Urinary Incontinence after Prostatectomy in Dogs

Eleven dogs with prostatic disease were treated by total prostatectomy. Urinary incontinence persisted in three of nine dogs, two of which were also incontinent before surgery. The incidence of postoperative incontinence may be reduced by undermining the prostatic capsule to preserve as much prostatic urethra as possible. The risk of postoperative incontinence appeared greater if there was prostatic neoplasia or preoperative urinary incontinence.     

Partial Resection and Omentalization: A New Technique for Management of Prostatic Retention Cysts in Dogs

Objective- The purpose of this study was to determine the results of a new technique for management of prostatic retention cysts in dogs.
Study Design- A retrospective clinical study.
Animals- Eighteen client-owned dogs.
Methods- Dogs with prostatic retention cysts were treated by celiotomy and drainage of the cysts. The majority of the cyst wall was resected and residual cyst cavities were packed with omentum. All dogs were castrated.
Results- Long-term resolution of clinical signs was achieved in all dogs, with follow-up periods ranging from 6 to 42 months. Five dogs developed urinary incontinence postoperatively. This persisted in two dogs, but was well controlled with phenylpropanolamine. In the remaining dogs, the incontinence was transient and resolved within 2 months of surgery.
Conclusions- Partial cyst resection combined with omentalization and castration was a simple and effective means of managing prostatic retention cysts. The incidence of serious complications, including postoperative urinary incontinence, was low.     

Subtotal intracapsular prostatectomy as a useful treatment for advanced-stage prostatic malignancies

OBJECTIVES: Palliative surgery for advanced-stage prostatic cancers was tested with regard to survival rate and complications in a prospective randomised clinical study of dogs. Currently, therapeutic approaches have a grave long-term prognosis in clinically significant prostatic cancer. METHODS: Of 167 dogs with prostatic disorders, 24 were diagnosed with prostatic cancer. Eleven dogs underwent subtotal intracapsular prostatectomy, while in 10 dogs total prostatectomy was performed. The remaining three dogs were euthanased at their owner's request. Dogs treated by subtotal intracapsular prostatectomy and those treated by total prostatectomy were followed until their death. RESULTS: It was found that dogs treated by subtotal intracapsular prostatectomy survived 5.63 times longer (mean [sd] 112.0 [63.03] days) than those treated by total prostatectomy (19.9 [10.67] days) (P<0.01). Moreover, a significant decrease in postoperative complications after subtotal intracapsular prostatectomy was recorded, especially with regard to urinary incontinence. CLINICAL SIGNIFICANCE: It was concluded that, in the authors' facility, treatment of prostatic cancer by subtotal intracapsular prostatectomy was superior to that by total prostatectomy, with respect to both postoperative survival and serious complications.     

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.     

Partial prostatectomy using Nd:YAG laser for management of canine prostate carcinoma

OBJECTIVE: To report a technique for partial prostatectomy by laser dissection and to evaluate outcome and complications in dogs with prostate carcinoma (PCA). STUDY DESIGN: Experimental and clinical case series. ANIMALS: Four normal dogs and 8 dogs with PCA. METHODS: Subcapsular partial prostatectomy, sparing the urethra and the dorsal aspect of the prostatic capsule, using Nd:YAG laser dissection to remove the prostatic parenchyma and control hemorrhage was performed in 4 normal dogs and subsequently in 8 dogs with histologically confirmed PCA. Additional treatment of PCA dogs included local application of interleukin-2 and systemic administration of meloxicam. Prostate size, complications, and survival time were recorded. Laser-associated thermal damage to surrounding tissue was evaluated by histology. RESULTS: In normal dogs, no damage to the dorsal prostatic capsule or urethra was detected. In PCA dogs, median survival was 103 days (range, 5-239 days). Three dogs died from complications within 16 days, whereas 5 (median survival, 183 days; range, 91-239 days) had improvement or resolution of clinical signs. Urinary incontinence did not occur. CONCLUSION: Laser assisted subcapsular partial prostatectomy can be performed in dogs with PCA without development of postoperative incontinence. CLINICAL RELEVANCE: Subcapsular partial prostatectomy is a potential palliative treatment for PCA in dogs and may lead to the resolution of clinical signs for several months.     

