Hypercalcaemia associated with Angiostrongylus vasorum in three dogs

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

OBJECTIVE

To describe arrhythmias associated with administration of lidocaine in dogs treated for supraventricular tachyarrhythmias.

CASE SUMMARIES

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

NEW OR UNIQUE INFORMATION PROVIDED

Arrhythmias associated with lidocaine should be considered when treating dogs with supraventricular tachyarrhythmia.

Vitamin D metabolism and disorders in dogs and cats

Vitamin D plays an important role in regulating calcium metabolism and in the development and maintenance of skeletal health of companion animals. There is also a growing interest in understanding the role vitamin D plays in non-skeletal health in both human and veterinary patients. This review provides an update of our current understanding of vitamin D biology in dogs and cats and gives an overview of how vitamin D metabolism can be assessed in companion animals. Congenital and acquired vitamin D disorders are then summarised before the review concludes with a summary of recent studies which have explored the role of vitamin D in the development and outcomes of non-skeletal diseases of dogs and cats.

First report of fatal autochthonous angiostrongylosis in a dog in Greece

Canine angiostrongylosis caused by Angiostrongylus vasorum is a life-threatening disease which is emerging in regions of Europe. Thus, there is the merit for a continuous epidemiological surveillance in dog populations. This is the first description of a clinical autochthonous case of canine angiostrongylosis in Greece. A 7-month-old, male, mixed-breed dog was presented with progressively worsening anorexia, respiratory distress, coughing, bleeding diathesis and succumbed four days post admission. Gross post mortem examination revealed numerous nodular fistulated lesions in the lungs, and pulmonary cytology and histopathology showed a verminous pyogranulomatous pneumonia. The definitive diagnosis was based on the morphological identification of first stage larvae (L1) retrieved in the feces by the Baermann method, the detection of the circulating antigen by an in-clinic test and the molecular identification of L1. This report underlines the epidemiological and clinical implications, as well as the infection risks when the index of clinical suspicion is low and the disease is unexpected in a country.

Vitamin D Metabolism and Profiling in Veterinary Species

The demand for vitamin D analysis in veterinary species is increasing with the growing knowledge of the extra-skeletal role vitamin D plays in health and disease. The circulating 25-hydroxyvitamin-D (25(OH)D) metabolite is used to assess vitamin D status, and the benefits of analysing other metabolites in the complex vitamin D pathway are being discovered in humans. Profiling of the vitamin D pathway by liquid chromatography tandem mass spectrometry (LC-MS/MS) facilitates simultaneous analysis of multiple metabolites in a single sample and over wide dynamic ranges, and this method is now considered the gold-standard for quantifying vitamin D metabolites. However, very few studies report using LC-MS/MS for the analysis of vitamin D metabolites in veterinary species. Given the complexity of the vitamin D pathway and the similarities in the roles of vitamin D in health and disease between humans and companion animals, there is a clear need to establish a comprehensive, reliable method for veterinary analysis that is comparable to that used in human clinical practice. In this review, we highlight the differences in vitamin D metabolism between veterinary species and the benefits of measuring vitamin D metabolites beyond 25(OH)D. Finally, we discuss the analytical challenges in profiling vitamin D in veterinary species with a focus on LC-MS/MS methods.

Investigation of the relationship between ionised and total calcium in dogs with ionised hypercalcaemia

OBJECTIVES

To investigate the relationship between total and ionised calcium concentrations in dogs with ionised hypercalcaemia and to evaluate how albumin influences this relationship.

METHODS

Initially, a reference interval for ionised and total calcium was established using a large population of healthy adult dogs. Our teaching hospital clinical database was searched to identify adult dogs with ionised hypercalcaemia between 2012 and 2017, a time frame when the same sample handling and analysis protocols were in place as for the healthy reference interval population. The relationship between ionised and total calcium concentrations was then examined in the ionised hypercalcaemia population.

RESULTS

Based on biochemical analysis of 351 healthy adult dogs, a reference interval of 1.18 to 1.53 mmol/L for ionised calcium and 2.24 to 2.85 mmol/L for total calcium was established. Using these reference intervals, 63 dogs with ionised hypercalcaemia were identified, of which 23 did not have total hypercalcaemia. Only seven of the 23 dogs with ionised hypercalcaemia and total calcium below the upper limit of the reference interval had hypoalbuminemia. The majority of dogs with ionised hypercalcemia and normal total calcium had a modest increase in ionised calcium.

