Canine multicentric lymphoma 2: Comparison of response to two chemothera-peutic protocols

This paper describes the chemotherapeutic response of 90 cases of canine multicentric lymphoma. All the dogs were treated with a combination protocol using cyclophosphamide, vincristine and prednisolone. Forty-seven dogs received additional intravenous cytosine arabinoside on the first four days of treatment. Eighty-eight per cent of all cases had shown either a complete or partial response to this treatment at six weeks from the start of treatment and the overall mean survival time was 37 weeks (SD = 35.8). There was no significant difference in response or survival rates between the two treatment groups. The age and sex of the patient, the clinical stage of the disease and previous treatment with corticosteroids were all analysed to determine whether these parameters were of prognostic significance. Those dogs in clinical stages 4 and 5 carried a worse prognosis than those in stages 1 to 3. Previous treatment with corticosteroids adversely affected both tumour response and patient survival rates.     

Canine subcutaneous mast cell tumor: characterization and prognostic indices

Histologic grading schemes for canine cutaneous mast cell tumors (MCTs) were not developed for subcutaneous MCTs. Despite this, subcutaneous MCTs are currently categorized by many as grade II or higher. The aim of this investigation was to assess the pathology and clinical outcome for subcutaneous MCTs to provide a more accurate prognosis. Information on clinical outcome for 306 dogs was obtained from veterinarians and correlated with histologic features. Mean and median follow-up was 842 and 891 days, respectively (range, 3-2,305 days). Only 27 (9%) were confirmed as mast cell-related deaths. Metastasis occurred in 13 (4%), and 24 (8%) had local reoccurrence, even though 171 (56%) cases had incomplete surgical margins. Median survival time was not reached, and the estimated 6-month, 1-, 2-, and 5-year survival probabilities were 95%, 93%, 92%, and 86%, respectively. Dogs were euthanized or died as a result of local tumor reoccurrence, additional MCT development distant to the surgical site, or metastasis. Decreased survival time was linked to mitotic index (number of mitotic figures per 10 high-power fields), infiltrative growth pattern, and presence of multinucleation. Both univariable and multivariable analysis showed mitotic index to be strongly predictive of survival, local reoccurrence, and metastasis. The results of the study indicate that the majority of subcutaneous MCTs have a favorable prognosis, with extended survival times and low rates of reoccurrence and metastasis.     

Canine TIMP-2: purification, characterization and molecular detection

Matrix metalloproteinases (MMPs), which degrade tissues in health and disease are under the control of the tissue inhibitors of MMPs, the TIMPs. TIMP-2 is particularly important for control of MMP-2 and both have been implicated in many pathological processes from arthritis to tumour invasion. This study characterized and detected TIMP-2 from canine cells; including synovial fibroblasts and three tumour-derived canine cell lines, K1, K6 and DH82. Gelatin zymography demonstrated that pro-MMP-2 is produced by synovial fibroblasts and the three cells lines. Reverse zymograms showed that all the cell sources tested secrete both TIMP-1 and TIMP-2. The 22 kDa band was purified and n-terminal amino acid sequencing showed it to be highly homologous to equine and human TIMP-2. Analysis of purified canine MMP-2 and MMP-9 showed that TIMP-2 is associated, and co-purifies with MMP-2. Polymerase chain reaction, using consensus primers, was used to detect TIMP-2 mRNA from the cell sources and proved positive in all cases. This work highlights the importance of TIMP-2 as the main inhibitor for MMP-2 and, therefore, opens the possibilities of targeting TIMP-2 for therapeutic intervention against connective amino acid tissue degradation in a range of diseases.     

Neutrophil-induced erythrocyte injury: a potential cause of erythrocyte destruction in the anemia associated with inflammatory disease

Activated neutrophils at effector/target ratios of 1:20 to 1:2,000 induced depletion of red blood cell (RBC)-reduced glutathione, increased membrane-bound hemoglobin and methemoglobin, and promoted immunoglobulin binding to the cell membrane. Superoxide dismutase/catalase ameliorated the decrease in reduced glutathione and the increase in methemoglobin and immunoglobulin binding. This is interpreted as evidence that activated neutrophils can alter the antigenic nature of the RBC membrane through generation of toxic oxygen radicals.     

Bone mineral response to ammonium sulphate offered as a lick supplement in beef calves

