Colonic lymphocyte and plasma cell populations in dogs with lymphocytic-plasmacytic colitis

OBJECTIVES: To quantitate immunoglobulin-containing cells (IgA, IgG, and IgM) and CD3+ T cells in colonic biopsy specimens obtained from dogs with lymphocytic-plasmacytic colitis (LPC), and to compare lymphocyte and plasma cell populations in dogs with LPC with those in healthy dogs. ANIMALS: 10 healthy dogs and 11 dogs with LPC. PROCEDURE: Colonic mucosal specimens obtained from healthy dogs and dogs with LPC were stained specifically for IgA-, IgG-, and IgM-containing cells and CD3+ T cells by use of immunoperoxidase techniques. Morphometric analyses were done to quantitate lymphocytes and plasma cells in standardized areas of colonic mucosa. Data analyses allowed determination of mean cell numbers in each dog group, and comparison of mean numbers of lymphocytes and plasma cells between dog groups. RESULTS: CD3+ T cells predominated in healthy dogs, whereas CD3+ T cells and IgA-containing cells were most numerous in dogs with LPC. In both dog groups, the IgG- and IgM-containing cells were considerably less numerous than the other 2 cell types. Comparison of cell populations between dog groups indicated that IgA- and IgG-containing cells and CD3+ T cells were significantly more numerous in the colonic mucosa of dogs with LPC. CONCLUSIONS: Dogs with LPC have significantly increased numbers of IgA- and IgG-containing cells and CD3+ T cells. These lymphocyte and plasma cell distributions indicate similarities to and differences from such distributions in human beings with inflammatory bowel disease. Results provide a basis for future correlation between histologic stage of disease activity and immunologic findings in dogs with LPC.     

Changes in Regulatory T Cells in Dogs with Cancer and Associations with Tumor Type

Background: Regulatory T cells (Treg) have been shown to suppress antitumor immunity and often are increased in humans and rodents with cancer. However, Tregs have not been well studied in dogs with cancer and it is not known if certain tumor types are associated with increased Tregs.
Hypothesis: We hypothesized that Treg percentages would be increased in dogs with cancer and that Treg percentages would be higher in dogs with certain types of cancer.
Animals: The percentages and numbers of Tregs and nonregulatory T cells and B cells were assessed in 34 dogs with cancer and 9 age-matched control dogs. Dogs evaluated included 14 dogs with sarcoma, 7 dogs with carcinoma, 7 dogs with lymphoma, and 6 dogs with mast cell tumor.
Methods: Numbers and percentages of Tregs, CD4⁺, and CD8⁺ T cells and B cells were determined using flow cytometry and compared between control dogs and dogs with cancer.
Results: The percentage of Tregs was significantly increased overall in dogs with cancer compared with control dogs. When tumor types were compared, Treg percentages were significantly increased in dogs with carcinoma. The Treg/CD8 T cell ratio was significantly higher in dogs with cancer compared with control dogs and was also significantly increased in 2 dogs with T-cell lymphoma.
Conclusions: Treg percentages in blood were increased in dogs with cancer, particularly in dogs with carcinoma. The Treg/CD8 ratio also identified tumor-specific abnormalities in dogs with cancer. These findings indicate that tumor-specific factors may affect Tregs in dogs.     

Decreased Ratio of CD8+ T Cells to Regulatory T Cells Associated with Decreased Survival in Dogs with Osteosarcoma

Background: Increased numbers of regulatory T cells (Treg) and decreased ratios of CD8+ T cells to Treg have been shown to correlate with decreased survival times (ST) in humans with certain malignancies. A possible connection between Treg and ST in dogs with cancer has not been investigated previously. Hypothesis: The purpose of this study was to compare numbers of Treg and T lymphocyte subsets in dogs with osteosarcoma (OSA) to those of healthy dogs and to determine whether pretreatment values were associated with disease‐free interval or with ST. We hypothesized that Treg numbers would be increased in dogs with cancer and that dogs with a high percentage of Treg would have a poorer prognosis. Animals: Twelve client‐owned dogs with appendicular OSA were entered into a prospective clinical trial. Twenty‐two healthy dogs were used as controls. Methods: The percentages and numbers of Treg and CD4+ and CD8+ T cells in blood, lymph nodes, and tumors were determined with flow cytometry and compared between dogs with OSA and control dogs. Results: Dogs with OSA had significantly fewer circulating CD8+ T cells and significantly more Treg compared with healthy dogs. The CD8/Treg ratio also was significantly lower in dogs with OSA compared with control dogs. In dogs with OSA, a decreased CD8/Treg ratio was associated with significantly shorter STs. Conclusions: These data support a role for Treg in the immune control of canine OSA and suggest that determination of the CD8/Treg ratio may be useful for assessing outcomes.     

