A neurological presentation caused by brain metastases in a dog with interventricular septal hemangiosarcoma.

BACKGROUND: Brain metastases are well known for disseminated hemangiosarcoma involving the right atrium/auricle. CASE REPORT: An 8-year-old male Australian Shepherd Dog presented with a 3-day history of circling to the left. A neurological examination revealed obtunded mentation, right hemi-inattention, bilateral strabismus towards the left side and absent physiological nystagmus. In addition, the dog had muffled heart sounds on auscultation and exercise-induced weakness. Laboratory findings included hypercoagulability and marked elevation in the C-reactive protein concentration. Electrocardiography detected a sinus rhythm with right bundle-branch block and ventricular bigeminy. Echocardiography revealed an extensive interventricular septal mass. Due to the grave prognosis, the owners elected for euthanasia, and a complete necropsy was performed. The main pathological findings were an interventricular septal and left ventricular hemangiosarcoma, with metastases in the brain, lungs, spleen and adrenal glands. No evidence of tumour infiltration was found in the right atrium. CONCLUSION: To the authors' knowledge, this is the first report of neurological signs due to confirmed brain metastases in a dog with interventricular septal hemangiosarcoma. Although the right atrium is the main location for cardiac hemangiosarcoma, the interventricular septum should be evaluated in all cases.

Trypanosomiasis in an Australian little red flying fox (Pteropus scapulatus).

CASE REPORT: An adult female Australian little red flying fox (Pteropus scapulatus) presented with icterus and anaemia. Examination of a blood smear revealed numerous trypanosomes 20.4-30.8 µm long with tapered ends. Necropsy and histological findings were consistent with trypanosome infection of lymphoid tissue and intravascular haemolysis. Sequence and phylogenetic analysis demonstrated this trypanosome species to be genetically distinct and most similar to Trypanosoma minasense and Trypanosoma rangeli (with a genetic distance of 1% at the 18S rRNA locus for both). CONCLUSION: To the authors' knowledge this is the first report of a trypanosome infection associated with clinical disease in bats.

Clinical, haematological, cytokine and acute phase protein changes during experimental Babesia gibsoni infection of beagle puppies.

Babesia gibsoni is a haemoprotozoan parasite of emerging global importance. The clinical presentation of babesial infections is diverse and the systemic inflammatory response induced by infection is considered to be a major feature of the pathophysiology of canine babesiosis. An experimental case-controlled longitudinal study was conducted to assess the clinical, haematological, cytokine and acute phase protein changes that occur during experimental B. gibsoni infection of beagle puppies. Infected dogs became transiently pyrexic and anaemic, intermittently neutropenic and transiently, but profoundly, thrombocytopenic, although this had no apparent adverse clinical effect. Experimental B. gibsoni infection also induced an acute phase response, characterised by a marked increase in the concentration of C-reactive protein, which was delayed in onset following infection but preceded the detection of peripheral parasitaemia. Experimental B. gibsoni infection was also associated with marked increases in the concentration of multiple cytokines which were also delayed in onset following infection and occurred subsequent to the detection of peripheral parasitaemia and the acute phase response. This study furthers our understanding of the immune response that occurs during babesial infections and the role that systemic inflammation plays in the pathophysiology of canine babesiosis.

Remaining vigilant for the exotic: cases of imported canine leishmaniosis in Australia 2000-2011.

BACKGROUND: Canine leishmaniosis (CL) caused by Leishmania infantum is a disease of worldwide importance, not only because it causes severe and potentially fatal disease in dogs, but also because of its zoonotic relevance. The parasite is the causative agent of human visceral leishmaniosis, a severe, debilitating disease that causes an estimated 59,000 deaths annually. Australia is considered to be free of zoonotic leishmaniosis. METHODS: A retrospective case series of five imported dogs diagnosed with CL between 2000 and 2011. Cases were identified by word-of-mouth and by referral. RESULTS: The dogs were diagnosed with CL between 2000 and 2011; clinical, clinicopathological, and serological data are presented, together with a review of the disease and its biosecurity implications for Australia. CONCLUSIONS: Because of the unique immunopathology and diagnostic challenges associated with CL, the importance of obtaining a travel history is reinforced because some dogs imported prior to 2006 may develop clinical signs of this disease and present for veterinary examination. Furthermore, it is possible for leishmaniosis to become established within Australia under certain circumstances.

