Comparison of Two Indwelling Central Venous Access Catheters in Dogs Undergoing Fractionated Radiotherapy

Twenty dogs with neoplasms requiring multiple radiation treatments received either percutaneous vascular access catheters (PVACs; Cook, Bloomington, IN) or subcutaneous vascular access ports (SVAPs; Vascular-Access-Ports, Norfolk Medical Products, Inc., Skokie, IL); 10 dogs were entered in each group. All catheters were implanted and removed aseptically and the catheter tips were cultured during implant removal. Complications with PVACs included mild incisional swelling and redness and accidental severance or rupture of the catheter. Complications with SVAPs included incisional or port swelling, bruising or redness, hematoma formation, and pain. Ports in 4 of these dogs could not be used for 1 to 3 days after surgery because of swelling and pain. Surgical wound complications, when pooled for comparison, occurred significantly more frequently with the SVAPs ( P = .023). Wound complications associated with both catheters were self-limiting and resolved within 7 days. Bacterial cultures were positive in two PVACs and four SVAP tips, however, none of these dogs had clinical signs of infection or sepsis. Although both types of indwelling catheters were functional in a clinical setting, PVACs were preferred to SVAPs for dogs undergoing radiation therapy because of decreased time for implantation and fewer overall complications.     

Long-Term Efficacy of a Percutaneously Adjustable Hydraulic Urethral Sphincter for Treatment of Urinary Incontinence in Four Dogs

Objective— To evaluate the efficacy of a surgically placed, static hydraulic urethral sphincter (SHUS) for treatment of urethral sphincter mechanism incompetency (USMI).
Study Design— Prospective study.
Animals— Spayed female dogs (n=4) with acquired USMI.
Methods— Urinary incontinence was assessed using a subjective continence score before and after implantation of an SHUS on the proximal urethra via ventral median celiotomy. Dogs were assessed for urinary continence, urinary tract infections, and implant-associated complications for 30 months. Residual incontinence was treated with percutaneous inflation of the SHUS with sterile saline solution through a biocompatible subcutaneous administration port.
Results— At last follow-up (26–30 months after surgery), continence scores improved from a median preoperative score of 3/10 to a median postoperative score of 10. One dog developed wound drainage over the subcutaneously placed administration port but remained continent after port removal. Three occluders were percutaneously filled with additional saline (median, 0.18 mL; mean, 0.16 mL) to improve continence after surgery.
Conclusions— Application and adjustment of an SHUS provided sustained improvements in continence score in all dogs.
Clinical Relevance— In this pilot study, 3 of 4 dogs with hydraulic urethral sphincter implantation had successful percutaneous adjustment and maintained improved continence scores for 2 years after surgery. Continence was maintained in the 4th dog even after administration port removal. Based on this pilot study, the SHUS warrants further clinical evaluation for treatment of dogs with USMI unresponsive to medical management.     

Efficacy and Toxicity of Intracavitary Administration of Pegylated Liposomal Encapsulated Doxorubicin (DOXIL) in Dogs with Hemangiosarcoma

Introduction:  Canine hemangiosarcoma (HSA) is a fatal malignancy and most dogs die within 6–8 months of diagnosis. The spleen is a common primary site, representing 50% of all cases. These dogs typically present with clinical signs due to tumor rupture and intra‐abdominal dissemination; the abdomen is also the main site of disease progression when these patients fail. Direct delivery of chemotherapy into the abdominal cavity may therefore be a rational approach in this malignancy.
Methods:  14 dogs with stage 2 or 3 splenic HSA were recruited. Doxil at a dose of 1 mg/kg was diluted in saline and administered via ultrasound‐guidance into the abdominal cavity. The dogs were scheduled to receive 4 treatments every 3 weeks. Samples of plasma and abdominal fluid were collected for pharmacokinetic analysis. All dogs were monitored for recurrence and complete necropsies were requested at death.
Results:  8 dogs with stage 3 and 6 dogs with stage 2 HSA were enrolled. All 14 dogs have died, 12/14 due to tumor and 2 from other causes. There was no difference in median survival days between stages (stage 2: 244, stage 3: 125, p = .22). All 12 dogs that died due to tumor‐related causes failed with intra‐abdominal recurrence. Necropsies showed that the dogs in this study had relatively fewer extra‐abdominal metastasis compared to dogs treated with systemic chemotherapy. Pk analysis showed detectable plasma doxorubicin 1 and 2 weeks after treatment.
Conclusion:  Direct abdominal administration of Doxil did not prevent intra‐abdominal recurrence; however, it appeared to provide effective systemic coverage.     

