Ponies, miniatures, and younger equids are at higher risk of fecalith obstruction compared to a general colic population.

OBJECTIVE: To determine breed, age, and sex predispositions for fecalith obstruction and to evaluate short-term survival and prognostic factors following surgical treatment of fecalith intestinal obstruction in equids. ANIMALS: 151 equids. METHODS: Medical records of equids undergoing surgery for fecalith obstruction from 2000 to 2020 were reviewed. Signalment, history, presenting clinicopathological data, surgical findings, complications, and short-term survival were recorded and compared between survivors and nonsurvivors. Signalment of the fecalith population was compared to a contemporaneous colic population. Clinical factors were assessed for association with outcome. RESULTS: 64 females, 53 castrated males, and 31 intact males were included. Three equids presented twice. Miniature horses, ponies, and miniature donkeys/mules represented 48% (71/148) of fecalith population and full-sized breeds represented 52% (77/148). Miniature horses and ponies were overrepresented and equids ≤ 1 year of age were overrepresented in the fecalith population compared to the colic population. One hundred thirty-nine equids (92%) survived to discharge, 6% (9/148) were euthanized intraoperatively, and 2% (3/148) were euthanized during hospitalization. Nonsurvivors showed more severe colic signs on admission, tachycardia on admission, and hyperlipemia. Equids with postoperative colic (P = .01) and complications (P = .002) were less likely to survive. CLINICAL RELEVANCE: Miniature horses and ponies were overrepresented compared to the colic population; however, full-sized breeds were also affected. Surgical treatment had an excellent short-term prognosis. Severe colic signs, tachycardia, hyperlipemia, postoperative colic, and surgical complications negatively affected short-term survival.

Successful high-resolution three-dimensional electroanatomical mapping and radiofrequency catheter ablation of a posteroseptal accessory pathway in a dog using CARTO 3.

A one-year-and-seven-month-old, 28 kg, male castrated crossbreed dog was presented for supraventricular tachycardia causing recurrent episodes of anorexia and lethargy. Sotalol (2.2 mg/kg q12 h) reduced the frequency of symptomatic episodes but did not provide full relief. Three-dimensional electroanatomical mapping was performed at the Ghent University Small Animal Teaching hospital using the CARTO 3. Right atrial activation mapping identified the earliest atrial activation right posteroseptal, near the tricuspid annulus. Fast retrograde ventriculoatrial conduction during tachycardia and extrastimulus testing confirmed the presence of a concealed right posteroseptal accessory pathway. Six radiofrequency catheter ablation applications were delivered, and tachycardia remained uninducible. The dog recovered well from the procedure. Sotalol was stopped three weeks later, and no more clinical signs were noted by the owner. Repeated 24-hour electrocardiography monitoring on day one and at one, three, and 12 months after the procedure showed no recurrence of tachycardia.

Effect of physiological and pharmacological stress on heart rate, blood pressure, and echocardiographic measurements in healthy Warmblood horses.