Streptomyces cyaneus dermatitis in a dog.

BACKGROUND: A nearly 4-year-old neutered male Australian Terrier was referred for a nodular pyogranulomatous mass of the right axilla. It had been poorly responsive to antibiotic therapy. CASE REPORT: Based on filamentous Gram-positive organisms identified in earlier biopsy material, infection by an Actinomyces sp. was suspected and the dog showed clinical improvement on a trial of potentiated sulfonamides. Recurrence 5 months later prompted euthanasia, with Streptomyces cyaneus being cultured and confirmed by genetic sequencing of part of the 16 s ribosomal RNA gene. CONCLUSION: Invasive Streptomyces spp. infections are uncommon in humans and animals, and isolations are sometimes considered to be contaminants, but the demonstration of the organism within the lesion in this instance indicates that the isolation of a Streptomyces sp. from veterinary cases should not always be considered as contamination, because this genus is clearly pathogenic.

Nonsurgical treatment of gastroesophageal intussusception in a puppy.

A 7-week-old, female Siberian husky was presented to Murdoch University Veterinary Hospital with an acute onset of respiratory distress and regurgitation. Thoracic imaging identified an intraluminal esophageal mass with concurrent aspiration pneumonia. Esophagoscopy identified the mass as stomach, and a diagnosis of gastroesophageal intussusception was made. The intussusception was reduced endoscopically, and fixation of the stomach to the abdominal wall was performed using a tube gastropexy. Gastroesophageal intussusception is an uncommon disease in small animals and traditionally has been managed surgically. This case report describes an alternative method of treatment associated with a good outcome in this puppy.

Persistent isolated hypocortisolism following brief treatment with trilostane.

A 12-year-old male neutered Miniature Poodle with confirmed pituitary-dependent hyperadrenocorticism was treated with trilostane. After three doses, it developed clinical and laboratory changes suggestive of isolated hypocortisolism ('atypical hypoadrenocorticism'), which persisted and progressed for more than 3 months despite immediate withdrawal of the trilostane. The clinical signs of hyperadrenocorticism resolved without further trilostane. After 3 months, prednisolone treatment was started and the clinical signs of hypocortisolism resolved. Prednisolone therapy was required for more than 1 year. Ultrasonography initially demonstrated large hypoechoic adrenal cortices, typical of dogs with hyperadrenocorticism, which then became small and heteroechoic, consistent with the development of adrenal necrosis. Persistent isolated hypocortisolism has not been reported previously as a complication of trilostane therapy. The case is also remarkable for the very short duration of trilostane therapy that elicited this complication. Clinicians should be aware that trilostane therapy may result in adrenal necrosis, even in the very earliest stages of therapy, but prompt action can prevent a life-threatening situation.

Acute necrotising pulmonary vasculitis and pulmonary hypertension in a juvenile dog.

A five-month-old female Jack Russell terrier was presented for investigation of acute lethargy, anorexia, coughing, respiratory distress and weakness. Examination findings included cyanosis, a grade 3 of 6 systolic heart murmur and prolonged capillary refill time. Radiography and echocardiography revealed severe pulmonary hypertension, cor pulmonale and right-sided heart failure. Indirect measurement of the systolic pulmonary artery pressure estimated pressures over 100 mmHg. Despite treatment the patient died. Post-mortem examination did not identify a congenital cardiovascular anomaly. Histopathology confirmed acute necrotising pulmonary arteritis and immunohistochemistry failed to identify any immune complex or complement deposition.

Hypokalaemic paresis, hypertension, alkalosis and adrenal-dependent hyperadrenocorticism in a dog.