Antitumor Activity of Mycobacterial Cell Wall‐DNA Complex (MCC) Against Canine Urinary Bladder Transitional Cell Carcinoma Cells

Introduction:  Mycobacterial cell wall‐DNA complex (MCC) is a bifunctional anticancer agent that induces cancer cell apoptosis and stimulates cytokine synthesis by immune cells. Intravesical MCC is currently being evaluated in humans with high‐grade urinary bladder cancer. Evaluation of MCC in dogs with transitional cell carcinoma (TCC) will allow mechanistic studies in a natural animal model of TCC, and a potentially beneficial therapy for dogs with this cancer. In this study, we have determined the anticancer activity of MCC against canine TCC cells in vitro .
Methods:  Canine TCC cells (K9TCC cell line) were incubated with MCC (0.05–100 μg/ml, 0.5–72 hours). Cellular proliferation was measured by MTT reduction. Cell cycle was analyzed by flow cytometry with propidium iodide. Apoptosis was identified by flow cytometry using anti‐active‐caspase‐3/PE and anti‐cleaved‐PARP/FITC antibodies. Apoptosis‐inducing activity of 100 μg/ml MCC in combination with piroxicam (0.1–1.0 uM) was evaluated.
Results:  MCC inhibited K9TCC cell proliferation in a concentration‐dependent manner (maximal activity – 45% at 100 μg/ml MCC) in association with the presence of activated caspase‐3 and cleaved PARP. Inhibition of proliferation and apoptosis‐inducing activities of MCC were independent of cell cycle phase. A thirty‐minute exposure of MCC was sufficient for optimal activity. Piroxicam (0.5 uM) enhanced apoptosis‐inducing activity of MCC.
Conclusions:  MCC induces apoptosis in K9TCC cells. This activity is potentiated by piroxicam. Following positive results in vitro , in vivo studies have been initiated. One dog, treated to date, has had a minor reduction in tumor volume following the first course of treatment with no treatment‐related toxicity.     

A Candidate Second‐Generation Photosensitizer for Photodynamic Therapy in Veterinary Medicine

Introduction:  Photodynamic therapy (PDT) involves the light activation of a drug within a tumor causing selective tumor cell death. Unfortunately, some photosensitizing drugs have been associated with adverse reactions in veterinary patients. Zinc phthalocyanine tetrasulfonate (ZnPcS4) is a promising second‐generation photosensitizer for use in veterinary medicine, however, it cannot be applied clinically until safety and efficacy data are available.
Methods:  Increasing intraperitoneal doses of ZnPcS4 were given to Swiss Webster mice to assess acute toxicity. Based on mouse toxicity data, a phase I clinical trial of ZnPcS4‐based PDT in tumor‐bearing dogs was designed, using an accelerated titration scheme starting at 0.5% of the minimum toxic dose in mice. 24‐hours after ZnPcS4 administration tumors were irradiated with 675 nm light and dogs were evaluated by routine hematology and serum biochemistry at regular intervals after PDT.
Results:  Doses >125 mg/kg were associated with acute toxicity and mortality in Swiss Webster mice, suggesting the minimum toxic dose is 120–125 mg/kg. One dog, a Golden retriever with a massive malignant fibrous histiocytoma, has been entered into the phase I clinical trial. No deleterious effects were noted after ZnPcS4 administration. Within 48 hours of PDT, the tumor was dark and necrotic, with no grossly visible changes to the surrounding normal tissues. Histological examination of the PDT‐treated tumor confirmed widespread necrosis and thrombosis consistent with PDT‐mediated damage. The owner reported no adverse effects after treatment.
Conclusions:  Although preliminary data are encouraging, additional evaluation of ZnPcS4‐based PDT is required to determine its role in veterinary medicine.     

