Acute hepatic failure and coagulopathy associated with xylitol ingestion in eight dogs

Impact of concerning excipients on animal safety: insights for veterinary pharmacotherapy and regulatory considerations

OBJECTIVES

Veterinarians and pharmacists are familiar with the efficacy and safety aspects attributed to active pharmaceutical ingredients included in medicines, but they are rarely concerned with the safety of excipients present in medicines. Although generally recognized as safe, excipients are not chemically inert and may produce adverse events in certain animal populations. This review aims to present excipients of concern to these populations and highlight their relevance for rational veterinary pharmacotherapy.

EVIDENCE ACQUISITION

A comprehensive review of the literature about the existence of adverse reactions in animals caused by pharmaceutical excipients was carried out based on an exploratory study. An overview of the correct conditions of use and safety of these excipients has also been provided, with information about their function, the proportion in which they are included in the different pharmaceutical dosage forms and the usual routes of administration.

RESULTS

We identified 18 excipients considered of concern due to their potential to cause harm to the health of specific animal populations: bentonite, benzalkonium chloride, benzoic acid, benzyl alcohol, ethanol, lactose, mannitol, mineral oil, monosodium glutamate, polyethylene glycol, polysorbate, propylene glycol, sodium benzoate, sodium carboxymethylcellulose, sodium lauryl sulfate, sulfites, polyoxyethylene castor oil derivatives, and xylitol. Among the 135 manuscripts listed, only 24 referred to studies in which the substances were correctly evaluated as excipients.

CONCLUSIONS

Based on the information presented in this review, the authors hope to draw the attention of professionals involved in veterinary pharmacotherapy to the existence of excipients of concern in medicines. This information contributes to rational veterinary pharmacotherapy and supports veterinary pharmacovigilance actions. We hope to shed light on the subject and encourage studies and new manuscripts that address the safety of pharmaceutical excipients to the animal population.

[Acute poisonings in dogs - a retrospective case study over 5 years]

OBJECTIVE

The aim of this retrospective study was to analyze the clinical signs, confirmed or suspected toxicants, treatments and outcomes of poisoning cases in dogs presented over a 5-year period to the emergency service of a small animal referral center.

MATERIAL AND METHODS

Medical records of 634 dogs were evaluated for a history of confirmed or presumed poisoning, suspected toxicant, clinical signs, treatment, and patient outcome. The probability of poisoning was graded based on the patient history, clinical findings, toxicologic examination and - in some cases - investigation of gastrointestinal contents.

RESULTS

Most dogs were hospitalized (77%) due to poisoning with mostly unknown toxicants (33%), food residues (18%), rodenticides (10%), tremorgenic mycotoxins (8%), medications (7%) and various plants (7%), followed by recreational drugs (5%), chemicals (4%), molluscicides (3%), antiparasitics (2%), feces (2%), nuts (2%), or toxins of animal origin (1%). Patients were presented predominantly showing neurologic signs (56%), reduced general condition (39%), and cardiovascular or hydration status abnormalities (26%). The survival rate was 97%. Most dogs were clinically unremarkable at the time of hospital discharge (70%). An additional 18% of the survivors had no apparent complications by the time of discharge. Toxicant-related complications (20.5%) included hemorrhage (4%), hepatic (4%), renal (4%), respiratory (3%), gastrointestinal (3%), cardiovascular (3%), and/or central nervous system (3%) complications, or clinically relevant hypoglycemia (0.3%).

CONCLUSION AND CLINICAL RELEVANCE

In the present study, poisoning in dogs was mostly associated with the ingestion of food residues, but the causative toxicant remained unidentified in many cases. Neurological signs were the major clinical presentation. The survival rate (97%) in this study was higher compared to those reported by other investigators.

Erythritol alters phosphotransferase gene expression and inhibits the in vitro growth of Staphylococcus coagulans isolated from canines with pyoderma

Staphylococcus coagulans (SC) belongs to a group of coagulase-positive staphylococci occasionally isolated from the skin lesions of dogs with pyoderma. We recently revealed that erythritol, a sugar alcohol, inhibited the growth of SC strain JCM7470. This study investigated the molecular mechanisms involved in this growth inhibition of JCM7470 by erythritol, and determine whether erythritol inhibits the growth of SC isolated from the skin of dogs with pyoderma. Comprehensive analysis of the gene expression of JCM7470 in the presence of erythritol revealed that erythritol upregulated the expression of glcB and ptsG genes, both of which encode phosphotransferase system (PTS) glucoside- and glucose-specific permease C, B, and A domains (EIICBA), respectively, associated with sugar uptake. Moreover, erythritol suppressed in vitro growth of all 27 SC strains isolated from the skin lesions of canine pyoderma, including 13 mecA gene-positive and 14 mecA gene-negative strains. Finally, the growth inhibition of the SC clinical isolates by erythritol was restored by the addition of glucose. In summary, we revealed that erythritol promotes PTS gene expression and suppresses the in vitro growth of SC clinical isolates from dogs with pyoderma. Restoration of the erythritol-induced growth inhibition by glucose suggested that glucose starvation may contribute to the growth inhibition of SC.

