, high; T2, 321 mg/dL) readings were significantly higher than LG (T1, 76.5 mg/dL; T2, 93.5 mg/dL) at T1 and T2. The median IGM (183 mg/dL) readings were significantly higher than LG (99 mg/dL) at T3. There was no significant difference between modalities at T0 nor from T6 on. On consensus error grid analysis, all PBGM readings at T1 and 1 of 6 readings at T2 were clinically unacceptable. All IGM readings at T1 and T2 and 2 of 6 readings at T3 were clinically unacceptable. Conclusions:A 200-mg/kg, IV, bolus of vitamin C in healthy dogs causes clinically significant elevations in PBGM and IGM glucose readings that normalize within 3 and 6 hours, respectively. Clinical Relevance:Avoid the use of PBGM and IGM until 3 and 6 hours, respectively, after HDIVC in healthy dogs.

Smoke contains a mixture of harmful gases, chemicals, and superheated particles. Inhalation of smoke causes generalized hypoxia and airway inflammation due to impaired oxygen transport and utilization, as well as thermal and chemical injury in the airways. Generally, treatment is supportive with oxygen therapy and airway management, including chest physiotherapy, bronchodilators, and nebulization. Immediate oxygen therapy is mandatory for all suspected smoke inhalation patients and should not be delayed pending diagnostic test results or due to "normal" oxygen saturation readings that can be falsely elevated in carbon monoxide intoxication. Smoke inhalation patients with mild clinical signs who respond well to initial stabilization generally have a favorable prognosis. However, patients with severe signs or progression despite initial stabilization may require more advanced or intensive care.

Objectives The study aimed to determine if an ultrasonic Doppler-guided technique (UDGT) leads to improved placement efficacy (time, success) of feline dorsal pedal arterial catheters vs the traditional palpation-guided technique (TPT). Methods A total of 26 adult, client-owned cats requiring sedation or general anesthesia for any reason, aged >12 months and weighing >3.0 kg, and with Doppler blood pressure measurements of at least 80 mmHg were enrolled. Each hindlimb was randomly assigned for dorsal pedal arterial catheterization using either the UDGT or TPT. With the UDGT, the location of the artery was identified by an audible sound using the Doppler. Successful catheter placement was confirmed by visualization of an arterial pressure waveform using a transducer and monitor system attached to the catheter. The Kaplan–Meier method and log-rank test were used to compare the two techniques. Results The overall proportion of successful arterial catheterization was 17% (9/52): 19% (5/26) via UDGT and 15% (4/26) via TPT. Among successful arterial catheterizations (n = 9), the mean time to catheterization was 339 ± 198 s: 328 ± 237 s (n = 5) with UDGT and 353 ± 171 s (n = 4) with TPT. The log-rank test showed the two techniques were not significantly different in likelihood of successful arterial catheter placement or time to successful catheterization ( P = 0.698). An arterial flash occurred in 62% (32/52) of the limbs, 58% (15/26) with the UDGT and 65% (17/26) with the TPT. Complications (self-limiting bruising, hematoma formation) were observed equally between UDGT (3/26 limbs) and TPT (3/26 limbs) in six cats. Conclusions and relevance The UDGT did not improve the efficacy of catheter placement compared with the TPT. Few complications were associated with arterial catheterization.

Seizures are a common presentation seen in small animal practices. Seizures require prompt management including initial interventions for triage, stabilization, and treatment with first-line anticonvulsant (AC) drugs like benzodiazepines. Concurrently, ruling out metabolic or extracranial causes with point-of-care diagnostics can help guide further diagnostics and treatments. Analysis of the history and a physical exam are also necessary to rule out common “look-alikes” that require specific diagnostic workup and treatments. Typically, causes of seizures can be grouped into intracranial and extracranial causes, with the latter being easier to diagnose with commonly available tests. This review presents a systematic approach to the diagnosis and treatment of single seizures, cluster seizures, and status epilepticus in dogs and cats.