Coarse Fractionated Radiation Therapy for Pituitary Tumours in Cats: A Retrospective Study of 10 Cases

Introduction:  Pituitary tumours are uncommon in cats. Signs may be due to either an expansile mass or paraneoplastic effects (acromegaly and/or unstable diabetes mellitus). There are a few small case series providing evidence of efficacy for radiotherapy of pituitary tumours in cats. This retrospective study describes the outcome of ten cats with pituitary tumours treated with course‐fractionated radiation.
Methods:  The medical records of cats with MRI‐confirmed pituitary tumours that underwent radiotherapy were reviewed. A standard coarse‐fractioned radiation protocol was used; 37 Gy in 5 once‐weekly fractions using two parallel‐opposed 4MeV X‐ray beams. Survival times were calculated from date of first radiation dose.
Results:  Ten cats with pituitary tumours underwent radiotherapy. 5 cats had CNS signs and 5 had evidence of growth hormone excess (1 cat also showed CNS signs). 2 cats with pre‐existing moderate to severe CNS signs died of unknown causes before completing the radiation course. Of the remaining 4 with CNS signs, 3 had complete resolution of signs and the fourth showed partial improvement. Of the 5 cats with unstable diabetes, 2 no longer required insulin and 3 became stable at a lowered dose. The median survival time was 77.6 weeks. 6 cats died: 2 without completing the radiation course, 2 from unrelated causes (CRF, VAFS) and 2 from relapse and/or progression of CNS signs. 4 cats remain alive (range 34–191 weeks).
Conclusions:  Radiation therapy is confirmed as an effective treatment for pituitary tumours in cats giving extended survival and control of both direct mass effect and paraneoplastic signs.     

Clinical Evaluation of Pancarpal Arthrodesis Using a CastLess Plate in 11 Dogs

Objective— To describe the use of a 3.5/2.7 mm CastLess Plate (CLP) for pancarpal arthrodesis (PCA) in dogs.
Study Design— Case series.
Animals— Dogs with traumatic/degenerative carpal disease (n=11).
Methods— Records (September 2006–July 2007) of dogs that had PCA using a 3.5/2.7 mm CLP were reviewed to determine intra- and postoperative complications and use of external coaptation. Follow-up (≥12 months) was obtained by telephone interview of owners.
Results— Thirteen PCA procedures were performed; 5 intraoperative complications occurred in 4 procedures and included iatrogenic metacarpal fissure fracture (2), inability to remove an alignment pin (1), and poor distal plate position (2). External coaptation was used in 4 dogs: concomitant or iatrogenic injuries (3), bilateral PCA (1), for 3–6 weeks. Clinical evaluation 6–24 weeks postoperatively revealed iatrogenic metacarpal fractures to have healed and that 1 postoperative complication (infection) developed. Telephone follow up for 10 dogs (mean, 14 months; range, 12–20 months) revealed no further problems.
Conclusion— PCA using a 3.5/2.7 mm CLP reduces the need for external coaptation and seemingly reduces postoperative morbidity associated with other internal fixation techniques.
Clinical Relevance— PCA can be performed safely and successfully using a 3.5/2.7 mm CLP, with low postoperative morbidity compared with other PCA techniques. Particular attention should be taken when applying the distal component of the plate.     

COX‐2 Expression in Feline Oral Squamous Cell Carcinoma (FOSCC)– An Immunohistochemical Study and Analysis of Survival

Introduction:  Cyclooxygenase‐2 (COX‐2) catalyses the rate‐limiting step in the conversion of arachidonic acid to eicosanoids and has been found to be overexpressed in many human and some animal cancers. Overexpression of COX‐2 in head and neck SCC in humans is associated with shorter survival times. Non‐resectable, FOSCC is a devastating disease with no effective therapy. Overexpression of COX‐2 in FOSCC may support the anecdotal use of NSAID therapy. Identification of a prognostic marker in cats may permit more effective, targeted therapy.
Methods:  Immunohistochemistry was performed on formalin‐fixed, paraffin‐embedded tissue from 59 FOSCC cases using an indirect staining technique and feline foetal kidney as positive control. Polyclonal antiserum specific to COX‐1 and COX‐2 were used after antigen retrieval with pH6 citrate buffer. Retrospective, observational data were collected by practitioner questionnaires. A Kaplan‐Meier survival plot was derived.
Results:  55/59 questionnaires were returned (93% response rate). Median age at presentation was 10.9 years (range 7–15.5). Median survival time was 44 days (95% CL: 31, 79). Preliminary results show that COX‐1 staining was positive in all tumour tissues and in 86.7%(13/15 cases) of normal tissues. COX‐2 staining was positive in 67.3%(37/55) of tumour tissues and absent in normal tissue. Results of proportional hazards regression for survival and multiple logistic regression for COX expression including age, sex, breed, prior NSAID administration, other medication and COX expression as potential explanatory variables will be presented.
Conclusions:  These results indicated that COX‐1 and COX‐2 expression is seen in FOSCC but may not be predictive for survival.     