Influence of Gallic Acid-Containing Mouth Spray on Dental Health and Oral Microbiota of Healthy Dogs: A Pilot Study

The pilot study aimed to investigate the effects of GAMS on oral microbiota in healthy dog subjects. Thirty-eight dogs were recruited and randomly allocated to the placebo (n = 19) and treatment groups (n = 19). The dogs were treated with mouth spray once daily for 42 days. The changes in the gingival index (GI), plaque index (PI), and calculus index (CI) were measured at baseline (day 0) and end of the study (42nd day). The changes in the oral microbial composition of representative dogs (placebo, n = 7; and treatment, n = 7) were also evaluated at baseline and end of the study. Oral microbial composition was assessed by sequencing. The sequences were annotated using the QIIME 2.0^TM. The GI, PI, and CI indexes were reduced after the GAMS usage. The abundance of the commensal bacterial phylum Actinobacteria and Chloroflexi, genera Frederiksenia, and Bergeyella was improved after six weeks of GAMS usage. GAMS reduced the pathogenic bacterial species, including Neisseria sp., Desulfobulbus sp., Capnocytophaga canis, and Corynebacterium mustelae. Moreover, some pathogenic bacterial abundances were increased at the end of the study. All the microbial variations were observed within the group. The inter-group analysis revealed that the changes were unrelated to GAMS usage. Further studies need to be carried out using more experimental subjects to confirm the effectiveness of GAMS. More metagenomic data are required to evidence the GMAS impact on the oral microbiome of healthy dogs.

Erythritol inhibits the growth of periodontal-disease-associated bacteria isolated from canine oral cavity

Periodontal disease (PD) is the most common oral disease that is caused by infection with periodontal-disease-associated bacteria (PDAB) such as Porphyromonas gulae and Porphyromonas macacae in dogs as well as in humans. Unlike humans, most dogs do not follow daily oral hygiene routine, and this results in many dogs being affected by PD. Thus, to prevent PD, it is important to control PDAB. Xylitol is a sugar alcohol that inhibits the growth of oral bacteria in humans. However, xylitol is poisonous to dogs and can lead to hypoglycemia and hepatic failure. Herein, we show the inhibitory effect of erythritol, a sugar alcohol that can be used safely in dogs, on the growth of PDAB isolated from dogs with PD. Oral bacteria were isolated from the oral cavities of dogs with PD, and the distribution of PDAB was evaluated. Interestingly, Porphyromonas gingivalis, a bacterium typically responsible for PD in humans, was not isolated from dog samples. The bacteriostatic effect of erythritol supplementation was investigated on isolated PDAB in vitro. Our results show that erythritol exert bacteriostatic effects on PDAB comparable to xylitol. Thus, application of erythritol can be suggested to control PDAB in dogs in the future.

Mortality rate and prognostic factors for dogs with severe anaphylaxis: 67 cases (2016-2018)

OBJECTIVE

To determine mortality rates for dogs with severe anaphylaxis and identify potential prognostic factors.

ANIMALS

67 dogs with suspected anaphylaxis graded as severe.

PROCEDURES

Dogs were classified on the basis of outcome as survivors and nonsurvivors. Medical records were reviewed, and data were extracted including signalment, examination findings, time to hospital admission from onset of clinical signs, CBC results, serum biochemical analysis results, coagulation testing results, and findings on abdominal ultrasonography. Initial treatment within the first 6 hours after hospital admission was recorded for analysis, specifically including the use of epinephrine, diphenhydramine, corticosteroids, antimicrobials, fresh-frozen plasma, and supplemental dextrose.

RESULTS

The overall mortality rate was 14.9% (10/67) for dogs with anaphylaxis graded as severe. Serum phosphorus concentration and prothrombin time (PT) were significantly higher in nonsurvivors, compared with survivors. Nonsurvivors had lower presenting body temperatures than survivors. Serum phosphorus concentration ≥ 12.0 mmol/L, hypoglycemia within 6 hours after hospital admission, high PT value, concurrently high PT and partial thromboplastin time (PTT) values > 50% above the reference range limit, and the need for supplemental dextrose were associated with death. The incidences of coagulopathy and peritoneal effusion were unexpectedly high (85.2% and 65.5% of dogs, respectively) but were not indicative of survival.

