The inheritance of extra-hepatic portosystemic shunts and elevated bile acid concentrations in Maltese dogs.

OBJECTIVES: To determine the heritability of extra-hepatic portosystemic shunts and elevated post-prandial serum bile acid concentrations in Maltese dogs. MATERIALS AND METHODS: Maltese dogs were recruited and investigated by a variable combination of procedures including dynamic bile acid testing, rectal ammonia tolerance testing, ultrasonography, portal venography, surgical inspection or necropsy. In addition, nine test matings were carried out between affected and affected dogs, and affected and unaffected dogs. RESULTS: In 135 variably related Maltese, shunt status could be confirmed in 113, including 19 with an extra-hepatic portosystemic shunt (17 confirmed at surgery, 2 at necropsy). Rectal ammonia tolerance testing results and post-prandial serum bile acid concentrations were retrievable for 50 and 88 dogs, respectively. Pedigree information was available for these 135 and an additional 164 related dogs. Two consecutive test matings were carried out between two affected animals (whose shunts had been attenuated), with 2 of 8 (25%) of offspring having an extra-hepatic portosystemic shunt. Six test matings were carried out between an affected and an unaffected animal, with 2 of 22 (9%) offspring affected. Heritability of extra-hepatic portosystemic shunt was 0·61 calculated using variance components analysis [95% confidence interval (CI) 0·14 to 1·0, P=0·001]. The best fitting model from segregation analysis was a common, partially penetrant, recessive model (allele frequency 0·34, penetrance 0·99, CI 0·09 to 1·0). The heritability of elevated post-prandial serum bile acid (and thus likely portal vein hypoplasia) was 0·81 (CI 0·43 to 1·0, P=0·2) after logarithmic transformation of post-prandial serum bile acid concentrations. CLINICAL SIGNIFICANCE: There is strong support for extra-hepatic portosystemic shunts and elevated post-prandial serum bile acid concentrations both being inherited conditions in Maltese.

Upper airway obstruction in Norwich Terriers: 16 cases.

BACKGROUND: Norwich Terriers have grown increasingly popular as show animals and pets, and awareness of respiratory problems within the breed is growing. OBJECTIVE: To describe components of obstructive upper airway syndrome in a nonbrachycephalic terrier breed. ANIMALS: Sixteen Norwich Terriers; 12 with and 4 without clinical signs of respiratory disease. METHODS: Prospective case series. Physical and laryngoscopic examinations were performed by 1 investigator in all dogs. Medical and surgical interventions were summarized and results of follow-up examination or owner reports were recorded. RESULTS: The study population was comprised of 9 females (6 intact) and 7 males (5 intact). Median age was 3.0 years (range, 0.5-11 years). Of 12 dogs presented for a respiratory complaint, physical examination was normal in 4 dogs. Laryngoscopic examination was abnormal in 11/12 dogs with redundant supra-arytenoid folds, laryngeal collapse, everted laryngeal saccules, and a narrowed laryngeal opening in most. Of 4 dogs lacking clinical signs, all had normal physical examination; however, 3/4 dogs had similar appearance of the larynx to dogs with clinical signs. Response to surgical intervention was minimal to moderate in all dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Norwich Terriers suffer from an upper airway obstructive syndrome that differs from that encountered in brachycephalic breeds. Affected dogs are difficult to identify without laryngoscopic examination because of the lack of clinical signs and abnormalities in physical examination findings, despite severe airway obstruction. Care is warranted when anesthetizing Norwich Terriers because of the small size of the laryngeal opening.

Evaluation of hepatic steatosis in dogs with congenital portosystemic shunts using Oil Red O staining.

