Cisplatin Therapy in 41 Dogs With Malignant Tumors

Forty-one dogs with a variety of histopathologically diagnosed, measurable tumors were treated with cisplatin (cis-diamminedichloroplatinum, Platinol, Bristol Laboratories, Syracuse, NY 13221-4755) as a single agent at a dosage of 60 mg/m2 given intravenously at 3-week intervals. In an attempt to avoid renal toxicity of cisplatin, saline diuresis was induced and maintained for 4 hours before and 2 hours following cisplatin administration. The dogs received one to ten doses of cisplatin. To determine response to therapy and to monitor toxicity of the drug, the dogs were evaluated with physical examinations including tumor measurements, radiography, complete blood counts, platelet counts, urinalyses, serum urea nitrogen concentrations, and serum creatinine concentrations. An overall response rate of 19% was observed. Complete remission occurred in one of 11 dogs with squamous cell carcinomas and one of one dog with a mediastinal undifferentiated carcinoma. Partial remissions were documented in one of 11 dogs with squamous cell carcinomas, two of three dogs with metastatic osteosarcomas, one of three dogs with nasal adenocarcinomas, and one of one dog with a thyroid adenocarcinoma. Toxic side effects were primarily gastrointestinal in nature, with vomiting occurring 1-6 hours after cisplatin administration in 27 of 41 dogs. Severe anorexia occurred in three dogs, and hemorrhagic diarrhea was observed in one dog. One dog developed grand mal seizures and died 3 hours following therapy. Granulocytopenia was documented in six dogs, and thrombocytopenia was observed in four dogs. One dog showed an increase in serum urea nitrogen and creatinine concentrations, but this patient had known pre-existing renal disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

SEPTIC COXOFEMORAL ARTHRITIS AND OSTEOMYELITIS IN A DOG

An 8-year-old male Labrador retriever presented with a rear limb lameness cased by an osteolytic lesion of the left acetabulum and femoral head and neck. Initial bone biopsy study was nondiagnostic. Histopathologic study and culture of the subsequently excised femoral head and neck revealed a Staphyloccocus intermedial arthritis and osteomyelitis. Neoplash was ruled out on the basis of histopathologic analysis.     

A review of calcium, phosphorus and magnesium metabolism in the horse

Mineral metabolism in the equine is a complex process involving absorption sites and interactions between the minerals themselves and other compounds. Factors such as the digestibility of the minerals and the extent of the interactions all play an important role in the mineral amounts required in the diet.Inadequate levels of minerals in the diet can lead to physiological maladies such as HNS and Ricketts. A knowledge and understanding of mineral metabolism is essential to the success of equine management.     

Isolation of Feline Herpesvirus 1 from the Trigeminal Ganglia of Acutely and Chronically Infected Cats

Feline herpesvirus 1 (FHV-1) is one of the most common viral infections of domestic cats worldwide, estimated to cause 50% of all respiratory infections in this species. Feline herpesvirus 1 is also an important ocular pathogen of cats, causing conjunctivitis, epithelial and stromal keratitis, symblepharon formation, keratocon-junctivitis sicca, and corneal sequestration. Despite the importance of this viral disease, major questions remain unanswered concerning the pathogenesis of its most important manifestation, the recrudescent infection. Although the taxonomic classification of FHV-1 as an alpha herpesvirus implies the ability of FHV-1 to establish neural latency, attempts at recovering the virus from the trigeminal ganglia of latently infected cats have typically yielded negative results. This failure has stimulated speculation that neural tissue is not an important site for latent FHV-1. However, in the most successful of such studies, FHV-1 was isolated from the trigeminal ganglia of 3 of 17 cats using an explant technique. In the present study, we describe the successful isolation of FHV-1 from the trigeminal ganglia of cats using a similar tissue culture method.     

Comparison of the properties of hyaluronate products used in treatment of joint dysfunction in horses

A standardized investigation was conducted to compare the biophysical properties of hyaluronate products used in the treatment of joint dysfunction in horses. Results showed that two of the five products, Hyvisc® and Hylartin®V, contained higher-weight molecular hyaluronate (greater than 1.5×10⁶). Other investigations have shown that higher molecular weight hyaluronate is effective in providing physical resistance to shear, in stimulating endogenous hyaluronate synthesis, and in inhibiting excess cell proliferation which may be associated with synovial pannus formation. It is suggested that the therapeutic benefits of hyaluronate products may be dependent on the molecular size of the hyaluronate molecules. Higher molecular weight hyaluronate products would be expected to be more effective than lower molecular hyaluronate products in providing therapeutic benefits.     

Gas Exchange during Xylazine–ketamine Anesthesia in Neonatal Calves

Ten neonatal calves were anesthetized with xylazine and ketamine intramuscularly and breathed air spontaneously. Drug injection was repeated after 45 minutes. Each injection resulted in a rapid and sustained increase in respiratory rate, but arterial carbon dioxide tension (PaCO2) increased, indicating hypoventilation. Arterial hypoxemia, primarily caused by hypoventilation, developed within 15 minutes of each injection, but gradually disappeared. Acidemia was primarily respiratory in origin. Heart rate and arterial blood pressure decreased for the duration of anesthesia (90 minutes). This form of anesthesia is a satisfactory alternative to inhalation anesthesia of neonatal calves.     

Hyperactivated Sperm Motility: Are Equine Sperm Different?

A recent study has suggested a central role for hyperactivated sperm motility in successful equine in vitro fertilization, as the highest apparent fertilization rates reported yet were obtained using exogenous stimulation of hyperactivated motility in sperm that had been incubated for capacitation. Hyperactivated motility has been studied intensively in other species, but little data are available in this area in the horse. Hyperactivated motility is associated with an influx of calcium from the extracellular space, and in other species this occurs because of an increase in intracellular pH during capacitation. Influx of calcium seems to trigger changes in flagellar function through calcium–calmodulin–calmodulin kinase-related effects on dynein function, but the exact mechanisms resulting in hyperactivated motility are still unclear. We have been exploring the physiology of hyperactivated motility in stallion spermatozoa and have found many of the mechanisms present in other species to be in place in the stallion. Further research is needed to determine why stallion spermatozoa seem to fail to undergo hyperactivation in response to capacitating environments that support this activity in other species.