OBJECTIVE To compare 4 point-of-care (POC) techniques to assess nasogastric (NG) tube placement versus radiographs as a reference standard. POC methods included air inflation with auscultation, fluid aspiration with pH measurement, ultrasonography, and capnography. DESIGN Prospective observational study in hospitalized dogs between 2020 and 2021. SETTING University teaching hospital. ANIMALS Fifty-one dogs requiring NG tube placement as part of their normal care. INTERVENTIONS After standard blind NG tube placement, each POC method was performed following standardized instructions. All POC methods were scored as to whether the investigator believed the tube to be in the gastrointestinal tract (as indicated by positive auscultation of borborygmus during insufflation, positive fluid aspiration with pH ≤5, presence of hyperechoic shadow in the esophagus, or absence of capnographic waveform). Subsequently, radiographs were taken to determine NG tube position as a gold standard. The sensitivity, specificity, and accuracy of each test as compared to 2-view thoracic radiographs were determined. MEASUREMENTS AND MAIN RESULTS Sensitivity, specificity, and accuracy for each POC technique were as follows: air auscultation (84.4%, 50.5%, and 80.4%, respectively), neck ultrasound (95.6%, 83.3%, and 94.1%, respectively), capnography (91.1%, 33.3%, and 84.3%, respectively), and fluid aspiration with pH measurement (22.2%, 100%, and 31.4%, respectively). CONCLUSIONS Among the 4 techniques evaluated, neck ultrasound had the best overall performance for assessing NG tube placement. Fluid aspiration with pH measurement might also have potential due to perfect specificity, but its clinical utility may be limited by low sensitivity and accuracy. Nonetheless, 2-view thoracic radiography should still be considered the standard method for confirmation of NG tube placement as none of the 4 POC techniques investigated showed both high sensitivity and perfect specificity.

OBJECTIVE:To compare the performance of an interstitial glucose monitor (IGM) versus a portable blood glucose monitor (PBGM) in sick juvenile dogs in a veterinary ICU. ANIMALS:16 client-owned dogs admitted to the university teaching hospital under 1 year of age with systemic illness. PROCEDURES:Paired interstitial and blood glucose samples were collected. A third glucose measurement with a reference method was obtained when IGM and PBGM values were clinically disparate. Analytical accuracy was measured by Pearson correlation and agreement statistics, including mean absolute relative difference (MARD), bias, and 95% limits of agreement. The Parkes consensus error grid analysis was performed to assess clinical accuracy. RESULTS:159 paired glucose measurements were available for analysis. Comparison of IGM readings to PBGM measurements resulted in an MARD of 15.4% and bias of -2.6%, with the 95% limits of agreement ranging from -42.5% to 37.4%. Positive correlation between IGM and PBGM (Pearson r = 0.65) was found. On consensus error grid analysis, 100% of the pairs fell into clinically acceptable zones (74.2% in zone A, and 25.8% in zone B). When disparate IGM and PBGM readings were compared to a laboratory reference standard (n = 13), both methods resulted in high MARD and wide limits of agreement. CLINICAL RELEVANCE:The IGM provides clinically acceptable glucose measurements compared to PBGM to monitor glucose levels in juvenile dogs in a clinical setting. Further clinical studies with a larger sample size, particularly in the hypoglycemic range, are needed to assess IGM performance in the lower glucose range.

Primary hemostatic disorders such as thrombocytopenia and thrombocytopathia are commonly encountered in small animal practice. The key stages of primary hemostasis include platelet adhesion, activation, and aggregation. Understanding the interaction between tissues, platelets, and signaling molecules not only helps clinicians comprehend clot formation but also better recognize thrombocytopathias. Although congenital thrombocytopathia is rare, commercially available platelet function tests allow veterinarians to narrow differentials in many clinical settings. Thrombocytopenia can be easily diagnosed in any clinical setting. In this paper, we review the current understanding of primary hemostasis in veterinary medicine, including the clinical presentation and available diagnostics to identify platelet abnormalities.