CONCLUSIONS AND CLINICAL RELEVANCE

Despite the poor presenting clinical condition seen in dogs with severe anaphylaxis, the rate of survival with treatment was fairly high. Coagulopathy and the presence of peritoneal effusion were common findings in dogs with severe anaphylaxis. Serum phosphorus concentration ≥ 12.0 mmol/L, high PT value, concurrent increases of PT and PTT values > 50% above reference range limits, hypoglycemia within 6 hours after hospital admission, and the need for supplemental dextrose were associated with death.

A review of hyperfibrinolysis in cats and dogs

The fibrinolytic system is activated concurrently with coagulation; it regulates haemostasis and prevents thrombosis by restricting clot formation to the area of vascular injury and dismantling the clot as healing occurs. Dysregulation of the fibrinolytic system, which results in hyperfibrinolysis, may manifest as clinically important haemorrhage. Hyperfibrinolysis occurs in cats and dogs secondary to a variety of congenital and acquired disorders. Acquired disorders associated with hyperfibrinolysis, such as trauma, cavitary effusions, liver disease and Angiostrongylus vasorum infection, are commonly encountered in primary care practice. In addition, delayed haemorrhage reported in greyhounds following trauma and routine surgical procedures has been attributed to a hyperfibrinolytic disorder, although this has yet to be characterised. The diagnosis of hyperfibrinolysis is challenging and, until recently, has relied on techniques that are not readily available outside referral hospitals. With the recent development of point-of-care viscoelastic techniques, assessment of fibrinolysis is now possible in referral practice. This will provide the opportunity to target haemorrhage due to hyperfibrinolysis with antifibrinolytic drugs and thereby reduce associated morbidity and mortality. The fibrinolytic system and the conditions associated with increased fibrinolytic activity in cats and dogs are the focus of this review article. In addition, laboratory and point-of-care techniques for assessing hyperfibrinolysis and antifibrinolytic treatment for patients with haemorrhage are reviewed.

Extraction and Analysis of Xylitol in Sugar-Free Gum Samples by GC-MS with Direct Aqueous Injection

Xylitol, a sugar substitute frequently used in sugar-free gum, is generally considered harmless to humans but it can be extremely toxic to dogs. Dog-owning customers are becoming increasingly aware of the risks associated with xylitol-containing chewing gums. However, there remains some uncertainty if these chewing gums are still dangerous to dogs after they have been partially consumed. In this work, a reliable low-cost analytical method has been developed to quantify the xylitol in sugar-free gum samples. Xylitol was extracted from gum samples using water as a solvent. Extractions were analyzed by GC-MS with direct aqueous injection (DAI). This method was successfully applied to over 120 samples including fresh gum and 5 min, 15 min, and 30 min chewed gum samples.

Xylitol toxicosis and serotonin-like syndrome occurring simultaneously in a dog secondary to ingestion of Natrol 5-HTP Fast Dissolve Tablets

Xylitol and serotonergic compounds are included in the manufacture of numerous over-the-counter products. Both compounds have been documented to cause toxicosis in dogs. This report details the first case of simultaneous xylitol toxicosis and serotonin-like syndrome in a dog, secondary to ingestion of a single over-the-counter product.

Acute liver failure in two dogs following ingestion of cheese tree (Glochidion ferdinandi) roots

OBJECTIVE

To describe the management and resolution of acute liver failure (ALF) in two dogs following ingestion of cheese tree (Glochidion ferdinandi) roots.

CASE SUMMARIES

A 2-year-old male entire Bullmastiff and a 5-year-old female neutered German Shepherd dog were presented for acute-onset lethargy and vomiting after chewing on tree roots of a cheese tree. Both dogs developed clinical abnormalities consistent with ALF, including hepatic encephalopathy, marked increase in alanine aminotransferase activity and bilirubin concentration, and prolonged coagulation times. Treatment included administration of intravenous fluids, hepatoprotectants, vitamin K₁ , antibiotics, lactulose, antacids, antiemetics, and multiple fresh frozen plasma transfusions. Follow-up examinations performed 30 days after initial presentation revealed the dogs to be clinically healthy with serum biochemical and coagulation profiles within reference intervals.

NEW OR UNIQUE INFORMATION

This is the first report describing ALF in two dogs following ingestion of cheese tree (G. ferdinandi) roots. In this clinical setting, despite a poor prognosis, survival and recovery of adequate liver function were possible with medical management.

