Evaluation of the use of a heparin dose-response test in dogs to determine the optimal heparin dose during intravascular procedures and assessment of the in vitro heparin response in healthy dogs

BACKGROUND

No guidelines for administering and monitoring anticoagulants intraprocedurally are currently available in dogs, despite the prevalence of procedures necessitating systemic anticoagulation with heparin.

OBJECTIVES

To evaluate an activated clotting time (ACT)-based heparin dose-response (HDR) test to predict the individual required heparin dose in dogs during intravascular procedures, and to investigate both the in vitro heparin - ACT and in vitro heparin - factor anti-Xa activity (anti-Xa) relationships in dogs.

METHODS

Blood was collected from eight healthy beagles undergoing a cardiac procedure and utilised to establish baseline ACT and for in vitro evaluation. Subsequently, 100 IU/kg heparin was administered intravenously (IV) and ACT was remeasured (HDR test). The required heparin dose for an ACT target response ≥300 s was calculated for each individual and ACT was remeasured after administration of this dose. For in vitro testing, a serial heparin blood dilution (0-0.5-1-2-4 international unit (IU)/mL) was prepared and ACT and anti-Xa were determined using whole blood and frozen plasma, respectively.

RESULTS

The HDR test overestimated the required heparin dose in 3/7 dogs. In vitro, ACT and anti-Xa increased significantly with increasing blood heparin concentration. Heparin - ACT was nonlinear in 4/8 dogs at heparin concentrations >2 IU/mL, whereas heparin - anti-Xa remained linear throughout the tested range.

CONCLUSIONS

The HDR test poorly estimated the required heparin dose in dogs. This is most likely attributed to a nonlinear heparin - ACT relationship, as observed in vitro. Anti-Xa is a promising alternative for ACT; however, unavailability as a point-of-care test and lack of in vivo target values restrict its current use.

Surgical correction of an infundibular pulmonic stenosis and ventricular septal defect in a Shetland Sheepdog

A four-month-old male Shetland Sheepdog presented with exercise intolerance. Physical examination revealed an IV/VI left cranial systolic heart murmur. Echocardiography showed a severe infundibular pulmonic stenosis and a concomitant restrictive ventricular septal defect. As clinical signs of congestive right-sided heart failure worsened and were refractory to medical treatment, surgical correction was advised. Via sternotomy, with cardiopulmonary bypass and cardioplegic cardiac arrest, ventricular septal defect closure and resection of the stenotic infundibular band were performed through right ventriculotomy, followed by patch enlargement. Postoperative recovery was uneventful and echocardiography showed complete resolution of the stenosis and successful closure of the ventricular septal defect. Follow-up echocardiography revealed restenosis after seven weeks and recurrence of right-sided heart failure three months postoperatively. Stenting of the restenosis was attempted via a hybrid procedure with sternotomy and direct transventricular approach. The dog developed fatal ventricular fibrillation during stent deployment. This is the first dog in which surgical right ventricular patch enlargement under cardiopulmonary bypass is reported for the treatment of a primary infundibular pulmonic stenosis.

Validation of a skin and coat scoring protocol in dogs

Skin and coat scores have been used to assess changes in skin and coat quality in dogs. The aim of this study was to evaluate a skin and coat protocol in dogs of different coat types. Skin and coat of long-haired, short-haired and wire-haired dogs were scored for alopecia, glossiness, greasiness, softness, scaliness and overall skin and coat quality by ten observers. Intraobserver and interobserver agreement was assessed using kappa values. Thirty-six client-owned dogs were included in the study. The overall intraobserver agreement was moderate when assessing greasiness and glossiness and substantial when assessing alopecia, softness, scaliness and overall skin and coat quality. The overall interobserver agreement was only slight to fair for all features assessed. In conclusion, the proposed skin and coat scoring protocol assesses different aspects of the skin and coat quality in dogs and is easy and non-invasive. Scoring skin and coat quality over time is only reliable if performed by the same person.

Is there a rationale to supplement hepatotropic factors to dogs with multiple acquired portosystemic shunts secondary to congenital portosystemic shunt attenuation?

