FISH mapping of 10 canine BAC clones harbouring genes and microsatellites in the arctic fox and the Chinese raccoon dog genomes

Cytogenetic mapping of the arctic fox and the Chinese raccoon dog were performed using a set of canine probes derived from the Bacterial Artificial Chromosome (BAC) library. Altogether, 10 BAC clones containing sequences of selected genes (PAX3, HBB, ATP2A2, TECTA, PIT1, ABCA4, ESR2, TPH1, HTR2A, MAOA) and microsatellites were mapped by fluorescence in situ hybridization (FISH) experiments to chromosomes of the canids studied. At present, the cytogenetic map on the arctic fox and Chinese raccoon dog consists of 45 loci each. Chromosomal localization of the BAC clones was in agreement with data obtained by earlier independent comparative chromosome painting. However, two events of telomere-to-centromere inversions were tentatively identified while compared with assignments in the dog karyotype.

Effect of Bio-Oss on osseointegration of dental implants surrounded by circumferential bone defects of different dimensions: an experimental study in the dog

OBJECTIVES: This study was designed to evaluate the effect of gap width and graft placement on bone healing around implants placed in simulated extraction sockets of various widths in four Labrador dogs. MATERIALS AND METHODS: Five Osseotite implants per dog were placed in the mandible of four dogs. Two implants were inserted into sites with a 2.37 mm and two with a 1 mm gap present between the implants and bone around the coronal 6 mm of the implants in each dog. For one of each gap sizes, the gap was filled with Bio-Oss, and the other two with blood alone. A fifth implant was inserted without a gap and used as a control. Ground sections were prepared from biopsies taken at 4 months and histometric measurements of osseointegration and bone between the threads made for the coronal 6 mm. RESULTS: The medians for osseointegration ranged from 5.2 mm for control to 1-2.6 mm for the test modalities. There were significant differences for linear measurements of osseointegration (chi(2) 18.27; df 4; P=0.0011) and bone area within threads (chi(2) 23.4; df 4; P=0.0001) between test modalities. CONCLUSIONS: The results suggest that the wider the gap around the implants, the less favourable the histological outcome at short time intervals following treatment. They also infer that bone grafting with an organic bovine bone xenograft seems to lead to a more favourable histological outcome for wider circumferential defects but not for narrower defects.

Adenocarcinoma metastasis of the intertransversarius cervicis muscle eliciting a right forelimb lameness in a dog

This article describes identification of a metastatic adenocarcinoma to the intertransversarius cervicis muscle using magnetic resonance imaging (MRI) in a dog that presented with chronic lameness of the right forelimb. Magnetic resonance imaging revealed a right sided, ovoid signal abnormality within the intertransversarius cervicis muscle lateral to the sixth cervical (C6) vertebra. The lesion was uniform, hyperintense on T2- and isointense on T1-weighted images to muscle and exhibited uniform contrast enhancement on T1-weighted images. The MRI findings were consistent with a neoplasia. Surgical excision was performed. Histopathological diagnosis was metastatic fibrous adenocarcinoma. The dog recovered rapidly but 6 months post-operatively he was killed because of lung metastases. Necropsy was declined and the primary tumour could not be identified.

Infectious endocarditis caused by gas-producing Escherichia coli in a diabetic dog

A 10-year-old, female West Highland white terrier was presented with poorly controlled diabetes mellitus and a previously undetected heart murmur. Emphysematous cystitis, emphysematous peritonitis and infective endocarditis of the tricuspid valve with gas accumulation were diagnosed with radiographs, including non-selective angiocardiography. The diagnoses were confirmed by post-mortem examination and positive cultures for Escherichia coli in blood, urine and tricuspid valve tissue samples.

[Elbow dysplasia in the dog: finite element analysis]

For young active dogs of large, fast-growing breeds, diseases of the elbow represent an increasing important disorder. Genetic predisposition, overweight and joint overload have been proposed as possible causes of elbow dysplasia. In this study, the influence of various biomechanical parameters on load transfer in healthy and pathological dog elbows has been analysed by means of a two-dimensional finite element model. Pathological changes in the elbow structure, such as altered material properties or asynchronous bone growth, have a distinct influence on the contact pressure in the joint articulation, internal bone deformation and stresses in the bones. The results obtained support empirical observations made during years of experience and offer explanations for clinical findings that are not yet well understood.

