Estimation of the intraoperative blood loss in dogs undergoing enucleation.

PURPOSE: To quantify the surgical blood loss during canine enucleation and to investigate the relationship between this and any patient, surgical, and anesthetic factors. METHODS: A prospective observational analysis was conducted on 121 client-owned dogs (130 eyes) undergoing enucleation at a referral ophthalmology clinic. Blood loss was estimated by the gravimetric method (weight difference between dry and blood-containing surgical materials) to provide absolute blood loss (ABL) in milliliters, expressed as a percentage of circulating blood volume, to establish relative blood loss (RBL). RESULTS: Median ABL was 12 ml (1.6-116 ml), and median RBL was 1.3% (0.1%-6.7%). A higher RBL was associated with the following: use of a bupivacaine splash block versus retrobulbar nerve block (1.9 vs. 1%; p < .001), transpalpebral versus subconjunctival approach (2.2 vs. 1.3%; p = .003), and small versus large breed dogs (1.7% vs. 1.1%; p = .001). Both ABL and RBL differed significantly between surgeons. There was no significant difference in hemorrhage associated with the presence of ocular hypertension, systemic illness, surgical time, administration of meloxicam or choice of pre-medicant (acepromazine vs medetomidine). No dog required supportive intervention in response to surgical hemorrhage. CONCLUSIONS: This study has established a surgical blood loss estimate for dogs undergoing enucleation at an ophthalmology referral centre. Subconjunctival enucleation may be preferred for patients at greater risk of haemodynamic complications.

Colonic perforation in 4 dogs following treatment with meloxicam.

OBJECTIVE: To describe the clinical findings and treatment of 4 dogs that developed colonic perforation shortly after meloxicam administration. SERIES SUMMARY: Three cases were treated with meloxicam for variable nonspecific signs including lethargy and pyrexia. Hemorrhagic diarrhea developed following meloxicam administration in 2 cases. Gastrointestinal perforation was suspected on diagnostic imaging leading to exploratory celiotomy in all 3 cases. Partial colectomy was performed in 2 cases and suture repair with serosal patching in 1 followed by broad spectrum antimicrobials. All 3 dogs recovered from surgery well. One dog that had undergone perineal herniorrhaphy and received meloxicam perioperatively collapsed and died 7 days postsurgery. Postmortem examination revealed ulceration and perforation of the ascending colon with resultant generalized septic peritonitis. Histopathologic findings in all cases showed full thickness infiltration of the colonic wall with inflammatory cells along with ulceration and perforation. Thrombosis of vessels underlying the ulcerated areas was also noted. NEW OR UNIQUE INFORMATION PROVIDED: This report suggests that colonic perforation may be a complication of nonsteroidal anti-inflammatory drug use in some cases. To the authors' knowledge, this has not previously been described in dogs. Colonic perforation associated with NSAIDs administration may be more commonly identified in dogs with concurrent morbidities. Caution may be warranted when using NSAIDs in dogs with colonic pathology or possible risk factors to develop such pathology. Prompt diagnosis and treatment is essential for a positive outcome.

Clinical, CT, and ultrasonographic features of canine and feline pleural and peritoneal carcinomatosis and sarcomatosis.

Carcinomatosis and sarcomatosis describe the widespread dissemination of metastatic neoplastic cells throughout the body. Studies describing their clinical and imaging features in veterinary patients are limited. The objective of this retrospective, multicenter, cross-sectional study is to describe the clinical, ultrasonographic, and CT features of pleural and peritoneal carcinomatosis and sarcomatosis in dogs and cats to aid detection and differentiation of these lesions. Medical records and CT and ultrasonographic images were reviewed. Although a large degree of overlap was observed between the imaging features and clinical signs of canine and feline carcinomatosis and sarcomatosis, some distinguishing features were observed. Dogs were significantly more likely to present with abdominal pain compared to cats (P = .022), whereas cats more commonly presented with inappetence (P = .019). Dogs with sarcomatosis had a significantly heavier bodyweight than dogs with carcinomatosis (P = .005), largely due to a higher prevalence of splenic hemangiosarcoma in this patient cohort. Peritoneal effusion was more frequently observed in dogs with carcinomatosis compared to dogs with sarcomatosis (P = .021). Imaging and clinical features observed in this study may help to distinguish sarcomatosis and carcinomatosis lesions. Due to the large degree of overlap observed, cytological or histopathological analysis is recommended for definitive diagnosis.