Immunohistochemical Differentiation and Clinicopathological Features of Canine Gastrointestinal Stromal Tumors and Leiomyosarcomas

Introduction:  Gastrointestinal stromal tumors (GIST) and leiomyosarcomas (LMS) have recently been differentiated by immunohistochemical staining techniques and have been shown to have different biological behaviors in humans. Expression of the c‐kit protein, a transmembrane tyrosine kinase receptor, occurs in nearly all GISTs. The aim of this study was to differentiate canine GIST from LMS, and to compare their clinicopathological features.
Methods:  Archived blocks of previously diagnosed LMS were analyzed. Immunohistochemical staining using antibodies against c‐kit, smooth muscle actin (SMA), desmin, vimentin and S100 was performed. GISTs were diagnosed based on positive c‐kit staining. LMS were diagnosed based on absence of c‐kit staining and positive SMA staining. Follow‐up information was obtained from medical records and telephone interviews with owners.
Results:  Forty‐two dogs were included in the study. Mean age was 10.9 yrs (range 5–15 yrs). There were 18 females and 24 males. Twenty‐eight tumors were GISTs, 10 were LMS and 4 stained negatively for c‐kit, SMA and S100 (sarcomas). GISTs were more likely to occur in the large intestine and LMS were more common in the small intestine (p = 0.01). All were surgically excised and only two were treated with adjunctive chemotherapy. Only two GISTs and one sarcoma had metastasized at the time of surgery. Survival time in dogs discharged after surgery for GIST, LMS and sarcomas was 1123, 233 and 88 days respectively (p = 0.08).
Conclusions:  Many previously diagnosed LMS should be reclassified as GIST based on the results of immunohistochemical staining. The biological behavior of these tumors appears to be different.     

Results of the Combined Treatment with Piroxicam and Carboplatin in Canine Oral Non‐Tonsillar Squamous Cell Carcinoma

Introduction:  Over‐expression of COX‐2 has been observed in several human and animal malignancies and is implicated in carcinogenesis through the conversion of arachidonic acid to PGE‐2. Use of platinum‐containing cytostatic agents and/or (non‐)specific COX‐2 inhibitors, has been reported as a treatment option for canine oral non‐tonsillar squamous cell carcinomas (ONT‐SCC). However, no study describes the effect of a combination of carboplatin and piroxicam on this tumor type.
Methods:  7 dogs with a T3 (WHO‐TNM) ONT‐SCC were treated with piroxicam and carboplatin. Five had bone involvement and no detectable metastasis. Two dogs without bone involvement had metastasis in the regional lymph nodes. Piroxicam was given orally 0.3 mg/kg s.i.d. Each dog was scheduled to receive between 6 and 12 carboplatin infusions (300 mg/m² i.v.) at 3 week intervals. Ondansetron and metoclopramide were used as anti‐emetic agents. The dogs are planned to receive piroxicam on a lifelong basis.
Results:  Complete response (CR) without adjuvant surgery was achieved in 4 of the 7 dogs. Two dogs needed adjuvant surgery to achieve CR. One dog had progressive disease and was euthanised 231 days after start of therapy. All the others were still alive and in CR at date of analysis. Median follow‐up was 335 days (107–689 days).
Conclusions:  Our study suggests that a combination of piroxicam and carboplatin is a useful treatment option for canine ONT‐SCC. All dogs tolerated therapy well and the 57% response rate for reaching a complete and durable remission without adjuvant surgery is promising.     