Experimental rat models and clinical trials in human patients with liver cirrhosis show evidence that supplementation with hepatotropic factors provides therapeutic benefits. This form of support has not yet been described in dogs with multiple acquired portosystemic shunts (MAPSS) despite similarities between both pathological conditions. Especially hepatocyte growth factor (HGF) and branched chain amino acids (BCAA) deserve closer attention. High-quality vegetable rather than animal proteins have been suggested to form an excellent dietary source of BCAA, and leucine seems the best candidate for supplementation given its stimulating effects on liver function in general and on HGF secretion specifically. Research on optimal ways of administration of HGF in dogs with MAPSS secondary to congenital portosystemic shunt attenuation is necessary before clinical trials can be initiated.

Serum insulin-like growth factor-1 as a marker of improved liver function and surgical outcome in dogs with congenital extrahepatic portosystemic shunts

Serum insulin-like growth factor-1 concentration (sIGF-1c) is reduced in various hepatopathies in humans and dogs. This work aimed to evaluate sIGF-1c in dogs before and after congenital extrahepatic portosystemic shunt (cEHPSS) attenuation, in relation to surgical outcome (closed vs. persistent shunting). Secondarily, it aimed to assess if sIGF-1c can discriminate between cEHPSS and portal vein hypoplasia (PVH) and finally compare sIGF-1c ratio (postoperative/preoperative sIGF-1c) to pre-prandial serum bile acids (preBA), post-prandial bile acids (postBA), bile acid stimulation test (BAST) and fasting ammonia (FA), regarding surgical outcome. Thirty-nine dogs were included: 15 with closed cEHPSS, 15 with persistent shunting and nine with PVH. Transplenic portal scintigraphy was used to classifiy surgical outcome. There was no significant difference in sIGF-1c between dogs with cEHPSS and those with PVH (P > 0.05). Postoperative sIGF-1c increased in all dogs (P < 0.001 and P = 0.023 for closed and persistent shunting, respectively) and the increase was more pronounced in closed cEHPSS than in persistent shunting (P = 0.006). Using an optimal sIGF-1c ratio cut-off of 2.23, the sensitivity was 93.3% and the specificity was 66.7% for differentiation between surgical outcomes. Serum pre-prandial bile acids, postBA BAST and FA had sensitivities of 80%, 86.7%, 86.7%, 60%; and specificities of 100%, 93.3%, 93.3%, 100%, respectively. There was a greater increase in sIGF-1c after shunt closure than during persistent shunting; nevertheless sIGF-1c ratio was inferior to advanced imaging to assess surgical outcome.

Neurological signs and imaging findings in three cats with multiple articular process hypertrophy

An eight-year-old British Shorthair (case 1), an eleven-year-old British Shorthair (case 2) and a six-year-old European Shorthair cat (case 3) showed signs of chronic T3–L3 myelopathy. Computed tomography of the thoracolumbar and lumbosacral region was performed in all three cases and magnetic resonance imaging was only performed in case 2. Cross sectional imaging revealed an enlargement of the articular process joints from T2 to T5 in case 1, from T11 to T13 in case 2 and from T10 to T13 in case 3 causing spinal cord compression. Based on the severity of the spinal cord compression, surgical decompression by hemilaminectomy was performed in case 1. In cases 2 and 3, conservative treatment was instituted, although this condition could have been an incidental finding in these two cases. To the authors’ knowledge, this is the first report describing the neurological signs, imaging findings and short-term outcome in cats with multiple thoracolumbar articular process hypertrophy.