Glomus cell tumour on the head of a cat.

CASE SUMMARY: A solitary, sessile, non-ulcerated, freely mobile cutaneous mass approximately 1 cm in diameter on the left temporal region of a 7-year-old neutered female cat was examined. A fine-needle aspirate and wedge biopsy were performed by the referring veterinary surgeon and indicated a neoplasm of uncertain cell lineage. On histopathological examination, the deep dermis contained a discrete, non-encapsulated and vascular neoplasm with morphological and immunophenotypical features typical of a glomus cell tumour. Neoplastic cells were immunopositive for vimentin, muscle actin and smooth muscle actin, and immunonegative for cytokeratin, S100, desmin and von Willebrand factor (factor VIII-related antigen). RELEVANCE AND NOVEL INFORMATION: Glomus cell tumours arise from modified smooth muscle cells and are rare in animals, particularly cats. Specific immunohistochemistry is of fundamental importance in the correct diagnosis of these tumours and should be considered for masses when cytology and histology results are inconclusive or uncertain.

Intramuscular mast cell tumors in 7 dogs.

Mast cell tumors (MCTs) are commonly encountered in dogs and have been reported in cutaneous, conjunctival, oral mucosal, and gastrointestinal locations, but not in an intramuscular location. Medical records at 2 referral centers in the UK were examined to find cases of MCTs in this location. Seven dogs were identified as having an intramuscular MCT by a combination of fine-needle aspirate cytology and computed tomography or ultrasound. None of the dogs had evidence of local lymph node metastasis. Six dogs had no evidence of distant metastasis and surgery was carried out as the primary treatment option. Three of those dogs also had adjunctive chemotherapy due to a high Ki67 value or high mitotic index. All 6 dogs that had had surgery were alive at follow-up with a minimum elapsed time of 7 months. One dog had a course of chemotherapy due to the location, size, and evidence of biological activity of the tumor and died 23 days afterwards. The prognosis of intramuscular mast cell tumors appears to be favorable in most cases.

Tumeurs à mastocytes intramusculaires chez sept chiens. Les tumeurs à mastocytes (MCT) sont couramment observées chez les chiens et elles sont signalées à des emplacements cutanés, conjonctivaux, gastrointestinaux et dans les muqueuses orales, mais non dans des régions intramusculaires. Les dossiers médicaux de deux centres spécialisés du Royaume-Uni ont été examinés afin de trouver des cas de MCT à cet endroit. Sept chiens ont été identifiés comme ayant un MCT intramusculaire en utilisant une combinaison de cytologie par aspiration à l'aiguille fine et de tomodensitométrie ou d'échographie. Aucun des chiens ne présentait des signes de métastase des ganglions lymphatiques locaux. Six chiens ne manifestaient aucun signe de métastase distante et la chirurgie a été réalisée comme option de traitement primaire. Trois de ces chiens ont aussi subi une chimiothérapie d'appoint en raison d'une valeur élevée de Ki67 ou d'un indice mitotique élevé. Les six chiens qui avaient subi la chirurgie étaient vivants au suivi avec un délai écoulé de 7 mois. Un chien a subi un traitement de chimiothérapie en raison de l'emplacement, de la taille et de signes d'activité biologique de la tumeur et est mort 23 jours plus tard. Le pronostic de tumeurs à mastocytes intramusculaires semble être favorable dans la plupart des cas.(Traduit par Isabelle Vallières).

Ocular biometry by computed tomography in different dog breeds.