A prospective, randomized comparison of Oxyglobin (HB-200) and packed red blood cell transfusion for canine babesiosis

Objective – To establish the efficacy of Oxyglobin (HB-200) in canine babesiosis and compare it to standard therapy, packed red blood cell transfusion (pRBCT) with respect to improvements in specific parameters of blood gas, acid-base, blood pressure, and subjective evaluations.
Design – Prospective, randomized, clinical trial.
Setting – Onderstepoort Veterinary Academic Hospital.
Animals – Twelve dogs (8–25 kg) naturally infected with Babesia rossi and a hematocrit of 0.1–0.2 L/L (10–20%).
Interventions – Treatment groups were randomized to receive either 20 mL/kg of Oxyglobin or pRBCT over 4 hours via a central venous catheter. Transfusions were followed by lactated Ringer's solution infusion. Rectal temperature, femoral arterial and mixed venous blood sampling, oscillometric blood pressure, and subjective assessment of patient status (habitus), and appetite were performed at time points 0, 1, 4, 8, 24, 48, and 72 hours.
Main Results – Dogs presented with a hypoalbuminemic alkalosis; hyperchloremic, dilutional acidosis; normotensive tachycardia; pyrexia; depression; and anorexia. Both treatments produced similar results, with the exception of significant differences in pH (4 h); PCO₂ (4 h); hemoglobin (8 h, 24 h); mean arterial pressure (48 h); albumin (4 h, 8 h); habitus (8 h, 48 h); and appetite (24 h). Arterial O₂ content was higher for pRBCT than Oxyglobin at 72 hours, but central venous PO₂ did not differ between groups or over time and was consistently subnormal.
Conclusions – Oxyglobin provides similar overall improvements to pRBCT in dogs with anemia from babesiosis, with respect to blood gas, acid-base and blood pressure, although patients receiving packed cells tended to have more rapid normalization of habitus and appetite.     

Use of wound soaker catheters for the administration of local anesthetic for post-operative analgesia: 56 cases

Objective  To describe the administration of local anesthetic through wound soaker catheters for post-operative veterinary patients and to characterize complications.
Study design  Retrospective study of hospital records.
Animals  Records of patients in which a wound soaker catheter was placed post-operatively between November 1, 2004 and July 1, 2006 at a veterinary teaching hospital. Records in which a limb amputation was performed between January 1, 2002 and August 1, 2007 and in which a wound soaker catheter was not placed were reviewed for historic control.
Results  A total of 56 cases were identified in which a wound soaker catheter was placed post-operatively including 52 dogs, 2 cats, and 2 goats. Twenty canine cases were identified in which limb amputation was performed and no wound soaker catheter was placed. The majority of surgical procedures for which a wound soaker catheter was placed included thoracic limb amputation (46.4%) and pelvic limb amputation (35.7%). Wound soaker catheters remained in place for an average of 1.6 ± 0.5 days. Feline and caprine patients received intermittent bupivacaine boluses every 6 hours. Canine patients received continuous lidocaine infusions. Complications included disconnection of the catheter from the infusion (7.7%), one seroma, and one suspected lidocaine neurotoxicity. Incisional infections were noted in 3/56 (5.3%) limb amputations with wound soaker catheters placed which was not higher than the incisional infection rate found in the historic control cases 3/20 (15%).
Conclusion and clinical relevance  Use of the wound soaker catheter was a viable means of providing local analgesia in post-operative veterinary patients. Studies are needed to evaluate efficacy of pain management, and to further investigate techniques for catheter placement and maintenance which may help to optimize the analgesia achieved using this technique.     

Increase in Regulatory T Cells in Dogs with Cancer Undergoing Chemotherapy

Introduction:  Regulatory T cells (Treg) are a naturally occurring population of T cells phenotypically identified by co‐expression of CD4 and the IL‐2 receptor (CD25). Theyplay a critical role in the control of tolerance and autoimmunity and have also been implicated in impairment of anti‐tumor responses. We hypothesized that levels of Treg would be higher in cancer‐bearing dogs than in normal dogs and that they would decrease with chemotherapy.
Methods:  Serial PBMC were isolated from twenty cancer‐bearing dogs receiving either single‐agent doxorubicin or the Madison‐Wisconsin protocol. The following time points were studied: pre‐treatment, day 2, week 1, week 3, 3 months and 6 months after initial treatment. Ten age‐matched, normal dogs were also studied. PBMC were immunostained with directly conjugated antibodies to CD4, CD8, CD44 and IL‐2 receptor and then evaluated by flow cytometry.
Results:  Low numbers of lymphocytes with the CD4+/IL‐2R+ phenotype were detectable in both normal and cancer‐bearing dogs. A statistically significant increase in the percentage of IL2‐R+/CD4+ T cells was observed in the cancer‐bearing dogs beginning two days after chemotherapy and persisting throughout treatment. The percentage of IL‐2R+/CD4+ T cells was also increased in pre‐treated cancer‐bearing dogs compared to control dogs.
Conclusion:  The percentage of IL‐2R+/CD4+ T cells was generally higher in dogs with cancer than in healthy dogs. Unexpectedly, the percentage of IL‐2R+/CD4+ cells increased during chemotherapy which suggests that chemotherapy may exert immunosuppressive effects through a previously undescribed mechanism. The identity of these CD4+/IL‐2R+ T cells as true Treg awaits additional characterization studies.     