BACKGROUND: Echocardiographic measurements are important prognostic indicators but might be influenced by heart rate and blood pressure. This is particularly important when comparing repeated examinations. HYPOTHESIS: To determine the effect of physiological stress at mildly increased heart rates and pharmacological challenge using IV administration of N-butylscopolammonium bromide and metamizol sodium on heart rate, blood pressure, and echocardiographic measurements. ANIMALS: Twenty healthy Warmblood horses. METHODS: Randomized crossover study. Horses were examined echocardiographically by 2-dimensional, M-mode, pulsed wave (PW) Doppler, and PW tissue Doppler imaging with simultaneous ECG recording and noninvasive blood pressure measurements during rest, physiological stress, and pharmacological challenge. Cardiac dimensions and functions were measured by a blinded observer. Data were analyzed using repeated-measures analysis of variance. RESULTS: Mean heart rate and arterial blood pressure were significantly higher during physiological stress (46 ± 2 bpm, 93 ± 16 mm Hg) and pharmacological challenge (62 ± 13 bpm, 107 ± 17 mm Hg) compared with rest (34 ± 3 bpm, 86 ± 12 mm Hg; P < .05). Compared with rest, physiological stress resulted in increased left atrial fractional area change (34.3 ± 7.5 vs 27.3 ± 5.1%; P = .01) and left ventricular late diastolic radial wall motion velocity (13 ± 3 vs 10 ± 2 cm/s; P = .01) but had no significant effect on most other echocardiographic variables. Compared with rest, pharmacological challenge led to significantly decreased left atrial and diastolic ventricular dimensions (left ventricular internal diameter: 10.3 ± 0.9 vs 10.7 ± 0.8 cm; P = .01), increased aortic and pulmonary diameters, and ventricular wall thickness. CONCLUSIONS AND CLINICAL IMPORTANCE: Physiological stress at mildly increased heart rates significantly enhanced atrial pump function. Larger heart rate and blood pressure increases during pharmacological challenge resulted in altered cardiac dimensions. This should be taken into account when evaluating echocardiographic measurements at increased heart rates.

Localization and characterization of atrial depolarization waves on the surface electrocardiogram in dogs with rapid supraventricular tachycardia.

BACKGROUND: Supraventricular tachycardias (SVTs), despite having various anatomical substrates and pathophysiological mechanisms, frequently show similar electrocardiographic presentations. OBJECTIVES: To locate and characterize atrial deflections (ADs) on 12-lead electrocardiograms in dogs with sustained rapid SVT and assess the utility of different electrocardiographic variables in differentiating types of tachycardia. ANIMALS: Ninety-two dogs with orthodromic atrioventricular reciprocating tachycardia, 17 with atrial flutter, 33 with focal atrial tachycardia recorded and confirmed by electrophysiological study, and 40 dogs with sinus tachycardia. METHODS: Atrial deflection position on the 12-lead surface electrocardiogram was assessed according to the sequence of intracardiac activation. Its features were evaluated together with the relationship between AD and QRS complex interval (AD-R) and QRS complex and AD interval (R-AD). RESULTS: Orthodromic atrioventricular reciprocating tachycardia was characterized by an AD-AD interval of 213 ± 30 ms, mean electrical axis (MEA) of AD of -90 (-90/-78)°, R-AD interval of 75 (65-80) ms, and R-AD/AD-R of 0.54 (0.45-0.64). Atrial flutter was characterized by an AD-AD interval of 199 ± 57 ms, MEA of 76° (72/81), R-AD of 120 (72-144) ms, and R-AD/AD-R of 0.81 (0.63-1.13). Focal atrial tachycardia was characterized by an AD-AD interval of 270 ± 38 ms, MEA of 49 (-72/76)°, R-AD of 160 (120-200) ms, and R-AD/AD-R of 1.45 (0.92-1.67). Sinus tachycardia was characterized by an AD-AD interval of 292 ± 31 ms, MEA of 66° (52/73), R-AD of 215 (192-222) ms, and R-AD/AD-R of 2.68 (2.25-3.08). CONCLUSIONS AND CLINICAL IMPORTANCE: Analyzing AD on 12-lead electrocardiogram is helpful in differentiating the most common SVTs in dogs.

Ventricular pre-excitation in cats: 17 cases.