The aims of this prospective study were to quantify steatosis in dogs with congenital portosystemic shunts (CPS) using a fat-specific stain, to compare the amount of steatosis in different lobes of the liver, and to evaluate intra- and interobserver variability in lipid point counting. Computer-assisted point counting of lipid droplets was undertaken following Oil Red O staining in 21 dogs with congenital portosystemic shunts and 9 control dogs. Dogs with congenital portosystemic shunts had significantly more small lipid droplets (<6 µ) than control dogs (P = .0013 and .0002, respectively). There was no significant difference in steatosis between liver lobes for either control dogs and CPS dogs. Significant differences were seen between observers for the number of large lipid droplets (>9 µ) and lipogranulomas per tissue point (P = .023 and .01, respectively). In conclusion, computer-assisted counting of lipid droplets following Oil Red O staining of liver biopsy samples allows objective measurement and detection of significant differences between dogs with CPS and normal dogs. This method will allow future evaluation of the relationship between different presentations of CPS (anatomy, age, breed) and lipidosis, as well as the impact of hepatic lipidosis on outcomes following surgical shunt attenuation.

Liposuction for removal of lipomas in 20 dogs.

OBJECTIVES: To review the success rates for liposuction of lipomas in dogs, report early complications and medium-term outcomes and formulate recommendations on the most appropriate candidates for liposuction. METHODS: Retrospective study of 20 dogs with 76 lipomas diagnosed by cytology, in which dry liposuction was attempted. Case records were reviewed for number and size of the lipomas, efficacy of liposuction, frequency and types of complication and likelihood of recurrence. RESULTS: Liposuction was successful in removing 73 of 76 lipomas (96%). Simple, encapsulated lipomas less than 15 cm in diameter were most easily removed, with minimal risk of complication. Giant lipomas contained fibrous trabeculae that hindered liposuction and resulted in poor fat retrieval. Giant lipomas were also associated with a high risk of bruising, haematoma and seroma, especially when inguinal in location. Regrowth was noted at follow-up between 9 and 36 months in 28% of lipomas. CLINICAL SIGNIFICANCE: Liposuction may be less invasive and more attractive to owners than conventional surgery for lipomas up to 15 cm in diameter. Liposuction is not recommended for infiltrative or giant inguinal lipomas. Regrowth can be expected in a high proportion of lipomas, which should be considered when choosing liposuction over conventional excision.

Wound healing after mulesing and other options for controlling breech flystrike in Merino lambs: quantitative and semiquantitative analysis of wound healing and wound bed contraction.

BACKGROUND: A two-part study examined wound healing and contraction occurring after mulesing and two alternative methods of preventing breech flystrike in sheep. OBJECTIVE: To quantify wound healing using a scoring system and to assess the contractility of the wound bed of the breech after mulesing, cetrimide-intradermal treatment and application of clips. METHOD: The study group of 30 mulesed, 30 cetrimide-intradermal treated, 30 control and 10 clip-treated sheep were humanely killed at six time points from 3 to 47 days after each treatment. Wound healing post treatment was assessed using a scoring system, and contractility was assessed by the quantification of myofibroblast expression. Statistical analyses allowed comparisons of temporal wound healing and contraction between treatment groups. RESULTS: Mulesing wounds healed faster in the first 11 days, but by 19 days wound healing was similar between the mulesing and cetrimide-intradermal groups. By 32 days, all three treatment groups had similar wound healing scores. There was greater myofibroblast expression in the mulesing group in the first 11 days after treatment, but by 19 days expression was similar in both the mulesing and cetrimide-intradermal groups. The clip group had significantly less myofibroblast expression from 32 days after treatment. CONCLUSION: Wound healing is initially most rapid after mulesing, but there are similar wound healing scores in the mulesing and cetrimide-intradermal treatment groups by 19 days. Both mulesing and the cetrimide-intradermal treatment induce a similar amount of wound bed contraction, with less contraction observed after application of clips.

Assessment of the short-term systemic effect of and acute phase response to mulesing and other options for controlling breech flystrike in Merino lambs.

