Jakob L. Willesen

Canine pulmonary angiostrongylosis: an update.

Canine pulmonary angiostrongylosis is an emerging snail-borne disease causing verminous pneumonia and coagulopathy in dogs. The parasite is found in Europe, North and South America and Africa, covering tropical, subtropical and temperate regions. Its distribution has been characterised by isolated endemic foci, with only sporadic occurrences outside these areas. In the last two decades, the literature has been dominated by several case reports and small case series describing sporadic disease in old or new endemic areas. Case reports and experimental studies with high doses of infective third stage larvae may not reflect what happens under field conditions. There is insufficient understanding of the spread of infection and the dynamic consequences of this parasite in the canine population. This review discusses the biology, epidemiology, clinical aspects and management of canine pulmonary angiostrongylosis.

Elucidating the spread of the emerging canid nematode Angiostrongylus vasorum between Palaearctic and Nearctic ecozones.

Angiostrongylus vasorum is an emerging parasite that is currently distributed through Western Europe and parts of South America. An isolated population is also present in Newfoundland, Canada. This presents a risk of onward spread into North America, but its origin is unknown. To ascertain the phylogeographic relationships and genetic diversity of A. vasorum within the western Palaearctic and eastern Nearctic ecozones, a total of 143 adult and larval nematode specimens were collected from foxes (Vulpes vulpes) and dogs (Canis lupus familiaris) in Canada, Denmark, France, Germany, Ireland, the Netherlands, Portugal and the United Kingdom, and a coyote (Canis latrans) in Canada. DNA was extracted and the second internal transcribed spacer and two mitochondrial loci were amplified and sequenced. Multiple haplotypes (n=35) based on combined mitochondrial sequences (1078bp) of the partial cytochrome oxidase subunit I (COI), large subunit ribosomal RNA (rrnL) and the complete nicotinamide adenine dinucleotide dehydrogenase 3 (NADH3) sequences, were observed throughout the Palaearctic countries sampled; however, only a single haplotype was observed for the Canadian A. vasorum population. The likely origin of A. vasorum in Newfoundland is therefore inferred to be within the western Palaearctic. There was no evidence of genetic segregation of parasites in dogs, foxes and coyotes, supporting the hypothesis that transmission occurs between wild and domestic canids. The transmission dynamics and population structure of this nematode are further discussed.

Prognostic Importance of Myocardial Injury in Critically Ill Dogs with Systemic Inflammation

BACKGROUND In noncardiac critical disease in humans, myocardial injury as detected by cardiac troponin I and T (cTnI and cTnT) has been linked to high intensive care unit (ICU) death independent of prognostic composite scoring. HYPOTHESIS Presence of myocardial injury predicts short-term death in critically ill dogs with systemic inflammation and provides additional prognostic information when combined with established canine prognostic composite scores. ANIMALS Forty-two dogs admitted to the ICU with evidence of systemic inflammation and no primary cardiac disease. METHODS Prospective cohort study. Blood samples were obtained at ICU admission for the measurement of cTnI and cTnT, C-reactive protein, and several cytokines. The acute patient physiologic and laboratory evaluation (APPLE) score and the survival prediction index were calculated within the first 24 hours of admission. Receiver operating characteristic (ROC) curves were used to examine the prognostic capacity of each biomarker and severity score. Multiple logistic regression analysis was performed to evaluate whether cardiac markers significantly contributed to severity scores. RESULTS Twenty-eight day case fatality rate was 26% (11/42 dogs). cTnI concentrations were (median [range]) 0.416 [0.004-141.5] ng/mL and cTnT concentrations were 13.5 [<13-3,744] ng/L. cTnI, cTnT, and the APPLE score were all significant prognosticators with areas under the ROC curves [95% CI] of 0.801 [0.649; 0.907], 0.790 [0.637; 0.900], and 0.776 [0.621; 0.889], respectively. cTnI significantly contributed to the APPLE score in providing additional prognostic specificity (P = .025). CONCLUSIONS AND CLINICAL IMPORTANCE Markers of myocardial injury predict short-term death in dogs with systemic inflammation and cTnI significantly contributes to the APPLE score.

Cardiac Troponin I and T as Prognostic Markers in Cats with Hypertrophic Cardiomyopathy