PHARMACOKINETICS OF ORAL GABAPENTIN IN CARIBBEAN FLAMINGOS ( PHOENICOPTERUS RUBER RUBER)

Gabapentin is a first-line treatment for neuropathic pain and adjunct anticonvulsant medication in humans and other species. Gabapentin may have advantages over other analgesics because of its broad therapeutic range with limited adverse effects and wide availability as an oral formulation. This study determined the pharmacokinetics of gabapentin in Caribbean flamingos ( Phoenicopterus ruber ruber) after a single-dose oral administration of either 15 mg/kg ( n = 6) or 25 mg/kg ( n = 6). Plasma gabapentin concentrations were determined using liquid chromatography with mass spectrometry, and pharmacokinetic analysis was performed using noncompartmental methods. Respectively for the 15 mg/kg and 25 mg/kg dose, mean peak plasma concentration ( C_max) was (mean ± pseudo SD) 13.23 ± 1.47 and 24.48 ± 5.81 μg/ml; mean time to peak plasma concentration ( T_max) was 0.50 ± 0.24 and 0.56 ± 0.28 hr; mean area under the curve (AUC) was 76.0 ± 26.3 and 114.7 ± 27.5 hr·μg/ml; and mean terminal half-life ( T_1/2) was 3.39 ± 0.90 and 4.46 ± 1.12 hr. Based on the results of this study, gabapentin dosed at 25 mg/kg orally in most Caribbean flamingos is likely to maintain plasma concentrations above the therapeutic range established for humans for approximately 12 hr.

Pathophysiology and aetiology of hypoglycaemic crises

Hypoglycaemia is a common, life-threatening complication that occurs as a component of a wide variety of disease processes. Despite its frequent occurrence, information concerning the aetiology, characteristics and outcomes of hypoglycaemic crises in veterinary medicine is limited. This review summarises the current understanding of the pathophysiology of hypoglycaemia, the body's counter-regulatory response, underlying aetiologies, diagnosis and treatment. Disease mechanisms are discussed and published evidence in veterinary literature regarding prognostic indicators, prevalence, diagnosis and treatment is examined for hypoglycaemia-related disease processes including insulinoma, glucose-lowering toxins and medications.

Xylitol Toxicosis in Dogs: An Update

Xylitol ingestions in dogs may result in severe hypoglycemia followed by acute hepatic failure and associated coagulopathies. Aggressive treatment may be needed, but the prognosis is generally expected to be good for dogs developing uncomplicated hypoglycemia. Because of increased availability of xylitol-containing products in the market and in the dog's environment, it is likely that there will continue to be increased exposures and toxicity in dogs.

Effects of p.o. administered xylitol in cats

Xylitol is commonly used as sugar substitute in households. While it has numerous beneficial effects on human health, it is highly toxic to dogs. The goal of this study was to examine whether xylitol has similar deleterious effects, such as hypoglycaemia and acute hepatic failure, on cats. Our research included six healthy middle-aged cats. Xylitol was dissolved in deionized water and administered p.o. at three doses (100, 500 and 1,000 mg/kg body weight). These dosages have been considered toxic and can cause liver failure or even death in dogs. After every xylitol administration, the basic health status and the blood glucose of cats were observed regularly. Additionally, prior to and 6, 24 and 72 hr after xylitol administration, blood samples were taken to check complete blood count, clinical biochemical parameters and enzymes such as ALT, ALKP, GGT, GLDH, bile acids, BUN, creatinine, phosphate, total protein, albumin, sodium and potassium. There were no significant changes (p > .05) in any of the haematological or biochemical parameters. Blood glucose concentrations did not show any significant alterations, except at 1,000 mg/kg dose, where a mild but significant increase was observed, but it was in physiological range. Based on our results, xylitol did not induce toxic effects on cats.

Acute, Fatal, Presumptive Xylitol Toxicosis in Cape Sugarbirds ( Promerops cafer)

Twenty-nine wild Cape sugarbirds ( Promerops cafer) died acutely after ingestion of a homemade xylitol nectar solution from a bird feeder. The most aggressive feeders were first affected. Most birds showed clinical signs within 15 minutes of nectar ingestion, including incoordination, weakness, falling from perches, collapse, and death. A few birds showing clinical signs seemed to spontaneously recover and fly away. Full necropsy examinations done on 27 birds were hampered by freezing artifact and autolysis, but results indicated death was caused by the consequences of acute hypoglycemia. A presumptive diagnosis of xylitol toxicity was made based on the history, clinical signs, and absence of other obvious causes of death. This is potentially the first record of xylitol toxicity in wild birds.