Serum hyaluronic acid, a marker for improved liver perfusion after gradual surgical attenuation of extrahepatic portosystemic shunt closure in dogs

Current liver function tests used in dogs do not consistently normalise after successful surgical attenuation of portosystemic shunts (PSS). Serum hyaluronic acid (sHA) concentrations in dogs with PSS are reported to be higher at diagnosis than in healthy dogs. The objective of this study was to assess sHA as a marker of liver perfusion by measuring sHA concentrations in dogs before and after gradual surgical attenuation of extrahepatic (EH)PSS and by determining whether sHA concentrations could differentiate closed EHPSS from persistent shunting. Specificity of sHA was assessed by comparing sHA concentrations in dogs with EHPSS to those in dogs with other liver diseases. Twenty dogs with EHPSS had sHA concentrations measured at diagnosis, 1, 3, and 6 months postoperatively. In addition, sHA concentrations were determined in 10 dogs with other liver diseases. At EHPSS diagnosis, median sHA concentration was 335.6 ng/mL (43.0-790.7 ng/mL). All dogs had a significant decrease in sHA concentrations from 1 month postoperatively onwards (P < 0.05), regardless of surgical outcome. At all postoperative follow-up visits, there was a significant difference between the median sHA concentration in dogs with closed EHPSS vs. those with persistent shunting (P < 0.05). Median sHA concentration in dogs with other liver diseases was 89.8 ng/mL (22.9-160.0 ng/mL), which was significantly lower than dogs with EHPSS at diagnosis (P < 0.001). In conclusion, sHA is a promising non-invasive biomarker that can help to determine liver perfusion after surgical attenuation of EHPSS. In addition, sHA could potentially be used to differentiate dogs with EHPSS from dogs with other liver diseases.

The effect of closed-incision negative pressure wound therapy on clinical and ultrasonographic seroma formation and wound healing following forequarter amputation in large dogs - a randomized pilot trial

This pilot study aimed at evaluating whether closed-incision negative pressure wound therapy (ciNPWT) has an effect on seroma formation and wound healing following forequarter amputation in dogs above 20 kg. Twelve client-owned dogs weighing more than 20 kg, presented for forequarter amputation, were randomly assigned after surgery into two groups (six ciNPWT and six controls with soft-padded bandage, both bandages applied for three days). A clinical and ultrasonographic control (newly developed scoring system) was performed at bandage removal (three days postoperatively) and ten days, postoperatively. A postoperative seroma was present in 4/6 dogs in the ciNPWT group and in 5/6 dogs in the control group. There were no apparent differences in the ultrasonographic scores or subcutis measurements at three versus ten days, postoperatively. The results of this pilot trial do not support expansion to a larger-scale study evaluating ciNPWT after forequarter amputation in dogs.

Epiglottic retroversion in nine dogs

Epiglottic retroversion (ER) is an uncommon and poorly understood disorder of the upper respiratory tract in small breed dogs. In this retrospective study, perioperative characteristics, surgical technique, outcome, and complications in nine dogs that underwent surgical treatment for ER and/or concurrent upper respiratory tract disorders, were evaluated. The most frequently reported clinical symptoms were chronic intermittent inspiratory stridor (89%), exercise intolerance (78%), and dyspnea (67%). Concurrent respiratory disorders were highly prevalent (78%). Five dogs initially underwent a temporary epiglottopexy and two a permanent epiglottopexy. In two dogs, both suffering from concurrent laryngeal paralysis, only a unilateral cricoarytenoid lateralization was performed. After initial clinical improvement, temporary and permanent epiglottopexy eventually failed in 4/6 dogs (67%) that were available for follow-up, necessitating partial epiglottectomy as revision surgery. This resulted in a successful long-term outcome in 5/6 of these dogs (83%). In the dogs with primary ER or in cases where the presence of secondary ER led to significant respiratory symptoms, partial epiglottectomy as a primary surgical technique appeared to be a more permanent treatment option than epiglottopexy. Both dogs with surgically corrected concurrent laryngeal paralysis without epiglottopexy or epiglottectomy showed clinical improvement. This might indicate that, in case of secondary ER, positive results can be achieved after management of the underlying respiratory disorder.