OBJECTIVES: Atrioventricular accessory pathways are abnormal electrical connections between the atria and ventricles that predispose to ventricular pre-excitation (VPE) and tachycardias. ANIMALS: Seventeen cats with VPE and 15 healthy matched-control cats. MATERIAL AND METHODS: Multicenter case-control retrospective study. Clinical records were searched for cats with VPE, defined as preserved atrioventricular synchrony, reduced PQ interval, and increased QRS complex duration with a delta wave. Clinical, electrocardiography, echocardiographic, and outcome data were collated. RESULTS: Most cats with VPE were male (16/17 cats), non-pedigree cats (11/17 cats). Median age and mean body weight were 5.4 years (0.3-11.9 years) and 4.6 ± 0.8 kg, respectively. Clinical signs at presentation included lethargy (10/17 cats), tachypnea (6/17 cats), and/or syncope (3/17 cats). In two cats, VPE was an incidental finding. Congestive heart failure was uncommon (3/17 cats). Nine (9/17) cats had tachyarrhythmias: 7/9 cats had narrow QRS complex tachycardia and 2/9 cats had wide QRS complex tachycardia. Four cats had ventricular arrhythmias. Cats with VPE had larger left (P < 0.001) and right (P < 0.001) atria and thicker interventricular septum (P = 0.019) and left ventricular free wall (P = 0.028) than controls. Three cats had hypertrophic cardiomyopathy. Treatment included different combinations of sotalol (5/17 cats), diltiazem (5/17 cats), atenolol (4/17 cats), furosemide (4/17 cats), and platelet inhibitors (4/17 cats). Five cats died, all from cardiac death (median survival time 1882 days [2-1882 days]). CONCLUSIONS: Cats with VPE had a relatively long survival, albeit showing larger atria and thicker left ventricular walls than healthy cats.

Detection of the origin of atrial tachycardia by 3D electro-anatomical mapping and treatment by radiofrequency catheter ablation in horses.

BACKGROUND: Atrial tachycardia (AT) can be treated by medical or electrical cardioversion but the recurrence rate is high. Three-dimensional electro-anatomical mapping, recently described in horses, might be used to map AT to identify a focal source or reentry mechanism and to guide treatment by radiofrequency ablation. OBJECTIVES: To describe the feasibility of 3D electro-anatomical mapping and radiofrequency catheter ablation to characterize and treat sustained AT in horses. ANIMALS: Nine horses with sustained AT. METHODS: Records from horses with sustained AT referred for radiofrequency ablation at Ghent University were reviewed. RESULTS: The AT was drug resistant in 4 out of 9 horses. In 8 out of 9 horses, AT originated from a localized macro-reentrant circuit (n = 5) or a focal source (n = 3) located at the transition between the right atrium and the caudal vena cava. In these 8 horses, local radiofrequency catheter ablation resulted in the termination of AT. At follow-up, 6 out of 8 horses remained free of recurrence. CONCLUSIONS AND CLINICAL IMPORTANCE: Differentiation between focal and macro-reentrant AT in horses is possible using 3D electro-anatomical mapping. In this study, the source of right atrial AT in horses was safely treated by radiofrequency catheter ablation.

NaHCO3, L-arginine, and vitamin C supplemented vegetable diet ameliorates tachycardia and polycythemia in the broiler chicken.

The study aimed to investigate if vegetable-based high-energy mash diets supplemented with NaHCO3, L-arginine + vitamin C, and vegetable oils were effective against tachycardia and polycythemia in the broiler chicken. A total of 256 Ross-308 day-old male broiler chicks were randomly distributed into eight dietary treatment groups in a three-way ANOVA with 2 × 2 × 2 factorial arrangement (three factors, i.e., NaHCO3, L-arginine + vitamin C, and vegetable oil each with two levels, e.g., 0 and 0.1% of NaHCO3 and L-arginine + vitamin C; 3 and 4% of vegetable oil supplemented with basal diet) for a period of 35 days. Iso-caloric and iso-nitrogenous diets were formulated and supplied ad libitum. The final live weight (FLW), average daily feed intake (ADFI), average daily gain (ADG), feed efficiency (FE), carcass traits, cardio-pulmonary morphometry, total protein (TP), hemoglobin (Hb), triiodothyronine (T3), incidence of tachycardia, and polycythemia were examined. Supplementation of NaHCO3 increased 2.2% ADFI, 5.5% FE, and 23.2% TP. The L-arginine + vitamin C increased 2.4% FLW and decreased 1.9% heart rate. Vegetable oil increased 1.3% ADFI, 4.2% ADG, 8.6% FE, 23.1% Hb, and 15.5% PCV. The NaHCO3, L-arginine + vitamin C, and vegetable oil additively interacted to increase 31.5% T3 at the expense of 21.1% of the weight of the right ventricle (RV). The RV:TV, carcass traits, and hemato-biochemical indices remained within normal range irrespective of the levels of the supplementations of the test ingredients. It was concluded that vegetable-based high-energy mash diets were not susceptible to tachycardia and polycythemia. The addition of NaHCO3 and L-arginine + vitamin C ameliorated the propensity of tachycardia and polycythemia without deteriorating performance, carcass traits, and hemato-biochemical indices of the broiler chicken in a dose-dependent manner.

