Objective—To identify the most common cutaneous neoplasms in dogs and evaluate breed and age distributions for selected neoplasms.
Design—Retrospective epidemiological study.
Sample—Records available through the Veterinary Medical Database of dogs examined at veterinary teaching hospitals in North America between 1964 and 2002.
Procedures—Information on tumor type and patient breed and age was collected. Incidence and odds ratios with 95% confidence intervals were calculated.
Results—Records of 1,139,616 dogs were reviewed. Cutaneous neoplasms were diagnosed in 25,996 of these dogs; records for the remaining 1,113,620 dogs did not indicate that cutaneous neoplasms had been diagnosed, and these dogs were considered controls. The most frequent age range for dogs with cutaneous neoplasms was 10 to 15 years. Lipoma, adenoma, and mast cell tumor were the most common skin tumor types.
Conclusions and Clinical Relevance—Results supported previously reported data regarding cutaneous neoplasia in dogs but provided updated information on the most common skin tumors and on age and breed distributions.
Objective—To evaluate use of a radiolabeled peptide nucleic acid–peptide conjugate (RaPP) targeting B-cell leukemia-lymphoma 2 (BCL2) mRNA for scintigraphic detection of neoplastic lymphocytes in dogs with B-cell lymphoma and to assess associations among RaPP uptake, time to tumor progression (TTP), and BCL2 mRNA expression.
Animals—11 dogs with B-cell lymphoma and 1 clinically normal dog.
Procedures—Scintigraphic images were acquired 1 hour after IV injection of the RaPP. Regions of interest (ROIs) were drawn around lymph nodes, liver, and spleen; ROI intensity (relative to that of an equally sized region of muscle in the same image) was measured. Each ROI was also subjectively categorized as positive or negative for increased RaPP uptake. Expression of BCL2 mRNA was determined via quantitative reverse transcriptase PCR assay of a lymph node sample from dogs with lymphoma. Associations among imaging results, TTP, and BCL2 mRNA expression were evaluated.
Results—Increased RaPP uptake was detected in affected tissues of dogs with lymphoma. Dogs with superficial cervical lymph node ROIs categorized as negative (n = 8) for increased RaPP uptake had a significantly longer TTP than did dogs for which this ROI was considered positive (2). Measured intensity of mandibular and superficial cervical lymph node ROIs was negatively associated with TTP. Associations among BCL2 mRNA and ROI intensity or TTP were not significant.
Conclusions and Clinical Relevance—Increased RaPP uptake at mandibular or superficial cervical lymph node ROIs may be a negative prognostic indicator in dogs with lymphoma. A larger investigation is needed to determine clinical value of the RaPP for disease detection and prognostication.
OBJECTIVE To conduct a phase I-II clinical trial of hyaluronan-cisplatin nanoconjugate (HA-Pt) in dogs with naturally occurring malignant tumors.
ANIMALS 18 healthy rats, 9 healthy mice, and 16 dogs with cancer.
PROCEDURES HA-Pt was prepared and tested by inductively coupled plasma mass spectrometry; DNA-platinum adduct formation and antiproliferation effects of cisplatin and HA-Pt were compared in vitro. Effects of cisplatin (IV) and HA-Pt (SC) in rodents were tested by clinicopathologic assays. In the clinical trial, dogs with cancer received 1 to 4 injections of HA-Pt (10 to 30 mg/m2, intratumoral or peritumoral, q 3 wk). Blood samples were collected for pharmacokinetic analysis; CBC, serum BUN and creatinine concentration measurement, and urinalysis were conducted before and 1 week after each treatment. Some dogs underwent hepatic enzyme testing. Tumors were measured before the first treatment and 3 weeks after each treatment to assess response.
RESULTS No adverse drug effects were detected in pretrial assessments in rodents. Seven of 16 dogs completed the study; 3 had complete tumor responses, 3 had stable disease, and 1 had progressive disease. Three of 7 dogs with oral and nasal squamous cell carcinoma (SCC) that completed the study had complete responses. Myelosuppression and cardiotoxicosis were identified in 6 and 2 dogs, respectively; none had nephrotoxicosis. Four of 5 dogs with hepatic enzymes assessed had increased ALT activities, attributed to diaquated cisplatin products in the HA-Pt. Pharmacokinetic data fit a 3-compartment model.
CONCLUSIONS AND CLINICAL RELEVANCE HA-Pt treatment resulted in positive tumor responses in some dogs, primarily those with SCC. The adverse effect rate was high.
IMPACT FOR HUMAN MEDICINE Oral SCC in dogs has characteristics similar to human head and neck SCC; these results could be useful in developing human treatments.
Dogs were randomly assigned to receive lomustine (approx 75 mg/m2, PO, q 21 d for 5 doses) alone (n = 5) or with prednisone (approx 1.5 mg/kg, PO, q 24 h for 12 weeks; 5). For each dog, a CBC, serum biochemical analysis, liver function testing, urinalysis, and ultrasonographic examination of the liver with acquisition of liver biopsy specimens were performed before and at predetermined times during and after lomustine administration. Results were compared between dogs that did and did not receive prednisone.
7 of the I0 dogs developed clinical signs of liver failure. For all dogs, serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities, bile acid concentrations, and liver histologic score increased and hepatic reduced glutathione content decreased over time. Peak serum ALT (r = 0.79) and ALP (r = 0.90) activities and bile acid concentration (r = 0.68) were positively correlated with the final histologic score. Prednisone did not appear to have a protective effect on histologic score.
CONCLUSIONS AND CLINICAL RELEVANCE
In dogs, liver enzyme activities, particularly ALT and ALP activities, should be closely monitored during lomustine treatment and acute increases in those activities may warrant discontinuation of lomustine to mitigate liver injury. Nonspecific ultrasonographic findings and abnormal increases in liver function tests were not detected until the onset of clinical liver failure. Glutathione depletion may have a role in lomustine-induced hepatopathy and warrants further investigation.
Objective—To evaluate samarium Sm 153 lexidronam (153Sm-EDTMP) as a treatment option for dogs with bony tumors of the skull.
Design—Retrospective case series.
Animals—Dogs with multilobular osteochondrosarcoma (MLO) or osteosarcoma (OSA) of the skull.
Procedures—Veterinary Medical Teaching Hospital records from the Universities of Missouri and Florida from 1986 to 2006 were searched for dogs with primary skull tumors treated with 153Sm-EDTMP.
Results—25 dogs were initially evaluated, with 5 dogs subsequently excluded because of inadequate follow-up or unrelated death. Seven OSAs and 13 MLOs were diagnosed. Tumors involved the occipital and frontal bones (n = 10), zygomatic arch and maxilla region (6), palate (3), and mandible (1). No clinically important adverse effects related to 153Sm-EDTMP treatment were documented. Of the 20 dogs evaluated 21 days after injection with 153Sm-EDTMP, 4 had subjective improvement, 13 had progressive disease, and 3 had insufficient follow-up. On the basis of radiographic findings, metastasis was suspected in 1 dog; 16 dogs had no metastasis evident, and medical records were insufficient for 3 dogs. Survival time, defined as the 153Sm-EDTMP injection date to the date of death, ranged from 3 to 1,314 days (median, 144 days).
Conclusions and Clinical Relevance—The subjective improvement in 4 patients and lack of clinical evidence of adverse effects suggested that 153Sm-EDTMP injection may be an option for the treatment of dogs with MLO or OSA of the skull when other treatments have failed or surgery is not possible.