OBJECTIVE:To evaluate agreement between 2 standard laboratory (SL) methods and an immunochromatographic strip (ICS) method to crossmatch dogs receiving RBC transfusions. A second objective was to evaluate uninterpretable SL crossmatch results as compared to ICS in the presence of autoagglutination.DESIGN:Prospective observational study (September 2018 to October 2019).SETTING:University teaching hospital.ANIMALS:Forty anemic dogs receiving RBC transfusions.INTERVENTIONS:None.MEASUREMENT AND MAIN RESULTS:All dogs received DEA 1-negative packed RBCs. Three crossmatch methods were evaluated against the same unit transfused to each dog: SL method performed at institutional laboratory (SL-I), SL method sent to a commercial laboratory (SL-C), and a commercially available point-of-care ICS method. Major and minor crossmatches were incompatible for 2.5%/7.5% of ICS tests, 82.5%/52.5% of SL-I tests, and 52.5%/27.5% of SL-C tests. Agreement between ICS and SL-C major (κ = 0.05) and minor (κ = 0.02) crossmatches and between ICS and SL-I major (κ = 0.009) and minor (κ = 0.03) crossmatches was slight. Agreement between SL-C and SL-I major (κ = -0.06) and minor (κ = -0.12) crossmatches was poor. Results of major and minor crossmatches were uninterpretable due to autoagglutination in 38%/38% for SL-I and 29%/18% for SL-C crossmatches. ICS method was interpretable for 93% (major) and 98% (minor) crossmatches. After exclusion of uninterpretable SL pairings, agreement still remained poor to slight between all tests. Only 1 of 40 dogs (2.5%; 95% confidence interval: <1.0%-13.2%) had an immediate immunological transfusion reaction.CONCLUSIONS:Lack of agreement between all methodologies was noted. The high level of incompatibility predicted by SL methods despite lack of clinically relevant reactions suggests a high false incompatibility rate as compared to the ICS test. ICS testing was also able to give results more frequently in the face of autoagglutination. Further work is needed to investigate the ICS method's ability to predict clinically significant transfusion reactions.

OBJECTIVE To evaluate physical compatibility of small animal (SAE) and large animal (LAE) injectable formulations of enrofloxacin with select IV fluids and drugs. SAMPLE 162 admixtures containing SAE or LAE with saline (0.9% NaCl) solution, lactated Ringer solution (LRS), Plasma-Lyte A (PLA), 6% hydroxyethylstarch 130/0.4 (HES), metoclopramide, or ampicillin-sulbactam. PROCEDURES In the first of 2 simultaneously conducted experiments, admixtures containing enrofloxacin (10 mg/kg) and a volume of IV fluid that would be administered over a 20-minute period when dosed at the maintenance infusion rate (40 mL/kg/d for saline solution, LRS, and PLA and 20 mL/kg/d for HES) were created. In the second experiment, enrofloxacin (10 mg/kg) was admixed with saline solution (40 mL/kg/d) and metoclopramide (2 mg/kg/d) or ampicillin-sulbactam (30 mg/kg). In both experiments, admixture components were infused into a flask over 20 minutes assuming patient weights of 5, 10, and 20 kg. Admixtures were created by use of undiluted SAE and SAE diluted 1:1 with saline solution and undiluted LAE and LAE diluted 1:1 and 1:10 with saline solution. Admixtures were assessed for physical incompatibility at 0, 15, 30, and 60 minutes after completion of mixing. Physical incompatibility was defined as gross precipitation, cloudiness, Tyndall effect, or change in turbidity. RESULTS Admixtures containing undiluted SAE or LAE were physically incompatible with saline solution, PLA, LRS, and HES. Because saline solution was used to dilute SAE and LAE, all admixtures containing diluted SAE or LAE were also physically incompatible. Physical compatibility of enrofloxacin with metoclopramide or ampicillin-sulbactam could not be assessed because those admixtures also contained saline solution. CONCLUSIONS AND CLINICAL RELEVANCE Enrofloxacin was physically incompatible with all tested solutions.

