Effect of clinical signs, endocrinopathies, timing of surgery, hyperlipidemia, and hyperbilirubinemia on outcome in dogs with gallbladder mucocele.

Gallbladder mucocele (GBM) is a common extra-hepatic biliary syndrome in dogs with death rates ranging from 7 to 45%. Therefore, the aim of this study was to identify the association of survival with variables that could be utilized to improve clinical decisions. A total of 1194 dogs with a gross and histopathological diagnosis of GBM were included from 41 veterinary referral hospitals in this retrospective study. Dogs with GBM that demonstrated abnormal clinical signs had significantly greater odds of death than subclinical dogs in a univariable analysis (OR, 4.2; 95% CI, 2.14-8.23; P<0.001). The multivariable model indicated that categorical variables including owner recognition of jaundice (OR, 2.12; 95% CI, 1.19-3.77; P=0.011), concurrent hyperadrenocorticism (OR 1.94; 95% CI, 1.08-3.47; P=0.026), and Pomeranian breed (OR, 2.46; 95% CI 1.10-5.50; P=0.029) were associated with increased odds of death, and vomiting was associated with decreased odds of death (OR, 0.48; 95% CI, 0.30-0.72; P=0.001). Continuous variables in the multivariable model, total serum/plasma bilirubin concentration (OR, 1.03; 95% CI, 1.01-1.04; P<0.001) and age (OR, 1.17; 95% CI, 1.08-1.26; P<0.001), were associated with increased odds of death. The clinical utility of total serum/plasma bilirubin concentration as a biomarker to predict death was poor with a sensitivity of 0.61 (95% CI, 0.54-0.69) and a specificity of 0.63 (95% CI, 0.59-0.66). This study identified several prognostic variables in dogs with GBM including total serum/plasma bilirubin concentration, age, clinical signs, concurrent hyperadrenocorticism, and the Pomeranian breed. The presence of hypothyroidism or diabetes mellitus did not impact outcome in this study.

A single dose of intravenous combretastatin A4-phosphate is reasonably well tolerated and significantly reduces tumour vascularization in canine spontaneous cancers.

Combretastatin A4-phosphate (CA4P) is an anti-tumour vascular targeting agent which selectively blocks tumour blood flow. Research on CA4P in rodent tumour models is extensive; however, knowledge of its effect on spontaneous cancer is scarce. This study was conducted in canine patients with spontaneous solid tumours. The goal was to assess the toxicity and efficacy of CA4P in various spontaneous tumour types. Eight dogs with spontaneous tumours were enrolled and treated with a single dose of 75 mg m-2 intravenous CA4P. The dogs were screened and monitored before and after injection. Pre- and post-treatment tumour blood flow was analysed in vivo by power Doppler ultrasound (PDUS) and contrast-enhanced ultrasound (CEUS). Vessel destruction and tumour necrosis were evaluated by histopathology. Clinically relevant toxicity was limited to one case of temporary tetraparesis; other adverse events were mild. Significant cardiovascular changes were mostly confined to changes in heart rate and cTnI levels. Macroscopic tumour size reduction was evident in 2 dogs. Based on PDUS and CEUS, CA4P induced a significant decrease in vascular index and tumour blood flow. Post-treatment, histopathology revealed a significant increase of necrotic tumoural tissue and a significant reduction in microvessel density in tumoural tissue. Anti-vascular and necrotizing effects of CA4P were documented in a variety of canine spontaneous cancers with only minimal side effects. This is the first study reporting the administration of CA4P to canine cancer patients with in vivo and ex vivo assessment, and a first step toward implementing CA4P in combination therapies in veterinary oncology patients. The use of CA4P in canine patients was approved and registered by the Belgian Federal Agency for Medicines and Health Products (FAMHP) (approval number 0002588, registration number 6518 ID 2F12).

Biodistribution and tolerance of intravenous iodine-131-labelled hypericin in healthy dogs.