Generalised paresis, severe hypokalaemia and kaliuresis, metabolic alkalosis and hypertension, characteristic of mineralocorticoid excess, were identified in a dog with hyperadrenocorticism due to a functional adrenocortical carcinoma. Aldosterone concentration was decreased and deoxycorticosterone concentration increased in the presence of hypokalaemia. These metabolic abnormalities resolved with resection of the carcinoma. Mineralocorticoid excess in dogs with hyperadrenocorticism is generally considered to be of little clinical significance but resulted in the acute presentation of this patient. The possible pathogenesis of mineralocorticoid excess in this case of canine hyperadrenocorticism is discussed.

Comparison of radioimmunoassay and chemiluminescent assay methods to estimate canine blood cortisol concentrations.

BACKGROUND: Non-radioactive assay methods are widely used in commercial laboratories to measure canine blood cortisol concentrations, despite a paucity of published validity data of these tests compared with the traditional 'gold standard' radioimmunoassay. OBJECTIVES: To compare a commercial chemiluminescence assay with radioimmunoassay for blood cortisol measurement, determine the effect of storage on the radioimmunoassay, and determine the impact of any differences on clinical decisions. METHODS: The study included 54 client owned dogs undergoing adrenal function testing. Fresh plasma or serum samples (n=170) were assayed for cortisol using radioimmunoassay (RIA1). Samples (n=196) were also frozen and stored in batches, and assayed by chemiluminescence and radioimmunoassay (RIA2). RESULTS: Overall, there was a strong correlation (r2=0.967, P<0.001) between RIA2 and chemiluminescence concentrations without significant difference between means. Strong correlations were present for RIA2 and chemiluminescence at concentration subgroups of >400 nmol/L (r2=0.869, P<0.001), <100 nmol/L (r2=0.790, P<0.001), and <40 nmol/L (r2=0.738, P<0.001). Significant differences between means were present for RIA2 and chemiluminescence concentrations in the <100 nmol/L, and <40 nmol/L (P<0.001) groups. Despite a significant difference in RIA1 and RIA2 results overall, there was no significant difference between RIA1 and RIA2 for any of the concentration groups. In seven cases, discrepant RIA2 and chemiluminescence results may have altered clinical decisions. CONCLUSIONS: Although RIA and chemiluminescence cortisol concentrations appear highly correlated, a significant difference may exist for concentrations less than 100 nmol/L in stored canine sera. Results of chemiluminescence cortisol assays should be interpreted with caution unless the specific assay method in the laboratory has been adequately validated in dogs.

Blood, Bull Terriers and Babesiosis: further evidence for direct transmission of Babesia gibsoni in dogs.

This study reports on the epidemiology of Babesia gibsoni in American Pit Bull Terriers living in a region of western Victoria in southern Australia. Both American Pit Bull Terriers (n = 100) and other dog breeds (n = 51) were screened for B gibsoni using immunofluorescent antibody testing (IFAT) and/or polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). A questionnaire was also completed by each dog owner, ascertaining the husbandry and habits of the dogs sampled. Fourteen dogs were positive for B gibsoni using IFAT and/or PCR-RFLP and all were American Pit Bull Terriers. Dogs that were male and/or had been bitten by or were biters of other American Pit Bull Terriers were more likely to be B gibsoni positive, thus suggesting that blood-to-blood transmission contributes to the spread of this disease between dogs.

Babesia gibsoni: detection during experimental infections and after combined atovaquone and azithromycin therapy.

Babesia gibsoni is a protozoan parasite of dogs worldwide yet both an effective treatment and a reliable method for detecting subclinical cases of this emerging infection remain elusive. Experimental B. gibsoni infections were established in vivo to investigate the efficacy of combined atovaquone and azithromycin drug therapy and to determine the detection limits of a nested-PCR, IFAT and microscopy during various stages of infection. While atovaquone and azithromycin produced a reduction in parasitaemia, it did not eliminate the parasite and drug resistance appeared to develop in one dog. Polymerase chain reaction was found to be most useful in detecting infection in the pre-acute and acute stages, while IFAT was most reliable during chronic infections. Microscopy is suggested to be only effective for detecting acute stage infections. This study also describes the detection of B. gibsoni in tissue samples during chronic infections for the first time, suggesting possible sequestration of this parasite.