Peripheral Nucleated Red Blood Cells as a Prognostic Indicator in Heatstroke in Dogs

Background: Heatstroke in dogs is often fatal and is associated with a high prevalence of secondary complications. Peripheral nucleated red blood cells (NRBC) occur in dogs with heatstroke, but their association with complications and the outcome is unclear.
Hypothesis: Peripheral NRBC are common in dogs with heatstroke and have prognostic significance.
Animals: Forty client-owned dogs with naturally occurring heatstroke.
Methods: Prospective, observational study. Dogs were followed from presentation to discharge or death. Serum biochemistry and coagulation tests were performed at presentation. CBC and evaluation of peripheral blood smears were performed at presentation and every 12 hours. The relative and the absolute NRBC numbers were calculated.
Results: Presence of NRBC was observed in 36/40 (90%) of the dogs at presentation. Median relative and absolute NRBC were 24 cells/100 leukocytes (range 0–124) and 1.48 × 10³/μL (range 0.0–19.6 × 10³/μL), respectively. Both were significantly higher in nonsurvivors (22) versus survivors (18) and in dogs with secondary renal failure and DIC versus those without these complications. Receiver operator curve analysis of relative NRBC at presentation as a predictor of death had an area under curve of 0.92. A cut-off point of 18 NRBC/100 leukocytes corresponded to a sensitivity and specificity of 91 and 88% for death.
Conclusions and Clinical Importance: Relative and absolute numbers of peripheral NRBC are clinically useful, correlate with the secondary complications, and are sensitive and specific markers of death in dogs with heatstroke, although they should never be used as a sole prognostic indicator nor should they replace clinical assessment.     

Idiopathic noncirrhotic portal hypertension in dogs: 33 cases (1982-1998)

OBJECTIVE: To describe clinical signs, diagnostic findings, and outcome in dogs with idiopathic intrahepatic portal hypertension. DESIGN: Retrospective study. ANIMALS: 33 dogs. PROCEDURE: Medical records of dogs with portal hypertension of intra-abdominal origin were reviewed. Dogs with intra-abdominal portal hypertension of vascular causes or with hepatic histopathologic changes consistent with severe diffuse hepatobiliary disease were excluded. History and results of physical examination, clinicopathologic tests, diagnostic imaging studies, histologic examination, and treatment were summarized. Outcome was determined in 26 dogs. RESULTS: Dogs were referred most often because of ascites, intermittent vomiting or diarrhea, and polydipsia of several months' duration. Microcytosis, high serum alkaline phosphatase and alanine transaminase activities, hepatic dysfunction, urine specific gravity < or = 1.021, and abdominal transudate were the predominant clinicopathologic features. Microhepatia, abdominal effusion, and multiple anomalous venous anastomoses were the major findings of diagnostic imaging. Hepatic histopathologic changes were consistent with idiopathic noncirrhotic portal hypertension and were indistinguishable from those of dogs with surgically created portocaval anastomosis. Outcome was determined for 19 dogs released from hospital; 13 dogs remained healthy with mostly palliative treatment for periods of 5 months to 9 years. CONCLUSIONS AND CLINICAL RELEVANCE: The clinical signs, clinicopathologic test results, portal pressure, and gross appearance of the liver of dogs with idiopathic noncirrhotic portal hypertension may be identical to those of dogs with cirrhosis; therefore liver biopsy is crucial. Because the prognosis for idiopathic noncirrhotic portal hypertension is generally favorable, owners of affected dogs should be discouraged from choosing euthanasia.     