The normal and abnormal features of blood coagulation and its diagnosis in cats and dogs are described.

This book contains 10 illustrated chapters that describe the normal and pathological clinical parameters of cats and dogs and their diagnosis, including physical examination, blood pressure monitoring, electrocardiography, pulse oximetry, venous and arterial blood gas analysis, capnography, ultrasonography, electrolyte monitoring, blood coagulation and manometry. It is intended to aid veterinary students and practitioners on how to use the available monitoring equipment to gather information about a specific case.

Abstract The normal and abnormal features of blood coagulation and its diagnosis in cats and dogs are described.

Abstract This chapter discusses the normal and abnormal acid–base parameters and analysis of the oxygenation/ventilation status in cats and dogs.

OBJECTIVETo assess the effect of packed RBC (pRBC) transfusion on thromboelastographic (TEG) tracings in dogs with naturally occurring anemia.ANIMALS22 clinically anemic dogs that received a pRBC transfusion.PROCEDURESFor each dog, a blood sample was collected before and within 3 hours after completion of the pRBC transfusion for a CBC, nonactivated TEG analysis, and measurement of blood viscosity. Wilcoxon signed rank tests were used to compare CBC, viscosity, and TEG variables between pretransfusion and posttransfusion blood samples. Multivariable linear regression was used to assess the effects of pretransfusion-posttransfusion changes in Hct, WBC count, and platelet count on changes in TEG variables.RESULTSMedian posttransfusion Hct (21%; range, 13% to 34%) was significantly greater than the median pretransfusion Hct (12.5%; range, 7% to 29%). Packed RBC transfusion was associated with a median increase in Hct of 6.2% (range, 1.2% to 13%). Maximum amplitude significantly decreased from 74.9 to 73.8 mm and clot strength significantly decreased from 14,906 to 14,119 dynes/s after pRBC transfusion. Blood viscosity significantly increased, whereas platelet and WBC counts significantly decreased after transfusion. Multivariable linear regression revealed that pretransfusion-posttransfusion changes in Hct, WBC count, and platelet count were not associated with changes in TEG variables.CONCLUSIONS AND CLINICAL RELEVANCEResults indicated that pRBC transfusion had only small effects on the TEG tracings of hemodynamically stable dogs. Therefore, large changes in TEG tracings following pRBC transfusion are unlikely to be the result of the transfusion and should be investigated further.

Immune-mediated hemolytic anemia (IMHA) is a life-threatening autoimmune disorder characterized by a self-mediated attack on circulating red blood cells. The disease occurs naturally in both dogs and humans, but is significantly more prevalent in dogs. Because of its shared features across species, dogs offer a naturally occurring model for studying IMHA in people. In this study, we used RNA sequencing of whole blood from treatment-naïve dogs to study transcriptome-wide changes in gene expression in newly diagnosed animals compared to healthy controls. We found many overexpressed genes in pathways related to neutrophil function, coagulation, and hematopoiesis. In particular, the most highly overexpressed gene in cases was a phospholipase scramblase, which mediates the externalization of phosphatidylserine from the inner to the outer leaflet of cell membranes. This family of genes has been shown to be critically important for programmed cell death of erythrocytes as well as the initiation of the clotting cascade. Unexpectedly, we found marked underexpression of many genes related to lymphocyte function. We also identified groups of genes that are highly associated with the inflammatory response and red blood cell regeneration in affected dogs. We did not find any genes that distinguished dogs that lived vs. those that died at 30 days following diagnosis, nor did we find any relevant genomic signatures of microbial organisms in the blood of affected animals. Future studies are warranted to validate these findings and assess their implication in developing novel therapeutic approaches for dogs and humans with IMHA.