BACKGROUND: Mulesing is an important method of preventing flystrike of Merino sheep in Australia, but because there are important short-term welfare issues associated with mulesing, alternative methods of removing the skin folds for breech flystrike prevention are being investigated. OBJECTIVE: To examine the short-term systemic effects of mulesing and two proposed alternatives, compared with two control methods, for controlling breech flystrike. METHOD: The five treatment groups comprised 10 lambs each: (1) mulesing, (2) intradermal-cetrimide treatment, (3) clip application, (4) tail docking only and (5) no treatment. Changes in body weight, haematological and biochemical profiles, and concentrations of fibrinogen, haptoglobin and serum amyloid A were measured repeatedly for 29 days post treatment. RESULTS: The mulesing and intradermal-cetrimide groups were the only treatment groups to lose weight during the first week, with greater weight loss in the mulesing group. The mulesing group had the most marked increases in all three acute-phase protein concentrations, closely followed by the intradermal-cetrimide group, with a mild increase observed for the clip group and even less for the tail-docked group. The mulesing group was the only group to develop mild anaemia, transient hyperglycaemia and a persistent decreased albumin : globulin ratio. The neutrophil : lymphocyte ratio was above the upper reference limit for both the mulesing and intradermal-cetrimide groups. CONCLUSION: Mulesing had the greatest systemic effect in terms of the magnitude and duration of increased acute-phase protein concentrations and haematological, biochemical and body weight changes. The clips had a significantly reduced systemic effect compared with mulesing, with the intradermal-cetrimide treatment in between the two. Tail docking had a minimal systemic effect.

Wound healing after mulesing and other options for controlling breech flystrike in Merino lambs: observations on gross and microscopic wound healing.

BACKGROUND: The mulesing procedure is the main procedure used to control breech flystrike of sheep in Australia, but other permanent methods of altering breech conformation are currently being investigated and wound healing is an important component of that comparative assessment. OBJECTIVE: To qualitatively assess the gross and microscopic tissue damage and wound healing that occurs in the immediate post-treatment period after mulesing, intradermal-cetrimide treatment and clip application. METHOD: The study group of 30 mulesed, 30 cetrimide-treated, 30 control and 10 clip-treated sheep were humanely killed at six time points during the 3-47 days post treatment. Treatment sites and wound beds were examined grossly and microscopically. RESULTS: Mulesing wounds healed rapidly in a predictable manner, producing long linear scars on either side of the breech and tail by 32-47 days post treatment. Although the time course for healing post cetrimide-treatment was similar to that for mulesing, complications occurred and included inadequate wound healing because of persistence of adherent necrotic tissue, poor skin tightening around the tail, and patchy or deep penetration of the cetrimide resulting in necrosis of adjacent skin and deeper structures. The clips resulted in skin tightening around the ventrolateral breech and tail, although the formation of skin tags and clip slippage were of concern in some sheep. CONCLUSION: Wounds healed rapidly after mulesing with minimal complications. The intradermal-cetrimide treatment appeared to produce imperfect and sometimes delayed wound healing compared with mulesing. The clips resulted in comparable wound healing to mulesing, but further field trials are required to assess their effectiveness in flystrike prevention.

The role of bronchoscopy in foreign body removal in dogs and cats: 37 cases (2000-2008).

BACKGROUND: Foreign body aspiration is a differential diagnosis for acute or chronic cough that requires medical or surgical management in animals. HYPOTHESIS: Success of bronchoscopy in airway foreign body removal is dependent on the size of the animal, duration of clinical signs, and location of the foreign body. ANIMALS: Thirty-two dogs and 5 cats with airway foreign bodies identified at the UC Davis Veterinary Medical Teaching Hospital. METHODS: Retrospective case study evaluating the role of duration of clinical signs and body size in successful bronchoscopic removal of foreign bodies. In addition, radiographic localization of disease was compared with bronchoscopic identification. Bronchoalveolar lavage (BAL) culture and cytologic findings are reported. RESULTS: Bronchoscopy was successful for removal of airway foreign bodies in 76% of animals (24/28 dogs and 2/5 cats), and in dogs was independent of duration of clinical signs or body size. One-third of thoracic radiographs lacked distinctive features of an airway foreign body, and therefore radiography was unable to predict the affected site. BAL fluid at the site of the foreign body contained more neutrophils and more often had intracellular bacteria than lavage fluid from a separate site. CONCLUSIONS AND CLINICAL IMPORTANCE: Bronchoscopy was successful in removing airway foreign bodies regardless of animal size or long duration of clinical signs. Results of this study confirm the utility of bronchoscopy with lavage in management of suspected foreign bodies, even in the absence of localizing radiographic findings.

Ultrasonographic characteristics of soft tissue tumours in dogs.