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.     

Urodynamic Alterations after Prostatectomy in Dogs without Clinical Prostatic Disease

Prostatectomy in dogs with clinical prostatic disease has been associated with a high incidence of urinary incontinence. In this study, urodynamic alterations after prostatectomy in 10 dogs without clinical prostatic disease were evaluated. Measurements of residual urine volume, simultaneous urethral pressure profilometry and electromyography, and carbon dioxide cystometry were made before and 14 and 20 weeks after prostatectomy. Voiding was observed daily for 20 weeks after prostatectomy. All dogs remained continent for 20 weeks after prostatectomy, and only minor urodynamic abnormalities were noted. Castration had no effect on urodynamic changes associated with prostatectomy. Prostatectomy produced minimal functional changes in dogs without clinical prostatic disease.     

Subtotal Canine Prostatectomy with the Neodymium: Yttrium-Aluminum-Garnet Laser

A technique was developed for subtotal prostatectomy in dogs with the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. In six normal dogs, full-thickness necrosis of the prostate occurred if the central-lateral region within 5 mm of the urethra was photoablated at 60 watts for 1 second. Moderate to superficial necrosis occurred when the prostate within 5 mm of the urethra was photoablated at 35 watts for 2 seconds or 60 watts for 0.5 second. At necropsy, leakage of the urethra occurred in two dogs at sites treated at 60 watts for 1 second. In a clinical study, complications associated with subtotal prostatectomy with the Nd:YAG laser (n = 6) were compared with complications associated with prostatic drainage (n = 6) in dogs with prostatic disease. Intraoperative death (2/6 dogs) and nocturnal incontinence (4/4 surviving dogs) occurred with subtotal prostatectomy. Uncontrolled prostatic infection (2/6 dogs) occurred with prostatic drainage and resulted in the death of one dog on day 11. Four of five dogs surviving prostatic drainage developed recurrent urinary tract infection.     

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.     

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.     

The diagnosis and management of paraprostatic and prostatic retention cysts in the dog

Eleven dogs were diagnosed as having solitary or multiple prostatic cysts in an abdominal, pelvic or perineal position. Common presenting signs included urinary dysfunction, faecal tenesmus and abdominal distension. Cystography was found to be the most consistently accurate technique for differentiating the cysts from the bladder and other abdominal soft tissue masses whilst urethrography often highlighted their prostatic origin. Complete surgical resection of the cysts was attempted in nine dogs, the complexity of dissection being dictated by cyst size and the extent of adhesions to adjacent organs. Nine dogs were castrated. Urinary incontinence continued post-operatively in four dogs but later resolved in three of these. Seven dogs were alive and symptom-free over post-operative periods ranging from one to three years. Despite some of its technical difficulties, surgical excision appears to be a successful approach to even the larger prostatic cysts. Few of the post-operative complications associated with other surgical procedures described for the management of cysts were encountered.     

Subtotal Intracapsular Prostatectomy Results in Normal Dogs

Subtotal intracapsular prostatectomy was performed on five normal dogs. All dogs were maintained for 60 days postoperatively. No urinary abnormalities were noted following surgery with the exception of transient urinary incontinence in one dog that lasted for 7 days. Upon termination of the study, the prostatic urethra had reepithelized in all dogs where a dorsal strip of epithelium was left in place during surgery.     

