Syncope associated with swallowing in two British Bulldogs with unilateral carotid body tumours.

Carotid body tumours were diagnosed in two British Bulldogs that each had a history of syncopal episodes induced by eating, drinking or pulling on the leash. In both dogs, a cervical mass was identified using computed tomography (CT) or magnetic resonance imaging, with carotid body tumour (CBT) being the histopathological diagnosis. A heart base mass was also identified in one dog by both CT and echocardiography. Swallowing syncope has been reported in the human literature in association with cervical mass lesions, but this is the first report in dogs. The present cases emphasise the value of advanced imaging of the head and neck in dogs presenting with clinical signs of syncope associated with swallowing and the importance of careful manipulation of the neck in patients with CBTs.

Identification of parvovirus in the bone marrow of eight cats.

OBJECTIVE: To determine if canine parvovirus (CPV) or feline panleucopenia virus (FPV) genomic sequences are present in adult feline bone marrow samples. DESIGN: Bone marrow samples were obtained from 32 semi-feral cats that were euthanased at an animal shelter. DNA was extracted and subjected to conventional polymerase chain reaction (PCR) designed to determine if CPV or FPV DNA was present. Positive PCR products were purified, cloned and sequenced to differentiate between CPV and FPV. RESULTS: Eight of the bone marrow samples contained parvoviral DNA (7 CPV, 1 FPV). CONCLUSION: CPV and FPV DNA can be found in the bone marrow of healthy adult cats.

Molecular subtyping of feline immunodeficiency virus from cats in Melbourne.

OBJECTIVE: To determine the subtypes of feline immunodeficiency virus (FIV) present in the domestic cat population in Melbourne. METHODS: Blood samples were collected from 42 cats that had serum antibodies against FIV. DNA was extracted and subjected to polymerase chain reaction (PCR) to amplify variable regions of the envelope (env) and group specific antigen (gag) genes of FIV. PCR products were directly sequenced or sequenced after cloning when direct sequencing yielded ambiguous results. Phylogenetic analysis was performed and comparisons made with representative sequences of different subtypes. RESULTS: The variable region of the env gene was successfully amplified by PCR from 41 of the 42 cats. All 41 were found to cluster with subtype A env sequences. The variable region of the gag gene was successfully amplified by PCR from all 42 cats. Forty-one were found to cluster with subtype A gag genes and one was found to cluster with subtype B sequences, suggesting that it may be derived from a recombinant env A/gag B virus. CONCLUSIONS: Subtype A is the predominant FIV type in Melbourne, although a subtype A/B recombinant was identified in the population of FIV positive cats. These results of env gene analysis were similar to those in a previous Australian study, suggesting that subtype A predominates in Australia. The results of the gag gene analysis show the importance of analysing multiple areas of the FIV genome when assigning FIV subtypes. Comparison with other major urban centres may provide useful information about the phylogenic diversity of FIV in Australia.

Dysgonic strain of Microsporum canis pseudomycetoma in a Domestic Long-hair cat.

A 4-year-old Domestic Long-hair cat was presented with two large non-painful, ulcerated and suppurative lesions over the flanks. Histopathology and cytology were consistent with fungal pyogranulomatous inflammation. Culture of tissue yielded a dysgonic strain of Microsporum canis. The cat was treated successfully by staged en bloc resections of the lesions, followed by oral ketoconazole, then oral terbinafine. This is the first reported case of dermatophytic pseudomycetoma in a Domestic Long-hair cat in Australia.

Evaluation of the class II region of the major histocompatibility complex of the greyhound with the genomic matching technique and sequence-based typing.

The class II region of the major histocompatibility complex was evaluated in 25 greyhounds by sequence-based typing and the genomic matching technique (GMT). Two new DLA-DRB1 alleles were identified. Twenty-four dogs carried the DLA-DRB1*01201/DQA1*00401/DQB1*01303/DQB1*01701 haplotype, which carries two DQB1 alleles. One haplotype was identified from which DQB1 and DQA1 appeared to be deleted. The GMT enabled detection of DQB1 copy number, discrimination of the different class II haplotypes and the identification of new, possibly biologically relevant polymorphisms.

Reference limits for urinary fractional excretion of electrolytes in adult non-racing Greyhound dogs.