OBJECTIVE: To identify and describe the ultrasonographic features of soft tissue tumours in dogs. PROCEDURE: Superficial soft tissue tumours of various histological types, including mast cell tumours (MCTs) and soft tissue sarcomas (STSs), were evaluated. Ultrasound was used to visualise internal characteristics of the tumour, including vascularity. Tumours were categorised according to size, shape, margin definition, tissue plane mobility, echogenicity, echotexture, acoustic shadowing or enhancement and vessel distribution. Objective measurements of intratumoural blood flow included velocities and maximal perfused cross-sectional area (fractional area). Logistic regression models incorporating a variety of data were used in an attempt to predict the histopathological type of tumours. RESULTS: The logistic regression model defined by the parameters echotexture, margin definition and presence of subcapsular vessels was highly predictive of MCTs (> 73%; P = 0.024). Several other trends, including a larger size for STSs and less vascularity for both MCTs and STSs, were observed, but did not reach statistical significance. CONCLUSION: This preliminary study has shown the potential diagnostic value of ultrasound in differentiating soft tissue tumours. However, at present, ultrasound cannot replace biopsy and histopathological evaluation for tumour diagnosis.

Congenital quadricuspid aortic valve detected on chest CT.

A quadricuspid aortic valve is a very rare congenital anomaly, previously detected at autopsy, or more recently, on echocardiography. This case is only the second to be reported following detection on chest CT.

Ligation of the caudal mesenteric artery during resection and anastomosis of the colorectal junction for annular adenocarcinoma in two dogs.

An 8-year-old terrier cross and a 10-year-old German Shorthaired Pointer presented to the University Veterinary Centre, Sydney, for investigation of long-standing tenesmus and dyschezia. Both patients had an annular adenocarcinoma at the colorectal junction. Exploratory laparotomy was performed and the affected large intestinal segment was removed by resection and anastomosis. In both dogs, the caudal mesenteric artery was intimately associated with the mass, necessitating its ligation and transection. Postoperatively, there was no evidence of anastomosis breakdown in either case and both animals recovered well from surgery. The dogs were euthanased 8 and 10 months, respectively, after surgery because of clinical signs relating to metastatic disease.

Haematological, biochemical and selected acute phase protein reference intervals for weaned female Merino lambs.

BACKGROUND: Merino lambs are currently the subject of much research into the welfare aspects of mulesing and mulesing alternatives. OBJECTIVE: Obtain haematology, biochemistry and acute phase protein reference intervals using modern methodologies for female Merino lambs. METHOD: Blood was collected from 50, weaned, 9- to 16-week-old, female Merino lambs. Haematology and biochemistry panels were performed using routine automated methods. The acute phase proteins, fibrinogen, serum amyloid A and haptoglobin, were also measured using commercially available techniques. The reference intervals were determined to be the central 95% of results. RESULTS: Differences in the concentrations for some analytes were seen when compared with reported studies in sheep, but may be explained by the use of sheep of a different signalment, as well as different methodologies for analyte measurement. Overall, most analytes gave similar values to those previously reported in other studies. Notable exceptions were alkaline phosphatase, phosphate and globulins, for which the different results were often attributed to the younger age of the sheep in the present study, and platelets and creatine kinase, for which the elevated levels may have been a result of stress and muscle exertion associated with blood collection and husbandry practices. CONCLUSION: Established haematological, biochemical and acute phase protein reference intervals are necessary for the investigation of the systemic impact of mulesing and mulesing alternatives and for the investigation of systemic diseases affecting weaned, 9- to 16-week-old, female Merino lambs in general.

Use of continuous positive airway pressure in the acute management of laryngeal paralysis in a cat.

Continuous positive airway pressure (CPAP) has been is used widely in humans to manage obstructive sleep apnoea syndrome, but it has not been widely used in animals. A brachycephalic cat, with previously undiagnosed laryngeal paralysis, that developed acute upper respiratory tract obstruction on recovery from anaesthesia, is presented. The condition was managed by CPAP, delivered via a facial mask.

Tachycardia-induced cardiomyopathy in a young Boxer dog with supraventricular tachycardia due to an accessory pathway.