Use of esmolol for control of tachycardia in 28 dogs and cats (2003-2020).

OBJECTIVE: To describe the indications and clinical response for dogs and cats treated with esmolol. DESIGN: Retrospective case series from 2003 to 2020. SETTING: Single university veterinary teaching hospital. ANIMALS: Twenty-two dogs and 6 cats. INTERVENTIONS: Animals received either a bolus or bolus and continuous rate infusion of the ultrashort-acting beta receptor antagonist, esmolol. MEASUREMENTS AND MAIN RESULTS: Twenty-two animals were treated for either a supraventricular or sinus tachycardia, 5 were treated for a ventricular tachycardia, and 1 was treated for atrial fibrillation. Esmolol was most frequently used in dogs (N = 9) who had ingested a toxin such as albuterol, amphetamine, or chocolate. Esmolol was administered at median bolus dose of 330 µg/kg (range 10-1000 µg/kg) and continued as a continuous rate infusion in 15 animals at a median dose of 50 µg/kg/min. Defining success as a reduction in heart rate of 20% or greater, esmolol therapy was considered successful in 13 of 28 animals (46%). Animals treated for a toxicosis were more likely to have a successful rate reduction than those treated for other causes (P = 0.006). Nineteen animals survived to discharge. Both treatment success (P = 0.046) and treatment for a toxicosis (P = 0.003) were associated with survival. CONCLUSIONS: Esmolol administration was well tolerated by dogs and cats with tachycardia due to intoxication. Heart rate reduction by at least 20% was achieved in 46% of cases. Animals with toxin ingestion were more likely to be discharged from the hospital.

Rhythm disturbances associated with lidocaine administration in four dogs with supraventricular tachyarrhythmias.

OBJECTIVE: To describe arrhythmias associated with administration of lidocaine in dogs treated for supraventricular tachyarrhythmias. CASE SUMMARIES: Four dogs with recent-onset supraventricular tachyarrhythmias: 3 dogs had atrial fibrillation (AF), and 1 had focal atrial tachycardia (FAT), which was thought to be AF at the time of assessment. The substrate of the supraventricular tachyarrhythmia was considered to be due to primary cardiomyopathy in 1 dog, high vagal tone in 2 dogs, and the change in hemodynamics from heavy sedation in 1 dog. Pharmacological cardioversion using lidocaine was only successful in the 2 dogs with vagally mediated AF. In these 2 cases, lidocaine administration resulted in a paroxysmal atrial flutter that was self-limiting and quickly led to sinus rhythm within 10 seconds in 1 dog but did not change over a 5-minute interval and required additional boluses in another dog. In the latter case, the dog showed severe bradycardia for 17.5 seconds prior to achieving sinus rhythm. The 2 unsuccessful cases both developed ventricular arrhythmias shortly after the lidocaine administration, with 1 case degenerating into ventricular fibrillation and cardiac arrest. NEW OR UNIQUE INFORMATION PROVIDED: Arrhythmias associated with lidocaine should be considered when treating dogs with supraventricular tachyarrhythmia.

The use of prolonged administration of low-dose intravenous lipid emulsion to treat ivermectin toxicosis in goats.