Development of a non-functional pancreatic neuroendocrine tumor and a duodenal ulceration after cholecystoduodenostomy in a cat

A six-year-old Ragdoll with previous extrahepatic biliary tract obstruction due to cholangiohepatitis, treated with cholecystoduodenostomy, was presented for acute vomiting, hyporexia, and weight loss. Abdominal ultrasound examination revealed randomly distributed hepatic nodules and dilated biliary ducts. Gastroduodenoscopy showed a patent cholecystoduodenostoma but disclosed a perforated duodenal ulceration. Conversion to celiotomy revealed extensive liver pathology, a discrete pancreatic nodule, and a duodenal ulcer opposite to the cholecystoduodenostoma. The cat was euthanized intra-operatively and necropsy was performed. The intrahepatic biliary tract of the right liver lobes was obstructed and severely dilated, whereas bile from the left lobes drained through the cholecystoduodenostoma. Histopathologic diagnoses were a primary pancreatic tumor, positive for glucagon on immunohistochemistry, with liver metastases, chronic purulent cholecystitis, and duodenal ulceration. To the authors’ knowledge, this is the first report in which the development of pancreatic neoplasia is described in a cat with a history of biliary tract disease.

Prevalentie van urolithiasis en andere urinaire afwijkingen bij honden met een congenitale extrahepatische portosystemische shunt

Honden met een portosystemische shunt (PSS) vertonen vaak urinaire afwijkingen. In deze retrospectieve studie werd de prevalentie van urolithiasis en andere urinewegklachten secundair aan extrahepatische (EH)PSS nagegaan vanaf het optreden van de eerste klachten tot en met de dag van de chirurgische correctie van de EHPSS. Enerzijds werd 67% van de onderzochte honden aangeboden met urinewegklachten die rechtstreeks (39%) of waarschijnlijk (28%) verband hielden met EHPSS. Zo werden sommige honden chirurgisch behandeld voor urolithiasis, waarna via kwantitatieve steenanalyse ammoniumbiuraat-urolieten vastgesteld werden, wat de aanwezigheid van een onderliggende PSS deed vermoeden. Anderzijds bleek 77% van de honden zonder urinewegklachten toch abnormaliteiten te vertonen op medische beeldvorming en/ of het urinewegonderzoek. In totaal werden er bij 70,4% van de honden urolieten vastgesteld. In dit onderzoek wordt het belang aangetoond van het uitvoeren van een volledig urineonderzoek aangevuld met medische beeldvorming van het urinaire stelsel bij alle honden met EHPSS. Daarnaast wordt de meerwaarde van een kwantitatieve steenanalyse beklemtoond, opdat bij aanwezigheid van ammoniumbiuraat aan een mogelijke PSS wordt gedacht.

Development of surgical site infections despite perioperative antimicrobial therapy in two dogs

Surgical site infections (SSI) are common complications with a prevalence of 0.8 to 18%. Many risk factors, such as patient, environmental and treatment factors can contribute to the development of SSI. Two dogs that developed a SSI after forelimb amputation are discussed. The first dog was presented with an open comminuted intra-articular fracture of the right elbow. The second dog was diagnosed with a soft-tissue sarcoma at the right elbow. Perioperative cefazolin was administered in both patients. Only in the first patient, antimicrobial therapy was continued in the postoperative period. Both dogs developed an SSI within four to five days postoperatively. Yet, prophylactic antimicrobials can help to prevent SSI, provided that the correct antimicrobial is used at the correct dose, at the right time and given IV. Factors, such as hypothermia, violating the Halsted’s principles and the number of people present in the theater may increase the risk of SSI. Besides the meticulous use of antimicrobials, perioperative management is thus also important in SSI prevention.

Closed incision management with negative pressure wound therapy after forelimb amputation in a dog

A four-year-old male castrated German shepherd dog was presented with severe left front leg lameness due to a fibrosarcoma lateral to the elbow. The ill-defined mass was not amendable to wide local excision and a curative-intent limb amputation was performed. Immediately postoperatively, closed incision management with negative pressure wound therapy (NPWT) was applied to minimize the risk of postoperative complications. The incision line was covered with a PrevenaTM dressing attached to a NPWT pump set at a continuous negative pressure of -125 mmHg. The dressing was removed 72 hours later. No wound complications were evident and further healing was unremarkable.