Comparison of Histopathologic Findings in Biopsies from the Duodenum and Ileum of Dogs with Enteropathy

Background: In the investigations of dogs with chronic small intestinal diarrhea collection of ileal biopsies lengthens procedural time and has been of uncertain value.
Objectives: To evaluate whether there was agreement between histologic changes present in samples of duodenal and ileal mucosa, and hence to provide initial information in the process of determining whether collection of ileal biopsies is clinically justified.
Animals: 40 dogs with chronic small and large intestinal diarrhea from which endoscopic (in 30 cases) or surgical (in 10 cases) duodenal and ileal biopsies had been collected.
Methods: Samples were reviewed concurrently by two observers (MJD and MDW) using the scoring system developed by the World Small Animal Veterinary Association (WSAVA) Gastrointestinal Standardization Group. Comparisons were made by kappa analysis.
Results: Microscopic pathology was observed in 30 cases. Only eight out of this 30 (27%) had the same histopathologic diagnosis in both the duodenum and the ileum. This dropped to 3 out of 30 (10%) if different disease severity was also considered as disagreement. Microscopic pathology would have been found in 60% and 80% of the 30 cases, if only duodenal or ileal biopsies respectively, had been available.
Conclusions and clinical importance: There was poor agreement between histopathological findings from duodenal versus ileal biopsies with abnormalities sometimes being more readily detected in the ileum. Routine collection of ileal plus duodenal samples appears warranted when concurrent small and large intestinal diarrhea is present.     

Pathologic changes in grossly normal menisci in dogs with rupture of the cranial cruciate ligament

OBJECTIVE: To determine whether histopathologic changes are detectable in grossly normal medial menisci from dogs with rupture of the cranial cruciate ligament (CCL). DESIGN: Case series. SAMPLE POPULATION: 40 medial menisci from dogs with rupture of the CCL and 20 medial menisci from control dogs without stifle joint disease. PROCEDURE: Data evaluated included age, duration of clinical signs, and whether rupture of the CCL was complete or incomplete. Three groups (n = 20/group) were also compared on the basis of 5 histologic criteria; group-1 menisci appeared grossly normal and were obtained from dogs with naturally occurring rupture of the CCL, group-2 menisci were grossly abnormal and were also obtained from dogs with naturally occurring CCL ruptures, and group-3 menisci were collected at postmortem from dogs without stifle joint disease that were of similar age and weight as dogs in groups 1 and 2. RESULTS: Group-2 menisci were significantly different from group-1 and -3 menisci in all histologic criteria. Group-1 menisci were significantly different from control menisci in only 1 of the 5 histologic criteria (cartilage differentiation). Dogs that were > or =3 years old had significantly more surface cellularity than did dogs that were < 3 years old. A significant difference was not detected between groups 1 and 2 with regard to completeness of rupture. CONCLUSIONS AND CLINICAL RELEVANCE: Histologic changes in meniscal cartilage correlate with gross appearance of the cartilage at time of surgery for rupture of the CCL. On the basis of minimal histologic changes, routine removal of grossly normal menisci does not appear to be warranted.     

Evaluation of a Collagenase Generated Osteoarthritis Biomarker in the Synovial Fluid from Elbow Joints of Dogs with Medial Coronoid Disease and Unaffected Dogs

Objective— To evaluate whether synovial fluid concentrations of an osteoarthritis biomarker in dysplastic canine elbows with medial coronoid disease (MCD) are elevated compared with unaffected elbows and to determine if these concentrations correlate to the degree of articular cartilage damage.
Study Design— Cross sectional clinical study.
Animals— Dogs (n=19; 35 elbows) with MCD and dogs (8; 16 elbows) with unaffected elbows.
Methods— Concentrations of a collagenase-generated cleavage neoepitope of type II collagen (Col2-3/4C_{long mono}, or C2C) in joint fluid from elbows were analyzed and compared between dogs with MCD and unaffected dogs. Correlation of C2C concentration with subjective grading of articular cartilage surface damage was also evaluated.
Results— Mean (±SD) C2C concentration from MCD dogs was significantly higher (112.3±24.8 ng/mL) than in unaffected dogs (76.1±16.9 ng/mL; P <.05). There was a moderate correlation between cartilage damage grade and increasing C2C concentrations ( P <.05, r=0.62)
Conclusion— C2C concentrations are elevated in the synovial fluid of dogs with MCD compared with unaffected elbows, and a moderate, significant correlation was identified between these concentrations and subjective grading of articular cartilage damage.
Clinical Relevance— This preliminary data suggest that C2C concentrations in synovial fluid may have potential as a biomarker for diagnosis of articular cartilage damage associated with MCD and as a means of objectively determining the degree of articular cartilage damage.     