CLINICAL SIGNIFICANCE

If relying on total calcium alone, more than one third of dogs with ionised hypercalcaemia will be classified as normocalcaemic and the majority of these dogs had normal serum albumin.

Beyond the skeleton: the role of vitamin D in companion animal health

While the role of vitamin D in the maintenance of skeletal health has been well-established for many years, the discovery that many non-skeletal tissues express the vitamin D receptor stimulated renewed interest in vitamin D and its wider physiological roles. Subsequently, a vast literature has emerged over the past three decades which has linked vitamin D deficiency to the development of many human diseases including cancer, autoimmune, infectious and cardiovascular disorders. In contrast, the role vitamin D plays in the physiology of non-skeletal tissues in cats and dogs has received little attention. The situation is now starting to change with the publication of several studies that have indicated that vitamin D metabolism is deranged in numerous companion animal disorders. This article reviews the biology of vitamin D in companion animals and highlights some of the recent studies which have advanced understanding of vitamin D homeostasis in cats and dogs. Finally, the essay discusses how a "One Health" approach could further the understanding of vitamin D metabolism in mammals. Investigating vitamin D homoeostasis in companion animals offers many advantages compared to human studies in which vitamin D status is influenced by many more variables.

[Acquired von-Willebrand factor and factor-VIII deficiencies caused by angiostrongylosis in a dog]

An 8-year-old male Australian Shepherd was presented with bleeding from the lip and hemoabdomen. Hematology demonstrated marked thrombocytopenia and anemia. Abdominal ultrasound followed by laparotomy did not detect the cause of bleeding. Plasma transfusion resulted in temporary stabilization. Severe von-Willebrand factor deficiency and factor-VIII deficiency were diagnosed. After subsequent bleeding episodes, infection with Angiostrongylus vasorum was found in both a fecal parasitological examination and by PCR from EDTA-blood. Following successful therapy with fenbendazole, von Willebrand factor and factor VIII were within the normal range. This is the second case report of an acquired von-Willebrand-factor deficiency associated with Angiostrongylus-vasorum infection in a dog, and the first case report with concurrent factor-VIII deficiency.

Geographical, clinical, clinicopathological and radiographic features of canine angiostrongylosis in Irish dogs: a retrospective study

Background

Angiostrongylus vasorum infection is associated with high morbidity and mortality in dogs. Although recognised in Ireland, there are no large series of cases reported. The aim of this retrospective study was to identify pertinent clinical and geographical features in Irish dogs.

Results

The case records of dogs presenting to the University College Dublin Veterinary Hospital (1999-2010) were reviewed. A contemporaneous review of external faecal parasitology and post mortem submissions was also performed. A positive diagnosis of angiostrogylosis was identified in 49 dogs including 24 clinical, 10 post mortem and 15 external faecal sample cases. The majority (n = 44 (90%)) resided on the East Coast.

In the clinical cases, the median age was 20 months, 29% of cases were older than 2 years. Clinical features included cardiorespiratory (63%), coagulopathic (71%) and other (63%) signs. Cough (n = 10), dyspnoea (n = 5) and tachypnoea (n = 3) were the most common cardiorespiratory abnormalities. Of animals with evidence of coagulopathy, excessive haemorrhage from a wound (n = 5), airway haemorrhage (n = 9), epistaxis (n = 3), haematoma (n = 4), suspected haemarthrosis (n = 3), neurological signs (n = 2) and haematuria (n = 1) were found. Ten dogs were anaemic, of which two were severe (haematocrit ≤ 0.20 L/L). Ten animals had thrombocytopenia, with four severely affected (≤50 × 10⁹/L). PT and APTT values were prolonged in 4 (24%) of 17 and a BMBT was prolonged in 5 (63%) of 8 cases. Vague signs of exercise intolerance (n = 6), lethargy (n = 6) and weakness (n = 2) were identified, with two (8%) animals having only these signs. In one animal the diagnosis appeared to be incidental. Thoracic radiographs (n = 19) identified abnormalities in 100% of cases. Four (17%) animals died before or within 24 hours of treatment and post mortem examinations confirmed angiostrongylosis. Fenbendazole was administered in 19 cases, 18 (95%) recovered. Two animals were euthanised, one which failed to respond to therapy and another in which an ante mortem diagnosis had not been made.