OBJECTIVE: To (i) correlate B-mode ocular ultrasound (US) and computed tomography (CT) (prospective pilot study), (ii) establish a reliable method to measure the normal canine eye using CT, (iii) establish a reference guide for some dog breeds, (iv) compare eye size between different breeds and breed groups, and (v) investigate the correlation between eye dimensions and body weight, gender, and skull type (retrospective study). PROCEDURE: B-mode US and CT were performed on ten sheep cadaveric eyes. CT biometry involved 100 adult pure-bred dogs with nonocular and nonorbital disease, representing eleven breeds. Eye length, width, and height were each measured in two of three planes (horizontal, sagittal, and equatorial). RESULTS: B-mode US and CT measurements of sheep cadaveric eyes correlated well (0.70-0.71). The shape of the canine eye was found to be akin to an oblate spheroid (a flattened sphere). A reference guide was established for eleven breeds. Eyes of large breed dogs were significantly larger than those of medium and small breed dogs (P < 0.01), and eyes of medium breed dogs were significantly larger than those of small breed dogs (P < 0.01). Eye size correlated with body weight (0.74-0.82) but not gender or skull type. CONCLUSIONS: Computed tomography is a suitable method for biometry of the canine eye, and a reference guide was established for eleven breeds. Eye size correlated with breed size and body weight. Because correlation between B-mode US and CT was shown, the obtained values can be applied in the clinical setting, for example, for the diagnosis of microphthalmos and buphthalmos.

Activity of the DNA minor groove cross-linking agent SG2000 (SJG-136) against canine tumours.

BACKGROUND: Cancer is the leading cause of death in older dogs and its prevalence is increasing. There is clearly a need to develop more effective anti-cancer drugs in dogs. SG2000 (SJG-136) is a sequence selective DNA minor groove cross-linking agent. Based on its in vitro potency, the spectrum of in vivo and clinical activity against human tumours, and its tolerability in human patients, SG2000 has potential as a novel therapeutic against spontaneously occurring canine malignancies. RESULTS: In vitro cytotoxicity was assessed using SRB and MTT assays, and in vivo activity was assessed using canine tumour xenografts. DNA interstrand cross-linking (ICL) was determined using a modification of the single cell gel electrophoresis (comet) assay. Effects on cell cycle distribution were assessed by flow cytometry and measurement of γ-H2AX by immunofluorescence and immunohistochemistry. SG2000 had a multi-log differential cytotoxic profile against a panel of 12 canine tumour cell lines representing a range of common tumour types in dogs. In the CMeC-1 melanoma cell line, DNA ICLs increased linearly with dose following a 1 h treatment. Peak ICL was achieved within 1 h and no removal was observed over 48 h. A relationship between DNA ICL formation and cytotoxicity was observed across cell lines. The formation of γ-H2AX foci was slow, becoming evident after 4 h and reaching a peak at 24 h. SG2000 exhibited significant anti-tumour activity against two canine melanoma tumour models in vivo. Anti-tumour activity was observed at 0.15 and 0.3 mg/kg given i.v. either once, or weekly x 3. Dose-dependent DNA ICL was observed in tumours (and to a lower level in peripheral blood mononuclear cells) at 2 h and persisted at 24 h. ICL increased following the second and third doses in a repeated dose schedule. At 24 h, dose dependent γ-H2AX foci were more numerous than at 2 h, and greater in tumours than in peripheral blood mononuclear cells. SG2000-induced H2AX phosphorylation measured by immunohistochemistry showed good correspondence, but less sensitivity, than measurement of foci. CONCLUSIONS: SG2000 displayed potent activity in vitro against canine cancer cell lines as a result of the formation and persistence of DNA ICLs. SG2000 also had significant in vivo antitumour activity against canine melanoma xenografts, and the comet and γ-H2AX foci methods were relevant pharmacodynamic assays. The clinical testing of SG2000 against spontaneous canine cancer is warranted.

The effect of cuff presence and cuff inflation on airway pressure in a canine tracheostomy tube model.