Prevalence of Diarrhea and Enteropathogens in Racing Sled Dogs

Background: Diarrhea is highly prevalent in racing sled dogs, although the underlying causes are poorly understood.
Hypothesis: Clostridium perfringens enterotoxin (CPE) and Clostridium difficile Toxin A and B are associated with diarrhea in racing sled dogs.
Animals: One hundred and thirty-five sled dogs.
Methods: Freshly voided feces were obtained from 55 dogs before racing and from 80 dogs after 400 miles of racing. Samples were visually scored for diarrhea, mucus, blood, and melena. CPE and C. difficile Toxin A and B were detected by ELISA. Samples were cultured for C. perfringens, C. difficile, Campylobacter, Salmonella , and Escherichia coli 0157; Giardia and Cryptosporidium spp. were detected via immunofluorescence.
Results: Diarrhea occurred in 36% of dogs during racing, and hematochezia, fecal mucus or melena, or all 3 occurred in 57.5% of dogs. Salmonella was isolated from 78.2% of dogs before racing, and from 71.3% of dogs during racing. C. perfringens and C. difficile were isolated from 100 and 58.2% of dogs before racing, and from 95 and 36.3% of dogs during racing. Dogs were more likely to test positive for CPE during than before racing (18.8 versus 5.5%, P = .021); however, no enteropathogens or their respective toxins were significantly associated with hematochezia or diarrhea.
Conclusions and Clinical Importance: Sled dogs participating in long distance racing have a high prevalence of diarrhea and hematochezia that is not associated with common enteropathogens. It is possible that diarrhea and hematochezia represent the effect of prolonged exercise on the gastrointestinal tract.     

Reclassification of small intestinal and cecal smooth muscle tumors in 72 dogs: clinical, histologic, and immunohistochemical evaluation

Objectives— To reclassify canine small intestinal and cecal leiomyoma (LM) and leiomyosarcoma (LMS) into smooth muscle and gastrointestinal stromal tumors (GIST) using histologic and immunohistochemical (IH) analysis and to report clinical findings and survival data.
Study Design— Retrospective review of cases.
Animals— Dogs (n=47) with small intestinal (40 LMS; 7 LM) and 25 dogs with cecal tumors (23 LMS; 2 LM).
Methods— Clinical and survival data were reviewed. Tissue sections were reevaluated for light-microscopic malignancy criteria and examined for expression of SMA, desmin, vimentin, S-100, and CD117 (KIT) by immunohistochemistry.
Results— Reclassification resulted in 2 LM, 9 LMS, 19 GIST, and 17 GIST-like tumors in the small intestine and 23 GIST and 2 GIST-like tumors in the cecum. GIST-like tumors were morphologic and IH identical to GIST but lacked KIT expression. No significant difference in survival was observed for tumor type, location, histologic, or IH characteristics; however, dogs with cecal tumors were significantly older in age, presented more commonly with intestinal perforation and peritonitis, and less commonly with weight loss. Cecal tumors had more histologic malignancy criteria than small intestinal tumors. After excision, 1 and 2 year recurrence-free periods were 80.1% and 67.2% for small intestinal and 83.3% and 61.9% for cecal tumors.
Conclusion— Prognosis for intestinal tumors with histologic smooth muscle appearance is good after excision and not related to tumor type, location, histologic, or IH characteristics.
Clinical Relevance— Clinical importance could not be demonstrated for reclassification, but may be for future treatment, of intestinal smooth muscle or stromal tumors.     

Evaluation of clinical, macroscopic, and histopathologic response to treatment in nonhypoproteinemic dogs with lymphocytic-plasmacytic enteritis

BACKGROUND: Lymphocytic-plasmacytic enteritis (LPE) is a common cause of chronic vomiting and diarrhea in dogs. However, little information is available about endoscopic or histopathologic improvement after therapy in dogs with LPE. HYPOTHESIS: The objective was to study the clinical, endoscopic, and histopathologic evolution of LPE during and after immunosuppressive treatment with prednisone and metronidazole. Most dogs also were treated symptomatically with metoclopramide and cimetidine. ANIMALS: Sixteen dogs with LPE and normal serum protein concentrations diagnosed at the Veterinary Medical Teaching Hospital of the Complutense University of Madrid were monitored during and after drug treatment. The control group consisted of 9 dogs that had no gastrointestinal signs for the preceding 12 months. METHODS: In this prospective clinical treatment trial, clinical, endoscopic, and histopathologic scores were evaluated to describe disease evolution during conventional therapy. Dogs with LPE were monitored for 120 days from the start of treatment. Re-evaluation was performed on post-treatment days 30, 60, 90 (end of treatment), and 120. RESULTS: The average disease activity index observed in our study fell progressively from its initial value, and the decrease between consecutive re-evaluations was statistically significant until day 60 (P = .04). Our results indicate that 75% of the animals revealed improvement of endoscopic gastric lesions (defined as a reduction of the endoscopic score) after treatment, and 75% exhibited improvement of endoscopic duodenal lesions. Statistical analysis of the data revealed significant differences between pre- and post-treatment gastric and duodenal macroscopic endoscopic lesions (P < .05). On the other hand, treatment did not lead to any significant changes in the severity of the gastric and duodenal histopathologic lesions of the affected dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Treatment of nonhypoproteinemic dogs with LPE led to clinical and endoscopic improvement, but histopathologic lesions were unchanged during therapy.     

