Incidence of Vitis fruit-induced clinical signs and acute kidney injury in dogs and cats.

OBJECTIVES: To determine the incidence of clinical signs and Vitis fruit-induced acute kidney injury in dogs and cats with a Vitis fruit ingestion reported to the Dutch Poisons Information Center, and a description of the therapies instituted by the veterinarians. MATERIALS AND METHODS: All cases of Vitis fruit ingestions in dogs and cats reported to the center between January 1, 2018 and December 31, 2018 were included in this study. Veterinarians and pet owners were contacted by phone or email to obtain follow-up information. Information was collected using a standardised data collection sheet. RESULTS: Ninety-five dogs and 13 cats with proven Vitis fruit ingestion were included. Fourteen dogs and two cats developed clinical signs: emesis (11/16, 68.8%), lethargy (5/16, 31.3%), diarrhoea (3/16, 18.8%), anorexia (3/16, 18.8%), tremor (2/16, 12.5%) and restlessness (1/16, 6.3%). The overall incidence for developing clinical signs was 14.7% in dogs and 15.4% in cats. One (1/95, 1%) dog developed acute kidney injury after ingestion of Vitis fruit. No cats developed acute kidney injury. Induction of emesis and/or administration of activated charcoal was instituted in 72 of 82 (88%) and eight of 11 (73%) of asymptomatic dogs and cats and six of 14 (43%) and two of two (100%) of symptomatic dogs and cats, respectively. Overall, emesis was induced in 72 of 95 (76%) dogs (100% success rate) and removed Vitis fruits in the majority of cases (98% when induced <4 hours after ingestion and 83% when induced 4 to 12 hours after ingestion). Emesis was induced in seven of 13 (54%) cats (86% success rate) and removed Vitis fruits in 83% of the cases. CLINICAL SIGNIFICANCE: In this study, a significant proportion (around 15%) of dogs and cats developed clinical signs after ingestion of Vitis fruits, which were predominantly related to the gastrointestinal tract. Symptomatic acute kidney injury was rare. Our findings suggest the use of decontamination measures, i.e. induction of emesis, may be warranted up to 12 hours after ingestion.

[Bitten by an exotic venomous snake]. / Gebeten door een exotische gifslang.

BACKGROUND: Patients who have been bitten by an exotic venomous snake are at risk of severe morbidity and a fatal outcome following an incorrect risk-assessment. Treatment with an antivenom can be necessary and can turn out to be lifesaving. In the Netherlands there are only a few cases of bites from exotic venomous snakes each year. CASE DESCRIPTION: A 28-year-old man presented at the emergency department (ED) after having been bitten by a monocled cobra (Naja kaouthia). Here he developed severe neurotoxicity with respiratory insufficiency requiring intubation and mechanical ventilation. The patient was successfully treated with an antivenom. CONCLUSION: An exotic snakebite victim is always a medical emergency. With early presentation at the ED, proper assessment, treatment and the availability of antivenom from the National Serum Depot, this will not necessarily cause insurmountable problems.

[Practical guidelines for the treatment of cases of adder envenomation in dogs]. / Praktische richtlijnen voor de behandeling van adderbeten bij de hond.

Every year, dogs are presented to veterinary clinics in the Netherlands after having been bitten by a viper. The viper is the only venomous snake native to the Netherlands. Clinical signs after an acquired viper bite can range from none (after a 'dry' bite) to very mild up to life threatening following a 'wet' bite. To prevent mortality it is important to monitor the animals for a period of time and provide adequate treatment. Clotting disorders and multiple organ failure can occur several days to a week after the viper bite, appropriate follow up is therefore important. In the Netherlands, a specific antiserum is available for veterinarians. The use of this antiserum is strongly recommended in severe cases of viper envenomation.

Establishment and first experiences of the National Serum Depot in the Netherlands.