OBJECTIVE: To evaluate the effect of cuff presence and cuff inflation on airway pressure in an inspiratory model of canine tracheostomy. DESIGN: Ex vivo experimental study. Cadaver tracheas from Beagle dogs were attached aborally to a vacuum. Airway pressure and flow rate was measured before and after placement of tracheostomy tubes. ANIMALS: None. INTERVENTIONS: Adult uncuffed tubes and cuffed tracheostomy tubes (sizes 4, 6, 8, and 10) were placed within tracheas. Cuffs were investigated without inflation and at maximum cuff inflation. Airway pressure was measured at constant airflow rates at 30 and 60 L/min. MEASUREMENTS AND MAIN RESULTS: At set flow rates, airway pressures of tracheostomy tubes were compared to the intact trachea. A size 4 uncuffed tracheostomy tube showed the lowest airway pressure and a size 4 cuffed trachestomy tube with inflation showed the highest airway pressures. For sizes 6, 8, and 10 tubes, the presence of a cuff with and without inflation significantly increased airway pressure. Inflation of a cuff always significantly increased airway pressure. Similar pressure is seen between sizes 4 and 6 uncuffed tubes. CONCLUSIONS: Cuffed tracheostomy tubes should not be used unless specifically indicated due to increased airway pressure.

Metabolic bone disease in juvenile koalas (Phascolartcos cinereus).

Due to climate restrictions in parts of North America and Europe, koalas (Phascolarctos cinereus) are housed indoors. Koala young (joeys) raised indoors are susceptible to the development of metabolic bone disease (MBD) due to a lack of exposure to natural ultraviolet light to themselves and their female parents (dams). In this retrospective study, radiographs from 27 koala joeys born at four zoos in North America and two zoos in Europe were evaluated for signs of MBD. Eight of the joeys were radiographically diagnosed with MBD and four additional joeys were considered suspect MBD cases; in two joeys absence or presence of MBD could not be determined. All joeys had mild to severe hip and shoulder dysplasia. There were significant associations between a lack of exposure to UV light and MBD development and between MBD and the degree of severity of hip and shoulder dysplasia. It is recommended to house breeding female koalas and their joeys outdoors whenever possible.

Effects of unilateral arytenoid lateralization technique and suture tension on airway pressure in the larynx of canine cadavers.

OBJECTIVE: To evaluate effects of the arytenoid lateralization technique and suture tension on airway pressure in the canine larynx. SAMPLE: 7 canine cadaver larynges. PROCEDURES: Negative pressure was elicited aboral to the larynx. Airway pressure was measured at airflows of 15 to 120 L/min before and after thyroarytenoid lateralization (TAL), cricoarytenoid lateralization (CAL), and combined TAL and CAL (cricothyroarytenoid lateralization [CTAL]) at 100 and 500 g of suture tension and with sectioning of the sesamoid cartilage (SSC) and disarticulation of the cricothyroid joint (DCTJ). Rima glottidis area (RGA) was measured. Effects of technique, modification, and suture tension on pressure and RGA were evaluated statistically. RESULTS: Increased suture tension significantly reduced airway pressure for TAL at 30 L/min, CAL at 45 to 120 L/min, and CAL after SSC and DCTJ at 60, 75, and 105 to 120 L/min. The CAL and CTAL caused significantly lower airway pressures than did TAL > 30 L/min, but SSC and DCTJ did not significantly reduce pressure. All procedures, except TAL at 100 g of tension, resulted in a significant RGA increase from baseline. The CAL and CTAL caused a significantly greater RGA than did TAL. For TAL at 100 g of tension, SSC significantly increased RGA. CONCLUSIONS AND CLINICAL RELEVANCE: CAL and CTAL caused lower airway pressures than did TAL. No significant pressure differences were detected between CAL and CTAL; SSC and DCTJ had little effect on pressure. Pressure may be a more sensitive indicator of airflow than is RGA in the larynx of canine cadavers.

Successful surgical management of spontaneous gastric perforations in three cats.

BACKGROUND: In the veterinary literature, feline gastroduodenal ulcer disease has been described only in individual case reports or retrospective studies reporting small numbers of cats. Although its canine counterpart is commonly encountered, less is known about factors predisposing cats to gastroduodenal ulceration and potentially perforation. Similarly the outcome following treatment is not well reported in this species. REPORTED RISK FACTORS: In dogs, hepatic disease and administration of non-steroidal anti-inflammatory drugs (NSAIDs) have been reported as the two most common causes of gastroduodenal ulceration. In cats, only one clinical report so far has implicated an NSAID as a risk factor for spontaneous gastroduodenal perforation. FINDINGS AND PRACTICAL RELEVANCE: This report describes the historical and physical findings, as well as the treatment and outcome, in three cats with spontaneous gastric perforation that were receiving anti-inflammatory medication immediately prior to presentation. It highlights the importance of thorough patient evaluation in any cat presenting with non-specific clinical signs and a history of anti-inflammatory drug administration.