Effects of cyclosporine A on clinical and histologic abnormalities in dogs with sebaceous adenitis

OBJECTIVE: To evaluate the effects of cyclosporine A in the treatment of sebaceous adenitis in dogs. DESIGN: Open-label clinical trial. ANIMALS: 12 dogs with sebaceous adenitis. PROCEDURE: Dogs were treated with cyclosporine A at a dosage of 5 mg/kg/d (2.3 mg/lb/d), PO, for 12 months and reevaluated every 4 months. A clinical score was calculated by grading the extent of alopecia and severity of follicular casts as absent, mild, moderate, or severe in each of 17 body regions. Biopsy specimens were obtained and examined histologically and by means of immunohistochemical staining. RESULTS: Mean clinical score was significantly decreased, compared with baseline score, after 4 months of treatment and remained low after 8 and 12 months. Histologically, the severity of inflammation was significantly decreased, as were numbers of macrophages, CD3+ T cells, and major histocompatibility complex class II-expressing cells. The percentage of hair follicles with sebaceous glands increased, suggesting regeneration of sebaceous glands. Clinical signs recurred when cyclosporine administration was discontinued. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of cyclosporine A at a dosage of 5 mg/kg/d may reduce the inflammation associated with sebaceous adenitis in dogs. Long-term treatment appears to be neccessary to control the disease.     

Cytologic and Histopathologic Evaluation of Extruded Canine Degenerate Disks

Objective— To describe the cytologic and histopathologic appearance of degenerate disk material in dogs with Hansen type I intervertebral disk disease (IVDD).
Study Design— Case series.
Animals— Dogs (n=45) that had surgical intervention for Hansen type I IVDD (January–November 2007).
Methods— Impression smears and histopathologic sections were prepared from surgically removed degenerate disk material. All slides were evaluated for overall cellularity, quantity and attributes of extracellular matrix, types of cells present, and their cytomorphology. Histopathologic sections were also examined for presence of neovascularization and hemorrhage.
Results— Cytologically, 11 of 45 samples consisted of only extracellular matrix, 30 had evidence of inflammation, and 20 contained dysplastic spindloid cells. Histologically, hyaline cartilage predominated in 35 of 45 samples, fibrocartilage in 4, and spindloid cells in 6; 37 of 45 were inflamed, 37 were hemorrhagic, and 13 had neovascularization.
Conclusions— The cytologic and histopathologic appearance of extruded degenerate disk material in dogs is variable and can include dysplastic spindloid cells.
Clinical Relevance— The variability in cytologic findings and frequent presence of dysplastic spindloid cells suggest that cytology alone may not be a reliable tool to differentiate degenerate canine disk material from a mesenchymal neoplasm.     

Epidural Idiopathic Sterile Pyogranulomatous Inflammation Causing Spinal Cord Compressive Injury in Five Miniature Dachshunds

Objective— To characterize the clinical signs, diagnostic and surgical findings, and outcome of dogs with idiopathic sterile pyogranulomatous inflammation (ISP) of epidural fat causing spinal cord compression.
Study Design— Retrospective study.
Animals— Dogs (n=5).
Methods— Dogs with epidural ISP (2002–2006) were identified retrospectively. Inclusion criteria were neurologic examination, myelography, and definitive diagnosis of ISP confirmed by surgery and histopathologic examination of epidural spinal cord compressive tissue.
Results— The most common clinical sign was paraparesis/paraplegia. No abnormalities were detected by laboratory testing or survey spine radiographs. On myelography, extradural spinal cord compressions were focal (dogs 1, 3, and 5) or multifocal (dogs 2 and 4). Surgical decompression of the spinal cord was completed by hemilaminectomy. Epidural fat collected surgically had pyogranulomatous inflammation of unknown cause and was histologically similar to subcutaneous ISP. All dogs had good long-term neurologic outcome (10–45 months follow-up). Some dogs had episodes of ISP at other sites before or after surgical treatment of epidural ISP, suggesting there may be a systemic form of ISP.
Conclusion— Epidural ISP may cause a spinal cord compressive lesion in Miniature Dachshunds, which can be treated by surgical decompression of the spinal cord with or without administration of adjunctive steroids.
Clinical Relevance— Epidural ISP should be considered as a possible cause of thoracolumbar myelopathy for Miniature Dachshunds.     