Chirurgische behandeling van een sublinguale sialocoele (ranula) bij een kat

In deze casuïstiek wordt een zeven jaar oude, mannelijke, gecastreerde, Europese korthaar met een ranula beschreven. De patiënt werd aangeboden vanwege een sublinguale zwelling aan de rechterkant die chirurgisch werd behandeld door middel van marsupialisatie en excisie van de mandibulaire en sublinguale speekselklieren. Histopathologisch onderzoek van de verwijderde weefsels bevestigde de diagnose van een ranula en toonde de onopzettelijke resectie van de rechter submandibulaire lymfeknopen. Vijf maanden na de ingreep werden er geen complicaties of recidieven vastgesteld.

Alfaxalone TIVA bij de chirurgische excisie van een tracheaal adenocarcinoma bij een kat

Een tien jaar oude, vrouwelijke, Europese korthaar werd aangeboden met klachten van progressief verergerende dyspnee, ademen met open muil en inspiratoire en expiratoire stridor. Met behulp van tracheoscopie met bioptname kon de histopathologische diagnose van een intraluminaal tracheaal adenocarcinoma gesteld worden. Computertomografie (CT) toonde aan dat er geen metastasen waren, waarna tijdens dezelfde anesthesie werd overgegaan tot excisie van de tumor. Omwille van de moeilijke hanteerbaarheid van de patiënt was intraveneuze premedicatie niet mogelijk en gebeurde de inductie van de anesthesie aan de hand van een intramusculaire injectie met alfaxalone. De anesthesie werd verder onderhouden met twee verschillende protocollen: initieel werd gebruik gemaakt van een inhalatieanesthesie -protocol, waarbij isofluraan via een laryngeaal masker werd verdampt in 100% zuurstof via een cirkelsysteem, waarna er werd overgeschakeld naar totale intraveneuze anesthesie (TIVA) met alfaxalone tijdens de eigenlijke excisie van de tumor. Door het verwijderen van zeven trachearingen kon de tumor volledig verwijderd worden.

Embryonal Rhabdomyosarcoma of the Oesophagus in a Young Dog

A 15-month-old great Dane dog, showing clinical signs related to hypertrophic osteopathy, was diagnosed radiographically with a mass in the region of the thoracic oesophagus. Exploratory thoracotomy revealed an extensive, highly vascularized and locally invasive oesophageal mass and the presence of nodules in adjacent lung lobes. The dog was humanely destroyed intra-operatively. Histological examination revealed that the mass was an embryonal rhabdomyosarcoma. This is the first report of rhabdomyosarcoma of the oesophagus of a dog. Rhabdomyosarcoma should be considered a differential diagnosis when a mass adjacent to the oesophagus is diagnosed.

Orofaryngeaal stoktrauma bij de hond

Tijdens het spelen met stokken kan een orofaryngeale perforatie ontstaan. Acute klachten zijn pijn, bloedverlies uit de mond, dysfagie of zelfs ademhalingsklachten. Chirurgische exploratie van de halsstreek is noodzakelijk om de perforatiegang te spoelen en eventueel aanwezige contaminanten (houtfragmenten, gras, zand) te verwijderen. Tenzij de oesofagus in het proces betrokken is (15-50% mortaliteit), is de prognose na stoktrauma gunstig. De kans op het ontwikkelen van een fistel bedraagt 1%. Wanneer het initiële trauma echter niet wordt herkend of behandeld, ontstaat een chronische presentatie (> 7 dagen oud) die wordt getypeerd door abcesvorming of drainerende fistelgangen. Medische beeldvorming is dan aangewezen om de locatie van de achtergebleven, migrerende houtfragmenten te bepalen. Ondanks uitgebreide chirurgische exploratie treden bij een derde van deze honden recurrente symptomen op.

Portal vein hypoplasia in dogs

Portal vein hypoplasia (PVH) is a congenital disorder, in which microscopic intrahepatic shunts are present, causing blood to bypass the liver sinusoids. As the clinical presentation and the laboratory findings are similar to those in dogs with an extrahepatic portosystemic shunt (EHPSS), differentiation between both disorders is based on the confirmation of a macroscopic shunt by diagnostic imaging techniques. This review highlights the major aspects of PVH, including the differentiation from EHPSSs, and the challenges to diagnose both disorders in dogs with concurrent PVH and EHPSS.