Acute Hepatic Failure in a Dog after Xylitol Ingestion

Xylitol is a five-carbon sugar alcohol produced from natural resources frequently used as a sugar substitute for humans. We report the development and successful treatment of acute hepatic failure and coagulopathy in a dog after xylitol ingestion. A 9-year-old 4.95 kg (10.9 lb) neutered male Chihuahua was evaluated at a veterinary clinic for vomiting after ingesting 224 g (45 g/kg, 20.5 g/lb) of granulated xylitol. Hypoglycemia developed within 1-2 h, elevated liver values, suggesting the development of acute hepatic failure, within 12 h and coagulopathy less than 24 h after ingestion. Treatment included maropitant, intravenous dextrose, phytonadione, metronidazole, and fresh frozen plasma. N-acetylcysteine (NAC) and S-adensoyl-L-methionine (SAMe) provided hepatic detoxification and support. The dog survived and liver values returned to normal within 1 month post ingestion. No adverse effects to hepatic function have been identified 2 years after acute xylitol toxicity. This paper is one of the few reports of successful management of a dog with hypoglycemia, hepatic failure, and coagulopathy caused by xylitol toxicity. To date, this is the highest published xylitol dose survived by a dog, as well as the only reported case that documents laboratory changes throughout the course of toxicity and includes normal hepatic indices for 7 months following xylitol toxicity. The rapidly expanding use of xylitol in a variety of products intended for human consumption has led to a rise in xylitol toxicity cases reported in dogs, and clinicians should be aware that more dogs may potentially be exposed and develop similar manifestations.

Acute Liver Injury and Failure

Acute liver injury and acute liver failure are syndromes characterized by a rapid loss of functional hepatocytes in a patient with no evidence of pre-existing liver disease. A variety of inciting causes have been identified, including toxic, infectious, neoplastic, and drug-induced causes. This article reviews the pathophysiology and clinical approach to the acute liver injury/acute liver failure patient, with a particular emphasis on the diagnostic evaluation and care in the acute setting.

[Emergency management of intoxications in the dog and cat]

Intoxications may lead to life-threatening emergencies. While stabilising the patient, therapy should focus on a rapid and effective elimination of the toxin. General measures for decontamination (gastrointestinal, dermal, ocular) aim to effectively decrease the absorption of the poisonous substance. Further classification of the substance and its properties can assist with the choice of specific treatment options, including dialysis and specific antidotal therapy. In recent years, treatment with lipid emulsions for enhanced elimination of lipophilic substances has become an important therapeutic option. In affected patients, it can rapidly improve clinical signs while side effects and complications are rarely encountered with this form of therapy.

Household Food Items Toxic to Dogs and Cats

Several foods that are perfectly suitable for human consumption can be toxic to dogs and cats. Food-associated poisoning cases involving the accidental ingestion of chocolate and chocolate-based products, Allium spp. (onion, garlic, leek, and chives), macadamia nuts, Vitis vinifera fruits (grapes, raisins, sultanas, and currants), products sweetened with xylitol, alcoholic beverages, and unbaked bread dough have been reported worldwide in the last decade. The poisoning episodes are generally due to lack of public knowledge of the serious health threat to dogs and cats that can be posed by these products. The present review aims to outline the current knowledge of common food items frequently involved in the poisoning of small animals, particularly dogs, and provides an overview of poisoning episodes reported in the literature.

Single oral dose safety of D-allulose in dogs

Healthy dogs were administered acute oral doses of D-allulose (also called D-psicose) to evaluate its toxicity. Six dogs received oral doses of either a placebo or D-allulose solution (1 and 4 g/kg) on three different study days. One dog experienced vomiting, and five dogs showed transient diarrhea when 4 g/kg of D-allulose was administered. All dogs were active and had a good appetite throughout the study period. Blood glucose concentration slightly decreased without a rise in plasma insulin concentration 2 hr after D-allulose administration. Plasma alkaline phosphatase activities showed a mild increase between 12 and 48 hr after D-allulose administration. These data suggested that a single oral dose of D-allulose does not show severe toxicity in dogs.

Thromboelastographic Evaluation of Dogs with Acute Liver Disease

BACKGROUND

Given the liver's pivotal role in hemostasis and fibrinolysis, the coagulopathy accompanying hepatic disease is complex.

HYPOTHESIS/OBJECTIVES

To prospectively evaluate kaolin-activated thromboelastography (TEG) in dogs with acute liver disease (ALD) and compare with plasma-based coagulation tests.

ANIMALS

Twenty-one dogs with a diagnosis of ALD based on recent onset of clinical signs accompanied by increases in serum bilirubin concentration and alanine aminotransferase activity.

METHODS

Clinical presentation, CBC, serum biochemistry, platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), and TEG analysis were evaluated in 21 dogs with a subset also having fibrinogen, antithrombin (AT) activity, protein C (PC) activity, d-dimers, and von Willebrand's factor (vWF) activity analyzed. A PT >1.5 times the upper limit of normal defined acute liver failure (ALF).