Clinical study of cryosurgery efficacy in the treatment of skin and subcutaneous tumors in dogs and cats

Objective— To evaluate the efficacy of cryosurgery for treatment of skin and subcutaneous tumors in dogs and cats.
Study Design— Prospective study.
Animals— Dogs (n=20), cats (10).
Methods— Cutaneous or subcutaneous tumors were treated by liquid nitrogen cryosurgical spray (1 cm from target tissue at 90° until a 5-mm halo of frozen tissue was achieved) for 15–60 seconds. Malignant lesions had 3 freeze–thaw cycles benign tumors, 2 cycles. The second or third freeze cycle was performed after complete thaw of the preceding freeze. Wounds healed by second intention. Follow-up was weekly for 1 month and then twice monthly until wounds healed, and final outcome was determined by telephone interview of owners.
Results— Tumor size ranged from 0.3 to 11 cm diameter with 28 (60%) being 0.3–1 cm; 8 (17%) 1.1–3 cm, and 11 (23%) >3.4 cm. Complications included edema, erythema and for extremity lesions, pain and lameness. Treated lesions (n=47) had an overall remission of 98% (mean follow-up, 345±172.02 days [range, 150–750 days]). One malignant peripheral nerve sheath tumor recurred 7 months after cryosurgical treatment.
Conclusion— Cryosurgery is an efficient method for treatment of skin and subcutaneous tumors in dogs and cats.
Clinical Relevance— Cryosurgical ablation is an effective means of treating small cutaneous or subcutaneous tumors in dogs and cats, especially in older animals where wound closure or cosmetic outcome might limit surgical excision alone.     

Efficacy of C/B‐OPP rescue for the treatment of relapsed canine lymphoma (1998–2004)

Introduction:  MOPP chemotherapy is useful for relapsed canine lymphoma. This study evaluates the efficacy of this protocol after substitution of CCNU (lomustine) or BiCNU (carmustine) for mechlorethamine (C/B‐OPP).
Methods:  Patient signalment, response to chemotherapy, toxicity and survival data were abstracted from medical records of dogs from receiving C/B‐OPP between 1998 and 2004.
Results:  Fifty‐eight dogs received C/B‐OPP rescue chemotherapy during the study period. The median remission duration after initial chemotherapy, consisting of CHOP‐based therapy in 91% of dogs, was 133 days (range, 10 to 932 days). Thirty‐eight of fifty‐eight dogs (66%) responded to C/B‐OPP rescue after relapse (22 CR, 16 PR), for a median of 48 days (range, 2 to 359 days). Overall, C/B‐OPP extended survival by a median of 90 days (range, 2 to 426 days). Twenty‐four dogs (41%) experienced one or more episodes of Grade II or higher gastrointestinal toxicity. Forty‐one dogs (71%) experienced one or more episodes of Grade II or higher hematologic toxicity. Twelve dogs (20%) developed regenerative anemia with diarrhea consistent with gastrointestinal hemorrhage. Treatment delays due to hematologic toxicity occurred in 37 dogs (63%). There were 16 nonfatal treatment‐related episodes of sepsis requiring hospitalization. 5 dogs died due to sepsis and/or chemotherapy‐related complications.
Conclusions:  C/B‐OPP chemotherapy has activity against relapsed canine lymphoma which is similar to that of traditional MOPP rescue therapy. Moderate to severe hematologic toxicity was observed. Further work is warranted to optimize drug doses and scheduling.     