Partial right ventriculectomy using the incised patch technique to treat double chambered right ventricle and chylothorax in a cat.

OBJECTIVE: To report successful surgical treatment of double chambered right ventricle (DCRV) in a cat. STUDY DESIGN: Clinical report. ANIMALS: Cat with DCRV. METHODS: DCRV was diagnosed in a 5-month-old male Maine Coon cat using echocardiography and angiocardiography. At 2 years, despite medical therapy, chylothorax developed. A section of the right ventricular free wall that spanned the fibromuscular obstruction was excised under total venous inflow occlusion (TVIO) using the incised pericardial patch technique. RESULTS: Short-term recovery was complicated by return of chylothorax but this resolved after thoracocentesis and diuretic therapy. Three years after surgery, the cat is free of clinical signs and no longer on any medical therapy. CONCLUSIONS: Partial right ventriculectomy can be performed under TVIO through an incised pericardial patch. CLINICAL RELEVANCE: DCRV in cat can be successfully treated by partial right ventriculectomy performed under TVIO through an incised pericardial patch.

Surgical management of an incidentally diagnosed true pleuroperitoneal hernia in a cat.

Diaphragmatic defects in cats are common and most frequently occur as a result of trauma. Congenital diaphragmatic defects include peritoneopericardial hernias, hiatal hernias and, infrequently, true diaphragmatic, or pleuroperitoneal, hernias. Only three reports of feline pleuroperitoneal hernias could be found in the veterinary literature. All of these cats presented for evaluation of respiratory distress and two were managed successfully with surgery. This report describes the incidental diagnosis and successfully surgical treatment of a pleuroperitoneal hernia in a cat. It highlights the fact that pleuroperitoneal hernias may not always be symptomatic and that they may not be as rare as previously considered.

Evaluation of in vitro performance of suction drains.

OBJECTIVE: To assess the in vitro performance of suction drains. SAMPLE POPULATION: 11 drainage systems (3 rigid drains and 8 compressible drains [2 grenade type, 5 concertina type, and 1 pancake type]). PROCEDURES: A pressure transducer was connected to the patient end of each drainage system. Serial pressure measurements were obtained during incremental addition and removal of air into the reservoir of each system, followed by incremental addition of water. The volume of air removed to restore the initial suction was recorded. Maximum filling volume was compared with the stated reservoir volume. For compressible drains, the suction generated following 3 compression methods was compared. RESULTS: The initial suction generated by the drainage systems ranged from -633.4 +/- 14.7 mm Hg to -90.1 +/- 19.5 mm Hg. Rigid drains had greater initial suction than compressible drains. For all compressible drains, compression with 2 hands, rather than 1, produced greater suction, apart from the pancake-type (200-mL reservoir) drains for which the reverse occurred. For grenade-type drains, rolling the reservoir from apex to base generated greater suction than 1-hand compression. Maximum filling volume was lower than stated for the concertina-type drains with 50-mL, 25-mL, and 400-mL reservoirs and the rigid-type drain with a 200-mL reservoir. As increments of air or water were added, compressible drains lost suction rapidly up to a fill of 20% to 30% and then more gradually. Rigid drains lost suction more slowly. CONCLUSIONS AND CLINICAL RELEVANCE: Drainage systems varied widely in their initial suction and rate of loss of suction during filling.

Radiographic definition of the anticlinal vertebra in the dog.