Clinical Features and Outcome of Heterobilharzia americana Infection in Dogs

Background: Heterobilharzia americana (HA), the causative agent of canine schistosomiasis, is a flatworm with a freshwater snail as an intermediate host. Only case reports or small case series evaluating naturally infected dogs have been published.
Objective: Describe clinical signs in dogs naturally infected with HA.
Animals: Twenty-two dogs naturally infected with HA from 1985 to 2009.
Methods: Retrospective study. All medical records were searched for HA and schistosomiasis. Only dogs with a diagnosis based on identification of ova on histopathology or fecal saline sedimentation were included.
Results: The median age was 3.1 years (1–12). The median duration of clinical signs before diagnosis was 0.63 months (0.03–12). The most common clinical signs were lethargy (91%), weight loss (77%), hyporexia (68%), vomiting (59%), and diarrhea (55%). Eleven of the 22 dogs were hypercalcemic. Hypercalcemia did not resolve without definitive treatment with praziquantel. HA infection was an incidental diagnosis in 7/22 dogs. Diagnosis was obtained via necropsy (4), histopathology (9), and fecal examination (9). Definitive treatment included praziquantel and fenbendazole. Eighteen dogs were diagnosed antemortem and 17 were treated. Twelve dogs were alive for 6 months to 3 years after diagnosis.
Conclusions and Clinical Importance: HA infection occurs in younger, larger breed, indoor dogs. Hypercalcemia does not resolve without praziquantel treatment. Prognosis is good and neither hypercalcemic-induced renal failure nor ascites appears to worsen prognosis. Dogs in affected areas or that have traveled to affected areas that present for weight loss, gastrointestinal or liver disease, and hypercalcemia, should be tested.     

Asparaginase and MOPP Treatment of Dogs with Lymphoma

Background: Dogs with multicentric lymphoma are treated with various cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-based chemotherapy protocols with variable success.
Objectives: To describe the progression-free survival (PFS) time and overall survival time (OST) of dogs with T-cell lymphoma or hypercalcemic lymphoma treated with l -asparaginase and mechlorethamine, vincristine, prednisone, procarbazine (MOPP).
Animals: Fifty dogs with T-cell lymphoma, hypercalcemic lymphoma, or both treated at 3 referral veterinary hospitals.
Methods: Retrospective study. Case were selected based on histologic or cytologic diagnosis of lymphoma; presence of the T-cell phenotype, presence of hypercalcemia or both; and absence of previous chemotherapy. The T-cell phenotype was determined by flow cytometry, immunocytochemistry, immunohistochemistry, or polymerase chain reaction of antigen receptor rearrangement.
Results: The overall response rate was 98% (78% complete response, 20% partial response). The median PFS for the entire study population was 189 days with 25% PFS at 939 days. The median OST for the entire study population was 270 days with 25% surviving 939 days. Twenty percent of the dogs required hospitalization for treatment related complications.
Conclusions and clinical importance: l -Asp/MOPP chemotherapy might result in longer PFS and OST for dogs with multicentric T-cell lymphoma, dogs with hypercalcemic lymphoma or both, than achieved with CHOP.     