OBJECTIVE: To determine reference limits for urinary fractional excretion of electrolytes in Greyhound dogs. METHODS: Urinary fractional excretion was calculated using a spot clearance method preceded by a 16 to 20 hour fast in 48 Greyhound dogs. Raw data analysed using the bootstrap estimate was used to calculate the reference limits. RESULTS: The observed range for urinary fractional excretion in Greyhound dogs was 0.0 to 0.77% for sodium, 0.9 to 14.7% for potassium, 0 to 0.66% for chloride, 0.03 to 0.22% for calcium and 0.4 to 20.1% for phosphate. Expressed as percentages, the suggested reference limits for fractional excretion in Greyhound dogs are as follows: sodium < or = 0.72, potassium < or = 12.2, chloride < or = 0.55, calcium < or = 0.13 and phosphate < or = 16.5. CLINICAL SIGNIFICANCE: Veterinary practitioners may use these reference limits for urinary electrolyte fractional excretion when investigating renal tubular disease in Greyhound dogs.

Granulomatous meningoencephalomyelitis with peripheral nervous system involvement in a dog.

A 9-year-old male neutered Labrador Retriever presented with signs consistent with multifocal neurological disease. Cerebrospinal fluid analysis revealed a mononuclear pleocytosis and electromyography revealed abnormal electrical activity in distal appendicular and masticatory muscles. Treatment was declined and necropsy revealed disseminated granulomatous meningoencephalomyelitis with extensive involvement of the peripheral nervous system.

Lymphoma(s) showing epitheliotropism and diffuse skeletal muscle involvement presenting as a polymyopathy in a young dog.

A 3-year-old dog presented with a severe polymyopathy and subsequently developed nodular skin lesions. The disease in this dog was caused by lymphoma, showing cutaneous epitheliotropism as well as infiltration of skeletal muscle in conjunction with polymyositis.

Acute renal failure following Bull ant mass envenomation in two dogs.

Acute renal failure was diagnosed in a German Short Haired Pointer bitch and a Kelpie cross-bred dog following envenomation by Bull ants. Both dogs had been tethered over a Bull ant nest and had experienced mass envenomation. There was local reaction at the envenomation sites and each dog had experienced vomiting that was poorly controlled by symptomatic therapy. Intensive treatment of renal failure was successful in the German Short Haired Pointer and the bitch remains well 19 months after envenomation. The Kelpie cross-bred deteriorated despite intensive treatment and was euthanased 36 hours after presentation. Necropsy examination revealed haemorrhage and necrosis of the small intestine and myocardium, bilateral nephrosis with tubular necrosis, and patchy haemorrhage of the lung alveoli, pancreas and adrenal cortices. Electron microscopy revealed necrosis of the small intestine and hydropic swelling of proximal renal tubules with necrosis of medullary tubules.

Effect of oral ursodeoxycholic acid on bile acids tolerance tests in healthy dogs.

OBJECTIVE: To determine whether oral administration of ursodeoxycholic acid (UDCA) to healthy dogs alters the results of the bile acids tolerance test. METHODS: UDCA (15 mg/kg once daily) was administered to 16 healthy dogs for 7 days. Health of the dogs was assessed by clinical examination, haematology, serum biochemistry and a bile acids tolerance test. Normal liver structure was confirmed by histopathology at the end of the study. Bile acids tolerance tests were performed before and at the end of the treatment period, with each dog serving as its own control. For the posttreatment bile acids tolerance test, UDCA was administered at the time of feeding. RESULTS: Pretreatment, the fasted serum total bile acid concentrations ranged between 0 and 9 micromol/L. In the majority of dogs, the postprandial total bile acid concentration was greater than the preprandial value, with a range of 0 to 16 micromol/L. The fasted total bile acid concentration was 0 micromol/L in most dogs (93.75%) after treatment with UDCA. Postprandial serum bile acids also remained within the reference range for the majority of dogs (93.75%) after UDCA treatment. A single dog had a postprandial bile acid concentration above the reference range, but the concentration was within the reference range when the assay was repeated the following day without concurrent administration of UDCA. The pre- and postprandial total serum bile acid concentrations were not significantly affected by UDCA treatment. CONCLUSION: The administration of UDCA does not alter the bile acids tolerance test of normal healthy dogs.

Diagnosis of sciatic nerve tumour in two dogs by electromyography and magnetic resonance imaging.

Sciatic nerve tumour was diagnosed in a Staffordshire Bull Terrier cross-bred and a Bichon Frise, both presenting with chronic left hind limb lameness. Neurological examination in each case was consistent with left sciatic nerve deficits and this was confirmed by EMG studies. Rectal examination of both dogs revealed a palpable intrapelvic mass that was not apparent on survey radiographs. A sciatic nerve tumour was identified using MRI in each case. Histological examination of tissue taken from the Staffordshire Bull Terrier cross-bred was consistent with a malignant peripheral nerve sheath tumour.

Acquired myasthenia gravis associated with a non-invasive thymic carcinoma in a dog.