CASE DESCRIPTION: 2 Nigerian Dwarf goats (a doe [goat 1] and a wether [goat 2]) with coughing and nasal discharge since they were purchased at an auction 6 days prior were empirically treated for suspected pneumonia and intestinal parasitism. An ivermectin dosing error (intended dose, 0.4 mg/kg, PO; administered dose, 10 mg/kg, PO) was retrospectively discovered, and the owner was urged to return the goats for hospitalization and treatment. CLINICAL FINDINGS: On admission 19 hours after iatrogenic ivermectin overdose, both goats had tachycardia, tachypnea, and absent menace responses. Goat 1 also had vomited in transit, was lethargic and febrile, had slow pupillary light reflexes, and walked into walls and obstacles. Goat 2 was quiet but responsive, not ataxic or febrile, and had pale mucous membranes and a prolonged capillary refill time. TREATMENT AND OUTCOME: Each goat received 20% IV lipid emulsion (2 mL/kg, IV bolus over 15 minutes, followed by 0.008 mL/kg/min, IV) and immediately improved. Activated charcoal was administered by orogastric tube, and 6 hours later, mineral oil was similarly administered. Goat 1 had complete resolution of signs and was discharged by 48 and 72 hours, respectively, after admission. Goat 2 improved but developed progressive respiratory distress after the second orogastric intubation and was euthanized. Necropsy findings were consistent with acute renal tubular necrosis, acute respiratory distress syndrome of unknown cause, ruminal tympany, and mesenteric caseous lymphadenitis. CLINICAL RELEVANCE: Results indicated that IV lipid emulsion could be used to successfully treat ivermectin toxicosis in goats. Treatment early in the course of ivermectin toxicosis is advisable to avoid severe clinical signs and secondary complications.

Collection of cerebrospinal fluid in 50 adult healthy donkeys (Equus asinus): clinical complications, and cytological and biochemical constituents.

BACKGROUND: Diseases of the central nervous system are a well-recognized cause of morbidity and mortality in equine. Collection and analysis of cerebrospinal fluid (CSF) give information about the type and stage of degenerative and inflammatory diseases in central nervous system (CNS). The present research aimed to assess the clinical complications of CSF collections and to establish range values of cytological and biochemical parameters of CSF in adult healthy donkeys (Equus asinus). The CSF samples were collected from fifty healthy donkeys at the lumbosacral (LS) and atlanto-occipital (AO) sites. RESULTS: Hypothermia, tachycardia, ataxia and recumbency may develop post-puncture. Erythrocytes were noticed in 35 of 50 CSF samples. Total nucleated cell counts ranged from 0 to 6 cells/µL, and lymphocytes predominated the cells (61%). The concentration of glucose (1.2 to 5.3 mmol/L) was lower than that of serum (P < 0.05). The CSF sodium concentration (123 to 160 mmol/L) was approximately like that of serum, but potassium (1.5-3 mmol/L) was lower than that of serum (P < 0.01). Urea concentrations (1.1-2.9 mmol/L) were markedly lower than serum (P < 0.001). Concentrations of CSF total proteins, and albumin ranged from 0.1 to 0.6 g/dL, and from 0.002 to 0.013 g/dL, respectively. The albumin quotient ranged from 0.06 to 0.56. CONCLUSIONS: Transient hypothermia, tachycardia, ataxia and recumbency may develop as clinical complications of CSF puncture procedures. The collection site has no impact on the constituents in CSF. Furthermore, this study presented the range values for normal cytological and biochemical constituents of CSF in donkeys (Equus asinus) that can provide a basis in comparison when evaluating CSF from donkeys with neurologic diseases.

Radiofrequency catheter ablation of cranial vena cava flutter in four dogs.