Combined Gemcitabine and Carboplatin Therapy for Carcinomas in Dogs

Background: Response and adverse reactions to combined gemcitabine (GEM) and carboplatin (CARBO) therapy in dogs with carcinomas are not documented.
Hypothesis: GEM and CARBO are safe for the treatment of dogs with carcinomas.
Animals: Thirty-seven dogs with histologically or cytologically confirmed carcinomas.
Methods: Prospective clinical trial. Dogs were treated with GEM (2 mg/kg, 20–30-minute infusion IV) on Days 1 and 8 and 4 hours later, CARBO (10 mg/kg IV) on Day 1. The cycle was repeated on Day 22.
Results: Thirty-seven dogs (29 with measurable tumor) received a median of 2 cycles (range 0.5–6) for a total of 101 cycles administered. Twelve dogs (32%) developed neutropenia (3 Grade 3, and 5 Grade 4) and 9 (24%) thrombocytopenia (2 Grade 3, and 1 Grade 4). Dogs >20 kg were twice as likely to develop thrombocytopenia ( P = .023). Twenty-seven dogs (73%) had evidence of gastrointestinal (GI) toxicosis, but most signs were of mild to moderate severity and self-limiting. One dog died of treatment-related complications. Overall tumor response rate was 13%. One dog with metastatic prostatic carcinoma achieved a complete remission and 1 dog with intestinal adenocarcinoma and 1 with tonsillar squamous cell carcinoma achieved partial remission. Twelve dogs achieved stable disease for a median of 72 days.
Conclusion and Clinical Importance: GEM and CARBO combination causes mild to moderate hematologic and GI toxicosis in dogs with carcinoma. Response rate in this study was modest, and optimization of dosing of this combination is required.     

Hypotonic water as adjuvant therapy for incompletely resected canine mast cell tumors: a randomized, double-blind, placebo-controlled study

Objective— To evaluate efficacy of hypotonic water as adjuvant therapy after marginal resection of canine mast cell tumors (MCT).
Study Design— Double-blinded, placebo-controlled, prospective, randomized study.
Animals— Dogs (n=30) with spontaneous, cutaneous, solitary MCT.
Methods— The wound bed of MCT, resected with margins <0.5 cm, was injected with either hypotonic or isotonic water according to a standardized protocol. Follow-up was obtained by clinical examination at 1, 2, 3, 6, and 12 months and annual telephone contact with the owner.
Results— Eighteen dogs were treated with isotonic lactated Ringer's solution and 12 dogs with hypotonic distilled water. All MCT were stage 0 tumors and most grade II. Six tumors (4 isotonic, 2 hypotonic) recurred locally, 3 of these dogs died from disease-related reasons within 4 months. The surviving 3 dogs were alive with a median survival time (ST) of 1092 days. The calculated 2-year recurrence-free rate was 92.7%; the 2-year disease-free rate 79.1%; and the 2-year survival rate 89.5%. No significant differences in local recurrence and ST were observed between treatment groups. Histologic grading was the only significant prognosticator for ST and recurrence-free periods.
Conclusion— No significant differences in local recurrence and ST were observed between adjunctive hypotonic water and placebo treatment after marginal resection of solitary MCT.
Clinical Relevance— Hypotonic water does not decrease the rate of local recurrence in dogs with solitary MCT after marginal surgical excision.     

Comparison of results of computed tomography and radiography with histopathologic findings in tracheobronchial lymph nodes in dogs with primary lung tumors: 14 cases (1999-2002)

OBJECTIVE: To compare results of computed tomography (CT) and radiography with histopathologic findings in tracheobronchial lymph nodes (TBLNs) in dogs with primary lung tumors. DESIGN: Retrospective case series. ANIMALS: 14 client-owned dogs. PROCEDURES: Criteria for inclusion were diagnosis of primary lung tumor, use of thoracic radiography and CT, and histologic confirmation of TBLN status. Medical records were reviewed for signalment; history; and physical examination, clinicopathologic, radiographic, CT, surgical, and histopathologic findings. RESULTS: Tracheobronchial lymphadenopathy was not identified via radiography in any dogs. Tracheobronchial lymphadenopathy was diagnosed in 5 dogs via CT. Six dogs had histologic confirmation of metastasis to TBLNs. Radiographic diagnosis yielded 6 false-negative and no false-positive results for tracheobronchial lymphadenopathy. Computed tomography yielded 1 false-negative and no false-positive results. Sensitivity of CT for correctly assessing TBLN status was 83%, and specificity was 100%. Positive predictive value was 100%, and negative predictive value was 89%. Dogs with lymphadenopathy via CT, histologic confirmation of TBLN metastasis, or primary tumors with a histologic grade > 1 had significantly shorter survival times than their counterparts. CONCLUSIONS AND CLINICAL RELEVANCE: Results of CT evaluation of TBLN status were in agreement with histopathologic findings and more accurate than use of thoracic radiography for evaluating TBLNs in dogs with primary lung tumors. Computed tomography imaging should be considered as part of the staging process to more accurately assess the TBLNs in dogs with primary lung tumors.