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.

PCR-RFLP for the detection and differentiation of the canine piroplasm species and its use with filter paper-based technologies.

Canine piroplasmosis is an emerging disease worldwide, with multiple species of piroplasm now recognised to infect dogs. A nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was developed for the detection and differentiation of each of the piroplasm species currently known to infect dogs on the basis of the 18S ribosomal RNA gene. The assay can potentially amplify and discriminate between Theileria annae, Theileria equi, Babesia conradae, Babesia gibsoni, Babesia sp. (Coco) and each of the Babesia canis subspecies. Non-canine piroplasm species can also potentially be detected using the described assay, however amplification of Neospora caninum was also observed. The PCR was found to have a high detection limit, capable of detecting a 2.7x10(-7)% parasitaemia or the equivalent of 1.2 molecules of target DNA when using DNA extracted from whole EDTA blood and detected a parasitaemia of 2.7x10(-5)% using blood applied to both Flinders Technology Associates (FTA) cards and IsoCodetrade mark Stix. The application of blood samples to filter paper may greatly assist in piroplasm identification in regions of the world where local technologies for molecular characterisation are limited. The assay reported here has the potential to be standardised for routine screening of dogs for piroplasmosis.

Primary hypoparathyroidism in dogs: a retrospective study of 17 cases.

OBJECTIVE: To evaluate the clinico-pathological findings, response to treatment and prevalence of complications in dogs with primary hypoparathyroidism. DESIGN: Retrospective study of 17 dogs presenting to the University of Melbourne Veterinary Clinical Centre and Murdoch University Veterinary Hospital over a 15 year period (1990 to 2004). Case records were evaluated for signalment, body weight, diet type, historical and clinical findings, serum total calcium, phosphate, albumin and parathyroid hormone concentrations, urinary fractional excretion ratios of calcium and phosphate, electrocardiogram (ECG) results, treatments administered, outcome and period of follow-up. RESULTS: The most common breeds identified were St Bernard (three dogs), Chihuahua (two dogs), German Shepherd (two dogs) and Jack Russell Terrier (two dogs). Three dogs were cross bred. Seizures, muscle tremors and fasciculations, stiff gait, tetany, muscle cramping, behavioural change and hyperventilation were the most common clinical signs. Vomiting, inappetence, diarrhoea, abdominal pain, hyperthermia, facial pruritus, ataxia, weakness, cataracts, and circling also occurred with less frequency. The mean duration of observed clinical signs preceding diagnosis was 33 days (median 13 days, range 1 to 173 days). All dogs had marked hypocalcaemia with normal or mildly increased serum albumin concentrations. Mean phosphate concentrations were significantly higher in inappetent dogs (P = 0.049). Mean serum calcium concentrations were significantly lower in dogs with cataracts compared to those without (P = 0.046). There were no other significant relationships between serum calcium or phosphate concentrations and the clinical presentation or outcome. No significant correlations were identified between the presence of a particular clinical sign and the duration of clinical signs. ECGs were obtained in four dogs and all exhibited QT interval prolongation due to a ST-segment prolongation. Sixteen of 17 dogs were treated successfully for hypocalcaemia and discharged from hospital. Acute management included parenteral calcium gluconate (10 dogs) and intravenous anticonvulsants (five dogs). Chronic therapy included oral vitamin D analogues and calcium supplementation. Treatment complications occurred in two dogs and included acute renal failure (one dog) and iatrogenic tissue necrosis following subcutaneous calcium administration (one dog). The mean follow-up period was 14.5 months (median 13 months, range 0 to 39 months). Twelve dogs were alive at the last follow up and two dogs were euthanased for unrelated reasons. The type of vitamin D analogue used was not associated with outcome. CONCLUSION: Primary hypoparathyroidism was an uncommon diagnosis in dogs. Saint Bernards, cross bred dogs, German Shepherd dogs and Terrier breeds were most commonly affected. Neurological signs were the most common presenting clinical signs, although alimentary signs may have been more common than previously reported. Dogs with primary hypoparathyroidism appeared to have a good prognosis following initiation of calcium supplementation and vitamin D therapy. Complications of treatment were uncommon and could be minimised with regular monitoring.