Four dogs were referred to our institution for incessant supraventricular tachycardias causing weakness; congestive heart failure was present in one dog. At admission, all dogs had a surface electrocardiogram showing a narrow QRS complex tachycardia with a ventricular rate ranging from 80 to 300 bpm, variable atrioventricular conduction ratio from 1:1 to 3:1, and positive atrial depolarizations in inferior leads (II, II, III, and aVF), with isoelectric lines between them. Three of four dogs had a dilated cardiomyopathy phenotype; one dog had a heart base tumor involving the cranial vena cava wall. According to the electrocardiographic findings, a presumptive diagnosis of reverse typical or atypical atrial flutter was considered, and endocardial mapping was planned for each dog. During the electrophysiologic study, continuous atrial activation compatible with atypical atrial flutter was observed in all dogs, with concealed entrainment obtained at the level of the isthmus located at the distal portion of the cranial vena cava, close to the entrance into the right atrium. A linear radiofrequency catheter ablation was performed from the right atrial wall to the distal part of the cranial vena cava with a permanent interruption of the isthmic conduction in all dogs at a 6-month follow-up.

Idioventricular tachycardia and unstable ventricular escape rhythm in a canine patient with third-degree atrioventricular block.

A 10-year-old female Labrador retriever was presented for evaluation and management of syncope. On presentation, idioventricular tachycardia (IT) was electrocardiographically evident but neither ventricular capture nor fusion complexes were recorded. Spontaneous termination of the IT resulted in prolonged ventricular asystole and revealed the underlying rhythm of third-degree atrioventricular block. The serum concentration of troponin-I was elevated, suggesting myocarditis, but this was not diagnostically confirmed. It is likely that overdrive suppression of subsidiary idioventricular pacemakers, and perhaps also disease of subsidiary ventricular pacemaker fibers, importantly contributed to the duration of asystole.

Histopathological changes in the pancreas due to decreased pancreatic blood flow in a canine tachycardia-induced cardiomyopathy model.

In dogs, pancreatic acinar cell injury is thought to be caused by decreased pancreatic blood flow due to heart failure. In previous our report, it demonstrated that decreased heart function causes a significant decrease in pancreatic blood flow in heart failure dog model caused by rapid ventricular pacing (RVP). However, the types of histopathological changes remain unclear. We aimed to verify the types of histopathological changes occurring in the pancreatic tissue due to decreased heart function. After RVP for 4 weeks, atrophy of pancreatic acinar cells, characterized by a decrease in zymogen granules, was observed in all areas of the pancreas. In conclusion, the result of this study suggests that attention should be paid to ischemia/hypoperfusion injury in the pancreas.

Prognostic values of physical and hematological parameters of dogs naturally infected with parvovirus PVC-2: retrospective study of 103 cases / [Valores prognósticos de parâmetros físicos e hematológicos de cães naturalmente infectados pelo parvovírus PVC-2: estudo retrospectivo de 103 casos]

Canine parvovirosis is a high mortality disease with acute clinical picture. However, there are few available resources to help stablish prognosis accurately. This study aimed to determine the prognostic threshold values for vital and hematological parameters of dogs naturally infected by the Carnivore protoparvovirus 1 (CPV). A retrospective study of 103 canine parvovirosis cases was carried out. Twenty seven percent of these (28/103) died, 96% (27/28) of which within the first four days of hospitalization. Deceased animals had significantly higher median values for heart (HR) and respiratory (f) rates, as well as significantly lower systolic blood pressure (SBP) than survivors. Severely leukopenic animals (<1,000 cells/µL), had a significantly higher mortality rate (68%, n=13) compared to that of other patients (P<0.0007). Animals with at least two of the following findings: severe hypotension (SBP< 90mmHg), tachycardia (HR > 150 bpm) and leukopenia, represented 34% (34/101) of the cases and had a survival rate of 29% (10/34), while animals with at most one of these parameters represented 66% (67/101) and had a survival rate of 94% (63/67). The presence of two or three abnormal parameters was significantly related to the higher death risk among dogs with parvovirosis (P<0.0001).(AU)