Hypericin (Hyp) is a necrosis-avid compound that can be efficiently labelled with radioiodine for both diagnostic and therapeutic purposes. Before 131 I-Hyp can be considered as a clinically useful drug in a combination therapy for canine cancer patients, evaluation of its toxicity is necessary. The aim of this study was to investigate the biodistribution and tolerance of a single dose administration of 131 I-Hyp. Three healthy dogs were included. 131 I-Hyp at a dose of 0.2 mg/kg and an activity of 185 MBq was intravenously injected. The effects on physical, haematological and biochemical parameters were characterized and the biodistribution and elimination pattern, the effective half-life and dose rate were assessed. Drug-related adverse events were limited to mild gastrointestinal signs, resolving within 48 hours. No significant differences were found in blood haematology and serum biochemistry before and after treatment. Following administration, highest percentage of injected dose (%ID ± SD) was found in the liver (5.5 ± 0.33), the lungs (4.17 ± 0.14) and the heart (3.11 ± 0.78). After 24 hours, highest %ID was found in colon (4.25 ± 1.45) and liver (3.45 ± 0.60). Clearance from all organs was effective within 7 days. Effective half-life was established at 80 hours, and the dose rate fell below <20 µSv/h at 1 m within 1 day. The current study reveals that single dose treatment with 131 I-Hyp at the described dose is well tolerated by healthy dogs and supports the use of radioiodinated hypericin in a combination therapy for canine cancer patients.

A dose-escalation study of combretastatin A4-phosphate in healthy dogs.

Combretastatin A4-Phosphate (CA4P) is a vascular disrupting agent revealing promising results in cancer treatments for humans. The aim of this study was to investigate the safety and adverse events of CA4P in healthy dogs as a prerequisite to application of CA4P in dogs with cancer. Ten healthy dogs were included. The effects of escalating doses of CA4P on physical, haematological and biochemical parameters, systolic arterial blood pressure, electrocardiogram, echocardiographic variables and general wellbeing were characterised. Three different doses were tested: 50, 75 and 100 mg m-2 . At all 3 CA4P doses, nausea, abdominal discomfort as well as diarrhoea were observed for several hours following administration. Likewise, a low-grade neutropenia was observed in all dogs. Doses of 75 and 100 mg m-2 additionally induced vomiting and elevation of serum cardiac troponine I levels. At 100 mg m-2 , low-grade hypertension and high-grade neurotoxicity were also observed. In healthy dogs, doses up to 75 mg m-2 seem to be well tolerated. The severity of the neurotoxicity observed at 100 mg m-2 , although transient, does not invite to use this dose in canine oncology patients.

Comparison of a 5-mm and 10-mm vessel sealing device in an open ovariectomy model in dogs.

The objectives of this study were to compare (1) the extent of thermal damage and (2) the time between the 5-mm LigaSure V (LS5) and 10-mm LigaSure Atlas (LS10) vessel sealing devices (VSD) when performing open ovariectomy in dogs. A prospective, randomised, clinical trial was performed in 40 client-owned sexually entire female dogs. In each dog, one ovary was randomly assigned to be surgically removed using LS5 and the contralateral using LS10. The depth of thermal spread, measured on histopathological preparations, was significantly larger for LS10 (LS10 1.35±0.23 mm v LS5 0.82±0.10 mm; P<0.001). Mean ovariectomy time was significantly faster when using LS10 (LS5 2.58±1.32 minutes v LS10 2.07±1.27 minutes; P=0.008). Bodyweight was positively correlated with the time required for ovariectomy using LS5 (P=0.004), but no such correlation was present for LS10 (P=0.611). In conclusion, during open ovariectomy using VSD, LS10 causes significantly more thermal spread but surgical time is shorter compared with LS5. When using LS5, the ovariectomy time increases with increasing bodyweight.

Combretastatin A4-phosphate and its potential in veterinary oncology: a review.

For many years, research on anticancer therapy has focussed almost exclusively on targeting cancer cells directly, to selectively kill them or restrict their growth. But limited advances in this strategy have led researchers to shift their attention to other potential targets. Active research is now on-going on targeting tumour stroma. Vascular disrupting agents (VDAs) appear a promising class of anticancer drugs that are currently under investigation as a sole or combined therapy in human cancer patients. This article will briefly touch on the history and biology of combretastatin A4-phosphate (CA4P) as a typical example of VDAs and will concentrate on the side effects that can be expected when used in veterinary patients. Particularly, the pathogenesis of these side effects and how they may be prevented and/or treated will be discussed. The purpose of this article is to illustrate the potentials of CA4P as anticancer therapy in veterinary oncology patients.

Immunological and angiogenic markers during metronomic temozolomide and cyclophosphamide in canine cancer patients.