An hGM‐CSF DNA‐Cationic Lipid Complexed Autologous Tumor Cell Vaccine did not Improve Remission Duration in Dogs with Lymphoma

Introduction:  Lymphoma is one of the most common cancers in dogs and while clinical remission can be induced using chemotherapy, very few dogs are cured. Since cytokine‐adjuvanted autologous whole‐tumor‐cell vaccines (ATCV) can induce potent antitumor immune responses against otherwise non‐immunogenic cancers we initiated a study of such an approach in dogs with lymphoma.
Methods:  Following achievement of a complete remission using a 19‐week CHOP‐based chemotherapy protocol, 51 dogs with B‐cell lymphoma were randomized to receive 8 treatments (4 weekly, then 4 additional at q2wk intervals) of vaccine or lipid‐equivalent placebo. Dogs were followed monthly for assessment of remission duration and survival. Surrogate indices of immune response (delayed‐type hypersensitivity, interferon‐γ quantitative RT‐PCR, lymphocyte proliferation, and flow cytometry for lymphoma‐specific antibodies) were also investigated before and after vaccination.
Results:  No significant difference in median remission duration was observed between dogs receiving vaccine (277 days) or placebo (258 days); the Kaplan‐Meier curves were virtually super‐imposable. No significant differences in surrogate indices of immune response were noted pre‐ and post‐vaccination.
Conclusions:  In this context, an hGM‐CSF DNA‐cationic lipid complexed ATCV vaccine did not enhance remission duration in dogs with lymphoma, likely due to lack of vaccine‐induced tumor‐specific immunity.     

RELATIONSHIP BETWEEN PROSTATOMEGALY, PROSTATIC MINERALIZATION, AND CYTOLOGIC DIAGNOSIS

Canine prostatic disease is commonly evaluated with abdominal ultrasound and radiographs. Mineralization of the prostate is often reported, but the clinical relevance of this finding is currently not known. The purpose of this study was to characterize the relationship between ultrasonographic and radiographic prostate mineralization and the final diagnosis. Medical records of 55 dogs with evidence of prostatomegaly or prostatic mineralization and a cytologic diagnosis were evaluated. Radiographs and ultrasound images were assessed for caudal retroperitoneal lymphadenopathy, vertebral lesions, or other signs of metastasis, and mineralization was assessed semiquantitatively. Twenty-two of 55 (40%) dogs had prostatic neoplasia. Regarding neoplasia, mineralization in neutered dogs had a positive predictive value (PPV) of 100%, a negative predictive value (NPV) of 50%, and a sensitivity and specificity of 84% and 100%, respectively. Mineralization in intact dogs had a PPV of 22%, an NPV of 96%, and a sensitivity and specificity of 67% and 77%, respectively. All neutered dogs with prostatomegaly but not prostatic neoplasia had bacterial prostatitis and were castrated within the previous 3 months. Intact dogs with prostatomegaly and mineralization but not neoplasia had paraprostatic cysts ( n =3), benign prostatic hyperplasia ( n =2) or prostatitis ( n =2). Mineralization score was not indicative of neoplasia. In conclusion, neutered dogs with prostatic mineralization were very likely to have prostatic neoplasia. Intact dogs were unlikely to have prostatic neoplasia if no mineralization was found on radiographs or ultrasound.     

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.     

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.     

Comparative Oncology Solution to Understanding Hormonal Impact in the Epidemiology of Lymphoma

Introduction:  Surveillance, Epidemiology & End Results (SEER) data indicate that non‐Hodgkin's lymphoma (NHL) is approximately 50% more common among men than women. A similar male predisposition is reported for canine lymphoma, yet the underlying role of gender in lymphoma etiology remains elusive. Because similarities exist between canine lymphoma and NHL, databases including the Veterinary Medical Database (VMDB) and Veterinary Cancer Registry (VCR) may prove useful in understanding lymphoma epidemiology. This study sought to determine the relationship between gender and development of canine lymphoma.
Materials:  Data from 1980 to 2000 were retrieved from the VMDB and sorted by gender and reproductive status. Spayed or neutered dogs diagnosed with lymphoma were compared to intact dogs seen each year in each gender category using a two‐tailed Student's t‐test. The VCR was searched for all canine lymphoma cases. The number of cases in each gender group was compared to the number of cancer diagnoses per group using a Chi‐square test (3 degrees of freedom). Differences were deemed significant when P < 0.050.
Results:  The VMDB included 15,091 lymphoma cases in a population of 1.34 million dogs. In the VCR database, 394 lymphoma cases were identified amongst 6,070 canine cancer diagnoses. In both analyses, intact females were significantly less likely to develop lymphoma than were other gender groups.
Conclusions:  In dogs, as in people, female gender and intact reproductive status appears to be protective against the development of lymphoma. This data suggests that further examination of the role of estrogen in lymphoma prevention is warranted.     