A 1-year-old male Boxer dog presented with sustained supraventricular tachycardia and tachycardia-induced cardiomyopathy. Conversion to sinus rhythm was achieved initially with intravenous lignocaine and subsequently with oral procainamide. Oral procainamide treatment was relatively successful in maintaining normal sinus rhythm with no side effects apart from a reversible change in coat colour. Electrophysiological studies demonstrated the presence of an accessory pathway connecting the right atrium to the right ventricle and confirmed the diagnosis of orthodromic atrioventricular reciprocating tachycardia. Radiofrequency catheter ablation of the accessory pathway led to permanent resolution of the supraventricular tachycardia and for 9.5 years the dog has had no further signs of cardiac disease. The successful treatment of this condition highlights the importance of differentiating tachycardia-induced cardiomyopathy from dilated cardiomyopathy.

Results of surgical correction of abnormalities associated with brachycephalic airway obstruction syndrome in dogs in Australia.

OBJECTIVES: To describe clinical features of brachycephalic airway obstructive disease in dogs, the incidence of laryngeal collapse in dogs presenting for surgery and the outcome after surgery in dogs with laryngeal collapse. METHODS: Basic clinical details were reviewed retrospectively in 73 dogs. Presence of laryngeal collapse and short-term outcomes after surgery were determined for 64 dogs with complete medical records. Long-term outcomes were reviewed for 46 dogs by telephone survey between 19 and 77 months following surgery. RESULTS: Stenotic nares were present in 31 dogs (42.5 per cent), elongated soft palate in 63 (86.3 per cent) and everted laryngeal saccules in 43 (58.9 per cent). The most common breeds were the pug (19 dogs, 26 per cent), Cavalier King Charles spaniel (15 dogs, 20.5 per cent), British bulldog (14 dogs, 19.2 per cent) and Staffordshire bull terrier (4 dogs, 5.5 per cent). Laryngeal collapse was present in 34 of 64 (53 per cent) dogs. No dogs died perioperatively and only one dog was euthanased as a result of its respiratory disease three years after surgery. Telephone interviews indicated that 26 dogs (56.5 per cent) were much improved after surgery, 15 (32.6 per cent) had some improvement and 5 (10.9 per cent) showed no improvement. Signs that persisted after surgery were snoring during sleep (34 dogs, 73.9 per cent), stertor/stridor while conscious (23 dogs, 50 per cent), excessive panting (13 dogs, 28.3 per cent) and dyspnoea (10 dogs, 21.7 per cent). Long-term outcome was considered good, even in dogs with laryngeal collapse. CLINICAL SIGNIFICANCE: Laryngeal collapse is relatively common in dogs presented for surgical correction of brachycephalic airway obstructive disease. Dogs with severe laryngeal collapse often respond well to surgery. Clinical signs rarely resolve completely following surgery.

Migration of wooden skewer foreign bodies from the gastrointestinal tract in eight dogs.

Wooden skewer foreign bodies were found in eight dogs. Five presented for evaluation of draining sinuses and two for inflammatory disease referrable to the thorax, abdomen or pelvic region. In an additional case, pneumothorax resulted from perforation of the stomach and diaphragm. Ingestion was considered the most likely mode of access of the foreign body in all cases. Although the wooden foreign bodies were seen radiographically in only two dogs, identification of soft tissue or bony changes, or the results of contrast sinography assisted diagnosis. Surgical retrieval led to resolution of signs in all cases.

Effect of breed on anatomy of portosystemic shunts resulting from congenital diseases in dogs and cats: a review of 242 cases.