Background Myocardial injury detected by cardiac troponin I and T (cTnI and cTnT) in cardiac disease is associated with increased risk of death in humans and dogs. Hypothesis Presence of myocardial injury predicts long‐term death in cats with hypertrophic cardiomyopathy (HCM), and ongoing myocardial injury reflects change in left ventricular wall thickness over time. Animals Thirty‐six cats with primary HCM. Methods Prospective cohort study. Cats with HCM were included consecutively and examined every 6 months. Echocardiography, ECG, blood pressure, and serum cTnI and cTnT were evaluated at each visit. Cox proportional hazards regression analysis was performed to evaluate prognostic potential of serum troponin concentrations at admission and subsequent examinations. Correlations were used to examine associations between troponin concentrations and cardiac hypertrophy. Results Troponin concentrations at admission were median [range] 0.14 [0.004–1.02] ng/mL for cTnI, and 13 [13–79.5] ng/L for cTnT. Both were prognostic for death (P = .032 and .026) as were the last available concentrations of each (P = .016 and .003). The final cTnT concentration was a significant predictor of death even when adjusting for the admission concentration (P = .043). In a model containing both markers, only cTnT remained significant (P = .043). Left ventricular free wall thickness at end‐diastole (LVFWd) at admission was correlated with cTnI at admission (r = 0.35, P = .035), however no significant correlations (r = 0.2–0.31, P = .074–.26) were found between changes in troponin concentrations and left ventricular thickness over time. Conclusions and Clinical Importance Myocardial injury is part of the pathophysiology leading to disease progression and death. Low sensitivities and specificities prevent outcome prediction in individual cats.

A coprological investigation of gastrointestinal and cardiopulmonary parasites in hunting dogs in Denmark.

A coprological survey was conducted to investigate the prevalence of parasites infecting hunting dogs with no history of recent anthelmintic treatments and with no overt clinical manifestations of cardiopulmonary or gastrointestinal illness. The hunting dogs were recruited from four different areas in Denmark, and fecal samples were obtained in October and November, 2007. For detecting gastrointestinal parasites, samples (N=178) were examined by a commercial flotation kit (Fecalyzer(®) EVSCO, USA). For detection of cardiopulmonary parasites, samples (N=181) were collected on three consecutive days and examined using the Baermann method. Parasites were recovered from 22.1% of the hunting dogs: Angiostrongylus vasorum (2.2%), Toxocara canis (12.4%), Uncinaria stenocephala (7.3%), Taenia spp. (1.7%), Toxascaris leonina (0.6%), Coccidia (0.6%) and unidentified trematode eggs (1.1%). Infection with only one species of parasite was more common (89.5%) than infection with two species (10.5%). A multiple logistic regression model showed that prevalence of intestinal parasites was not influenced by age, gender or breed in adult dogs. There was a significantly higher prevalence of intestinal parasites in the densely populated area of the island Zealand compared with the less populated regions of the peninsular Jutland. The present study reports the first case of A. vasorum in a dog from Jutland. The dog had been visiting the endemic area of western Zealand, suggesting that translocation of sub-clinically infected dogs may contribute to introduction of A. vasorum into non-endemic areas.

Evaluation of a high‐sensitivity assay for measurement of canine and feline serum cardiac troponin I

BACKGROUND Cardiac troponins are established as the gold standard biomarkers for acute cardiac injury. As even small elevations of cardiac troponins have prognostic relevance in people, it is important to investigate the performance of sensitive assays for use in veterinary medicine. OBJECTIVES The aim of this study was to evaluate analytical and overlap performance of a high-sensitivity cardiac troponin I (cTnI) assay, the ADVIA Centaur CP TnI-Ultra assay, in dogs and cats. METHODS Serum samples from dogs and cats with cardiac disease or arrhythmias, along with samples of purified canine free cTnI and complexed cTnI, T, and C (cTnI-T-C) were used in the assay validation study. Intra- and inter-assay variation, linearity under dilution, spike-and-recovery analysis, and detection limit were investigated to assess analytical performance. Overlap performance was evaluated based on the ability of the assay to discriminate between healthy animals and animals with cardiac disease or arrhythmias. RESULTS Intra-assay variation of cTnI in canine and feline serum ranged from 3.9 to 6.4% and from 4.0 to 4.8%, respectively. Inter-assay variation ranged from 2.7 to 4.7% and from 4.0 to 7.8%, respectively. The assay demonstrated acceptable linearity under dilution within a clinically relevant range of cTnI concentrations. Spike-and-recovery analysis showed excessive recovery in the range 150.7%-242.0% for free cTnI and 121.1-196.3% for complexed cTnI-T-C, partly due to a matrix effect. Overlap performance was acceptable as animals with cardiac disease or arrhythmias (n = 45 dogs, n = 53 cats) had significantly higher cTnI concentrations than healthy controls (P < .0001). CONCLUSIONS The results confirm the ADVIA Centaur CP TnI-Ultra assay as a valuable tool for assessing cTnI and thus myocardial injury in dogs and cats.

Left atrial volume and phasic function in clinically healthy dogs of 12 different breeds.

The left atrium (LA) of the heart is a validated marker of clinical and subclinical cardiovascular disease. Since the LA is a three-dimensional structure, volume-based methods of chamber quantification might be more accurate than linear methods. The aims of this study were to establish the feasibility and reproducibility of biplane two-dimensional echocardiographic LA volume measurements and to provide reference ranges for LA volume and phasic function in adult dogs (n=237) without cardiovascular disease. The study also assessed the effects of bodyweight (BW), breed, sex, age and heart rate (HR) on LA volume and function. The biplane area-length method was used to calculate LA volumes from the left apical four- and two-chamber views. LA volume and function were correlated with body size and there were significant breed differences. For dogs of all sizes and breeds, LA maximal volume had a 95th percentile of 0.92 mL/kg. There was no correlation between age or sex and LA volume or LA reservoir function, but conduit function decreased and booster pump function increased with age. LA volume and function varied with HR. LA size was calculated using the biplane area-length method, with good reproducibility and little inter-observer variability. The reference ranges presented for LA volume and function in healthy dogs could be used to refine the diagnostic criteria for the assessment of LA enlargement and altered function by conventional echocardiography.