New data on epizootiology and genetics of piroplasms based on sequences of small ribosomal subunit and cytochrome b genes.

As a continuation of our studies on molecular epizootiology of piroplasmosis in Spain and other countries, we present in this contribution the finding of new hosts for some piroplasms, as well as information on their 18S rRNA gene sequences. Genetic data were complemented with sequences of apocytochrome b gene (whenever possible). The following conclusions were drawn from these molecular studies: Theileria annulata is capable of infecting dogs, since it was diagnosed in a symptomatic animal. According to cytochrome b sequences, isolates from cows and dog present slight differences. The same isolates showed, however, identical sequence in the 18S rRNA gene. This exemplifies well the usefulness of the mitochondrial gene for examining infra-specific variation. Babesia bovis is an occasional parasite of equines, since it was detected in two symptomatic horses. We found evidence of genetic polymorphism occurring in the 18S rRNA gene of Spanish T. equi-like and B. ovis isolates. B. bennetti from Spanish seagull is loosely related to B. ovis, and might represent a genetically distinct branch of babesids. A partial sequence of a cytochrome b pseudogene was obtained for the first time in Babesia canis rossi from South Africa. The pseudogene is distantly related to B. bigemina cytochrome b gene. These new findings confirm the ability of some piroplasms to infect multiple hosts, as well as the existence of a relatively wide genetic polymorphisms with respect to the cytochrome b gene. On the other hand, the existence of mtDNA-like pseudogenes of possible nuclear location in piroplasms is interesting due to their possible impact on molecular phylogeny studies.

Successful management of histiocytic ulcerative colitis with enrofloxacin in two Boxer dogs.

Two Boxer dogs with histologically confirmed histiocytic ulcerative colitis were treated with enrofloxacin, one as sole therapy and one in conjunction with prednisolone, after failure of standard therapy. Clinical remission occurred rapidly in both dogs after commencement of enrofloxacin and in one case where repeat colonoscopy was performed the endoscopic appearance of the mucosa was normal within 2 weeks. Histological examination of the colonic mucosa in this dog after 7 months showed resolution of the cellular infiltration characteristic of histiocytic ulcerative colitis. Histological improvement following therapy in Boxer dogs with histiocytic ulcerative colitis has not been reported previously.

Pulmonic stenosis in two cats.

The clinical, radiographic and echocardiographic features of two cases of pulmonic stenosis in cats are presented. A rarely reported combination of pulmonic stenosis and tricuspid valve dysplasia is described.

Degenerative neurological and neuromuscular disease in young rottweilers.

A number of idiopathic degenerative diseases affecting the central nervous system, peripheral nerves and muscles of immature and young adult rottweilers are reported. Tetraparesis or ataxia causing abnormalities in gait and posture are clinical findings common to these conditions. The current knowledge about these syndromes is presented in this review, with an emphasis on the clinical characteristics. Knowledge of these syndromes and a methodical approach to neurological diagnosis can help the veterinarian to identify the underlying disease and establish a prognosis when presented with a tetraparetic or ataxic young rottweiler.

Genomic hypomethylation in neoplastic cells from dogs with malignant lymphoproliferative disorders.

DNA methylation is an epigenetic modification in which a methyl group is added usually to the fifth carbon position of a cytosine residue. Dysregulation of this process is an important molecular event which has been shown to be associated with neoplastic transformation and tumour progression in humans and mice. Features of methylation dysregulation in many different types of neoplasms include general genomic hypomethylation, focal hypermethylation, and altered expression of genes which encode a series of DNA (cytosine-5) methyltransferases. Interestingly, many types of neoplasia that are recognised in humans also develop spontaneously in the dog. By comparing the restriction patterns of MspI and HpaII, this study demonstrates that as in human, genomic hypomethylation is a feature of neoplastic cells in the majority of canine lymphoma cases and approximately one-third of canine leukemia cases confirming that dysregulation of the DNA methylating machinery is implicated in malignant transformation of lymphoid cells in some dogs.