Feline Sinonasal Neoplasia: CT Staging and Prognosis with Mega Voltage Radiation Therapy

Introduction:  Megavoltage radiation is considered standard therapy for feline sinonasal neoplasia, but a paucity of published reports and the lack of a staging system based on advanced sectional imaging render accurate prognostication difficult. The aims of this retrospective study on feline sinonasal neoplasia were to adapt or develop a staging system based on advanced imaging, and to further define the prognosis with megavoltage radiation therapy.
Methods:  Medical records were reviewed, and CT images were evaluated by a single radiologist (JBG) and staged using a modified system previously reported for dogs. Further follow‐up information was obtained by telephone interviews with the referring veterinarians or owners.
Results:  Thirty‐six cats received megavoltage radiation for sinonasal neoplasia. Carcinomas (n = 17) and lymphomas (n = 16) were most common, followed by sarcomas (n = 3). A majority of immunophenotyped lymphomas were B‐cell (89%). Diagnostic CT images were available for review on 33 cats. The stage distribution was as follows: T1 (n = 3), T2 (n = 11), T3 (n = 5), T4 (n = 14). Lymphomas were more commonly T2 (n = 8) while a majority of carcinomas were T4 (n = 8). The median survival times have not yet been reached for any stage or disease subtype. The most common cause for euthanasia was local recurrence (15/19, 79%). Four cats that died of other causes lived between 1,124 and 2,322 days.
Conclusions:  Feline sinonasal neoplasia is uncommon, with carcinomas and lymphomas being most frequently encountered. Megavoltage radiation therapy appears to offer improved quality and duration of life for most patients, despite advanced staged at diagnosis in a majority.     

Effects of Mycobacterial Cell Wall‐DNA Complex (MCC), Alendronate and Pamidronate on Canine Osteosarcoma Cell Lines

Introduction:  MCC, a cell wall composition prepared from Mycobacterium phlei ., inhibits the proliferation and induces apoptosis in a wide range of tumor cells. Bisphosphonates have been reported to inhibit the proliferation of canine osteosarcoma cell lines. In this study, we have determined the activity of MCC alone and in combination with the bisphosphonates alendronate and pamidronate on canine osteosarcoma cell lines.
Methods:  Canine osteosarcoma cell lines D17 and D22 were incubated with different concentrations of MCC (0.01–100 μg/ml) and suboptimal concentrations of alendronate and pamidronate for 72 hours. Cellular proliferation was measured by MTT reduction. Nuclear DNA condensation was determined using with Hoescht 33258 staining, and apoptosis by flow cytometry using active‐caspase‐3/PE and anti‐cleaved‐PARP/FITC antibodies.
Results:  MCC inhibited the proliferation of both canine osteosarcoma D17 and D22 cell lines in a concentration‐dependent manner. The IC₅₀ for D17 cells was 3.9 μg/ml and for D22 cells 44.4 μg/ml. Cells incubated with 100 μg/ml MCC were positive for Hoescht staining, active caspase‐3 and cleaved PARP, indicative of cell death by apoptosis. The addition of alendronate or pamidronate was found to potentiate the apoptosis‐inducing activity of MCC. Maximal activity was observed when 5 μM alendronante or 10 μM pamidronate were used in combination with 100 μg/ml MCC.
Conclusion:  MCC inhibits the proliferation and induces apoptosis in canine osteosarcoma cell lines in vitro . This anticancer activity can be potentiated by the use of alendronate and pamidronate. These data support the development of MCC as a therapeutic agent for the treatment of canine osteosarcoma.     

Cyclooxygenase ‐2 Expression in Mammary Tumors in Dogs and its Correlation to Histologic and Biologic Behavior