Since 2008, a National Serum Depot is operational in the Netherlands, guaranteeing antivenom supply, 24 h per day, during medical emergencies. In this article the organisation structure, choice of antivenoms, problems encountered during the establishment, and the results from establishment in 2008 till December 2011 are discussed. The Serum Depot is organised by the National Institute for Public Health and the Environment in cooperation with the Dutch National Poisons Information Center. During establishing and maintaining of the Serum Depot several antivenom purchase difficulties were encountered. Some antivenom producers did not respond upon (initial) contact and some antivenoms were (temporarily) unavailable. Good contacts with professional herpetologists are necessary in order to keep the content of the depot up-to-date. At the same time, it is important to remain well informed concerning the safety and efficacy of the currently available antivenoms and development of new antivenoms. During the first four years of the National Serum Depot, the Dutch National Poisons Information Center was consulted on average 10 times a year about exotic venomous bites and stings in which antivenom treatment might play a role. Almost half of these consultations were related to bites by venomous exotic snakes, the other half to scorpion and fish stings. Antivenom was delivered in five cases, all after a bite by an exotic venomous snake, and actually administered twice because of the severity of local effects. To reduce costs and extend coverage of the Serum Depot of antivenoms for more unfamiliar snake species, international cooperation between the various owners of the antivenom Serum Depots in Europe is recommended.

Decrease in coronary vascular volume in systole augments cardiac contraction.

Coronary arterial inflow is impeded and venous outflow is increased as a result of the decrease in coronary vascular volume due to cardiac contraction. We evaluated whether cardiac contraction is influenced by interfering with the changes of the coronary vascular volume over the heart cycle. Length-tension relationships were determined in Tyrode-perfused rat papillary muscle and when coronary vascular volume changes were partly inhibited by filling it with congealed gelatin or perfusing it with a high viscosity dextran buffer. Also, myocyte thickening during contraction was reduced by placing a silicon tube around the muscle. Increasing perfusion pressure from 8 to 80 cmH2O, increased developed tension by approximately 40%. When compared with the low perfusion state, developed tension of the gelatin-filled vasculature was reduced to 43 +/- 6% at the muscle length where the muscle generates the largest developed tension (n = 5, means +/- SE). Dextran reduced developed tension to 73 +/- 6% (n = 6). The silicon tube, in low perfusion state, reduced the developed tension to 83 +/- 7% (n = 4) of control. Time-control and oxygen-lowering experiments show that the findings are based on mechanical effects. Thus interventions to prevent myocyte thickening reduce developed tension. We hypothesize that when myocyte thickening is prevented, intracellular pressure increases and counteracts the force produced by the contractile apparatus. We conclude that emptying of the coronary vasculature serves a physiological purpose by facilitating cardiomyocyte thickening thereby augmenting force development.

Perfusion-induced changes in cardiac contractility depend on capillary perfusion.

The perfusion-induced increase in cardiac contractility (Gregg phenomenon) is especially found in heart preparations that lack adequate coronary autoregulation and thus protection of changes in capillary pressure. We determined in the isolated perfused papillary muscle of the rat whether cardiac muscle contractility is related to capillary perfusion. Oxygen availability of this muscle is independent of internal perfusion, and perfusion may be varied or even stopped without loss of function. Muscles contracted isometrically at 27 degrees C (n = 7). During the control state stepwise increases in perfusion pressure resulted in all muscles in a significant increase in active tension. Muscle diameter always increased with increased perfusion pressure, but muscle segment length was unaffected. Capillary perfusion was then obstructed by plastic microspheres (15 microns). Flow, at a perfusion pressure of 66.6 +/- 26.2 cmH2O, reduced from 17.6 +/- 5.4 microliters/min in the control state to 3.2 +/- 1.3 microliters/min after microspheres. Active tension developed by the muscle in the unperfused condition before microspheres and after microspheres did not differ significantly (-12.8 +/- 29.4% change). After microspheres similar perfusion pressure steps as in control never resulted in an increase in active tension. Even at the two highest perfusion pressures (89.1 +/- 28.4 and 106.5 +/- 31.7 cmH2O) that were applied a significant decrease in active tension was found. We conclude that the Gregg phenomenon is related to capillary perfusion.

Perfusion-induced changes in cardiac contractility and oxygen consumption are not endothelium-dependent.