Polymorphism and chromosomal location of the MC4R (melanocortin-4 receptor) gene in the dog and red fox

The melanocortin-4 receptor (MC4R) is expressed in the hypothalamus and regulates energy intake and body weight. In silico screening of the canine chromosome 1 sequence and a comparison with the porcine MC4R sequence by BLAST were performed. The nucleotide sequence of the whole coding region and 3'- and 5'-flanking regions of the dog (1214 bp) and red fox (1177 bp) MC4R gene was established and high conservation of the nucleotide sequences was revealed (99%). Five sets of PCR primers were designed and a search for polymorphism was performed by the SSCP technique in a group of 31 dogs representing nineteen breeds and 35 farm red foxes. Sequencing of DNA fragments, representing the identified SSCP patterns, revealed three single nucleotide polymorphisms (including a missense one) in dogs and four silent SNPs in red foxes. An average SNP frequency was approx. 1/400 bp in the dog and 1/300 bp in the red fox. We mapped the MC4R gene by FISH to the canine chromosome 1 (CFA1q1.1) and to the red fox chromosome 5 (VVU5p1.2).

Effect of two different bioabsorbable collagen membranes on guided bone regeneration: a comparative histomorphometric study in the dog mandible

BACKGROUND: This study compared bone regeneration following guided bone regeneration with two bioabsorbable collagen membranes in saddle-type bone defects in dog mandibles. METHODS: Three standardized defects were created, filled with bone chips and deproteinized bovine bone mineral (DBBM), and covered by three different methods: control = no membrane; test 1 = collagen membrane; and test 2 = cross-linked collagen membrane (CCM). Each side of the mandible was allocated to one of two healing periods (8 or 16 weeks). The histomorphometric analysis assessed the percentage of bone, soft tissue, and DBBM in the regenerate; the absolute area in square millimeters of the bone regenerate; and the distance in millimeters from the bottom of the defect to the highest point of the regenerate. RESULTS: In the 8-week healing group, two dehiscences occurred with CCM. After 8 weeks, all treatment modalities showed no significant differences in the percentage of bone regenerate. After 16 weeks, the percentage of bone had increased for all treatment modalities without significant differences. For all groups, the defect fill height increased between weeks 8 and 16. The CCM group showed a statistically significant (P = 0.0202) increase over time and the highest value of all treatment modalities after 16 weeks of healing, CONCLUSIONS: The CCM showed a limited beneficial effect on bone regeneration in membrane-protected defects in dog mandibles when healing was uneventful. The observed premature membrane exposures resulted in severely compromised amounts of bone regenerate. This increased complication rate with CCM requires a more detailed preclinical and clinical examination before any clinical recommendations can be made.

Primary prostatic haemangiosarcoma causing severe haematuria in a dog

A 10-year-old, entire, male, mixed-breed dog was presented for severe haematuria and stranguria. Ultrasound revealed a large intraluminal urinary bladder blood clot and a prostatic space-occupying lesion. Invasion of the lesion into the prostatic urethra was detected ultrasonographically during compression of the urinary bladder. Post-mortem examination revealed primary prostatic haemangiosarcoma infiltrating the urethra. Haemangiosarcoma should be considered as a rare cause of prostatic mass lesions, haematuria or lower urinary tract signs in dogs.

Hormographiella aspergillata keratomycosis in a dog

A 4-year-old, female, Border Collie was presented to the University of Bern Veterinary Teaching Hospital, because of a corneal lesion of 10 days duration. The axial cornea presented a whitish fluorescein-positive plaque with irregular margins. A diagnosis of keratomycosis was made based on cytology. Medical therapy with local broad-spectrum antibiotic and fluconazole was instituted. After 1 week of treatment, the improvement was deemed unsatisfactory. Therefore, a lamellar keratectomy and conjunctival pedicle flap were performed. After surgery, the cornea healed uneventfully. Histology confirmed the diagnosis of keratomycosis. The fungus could not be grown in culture and a precise etiological diagnosis could only be obtained with genetic identification of the fungus. A PCR technique was used to amplify the fungal genome from the cornea. Hormographiella aspergillata, the asexual reproductive form of the basidiomycete Coprinopsis cinerea, was identified. As advised in human medicine, we encourage the use of this molecular technique to obtain an early species diagnosis, allowing targeted medical therapy.