RESULTS

Dogs with ALD had mean increases in R, K, LY30, PT, aPTT, and vWF activity, and decreases in angle, maximal amplitude (MA), G, AT activity, and PC activity. The TEG results defined dogs as hypocoagulable (11/21), normocoagulable (8/21), or hypercoagulable (2/21). Increases in LY30 defined 8/21 dogs as hyperfibrinolytic. Hypocoagulable and hyperfibrinolytic dogs had lower fibrinogen and PC activity than dogs without these abnormalities. Overall, ALF dogs had greater increases in K and LY30, and decreases in MA, G, and PC activity than dogs with less severe hepatic impairment. Results for MA and LY30 were positively correlated with serum bilirubin concentration and white blood cell count, and negatively correlated with serum cholesterol concentration.

CONCLUSIONS AND CLINICAL IMPORTANCE

ALD dogs have a range of coagulation abnormalities that trend toward hypocoagulability and hyperfibrinolysis as functional impairment occurs.

Acute liver failure in dogs and cats

OBJECTIVE

To define acute liver failure (ALF), review the human and veterinary literature, and discuss the etiologies and current concepts in diagnostic and treatment options for ALF in veterinary and human medicine.

ETIOLOGY

In veterinary medicine ALF is most commonly caused by hepatotoxin exposure, infectious agents, inflammatory diseases, trauma, and hypoxic injury.

DIAGNOSIS

A patient may be deemed to be in ALF when there is a progression of acute liver injury with no known previous hepatic disease, the development of hepatic encephalopathy of any grade that occurs within 8 weeks after the onset of hyperbilirubinemia (defined as plasma bilirubin >50 μM/L [>2.9 mg/dL]), and the presence of a coagulopathy. Diagnostic testing to more specifically characterize liver dysfunction or pathology is usually required.

THERAPY

Supportive care to aid the failing liver and compensate for the lost functions of the liver remains the cornerstone of care of patients with ALF. Advanced therapeutic options such as extracorporeal liver assist devices and transplantation are currently available in human medicine.

PROGNOSIS

The prognosis for ALF depends upon the etiology, the degree of liver damage, and the response to therapy. In veterinary medicine, the prognosis is generally poor.

In vitro safety assessment of food ingredients in canine renal proximal tubule cells

In vitro models are useful tools to initially assess the toxicological safety hazards of food ingredients. Toxicities of cinnamaldehyde (CINA), cinnamon bark oil, lemongrass oil (LGO), thymol, thyme oil (TO), clove leaf oil, eugenol, ginger root extract (GRE), citric acid, guanosine monophosphate, inosine monophosphate and sorbose (SORB) were assessed in canine renal proximal tubule cells (CPTC) using viability assay and renal injury markers. At LC50, CINA was the most toxic (0.012mg/ml), while SORB the least toxic (>100mg/ml). Toxicities (LC50) of positive controls were as follows: 4-aminophenol (0.15mg/ml in CPTC and 0.083mg/ml in human PTC), neomycin (28.6mg/ml in CPTC and 27.1mg/ml in human PTC). XYL displayed lowest cytotoxic potency (LC50=82.7mg/ml in CPTC). In vivo renal injury markers in CPTC were not significantly different from controls. The LGO toxicity mechanism was analyzed using qPCR and electron microscopy. Out of 370 genes, 57 genes (15.4%) were significantly up (34, 9.1%) or down (23, 6.2%) regulated, with the most upregulated gene gsta3 (∼200-fold) and the most affected pathway being oxidative stress. LGO induced damage of mitochondria, phospholipid accumulation and lack of a brush border. Viability assays along with mechanistic studies in the CPTC model may serve as a valuable in vitro toxicity screening tool.

Efficacy of intravenous administration of combined acid suppressants in healthy dogs

Background

Short‐term intravenous co‐administration of famotidine and pantoprazole is used by some veterinarians to treat gastrointestinal bleeding in critically ill dogs. However, clinical studies have not evaluated the efficacy of combination acid suppressant treatment in dogs.

Hypothesis/Objectives

To compare the effect of intravenous co‐administration of famotidine and pantoprazole to monotherapy with pantoprazole on intragastric pH in dogs. We hypothesized that single agent pantoprazole would be more effective than combination with famotidine.

Animals

Twelve healthy adult colony dogs.

Methods

Randomized, 2‐way crossover design. All dogs received placebo (0.9% saline) for 24 hours followed by 1.0 mg/kg IV q12h pantoprazole or combination treatment with famotidine and pantoprazole for 3 consecutive days. Intragastric pH monitoring was used to continuously record intragastric pH for 96 hours beginning on day 0 of treatment. Mean percentage time (MPT) that intragastric pH was ≥3 and ≥4 were compared between groups using ANOVA with a posthoc Tukey‐Kramer test (α = 0.017).