Metronomic chemotherapy stimulates the immune response via depletion of regulatory T cells (Tregs) and suppresses angiogenesis by modulating the secretion of thrombospondin-1 (TSP-1) and vascular endothelial growth factor (VEGF). In this study, blood was collected from 10 healthy dogs and from 30 canine cancer patients before and 2 and 4 weeks after treatment with metronomic temozolomide (6.6 mg m-2 ), cyclophosphamide (12.5 mg m-2 ) or cyclophosphamide and temozolomide. The percentage of circulating CD25+ Foxp3+ CD4+ Tregs and the plasma levels of TSP-1 and VEGF were measured. There was a significant difference in the percentage of Tregs between cancer patients and healthy dogs. A significant decrease in Tregs was noted in patients treated with metronomic cyclophosphamide and the combination. Treatment with temozolomide had no effect on the percentage of Tregs. TSP-1 and VEGF levels were, respectively, significantly lower and higher in cancer patients than in healthy dogs, but they were not influenced by any of the studied metronomic treatment regimens.

Embryonal Rhabdomyosarcoma of the Oesophagus in a Young Dog.

A 15-month-old great Dane dog, showing clinical signs related to hypertrophic osteopathy, was diagnosed radiographically with a mass in the region of the thoracic oesophagus. Exploratory thoracotomy revealed an extensive, highly vascularized and locally invasive oesophageal mass and the presence of nodules in adjacent lung lobes. The dog was humanely destroyed intra-operatively. Histological examination revealed that the mass was an embryonal rhabdomyosarcoma. This is the first report of rhabdomyosarcoma of the oesophagus of a dog. Rhabdomyosarcoma should be considered a differential diagnosis when a mass adjacent to the oesophagus is diagnosed.

Intratumoural interleukin 12 gene therapy stimulates the immune system and decreases angiogenesis in dogs with spontaneous cancer.

Interleukin 12 (IL-12) is a powerful immunostimulatory cytokine with a strong antitumoural activity. In this work, the immunological, anti-angiogenic and clinical effects of three consecutive intratumoural IL-12 electrogene therapy (EGT) treatments were evaluated in nine dogs with spontaneous cancer. In all the dogs, tumour biopsies and blood samples were taken prior, during and after the intratumoural IL-12 EGT (on days 1, 8, 35 and 1, 3, 8, 15, 35, respectively). An initial decrease in immune cells was followed by an increase above baseline 1-3 weeks after treatment initiation. Interestingly, the decrease in peripheral leukocytes 2 days after the first intratumoural IL-12 EGT coincided with erythema and tumour swelling. Transient increases of IL-12 and interferon γ were measured in the serum and the tumour tissue, whereas IL-10 transiently increased only in the serum. The effect of intratumoural IL-12 EGT on the levels of IL-24 and vascular endothelial growth factor in the sera and tumour biopsies differed per dog. Via contrast-enhanced ultrasound (US) (on days 1, 8 and 35), we demonstrated that intratumoural IL-12 EGT resulted in a significant decrease of the relative blood volume and blood flow speed in the tumour compared with baseline. Metastases were present in two dogs. In one of these dogs, IL-12 EGT of the primary tumour caused a transient partial regression of the metastases, but not of the primary tumour. The second dog with metastases did not survive long enough to complete the entire treatment cycle. Despite encouraging immunostimulatory and anti-angiogenic effects after intratumoural IL-12 EGT, no clinically relevant outcomes were observed in this study, as persistent tumour regression could not be obtained. On the other hand, the laboratory and US results hold great promise for combinatorial strategies of intratumoural IL-12 EGT with conventional antitumour (immuno)therapies.

The Microscopic Structure of the Omentum in Healthy Dogs: The Mystery Unravelled.

The canine omentum has many valuable properties but is still an underestimated organ. It contributes in many ways to the protection of the peritoneal cavity through its versatility on immunological level, but also through its role during angiogenesis, absorption, adhesion and fat storage. Despite a wide range of applications, the basic structure of the omentum is not well documented. This study provides an insight in the microscopic structure of the canine omentum through both light microscopic and electron microscopic investigations. Two regions could be distinguished in the canine omentum: translucent and adipose-rich regions. The translucent regions were composed of two different layers: a continuous flattened mesothelium on top of a submesothelial connective tissue matrix. The adipose-rich regions consisted of a substantial layer of adipocytes on which a flattened continuous mesothelium was present. Between those two layers, a few strands of collagen fibres could be detected. Large aggregates of immune cells, the so-called milky spots, were not observed in the omentum of healthy dogs. Only a limited number of leucocytes, macrophages and neutrophils were found, scattered throughout the connective tissue in the translucent regions. At the level of the adipose-rich regions, the immunological population was virtually non-existent.