OBJECTIVE: Are substances released from rat coronary endothelial cells responsible for the increase in contractility and oxygen consumption (Gregg phenomenon) seen with an increase in cardiac perfusion? METHODS: In an isovolumically contracting, Langendorff, crystalloid perfused rat heart (n = 6) at 27 degrees C, coronary flow was changed (from 4.4 to 15.4 ml.min-1.gww(-1)) before and after the endothelium was made dysfunctional by Triton X-100. Vascular endothelium and smooth muscle function were tested with bradykinin (BK, 1 microM, an endothelium-dependent dilator) and papaverine (PAP, 1 microM, an endothelium-independent dilator) in a preconstricted vascular bed (vasopressin, VP, 3 nM). RESULTS: Before Triton X-100, coronary resistance (at constant flow) decreased significantly in response to BK and to PAP. After Triton X-100 treatment the dilatory response to BK was abolished while the PAP response was still present, suggesting endothelial dysfunction with intact smooth muscle function. Due to Triton X-100 treatment, coronary resistance increased significantly. Therefore coronary flow changes were also applied during a similar increase in coronary resistance induced by VP infusion (3 nM) before Triton X-100 treatment. During control, developed left ventricular pressure (dev Plv) increased with 68 +/- 21% and oxygen consumption (VO2) increased with 122 +/- 25% in response to the maximal increase in coronary flow. During increased coronary resistance with and without functional endothelium, dev Plv increased by 57 +/- 16 and 64 +/- 22%, respectively, and VO2 increased by 126 +/- 21 and 103 +/- 20%, respectively, in response to the maximal increase in flow. These changes were not significantly different from control. CONCLUSION: The results suggest that the arterial endothelium is not involved in the Gregg phenomenon.

Reoxygenated effluent of Tyrode-perfused heart affects papillary muscle contraction independent of cardiac perfusion.

OBJECTIVE: We determined, via a bioassay, if inotropic factors are released in the coronary circulation of the rat heart and if changes in cardiac perfusion change papillary muscle inotropy. METHODS: An isolated isometrically contracting rat papillary muscle (n = 5, acceptor) was superfused with Tyrode or with reoxygenated coronary venous effluent from an isolated isovolumically beating rat heart (donor) at 27 degrees C, which was perfused with Tyrode according to Langendorff. The superfusion solution in the muscle bath was exchanged completely in 90 s. During coronary venous effluent superfusion, the flow of the heart (donor) was changed in steps. RESULTS: The peak force of the papillary muscle (acceptor) was unaffected by a change from Tyrode to coronary venous effluent superfusion, but time to half relaxation (RT 1/2) significantly increased by 23.0 +/- 9.0% (mean +/- s.d.) and positive dF/dtmax significantly decreased by 14.6 +/- 4.7%. These twitch characteristics were unaffected by changes in coronary perfusion while in the heart isovolumic developed left ventricular pressure did increase with perfusion (the Gregg phenomenon). CONCLUSIONS: Factors that affected papillary muscle contractility are released into the coronary circulation, but their effect is independent of the magnitude of coronary perfusion.

Perfusion-induced changes in cardiac O2 consumption and contractility are based on different mechanisms.

Increased cardiac perfusion results in increased oxygen consumption (VO2) and increased contractility (Gregg phenomenon) in the isolated heart. We investigated whether these two aspects of the Gregg phenomenon are related to coronary flow or arterial pressure. Coronary flow and, thus, arterial pressure were changed in the reference state and during vasoconstriction (3 nM vasopressin) in the Langendorff-perfused rat heart contracting isovolumically (ventricular balloon) at 27 degrees C (n = 5). All hearts showed an increase in developed isovolumic left ventricular pressure (measure of contractility) and in VO2 with increased perfusion. Developed left ventricular pressure depended primarily on arterial pressure, so its relationship with coronary flow was shifted by vasoconstriction. Conversely, VO2 primarily depended on coronary flow, so its relationship with arterial pressure was shifted with vasoconstriction. By use of vasoconstriction (decreased vascular radii), the effects of arterial pressure and wall shear stress (proportional to arterial pressure x radius) should be separable, but the results did not reach significance. Thus contractility is related to arterial pressure or shear stress, whereas VO2 is related to coronary flow. We conclude that the two aspects of the Gregg phenomenon are based on different mechanisms.