Results

The MPT ± standard deviation intragastric pH was greater than ≥3 and 4 were 79 ± 17% and 68 ± 17% for pantoprazole and 74 ± 19% and 64 ± 23% for combination treatment, respectively. There were no significant differences in MPT intragastric pH was ≥3 and 4 between groups. Pantoprazole administered alone achieved pH goals established for humans with acid‐related disorders.

Conclusions and Clinical Importance

These results suggest that short‐term combination treatment with famotidine and pantoprazole is not superior to pantoprazole alone for increasing intragastric pH in dogs.

Binding affinity of anti-xylitol antibodies to canine hepatic vessels

Xylitol is used as a sugar substitute in food products. Dogs have been reported to experience lethal liver injury after accidental ingestion of xylitol. Because liver injury may be a serious consequence of canine immune-mediated reactions, antibodies produced against xylitol may attack the liver. Therefore, in the present study, we evaluated whether binding sites for xylitol antibodies are located at the liver or not. Anti-xylitol antibodies were generated by immunization of rabbits with a xylose-bovine serum albumin conjugate. Immunohistological examination showed that binding sites for the anti-xylitol antibodies were located in the hepatic arteries and the portal veins. Western blotting analyses by using a canine liver homogenate showed 4 protein bands with different molecular weights which reacted with anti-xylitol antibodies. Therefore, binding of anti-xylitol antibodies to the vessels may be the first step in an immune-mediated pathogenic response in xylitol toxicity. Further studies are necessary to determine the effects of anti-xylitol antibodies on the liver in the pathogenesis of xylitol toxicity.

Coagulation in hepatobiliary disease

OBJECTIVE

To review the pathogenesis and clinical consequences of coagulation abnormalities accompanying hepatobiliary disorders and to highlight the need for further studies to characterize these derangements and their treatment options in small animal patients.

DATA SOURCES

Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent texts.

SUMMARY

The liver plays an important role in the production and clearance of many components of coagulation. A wide range of hemostatic derangements can occur in patients with hepatobiliary disease including alterations in platelet number and function, coagulation factor levels, anticoagulants, vascular endothelial function, and fibrinolysis. As these hemostatic alterations include both pro- and anticoagulation pathways, the net result is often a rebalanced hemostatic system that can be easily disrupted by concurrent conditions resulting in either clinical bleeding or thrombosis. Conventional coagulation tests are inadequate at identifying the spectrum of coagulation alterations occurring in patients with hepatobiliary disease, but their evaluation is necessary to assess bleeding risk and provide prognostic information. A paucity of information exists regarding the treatment of the coagulation derangements in small animals with hepatobiliary disease. Extrapolation from human studies provides some information about potential treatment options, but further studies are warranted in this area to elucidate the best management for coagulation abnormalities in dogs and cats with hepatobiliary disease.

CONCLUSION

Hepatobiliary disease can have profound effects on coagulation function leading to hypercoagulable or hypocoagulable states. Overall coagulation status with hepatobiliary disease depends on both the type and severity of disease and the presence of associated complications.

Safety assessment of nebulized xylitol in beagle dogs

Xylitol, a potential cystic fibrosis treatment, lowers the salt concentration of airway surface liquid and enhances innate immunity of human airways. The study objective was to evaluate the potential toxicity/recovery from a 14-consecutive day (7 days/week), facemask inhalation administration of nebulized xylitol solution in Beagle dogs. Aerosolized xylitol was generated through three Aerotech II nebulizers operating at approximately 40 psi driving pressure. Test article groups were exposed to the same concentration of aerosolized xylitol for 1, 0.5, or 0.25 h for the high, mid, and low exposures, respectively. A control group was exposed for 1 h to a nebulized normal saline solution. Animals were sacrificed the day following the last exposure or subsequently after 14 non-exposure days. Study endpoints included clinical observations, body weights, ophthalmology, and physical examinations, food consumption, clinical pathology, urinalyses, organ weights, and histopathology. Mean xylitol aerosol concentrations for all groups were approximately 3.5 mg/l. Mean total deposited doses to the pulmonary region were estimated as 21, 11, and 5 mg/kg, for the high-, mid-, and low-exposure groups, respectively. All dogs survived to the scheduled necropsy. No treatment-related findings were observed due to xylitol exposure in any end point examined. Lung findings (mild interstitial infiltration, macrophage hyperplasia, alveolitis, and bronchitis) were consistent among exposed and control groups. No exposure-related effect of xylitol in any parameter assessed was seen during or after the 14-day exposure in Beagle dogs. The No Observed Effect Level was the high-exposure level and suggests that inhaled xylitol is safe for clinical administration.