An 8 1/2-year-old neutered male Beagle was diagnosed with acquired myasthenia gravis associated with a non-invasive thymic carcinoma. The thymic mass was surgically excised and the dog was treated with pyridostigmine, prednisolone and azathioprine. Serial acetylcholine receptor antibody titres were increased initially but slowly declined to normal values over a period of 24 weeks. Improved exercise tolerance was seen following therapy, however, oesophageal dysfunction persisted. The dog was euthanased 26 weeks after initial presentation due to a complicating illness. A necropsy showed no regrowth or metastasis of the thymic carcinoma.

Treatment of an acromegalic cat with the dopamine agonist L-deprenyl.

Acromegaly was diagnosed in a 14-year-old domestic short hair cat presented for investigation and management of apparently insulin-resistant diabetes mellitus. Treatment with L-deprenyl and high doses of insulin was commenced. The L-deprenyl did not reduce the requirement for high doses of insulin and did not appear to reduce the clinical signs associated with the disease. The cat was euthanased one year after initial presentation.

The use of ultrasound in the investigation of gastric carcinoma in a dog.

Gastric neoplasia accounts for less than 1% of all canine malignancies. Malignant epithelial tumours are the most common gastric neoplasm in dogs and are referred to as carcinoma or adenocarcinoma. Dogs with gastric carcinoma usually present with vomiting, anorexia, and weight loss. The duration of clinical signs is from weeks to months. 1 Survey and contrast radiography, endoscopy, and ultrasonography have been used in the diagnosis of gastric carcinoma in dogs. This report describes a case of gastric carcinoma in which the survey and contrast radiographs and endoscopic findings were normal. Gastric neoplasia was suspected on ultrasound examination and confirmed histologically.

Analysis of equine herpesvirus 2 strain variation using monoclonal antibodies to glyucoprotein B.

The antigenic relationships of four genomically divergent strains of equine herpesvirus 2 (EHV2.86/67, EHV2.5FN, EHV2.141 and EHV2.T-2) and equine herpesvirus 5 (EHV5) were examined in ELISA using a panel of EHV2.86/67 gB-specific MAbs. EHV2.86/67 and EHV2.5FN were shown to be more similar to each other than to EHV2.T-2, EHV2.141 or EHV5. Seven of nine EHV2.86/67 gB specific MAbs tested in serum neutralisation assays were shown to neutralise EHV2.86/67 and EHV2.5FN but not EHV2.141, EHV2.T-2 or EHV5. The complete nucleotide and deduced amino acid sequences of EHV2.86/67, EHV2.5FN, EHV2.141 and EHV2.T-2 gB were compared and contrasted with each other and with EHV5 gB. The four EHV2 strains were 94-96% similar at the amino acid level and variability in amino acid sequence mapped to three mains sites designated I, II and III. By contrast, the four EHV2 strains were 77-79% similar to EHV5 gB at the amino acid level. The epitope of these seven gB specific neutralising MAbs has been previously mapped to amino acids 29-74 of EHV2 gB and examination of the deduced amino acid sequence of the four sequenced strains localised the epitope of the seven MAbs to amino acids 30 to 49 located within Site I. Six other divergent strains of EHV2 were examined for variability at Site I using DNA sequencing. Examination of the deduced amino acid sequences of all ten EHV2 strains tested indicated, that based on the epitope of the neutralising MAbs the EHV2 strains formed two distinct antigenic groups, EHV2.86/67-like and EHV2.141-like. EHV5 gB showed divergence from all of the EHV2 gB sequences between amino acids 29-74.

Genomic variability of equine herpesvirus-5.

Seventeen New Zealand isolates of equine herpesvirus 5 (EHV-5) were compared to the Australian prototype strain. PCR primers were designed to amplify EHV-5 glycoprotein B (gB) gene, and Restriction Fragment Length Polymorphism (RFLP) was used to detect differences between cloned PCR products. EHV-5 isolates from different horses showed a high degree of heterogeneity. However, EHV-5 isolates from individual horses remained homogeneous when examined over a period of time or isolated from different sites. A single EHV-5 gB RFLP profile was detected in isolates from each individual horse but one. Two or possibly three different genotypes of EHV-5 were detected in cultures inoculated with a nasal swab of this horse. The heterogeneity observed between EHV-5 isolates from different horses suggests that the use of RFLP may provide a useful epidemiological approach to gain more knowledge about the biology of EHV-5.

Identification, sequence analysis and characterisation of equine herpesvirus 5 glycoprotein B.