The anticlinal vertebra is a point in the caudal thoracic vertebral column at which vertebral anatomic features change. It may be used as a point of reference in diagnostic imaging studies. However, its exact definition and anatomic location are not consistent between anatomic texts. The position of the anticlinal vertebra was evaluated radiographically in 100 dogs, using three different definitions of the anticlinal vertebra. Definition P referred to perpendicularity of the spinous proceses, definition V referred to verticality of the spinous processes, and definition J referred to the orientation of the intervertebral joints. The anticlinal vertebra was assessed to be T11 in 85%, 75%, and 89% of dogs for definitions P, V, and J, respectively. Combining definitions improved the likelihood that the vertebra assessed to be the anticlinal vertebra was T11, if the combination included definition J, but at the expense of loss of sensitivity. The degree of agreement between the definitions ranged from fair to poor. The level of agreement between definitions P and J was improved for small and large dogs and the level of agreement between definitions V and J was improved for medium and large dogs. Compared with large breed dogs, small breed dogs were more likely to have T10 described as the anticlinal vertebra. The presence of transitional vertebra did not affect the position of the anticlinal vertebra. It should not be assumed that the anticlinal vertebra is T11 in all dogs. Care should be taken to define this anatomic feature accurately when using it as an anatomic landmark.

Assessment of humeral length in dogs after repair of Salter-Harris type IV fracture of the lateral part of the humeral condyle.

OBJECTIVE: To evaluate the effect of fracture and subsequent repair on future bone growth of the humerus after Salter-Harris type IV fracture of the lateral part of the humeral condyle (LPHC). STUDY DESIGN: Prospective study. ANIMALS: Dogs (n=11). METHODS: Dogs that had LPHC fracture and an open distal humeral physis repaired (1992-2006) were re-examined and radiographed at >or=12 months of age and humeral length was measured. RESULT: Measurements from 11 dogs showed a significant (P=.02) increase in length of the humeral diaphysis of the affected leg compared with that of the intact limb (median, 1.2%; range, 1.3-3.4%). Condylar deformity secondary to growth disturbance was not observed. CONCLUSION: Shortening or growth deformity was not observed after fracture and repair even if a transcondylar screw was placed through the distal humeral growth plate. A mild overgrowth of the humeral diaphysis was observed, although likely considered clinically unimportant. CLINICAL RELEVANCE: Fracture of the LPHC and subsequent repair in dogs >3 months of age do not impair growth of the humeral diaphysis. A transcondylar humeral screw placed through the humeral physis will not result in shortening of the humeral diaphysis. Implant removal to allow for further growth is therefore not indicated.

Use of a latissimus dorsi myocutaneous flap for one-stage reconstruction of the thoracic wall after en bloc resection of primary rib chondrosarcoma in five dogs.

OBJECTIVE: To describe a thoracic wall reconstructive technique using a latissimus dorsi myocutaneous flap after en bloc resection of primary rib chondrosarcoma and report outcome in 5 dogs. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=5) with primary rib chondrosarcoma. METHODS: Medical records (2003-2005) were reviewed for signalment, staging investigations, surgical findings, complications, and outcomes. Owners and veterinary surgeons were contacted for outcome information. RESULTS: A latissimus dorsi myocutaneous flap provided an air-tight thoracic wall closure after chondrosarcoma resection. Paradoxical respiratory movement of the flap occurred; however, from physical examination and blood gas analysis (2 dogs), ventilation was adequate. All flaps survived, 1 had superficial skin necrosis distally and 2 had minor wound dehiscence. One dog without tumor-free margins died of tumor-related disease 56 days after surgery. Tumor recurrence did not occur in 4 dogs with tumor-free margins. One dog was euthanatized 10 months after surgery for unrelated disease; 3 dogs were alive at writing (median follow-up: 20 months; range, 18-27 months) and all had a satisfactory functional and cosmetic outcome. CONCLUSIONS: Reconstruction of ventral thoracic wall defects using a latissimus dorsi myocutaneous flap yields a functional, cosmetic outcome. CLINICAL RELEVANCE: A latissimus dorsi myocutaneous flap can be used as a successful 1-stage reconstructive technique for ventral thoracic wall defects.

Lingual haemangiosarcoma in a crossbred dog.

An eight-year-old, male neutered, crossbred dog was presented for investigation of a lingual mass of four months duration. Oral examination revealed a 7 cm × 5 cm soft, fluctuant mass at the caudal aspect of the tongue. Ultrasound examination of the mass demonstrated mixed echogenicity, with cavitations containing hypoechoic and anechoic regions. Lingual haemangiosarcoma was diagnosed on histopathological examination of multiple biopsy samples, with confirmation of the vascular endothelial origin of tumour cells by positive immunolabelling for factor VIII-related antigen.