A parvovirose canina é uma doença de alta mortalidade e de quadro clínico agudo. No entanto, existem poucos recursos para se estabelecer prognóstico de maneira precisa. Este estudo objetivou analisar os valores prognósticos de parâmetros físicos e hematológicos de cães naturalmente infectados pelo Carnivore protoparvovirus 1 (CPV). Um estudo retrospectivo de 103 casos de parvovirose canina foi realizado. Desses, 27% dos animais (28/103) foram a óbito, sendo 96% (27/28) com ocorrência nos primeiros quatro dias de internamento. Os cães que foram a óbito apresentaram medianas das frequências cardíaca (FC) e respiratória (f) significativamente maiores e pressão arterial sistólica (PAS) consideravelmente menor que a dos sobreviventes. Entre os animais mais intensamente leucopênicos (<1.000 células/(L), a taxa de mortalidade (68%, n=13) foi expressivamente maior que a dos demais pacientes (P<0,0007). Os animais com hipotensão grave (PAS<90mmHg), taquicardia (FC>150bpm) e leucopenia intensa (leucometria<1.000 células/µL), ou duas dessas alterações clínicas, representaram 34% (34/101) dos casos e tiveram taxa de sobrevida de 29% (10/34), enquanto os animais com, no máximo, um desses parâmetros alterados representaram 66% (67/101) dos animais, com taxa de sobrevida de 94% (63/67). A presença de dois ou três parâmetros alterados esteve significativamente relacionada ao maior risco de óbito de cães com parvovirose (P<0,0001).(AU)

Catheter-based electrical interventions to study, diagnose and treat arrhythmias in horses: From refractory period to electro-anatomical mapping.

Minimally-invasive catheter-based interventional cardiology is a mainstay for the diagnosis and treatment of arrhythmias in human medicine. Very accurate imaging using fluoroscopy, CT and MRI is essential during interventional cardiology procedures. Because these imaging techniques are either not possible or provide too little anatomical detail in horses, echocardiography is currently the best technique to visualize catheters in horses. Over the past decades, catheter-based techniques have been applied to induce arrhythmias using pacing and to perform arrhythmia research using electrophysiological studies. In bradycardic animals with clinical signs, permanent pacing can be achieved by pacemaker implantation via the cephalic vein. Transvenous electrical cardioversion, based on one cardioversion catheter in the pulmonary artery and one in the right atrium, has become the treatment of choice for atrial fibrillation in horses, even for longstanding or drug-resistant atrial fibrillation. Recently, the highly advanced technique of three dimensional electroanatomical mapping has been described in horses. This technique has not only revealed essential electrophysiological data in horses, but has also facilitated the successful ablation of atrial tachycardia in horses.

Accidental Overdose of Pergolide (Prascend) Followed by Loss of Appetite, Tachycardia, and Behavioral Abnormalities in a Pony Mare.

A 26-year-old pony mare (ca. 180 kg bodyweight) was presented as an emergency because it had erroneously received 110 times its standard dose of pergolide (Prascend) per os approximately 4 hours earlier. Clinical examination initially was normal except tachycardia of 52 beats/min. The pony was treated symptomatically with paraffin oil and activated charcoal per nasogastric tube to prevent further systemic absorption and accelerate intestinal excretion of the pergolide. Furthermore, the pony received 400 mg of dopamine antagonist azaperone (Stresnil) intramuscularly (i.m.) followed by 80 mg every 6 hours twice i.m. and then 60 mg every 6 hours twice i.m. In addition, 40 mg verapamil (Verapamil-ratiopharm) was given every 4 hours per os for two days, followed by 40 mg every 6 hours for another 5 days. The pony was closely monitored clinically. It remained bright and alert with heart rate returning to normal within one day. The only abnormalities noticed 24 hours after ingestion of the pergolide overdose were a decreased appetite and anxiety, possibly a dopaminergic central nervous effect. Over the next days, appetite returned and anxiety disappeared. Overdosing pergolide is considered very rare and to the authors' knowledge this is the first report with a severe overdose of pergolide (Prascend). As accidental drug overdosing is a common error in medicine, it is important to know about possible side effects and how to react in cases like this.