The complete nucleotide sequence of the gammaherpesvirus equine herpesvirus 5 (EHV5) glycoprotein B (gB) was determined and the deduced amino acid sequence compared with that of the second equine gammaherpesvirus EHV2. EHV5 gB is an 870 amino acid protein and is 79% similar and 66% identical with EHV2 gB at the amino acid level. EHV5 gB like EHV2 gB is a disulphide linked heterodimer with subunits of 92 and 68 kDa. EHV5 gB is an integral membrane glycoprotein containing only N-linked oligosaccharides and contains a putative endoproteolytic cleavages site at amino acids 422-485. The EHV5 gB amino acid sequence showed greatest homology with other members of the Rhadinovirus genus of the subfamily Gammaherpesvirinae. Alignment of EHV5 gB sequence with the gB sequence of seven other gammaherpesviruses showed conservation of 10 cysteine residues as well as conservation of three predicted sites of N-linked glycosylation; the highest degree of conservation of the predicted sites of N-linked glycosylation was observed between EHV5 and the other members of the Rhadinovirus genus. Phylogenetic analysis confirmed EHV2 and EHV5 were most closely related to each other and equally distant from other members of the Rhadinovirus genus included in the analysis.

Characterization of glycoprotein B of the gammaherpesvirus equine herpesvirus-2.

Twenty-two monoclonal antibodies (MAbs) were generated to the gammaherpesvirus equine herpesvirus-2 (EHV-2). Using Western blot analysis, eight MAbs recognized an Escherichia coli glutathione S-transferase (GST)-glycoprotein B (gB) fusion protein and, using overlapping GST-gB fusion proteins, a neutralization epitope was mapped to amino acids 29-74. One of the gB-specific MAbs was used to characterize the glycosylation and kinetics of synthesis of EHV-2 gB. EHV-2 gB is synthesized as a 97 kDa polypeptide that is co-translationally modified to a 130 kDa high-mannose precursor that forms a 260 kDa dimer shortly after synthesis. Each 130 kDa precursor is endoproteolytically cleaved to disulphide-linked subunits of 75 and 58 kDa prior to further processing to complex oligosaccharide-containing subunits of 89 and 65/62 kDa. The 89 and 65/62 kDa subunits of EHV-2 gB contain 39 and 17 kDa of N-linked oligosaccharides, respectively, and do not contain any O-linked oligosaccharides. Western blot analysis of purified EHV-2 virions established that gB exists as a 320 kDa dimer in the virion envelope.

Effect of acute induced metabolic alkalosis on the acid/base responses to sprint exercise of six racing greyhounds.

To investigate the effect of acute induced metabolic alkalosis on the haematological, biochemical and metabolic responses to sprint exercise, six greyhound dogs with previously placed carotid arterial catheters were raced four times over a distance of 400 metres. Each dog was raced twice after receiving oral sodium bicarbonate solution (NaHCO3) (400 mg kg-1) or lactated Ringer's solution (LRS). Before, and for intervals of up to one hour after, the exercise arterial blood samples were collected for the measurement of blood gases, packed cell volume, total protein, serum biochemistry and plasma lactate. The time to complete the 400 metre sprint ranged from 32.7 seconds to 36.9 seconds. There was no significant difference in racing times between the dogs treated with NaHCO3 and LRS, and there was no significant difference between the plasma lactate measurements after the treatments with NaHCO3 or LRS. Serum chloride concentrations were significantly lower after NaHCO3 than after LRS, and there was a trend towards a lower serum potassium concentration after NaHCO3 treatment. Plasma lactate concentrations showed a similar increase and time course of disappearance after both LRS and NaHCO3 treatments. There were significant changes in all the parameters measured after the exercise, but there were large variations between individual dogs and between races when the dogs were receiving the same treatment.

Age and exercise effects on mitochondrial density and capillary fibre ratio in bird leg muscle.

1. Muscle fibre composition, capillary-fibre ratio and mitochondrial density of the Iliotibialis lateralis muscle were monitored during growth from the age of 8 weeks to sexual maturity (24 weeks) in sedentary birds and in birds subjected to regular treadmill exercise. 2. The Iliotibialis lateralis muscle consists almost exclusively of type IIA and IIB fibres with a small percentage of "unclassified" fibres. Over the 16-week period of growth there was no change in fibre composition but a marked fibre hypertrophy linked with a fall in the capillary-fibre ratio. Mitochondrial volume density increased with age but this was not significant. 3. Exercise significantly increased the IIA:IIB fibres ratio from 0.77 to 1.1 but had no significant effect on any other measured characteristics. 4. It is concluded that exercise at the intensity and duration employed (10-15 min daily, ca. 70-80% maximum oxygen consumption) has little effect on the growth and development of avian skeletal muscle although there was evidence of an increased oxidative capacity of the muscle.