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.     

Xenogeneic Human Tyrosinase DNA Vaccination Induces Specific Immune Response in Dogs with Advanced Malignant Melanoma

Introduction:  Xenogeneic melanosomal differentiation antigens, delivered in the form of a plasmid DNA vaccine, can overcome host immune ignorance/tolerance in preclinical animals to melanoma by: 1) generating humoral and cytotoxic T cell responses and 2) inducing protection from tumor challenge. Initial trials of human tyrosinase (huTyr) DNA vaccination of dogs with advanced malignant melanoma (Bergman et al , 2003) demonstrated safety and prolongation of survival with this therapeutic modality. We investigated antigen‐specific immunity in dogs receiving huTyr DNA vaccination.
Methods:  Three cohorts of three dogs each with advanced (WHO stage II‐IV) canine malignant melanoma (CMM) received four biweekly IM injections (dose levels 100, 500, or 1,500 ug, respectively/vaccination) of huTyr plasmid DNA via the Biojector2000 jet delivery device. Sera samples were taken before and after vaccination to detect specific antibody formation to huTyr by Enzyme‐Linked ImmunoSorbent Assays (ELISAs) and flow‐cytometry.
Results:  Three dogs have measurable, 2 to 4 fold huTyr‐specific antibody titers. Preliminary studies by flow‐cytometry have confirmed antibody response to huTyr by positive binding to endogenous human tyrosinase in SK‐Mel188 cells using post‐vaccinate serum.
Conclusions:  Xenogeneic (huTyr) DNA vaccination generates antigen‐specific humoral responses, which may partially explain the previously reported clinical efficacy and anti‐tumor responses. Ongoing studies include: 1) a comprehensive analysis by flow‐cytometry to detect huTyr‐specific antibodies and 2) a quantitative measure of potential cytotoxic T‐cell responses in these dogs by the DNA vaccination.     

Predictors of outcome after dorsal decompressive laminectomy for degenerative lumbosacral stenosis in dogs: 69 cases (1987-1997)

OBJECTIVE: To identify predictive factors of long-term outcome after dorsal decompressive laminectomy for the treatment of degenerative lumbosacral stenosis (DLSS) in dogs. DESIGN: Retrospective study. SAMPLE POPULATION: 69 client-owned dogs. PROCEDURE: Medical records of dogs that had undergone dorsal laminectomy at North Carolina State University and the University of Tennessee between 1987 and 1997 were reviewed. Dogs with diskospondylitis, traumatic lesions, or neoplasia of the lumbosacral region were excluded. All dogs had evidence of cauda equina compression on myelography, epidurography, computed tomography, or magnetic resonance imaging, along with subsequent confirmation of the lesion at surgery. Follow-up was performed by telephone inquiries to the referring veterinarian, the owner, or both, using a detailed questionnaire. RESULTS: The outcome was excellent or good in 54 of 69 (78%) dogs over a mean follow-up period of 38+/-22 months. Five of these 54 dogs had been incontinent for a median of 2 weeks prior to surgery. Six of the 15 dogs with a poor outcome had been incontinent for a median of 8 weeks before surgery. A significant correlation was detected between the presence of urinary and fecal incontinence prior to surgery and outcome. When duration of signs was considered, urinary incontinence was the only variable that significantly affected outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Decompressive laminectomy is an effective treatment for DLSS, although dogs with urinary or fecal incontinence have a worse prognosis than dogs that are continent before surgery. Chronic urinary incontinence is a predictor of poor outcome for dogs with DLSS.