Acute neurological signs as the predominant clinical manifestation in four dogs with Angiostrongylus vasorum infections in Denmark

Four dogs with acute neurological signs caused by haemorrhages in the central nervous system were diagnosed with Angiostrongylus vasorum infection as the underlying aetiology. Two dogs presented with brain lesions, one dog with spinal cord lesions and one with lesions in both the brain and spinal cord. Only one dog presented with concurrent signs of classical pulmonary angiostrongylosis (respiratory distress, cough), and only two dogs displayed overt clinical signs of haemorrhages. Results of coagulation assays were inconsistent. Neurological signs reflected the site of pathology and included seizures, various cranial nerve deficits, vestibular signs, proprioceptive deficits, ataxia and paraplegia. One dog died and three were euthanised due to lack of improvement despite medical treatment. This emphasises canine angiostrongylosis as a potential cause of fatal lesions of the central nervous system and the importance of including A. vasorum as a differential diagnosis in young dogs with acute neurological signs in Denmark.

Myocardial injury in dogs with snake envenomation and its relation to systemic inflammation

OBJECTIVE To investigate the presence of myocardial injury in dogs hospitalized for snake envenomation and to examine its relationship with systemic inflammation. DESIGN Prospective case-control study. SETTING University teaching hospital and small animal referral hospital. ANIMALS Dogs naturally envenomed by the European viper (Vipera berus; n = 24), African puff adder (Bitis arietans; n = 5), or snouted cobra (Naja annulifera; n = 9). INTERVENTIONS Blood was collected from dogs envenomed by V. berus at admission, 12-24 hours postadmission, and 5-10 days postadmission. Blood was collected from dogs envenomed by B. arietans or N. annulifera at admission, and 12, 24, and 36 hours postadmission. MEASUREMENTS AND MAIN RESULTS Concentrations of cardiac troponin I (cTnI), a marker of myocardial injury, and C-reactive protein (CRP), a marker of systemic inflammation, were measured in each blood sample. Evidence of myocardial injury was found in 58% of dogs envenomed by V. berus at one or more time points. A significant correlation between cTnI and CRP concentrations was found at all time points. Evidence of myocardial injury was found in 80% of dogs envenomed by B. arietans at one or more time points; however, no correlation was found between cTnI and CRP concentrations. Evidence of myocardial injury was found in 67% of dogs envenomed by N. annulifera at one or more time points. A significant correlation between cTnI and CRP concentrations was found at admission, but not at other time points. CONCLUSIONS Myocardial injury frequently occurred in dogs with snake envenomation. While the degree of systemic inflammation was significantly correlated with degree of myocardial injury in V. berus envenomation at all time points, this was not the case in dogs envenomed by N. annulifera or B. arietans. This could be due to differences in the toxic substances of the snake venoms or to differences in the cytokines induced by the venom toxins.

Diversity and prevalence of metastrongyloid nematodes infecting the red panda (Ailurus fulgens) in European zoos.

Metastrongyloid induced pneumonia has been described sporadically in the red panda (Ailurus fulgens). Early descriptions in pandas recently imported to the USA from China involved parasites morphologically similar to Angiostrongylus spp. and Crenosomatidae. More recently, four cases of severe verminous pneumonia associated with Angiostrongylus vasorum have been reported from European zoos. A coprological survey of the red panda population within European zoos was conducted in 2008. Faecal samples from 115 pandas originating from 54 zoos were collected on 3 consecutive days. Using Baermann technique, 40 animals (35%) from 20 zoos (37%) were found to shed metastrongyloid first stage larvae (L(1)). Based on their morphology and size, the L(1) observed could be divided into three morphologically distinct types: (1) a Crenosoma sp. type (n=5, overall prevalence: 4.3%), (2) an A. vasorum type (n=3, 2.6%), and (3) an unidentified metastrongyloid species, similar to, but morphologically distinct from A. vasorum (n=32, 27.8%). Further confirmation of species identification was provided by PCR amplification and sequencing of the 18S rRNA gene, which confirmed three different species. The novel Crenosoma species was most genetically analogous to Crenosoma mephitidis and the unidentified metastrongyloid species was most similar to Stenurus minor and Torynurus convulutus. Routine and quarantine health care of red pandas in captivity should take account of the risk of Angiostrongylus and Crenosoma infection in endemic areas, but should also be cognisant of the widespread presence of an apparently less pathogenic species of lungworm. The identity of the two potentially novel species is subject to further work.