Use of greater omentum in the surgical treatment of a synovial cyst in a cat.

A 13-year-old cat was diagnosed with a synovial cyst originating from the glenohumeral joint. The cat presented with severe front limb lameness and a non-painful fluctuating swelling on the medial aspect of the humerus. Radiographic examination showed severe bilateral shoulder osteoarthritis with osteophyte formation. The mass was surgically resected and histopathology confirmed the diagnosis of a synovial cyst. Three weeks postoperatively the cyst recurred. Surgical resection was repeated followed by omentalisation of the defect. Throughout the following 3 months the cyst did not recur. Unfortunately, for reasons unrelated to the presented disease, the cat was euthanized shortly afterwards, therefore making a long-term follow-up impossible.

Vessel sealing versus suture ligation for canine ovarian pedicle haemostasis: a randomised clinical trial.

Vessel sealing (VS) is well established in laparoscopic ovariectomy (OVE) in dogs. The objectives of this study were to evaluate the efficacy of ovarian pedicle haemostasis by VS using a commercially available VS tool in open OVE and compare it with suture ligation (SL). A prospective, randomised clinical trial including 20 female dogs was designed. Open OVE was performed via a standard mid-line celiotomy by a single surgeon using a standardised protocol. At random, the right ovarian pedicle was sealed (VS) or ligated (SL) whereas the left pedicle was treated by the alternative technique. Surgical times for procedural stages and intra-operative complications were recorded and statistically evaluated. Total surgical time was 29.28±11.13 minutes (range 12.50-62.13 minutes) and time from identification to removal of the ovary was significantly less when sealing (VS 2.22±0.58 minutes) than when ligating (SL 4.10±1.13 minutes P=0.0001). Intra-operative complications were rare for both techniques (failure of the electrode of the VS device (n=3); ovarian pedicle haemorrhage due to ligature slippage (n=1)). The results of the current study indicate that ovarian pedicle haemostasis achieved by VS is significantly faster than by placement of ligatures without appearing to compromise safety.

Clinical, pathologic, and immunohistochemical prognostic factors in dogs with thyroid carcinoma.

BACKGROUND: Prognostic markers for dogs with thyroid tumors are limited. HYPOTHESIS/OBJECTIVES: To identify clinical, pathologic, and immunohistochemical prognostic factors for dogs with thyroid tumors. ANIMALS: Seventy dogs with thyroid neoplasia. METHODS: Retrospective study. Dogs with thyroid neoplasia were included when follow-up information and formalin-fixed paraffin-embedded tumor samples were available. Immunohistochemistry (IHC) was performed for thyroglobulin, calcitonin, Ki-67, and E-cadherin. Correlation of tumor variables (diameter, volume, localization, scintigraphic uptake, thyroid function, IHC) with local invasiveness and metastatic disease was performed on all tumor samples. Forty-four dogs treated by thyroidectomy were included in a survival analysis. RESULTS: Fifty dogs (71%) had differentiated follicular cell thyroid carcinoma (dFTC) and 20 (29%) had medullary thyroid carcinoma (MTC). At diagnosis, tumor diameter (P = .007; P = .038), tumor volume (P = .020), tumor fixation (P = .002), ectopic location (P = .002), follicular cell origin (P = .044), and Ki-67 (P = .038) were positively associated with local invasiveness; tumor diameter (P = .002), tumor volume (P = .023), and bilateral location (P = .012) were positively associated with presence of distant metastases. Forty-four dogs (28 dFTC, 16 MTC; stage I-III) underwent thyroidectomy. Outcome was comparable between dogs with dFTC and MTC. Macroscopic (P = .007) and histologic (P = .046) vascular invasion were independent negative predictors for disease-free survival. Although time to presentation, histologic vascular invasion and Ki-67 were negatively associated with time to metastases, and time to presentation was negatively associated with time to recurrence, no independent predictors were found. E-cadherin expression was not associated with outcome. CONCLUSIONS AND CLINICAL IMPORTANCE: Prognostic factors have been identified that provide relevant information for owners and clinicians.

Prepubertal gonadectomy in cats: different surgical techniques and comparison with gonadectomy at traditional age.