Treatment of aseptic dogs with hemorrhagic gastroenteritis with amoxicillin/clavulanic acid: a prospective blinded study

BACKGROUND

Antibiotics generally are recommended to treat hemorrhagic gastroenteritis (HGE). Inappropriate use of antibiotics may promote risk of antimicrobial resistance and unnecessary adverse drug reactions. The necessity of antimicrobial therapy in dogs with HGE has not been demonstrated.

OBJECTIVE

The purpose of this prospective, placebo-controlled, blinded study was to evaluate whether treatment with amoxicillin/clavulanic acid improves the clinical course and outcome of HGE in dogs that show no signs of sepsis.

ANIMALS

The study included 60 dogs diagnosed with HGE between 2007 and 2009 at the Clinic of Small Animal Medicine, LMU University of Munich, Germany. The inclusion criterion was the presence of acute hemorrhagic diarrhea (<3 days). Dogs pretreated with antibiotics, with signs of sepsis, or diagnosed with any disease known to cause bloody diarrhea were excluded from the study.

METHODS

Patients were randomly divided into treatment (amoxicillin/clavulanic acid for 7 days) and placebo groups. To evaluate treatment efficacy, severity of clinical signs (based on a newly developed HGE index), duration of hospitalization, and mortality rate were compared between the 2 groups.

RESULTS

Fifty-three of 60 dogs completed the study. No significant difference between treatment groups concerning mortality rate, dropout rate, duration of hospitalization, or severity of clinical signs, either on any individual day or over the course of disease, was observed.

CONCLUSIONS AND CLINICAL IMPORTANCE

In some dogs with HGE that show no signs of sepsis, antibiotics may not change the case outcome or time to recovery.

Emesis in dogs: a review

Emesis is a common presenting sign in small animal practice. It requires a rational approach to management that is based upon a sound understanding of pathophysiology combined with logical decision making. This review, which assesses the weight of available evidence, outlines the physiology of the vomiting reflex, causes of emesis, the consequences of emesis and the approach to clinical management of the vomiting dog. The applicability of diagnostic testing modalities and the merit of traditional approaches to management, such as dietary changes, are discussed. The role and usefulness of both traditional and novel anti-emetic drugs is examined, including in specific circumstances such as following cytotoxic drug treatment. The review also examines areas in which common clinical practice is not necessarily supported by objective evidence and, as such, highlights questions worthy of further clinical research.

Some food toxic for pets

According to world statistics, dogs and cats are the species that owners most frequently seek assistance with potential poisonings, accounting 95-98% of all reported animal cases. Exposures occur more commonly in the summer and in December that is associated with the holiday season. The majority (>90%) of animal poisonings are accidental and acute in nature and occur near or at the animal owner's home. Feeding human foodstuff to pets may also prove dangerous for their health.The aim of this review was to present common food items that should not be fed (intentionally or unintentionally) to dogs, i.e. chocolate, caffeine, and other methylxanthines, grapes, raisins, onion, garlic, avocado, alcohol, nuts, xylitol contained in chewing gum and candies, etc. Onion and avocado are toxic for cats, too. The clinical effects of individual toxicants and possible therapy are also mentioned. Knowing what human food has the potential to be involved in serious toxicoses should allow veterinarians to better educate their clients on means of preventing pet poisonings.It can be concluded that the best advice must surely be to give animal fodder or treats specifically developed for their diets.

Evaluation of the effect of topical application of lavender oil on autonomic nerve activity in dogs

OBJECTIVE

To investigate the effect of topical application of undiluted lavender oil on sympathovagal activity in dogs.

ANIMALS

5 healthy adult male Beagles.

PROCEDURES

An ambulatory ECG monitor (Holter recorder) was placed on each dog (day0), and 48-hour ECGs were recorded, beginning at 8:00 the next day (day 1). Lavender oil (0.18 mL) or saline (0.9% NaCl) solution (0.18 mL) was topically applied to the inner pinnas of both ears of all dogs at 8:30, 12:00, 15:30, and 19:00 on day 2. Each trial was duplicated in each dog, with an interval of 3 to 4 days between trials. Spectral indices of heart rate variability, power in the high-frequency range, and the ratio of low-frequency to high-frequency power were calculated as an indirect estimate of autonomic nerve activity.

RESULTS

When dogs were treated with lavender oil, the mean heart rate was significantly lower during the period of 19:00 to 22:30 on day 2, compared with the mean heart rate during the same period when dogs were treated with saline solution. On the other hand, high-frequency power during the period of 15:30 to 19:00 was significantly higher when dogs were treated with lavender oil, compared with the high-frequency power during the same period when dogs were treated with saline solution.

CONCLUSIONS AND CLINICAL RELEVANCE

The study revealed some evidence that topical application of lavender oil affected vagal activity in dogs. However, whether such an effect exists and whether lavender oil has a calming effect on dogs remains equivocal and requires additional investigation.