Conclusions

Angiostrongylosis is not uncommon in Ireland, is not confined to young dogs or the East Coast and can present with a wide variety of signs, particularly coagulopathic, respiratory or neurological signs.

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.

Clinical, laboratory and pathological findings in dogs experimentally infected with Angiostrongylus vasorum

The aim of this comparative study was to investigate the development of clinical signs and accompanying haematological, coproscopic and pathological findings as a basis for the monitoring of health condition of Angiostrongylus vasorum infected dogs. Six beagles were orally inoculated with 50 (n=3) or 500 (n=3) A. vasorum third stage larvae (L3) obtained from experimentally infected Biomphalaria glabrata snails. Two dogs were treated with moxidectin/imidacloprid spot-on solution and two further dogs with an oral experimental compound 92 days post infection (dpi), and were necropsied 166 dpi. Two untreated control dogs were necropsied 97 dpi. Prepatency was 47-49 days. Dogs inoculated with 500 L3 exhibited earlier (from 42 dpi) and more severe respiratory signs. Clinical signs resolved 12 days after treatment and larval excretion stopped within 20 days in all four treated dogs. Upon necropsy, 10 and 170 adult worms were recovered from the untreated dogs inoculated with 50 and 500 L3, respectively. Adult worms were also found in two treated dogs, in the absence of L1 or eggs. Despite heavy A. vasorum infection load and severe pulmonary changes including vascular thrombosis, only mild haematological changes were observed. Eosinophilia was absent but the presence of plasma cells was observed. Neutrophilic leucocytes showed a transient increase but only after treatment. Signs for coagulopathies were slight; nevertheless coagulation parameters were inoculation dose dependent. Ten weeks after treatment pulmonary fibrosis was still present. Infections starting from 50 L3 of A. vasorum had a massive impact on lung tissues and therefore on the health of affected dogs, particularly after prepatency, although only mild haematological abnormalities were evident.

Pathological findings in dogs naturally infected with Angiostrongylus vasorum in Newfoundland and Labrador, Canada

Fifty-six dogs from St. John's, Newfoundland, Canada, were evaluated for Angiostrongylus vasorum infection. Small numbers of nematodes were found within pulmonary arteries of 6 dogs. Larvae were identified in fecal samples in 2 of 6 dogs. All 6 dogs had multifocal granulomatous pneumonia and sometimes foci of chronic thrombosis, which varied from very mild to severe. One dog had extensive pulmonary lesions resulting in cor pulmonale. Right heart failure was characterized by right ventricular hypertrophy, hepatic congestion, ascites, and hydrothorax. Microscopically, in most cases, eggs, larvae, and sometimes intravascular adults, were present within lung tissue sections. Small foci of granulomatous inflammation with and without larvae were present in kidney and brain in 4 dogs. An additional dog, diagnosed antemortem with angiostrongylosis via fecal examination, was also examined. Pathological findings consisted of severe pyogranulomatous interstitial pneumonia with myriad eggs, larvae, and numerous intravascular pulmonary adult nematodes with extensive arterial thrombosis. Five hundred and seventy-two adult worms were removed from pulmonary arteries. Foci of granulomatous inflammation, often associated with larvae and/or eggs, were present in tracheobronchial lymph nodes, adrenal gland, brain, and kidneys. Severe seizuring noted antemortem was attributed to several large, discrete areas of acute hemorrhagic infarction within the cerebrum and cerebellum. Natural A. vasorum infection in domestic dogs in eastern Newfoundland causes lung pathology of variable severity, which in some cases, may progress to cor pulmonale and which may be associated with extrapulmonary lesions and clinical signs.

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.

Angiostrongylus vasorum (French heartworm) in a dog imported into Australia

This report describes a case of Angiostonglyus vasorum infection, sometimes referred to as French heartworm disease, in a dog imported into Western Australia from the United Kingdom. Diagnosis was made by identification of first stage larvae on fine needle aspiration of a consolidated lung lobe. First stage larvae were also identified in the faeces by the Baermann technique. The main clinical signs in this case were coughing and tachypnoea. The dog was treated successfully with fenbendazole at 50 mg/kg once daily for 10 days.