Feasibility, surgical time and complications of different surgical techniques for prepubertal gonadectomy (PPG; 8-12 weeks of age) in cats were studied and compared to gonadectomy at traditional age (TAG; 6-8 months of age). Kittens were randomly assigned to PPG or TAG. Ovarian pedicle haemostasis for PPG was achieved by ligatures (n=47), vascular clips (n=50), bipolar electrocoagulation (n=50), or pedicle tie (n=50); for TAG (n=34) ligatures were used. In male cats, PPG consisted of closed castration by spermatic cord knot (n=92) or ligature (n=91) while TAG (n=34) was an open castration by spermatic cord knot. A linear (surgical time) and a logistic regression (complications) model were designed. Significance was set at 0.05. For female PPG, clips and coagulation were the fastest procedures; placement of ligatures was most time-consuming. In male PPG, knot placement was significantly faster than ligation. In both sexes, very few intraoperative or wound complications were observed, irrespective of the surgical technique used. Surgical times in females (ligatures) as well as in males (knot) were significantly shorter for PPG than for TAG. PPG was as safe as TAG, yet took less time to perform and did not result in a greater rate of postoperative complications.

Canine mammary tumours, an overview.

Canine mammary tumours (CMTs) are the most common neoplasms in intact female dogs. Although the prevalence of these tumours decreases in regions where preventive ovari(ohyster)ectomy is performed, it remains an important disease entity in veterinary medicine. Moreover, treatment options are limited in comparison with human breast cancer. Nevertheless, recent human treatment protocols might have potential in bitches suffering from CMTs.

Metabolic correlates of tumour hypoxia in malignant canine mammary carcinoma.

Given its importance in human and canine tumour biology, a profound understanding of tumour hypoxia is of paramount importance. Therefore, the aim of this work was to investigate the relationship between tumour hypoxia and the expression of a number of hypoxia-induced proteins that play a role in tumour metabolism. The hypoxia marker pimonidazole was administered to dogs affected by spontaneous mammary carcinoma and compared with immunohistochemical staining for GLUT1 and 3, HK 2 and CA IX. A statistically significant correlation was found between pimonidazole staining and GLUT1-expression (R=0.607; p=0.001). These results indicate a strong interaction between tumour hypoxia and tumour metabolism by the induction of proteins essential to maintain a stable tumour microenvironment.

Osteochondritis dissecans of the humeral head in two small-breed dogs.

Shoulder pathology consistent with osteochondritis dissecans of the humeral head was diagnosed in two small-breed dogs. In both cases, the diagnosis was made tentatively on the basis of radiography and confirmed by arthroscopy of the affected shoulder joint. Both dogs were successfully treated by surgical removal of a flap of cartilage from the affected area. Clinical and radiographic follow-up was available in both cases. The excised cartilage flaps were examined histopathologically and showed the same characteristics as cartilage flaps from dogs of large breeds prone to developing osteochondritis dissecans of the shoulder.

Excision arthroplasty of the interphalangeal joint as an alternative to digit amputation in two dogs.

Excision arthroplasty of the interphalangeal joint was used as an alternative to digit amputation for comminuted fractures of the phalangeal bones in two dogs. Both patients had return of pain-free use of the affected limb, even though both weight-bearing digits were involved in one case. This type of surgery might prove to be superior to the more invasive digit amputation, salvaging the digits and providing a better functional outcome.

Radiographic, computed tomographic and arthroscopic findings in 23 dogs with osteochondrosis of the tarsocrural joint.

Twenty-three dogs with osteochondrosis of the tarsocrural joint were evaluated by radiography, computed tomography (CT) and arthroscopy. The radiographic examination included an extended and flexed mediolateral, a plantarodorsal, a flexed dorsoplantar skyline view, and a plantaromedial-dorsolateral and a plantarolateral-dorsomedial view (two oblique views). The CT examination was carried out in ventral recumbency and 1 mm slices were taken with a bone window setting; 31 lesions were identified in the 46 joints examined. The arthroscopic exploration used either a plantar or a dorsal puncture, depending on the site of the lesion. In six cases the lateral, and in 17 cases the medial trochlear ridge was involved. Although the survey radiographs were sufficient to make a diagnosis, the CT examination helped to determine the exact site, and the number and size of the fragments of bone. A four-stage classification system comparable to the one used in man was established. Arthroscopy provided information about synovial inflammation and damage to the joint cartilage, and made it possible to remove fragments of bone from one-third of the cases.