OBJECTIVE: To evaluate the effect of species and breed on the anatomy of portosystemic vascular anomalies in dogs and cats. DESIGN: Retrospective study of 233 dogs and nine cats presenting to the University Veterinary Centre, Sydney. METHODS: Case records were evaluated for breed, sex, age, anatomical and histological diagnosis. Cases were included when a portosystemic vascular anomaly resulted from a congenital or developmental abnormality of the liver or portal venous system. RESULTS: Disease conditions included single congenital portosystemic shunt with patent portal vasculature (214 dogs, nine cats), portal vein aplasia (nine dogs), multiple acquired shunts resulting from portal vein hypoplasia (seven dogs), biliary atresia (one dog) and microvascular dysplasia (one dog). One Maltese had a single, congenital shunt and multiple acquired shunts resulting from hepatic cirrhosis. Breeds that were significantly over-represented included the Maltese, Silky Terrier, Australian Cattle Dog, Bichon Frise, Shih Tzu, Miniature Schnauzer, Border Collie, Jack Russell Terrier, Irish Wolfhound and Himalayan cat. Bichon Frise with shunts were significantly more likely to be female than male (12:2, P < 0.001). Two hundred and fourteen dogs (91.4%), and all cats, had shunts that were amenable to attenuation. Inoperable shunts occurred in 19 dogs (8.2%). Fifty six of 61 (92%) operable shunts in large breed dogs were intrahepatic, versus 10/153 (7%) in small breeds (P < 0.0001). Breeds that were not predisposed to portosystemic shunts were significantly more likely to have unusual or inoperable shunts than dogs from predisposed breeds (29% versus 7.6%, P < 0.0001). No significant relationship between breed and shunt type could be determined in cats. CONCLUSION: Breed has a significant influence on shunt anatomy in dogs. Animals presenting with signs of portosystemic shunting may suffer from a wide range of operable or inoperable conditions. Veterinarians should be aware that unusual or inoperable shunts are much more likely to occur in breeds that are not predisposed to congenital portosystemic shunts.

Soft tissue sarcomas and mast cell tumours in dogs; clinical behaviour and response to surgery.

OBJECTIVE: To characterise the types of canine soft tissue sarcoma and mast cell tumour treated surgically at the University Veterinary Centre, Sydney. To evaluate the success of surgical treatment of these tumours and identify variables predictive of local recurrence and survival. To establish whether conclusions drawn from previous international studies are applicable to the University Veterinary Centre, Sydney, dog population and vice versa. DESIGN: Clinical presentation and results of surgical excision of 54 soft tissue sarcomas and 70 mast cell tumours affecting the trunk and limbs of dogs at the University Veterinary Centre, Sydney, between 1989 and 2001 were reviewed retrospectively. RESULTS: Cross-bred dogs and Rhodesian Ridgebacks were at significantly greater risk of developing soft tissue sarcomas, and Boxers, Australian Cattle Dogs and Staffordshire Bull Terriers were at significantly greater risk of developing mast cell tumours than other breeds. Fine needle aspiration biopsy yielded a correct diagnosis in 62.5% of soft tissue sarcomas and 96% of mast cell tumours. Local recurrence was encountered after surgical excision in 7.4% of soft tissue sarcomas and 7.3% of mast cell tumours. Metastasis occurred in 6% of soft tissue sarcomas and 12% of mast cell tumours. The most significant risk factors for local recurrence were contaminated surgical margins (soft tissue sarcomas) and histological grade (mast cell tumours). Due to the low number of animals experiencing metastasis, no conclusions could be drawn about significant risk factors. CONCLUSIONS: Aggressive surgical management of soft tissue sarcomas and mast cell tumours is associated with a low incidence of local recurrence. The type, location and behaviour of mast cell tumours and soft tissue sarcomas in the population of dogs presented to the University Veterinary Centre, Sydney are similar to those reported by others.

Complete heart block associated with lupus in a dog.

A 5-year-old Poodle-cross was initially presented for exercise intolerance and difficulty in chewing and yawning. Some months later it acutely developed lethargy referable to complete heart block. Further investigations before and after permanent pacemaker implantation demonstrated Coombs-positive immune-mediated haemolytic anaemia, presumptive masticatory myositis and hypoadrenocorticism, suggesting the possibility of multisystem auto-immune disease. A diagnosis of systemic lupus erythematosus (SLE) was made based on these findings and a positive anti-nuclear antibody titre. It was thought that immune-mediated destruction of cardiac conduction tissues was responsible for the development of atrioventricular conduction block. Glucocorticoid deficiency was corrected using cortisone replacement therapy. SLE was controlled successfully for 10 months using azathioprine monotherapy until signs, subsequently shown to be due to subacute bacterial endocarditis, resulted in the death of the patient. Lupus should be considered as a potential underlying aetiology in dogs that develop heart block.