Introduction:  Cyclooxygenase‐2 (Cox‐2) is the inducible form and the rate‐limiting enzyme, for conversion of arachidonic acid to prostaglandins. Cox‐2 overexpression, common in carcinomas, is associated with increased growth rate, resistance to apoptosis, angiogenesis, and overall, both local and distant aggressive behavior. Cox‐2 overexpression has been detected in human and canine mammary tumors (MTs). Histopathology of canine MT is not always predictive of biologic behavior, and anecdotally, only 50% of the malignant MTs are expected to metastasize. We hypothesize that Cox‐2 expression correlates with aggressive behavior.
Methods:  This retrospective study evaluated 48 bitches, presented for excision of MT between 2000 and 2003 at FMVZ de Botucatu‐UNESP, Brasil. Follow‐up varied from 18 months to 24 months and included physical examination and thoracic radiographs. Histopathologic examination was performed in all tumors, as well as in metastatic lesions when detected in the follow‐up period. Immunohistochemistry was used to detect expression of Cox‐2 in paraffin blocks (Rabbit polyclonal anti‐PGHS‐2. Oxford Biomedical). 10 adenomas, 10 carcinomas, 10 benign mixed tumors, 10 malignant mixed tumors and 8 cases of primary carcinomas and their metastatic lesions.
Results:  Expression of Cox‐2 varied among groups. Adenomas (32.1%), mixed benign tumors (38%), carcinomas (60.3%), malignant mixed tumors (65.8%), and metastatic carcinomas (81.25%) and their metastatic lesions (84.35%). Statistically significant differences (p < 0.05) were observed between the benign and malignant counterparts and between carcinomas and metastatic carcinomas.
Conclusions:  Cox‐2 expression correlates with both histologic and biologic behavior in mammary carcinomas, and may serve as a predictor of metastatic potential.     

Intracapsular lensectomy and sulcus intraocular lens fixation in dogs with primary lens luxation or subluxation

Objective  To evaluate the postoperative results of lensectomy and sulcus intraocular lens fixation (SIOLF) via an ab interno approach in dogs with progressive lens subluxation or early luxation.
Study design  Retrospective study.
Animals studied  Twenty eyes from 19 dogs presented to the Animal Eye Clinic for lens luxation or subluxation between 1999 and 2006.
Methods  Medical records were reviewed to evaluate preoperative lens position, vision status, intraocular pressure (IOP), and whether surgery was performed on an emergent or elective nature. Lensectomy and SIOLF were performed and postoperative status including vision, glaucoma, and retinal detachment was assessed.
Results  Average age was 8.6 years (range 4–14 years) and 55% (11/20) were terriers. Patients were followed a mean of 29.2 months (range 1–92 months) after surgery. Retinal detachment or secondary glaucoma was observed in 1 of 20 (5%) and 5 of 20 (20%) eyes, respectively, with 1 of 20 (5%) exhibiting both. Mean preoperative IOP was 16 mmHg and preoperative lens position was equally divided between luxated and subluxated lenses. Surgery was performed more frequently as an elective procedure (18/20; 90%) due to normalized IOP vs. an emergency procedure (2/20; 10%). Vision was retained in 70% (14/20) of eyes with a mean time to vision loss of 41 months in the remaining eyes due to glaucoma, retinal detachment, or retinal degeneration.
Conclusions  Complications of glaucoma and retinal detachment after SIOLF in this study were less when compared with previously reported incidence rates in the literature for lensectomy alone which may reflect improved patient selection.     

Complications associated with the use of vascular access ports in dogs receiving external beam radiation therapy

OBJECTIVE: To assess the perioperative and postoperative complications associated with use of vascular access ports (VAPs) in the jugular and lateral saphenous veins of dogs requiring frequent anesthetic episodes for radiation therapy. DESIGN: Cohort study. ANIMALS: 40 dogs referred to a veterinary teaching hospital. PROCEDURES: VAPs were used in 23 dogs, and intravenous catheters inserted in a peripheral vein were used in 17 dogs. The frequency of perioperative and postoperative complications associated with VAP use and the frequency of infection associated with intravenous catheter use were recorded. Results of bacterial culture of VAP tips and amount of time required for VAP placement and removal and for anesthetic induction were also recorded. RESULTS: VAP-associated perioperative complications included malposition of the catheter tip in 4 of 23 (17.4%) dogs. The VAP-associated postoperative complications included seroma formation in 7 (30.4%) dogs, breakage of port-anchoring sutures in 3 (13.0%) dogs, suspected fatal catheter-related septicemia in 1 (4.3%) dog, and temporary partial withdrawal occlusion in 18 of 255 (7.1%) anesthetic episodes. CONCLUSIONS AND CLINICAL RELEVANCE: Placement of VAPs provided ready access in dogs receiving radiation therapy. Most complications were minor and self-limiting; however, a low risk of serious complications existed. Use of fluoroscopy to assess position of the catheter tip is recommended to decrease the risk of malposition. Immediate removal of a VAP is recommended when clinical signs of infection develop. Removal of a VAP at the completion of radiation therapy should be performed unless the benefit of continued vascular access outweighs the risks.