Sixteen Bonsmara calves (4 males, 12 females) between 10 and 18 months of age were blocked according to age and sex and randomly assigned to 2 groups. They were offered licks containing bone meal and salt (50:50 ratio) (control) and bone meal and ammonium sulphate (NH4SO4) at 1.25, 2.5, 5, 10, 15, and 18% (treatment) to evaluate the effects of dietary anions on bone phosphate (P) concentration. Bone P concentration was significantly (P < 0.05) higher in the NH4SO4 group compared with the control group, indicating that NH4SO4 was able to increase the P content of bone at each of the 6 concentrations used in the lick relative to the control animals, thereby improving the P status of the animals. Ammonium sulphate at 15% and 18 % in the lick also significantly (P < 0.05) increased bone P compared with the lower concentrations of NH4SO4. Bone calcium (Ca) fluctuated as a result of the acidogenic lick. There was absorption of Ca when P was being resorbed and resorption of Ca when P was being absorbed into and out of bone. Bone Ca:P ratio ranged from 3.2 to 6.4 among the control group and 1.6 to 4.3 among the treatment group. Animals receiving the acidogenic lick had a higher percentage ash compared to the control group for most of the experimental period. Bone magnesium (Mg) fluctuated in response to the acidogenic lick, and it was difficult to show a relationship between bone Mg and Ca or P. The overall mean cortical bone thickness was significantly (P < 0.05) greater in treatment (1.60 mm) compared with control (1.43 mm) calves and this was also true at sampling periods 2, 4, 5 and 6. Bone thickness followed bone P and not bone Ca. Results from this research indicate that the addition of ammonium sulphate to a lick had a beneficial effect in improving the P status by increasing bone P and improving the mineral status of bone by increasing the thickness of cortical bone and percentage ash.     

Canine lymphocyte cultures in vitro: Evaluation of peripheral blood lymphocyte response to mitogens

Lymphocytes from dog peripheral blood have been stimulated in vitro with 3 different mitogens (Con A, PHA and PWM). Culture medium was RPMI 1640 enriched with either autologous plasma, fetal calf serum or a newly described defined serum substitute. In such cultures the number of surviving and activated cells was measured by cytofluorometry and the proliferation was assessed by thymidine incorporation. In unstimulated cultures, up to 70% of all cells had disappeared (died) during the first 42 hours of incubation, whereas the number of viable cells was reduced to 50–60% in mitogen stimulated cultures. Of the surviving lymphocytes, between 25–40% of the cells appeared to have an elevated RNA-content (activated or G₁ cells). By comparison between thymidine incorporation and number of mitogen induced G₁ cells, a very high correlation was found (r=0.92). However, the slope of the regression line was much lower than expected. The low thymidine incorporation per activated cell was primarily related to the high cell death and a resulting dilution of tritiated thymidine. Indeed, preliminary results suggested that the same thymidine incorporation per G_1b cells could be obtained if peripheral blood lymphocytes were washed immediately before pulsing as could be obtained with lymphnode cells without washing.     

Canine dacryolithiasis: a case description and mineral analysis

A 4‐year‐old, female, spayed, Labrador retriever was presented with a painless swelling of the left ventromedial eyelid and epiphora of 3 months duration. Bilateral patency of the nasolacrimal system was confirmed by the appearance of fluorescein dye at both nares. Ultrasonography revealed a well‐demarcated fluid‐filled structure containing echogenic ill‐defined material in close proximity to the nasolacrimal system. A transconjunctival surgical approach confirmed the close anatomical proximity of the cyst and the absence of a communication with the inferior canaliculus. The cyst contained multiple intraluminal calculi (dacryoliths). Following surgical excision of the cyst, the epiphora resolved and no recurrence was noted over a 12‐month follow‐up period. On histopathology, the cystic structure was lined by stratified squamous epithelium, consistent with lacrimal canaliculus epithelium. Presumed progression of a canalicular diverticulum to a cyst with the formation of intraluminal dacryoliths was suspected. Mineral analysis of the dacryoliths revealed a calcium carbonate composition.     

Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: a review

In recent years, zinc oxide nanoparticles(ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles(NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods.Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, nontoxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal's body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.     

Canine urinary tract infections: a comparison of in vitro antimicrobial susceptibility test results and response to oral therapy with ampicillin or with trimethoprim-sulfa

In vitro susceptibility testing correctly predicted the outcome of ampicillin therapy in all 56 urinary tract infections (UTI) caused by coagulase-positive staphylococci (Staphylococcus aureus and S intermedius), in all 26 UTI caused by Proteus mirabilis, in 38 of 44 UTI caused by Escherichia coli, in 29 of 31 UTI caused by Streptococcus spp, in 8 of 10 UTI caused by Klebsiella pneumoniae, and in 16 of 20 UTI caused by other bacterial species. Thus, 173 of 187 (92.5%) isolates responded to ampicillin therapy in a manner predicted by in vitro susceptibility test results. In vitro susceptibility testing correctly predicted the outcome of therapy with trimethoprim-sulfa in 119 of 138 UTI caused by Escherichia coli, in 33 of 45 UTI caused by Klebsiella pneumoniae, in 38 of 43 UTI caused by Proteus mirabilis, in 21 of 25 UTI caused by Streptococcus spp, in 9 of 11 UTI caused by coagulase-positive staphylococci, and in 19 of 21 UTI caused by other bacterial species. Thus, 239 of 283 (84%) isolates responded to trimethoprim-sulfa therapy in a manner predicted by in vitro susceptibility test results.     

Canine pubic symphysiodesis: investigation of electrocautery dose response by histologic examination and temperature measurement

OBJECTIVES--To determine thermal necrosis zone and the maximal temperature achieved with various electrocautery doses applied to the pubic symphysis of immature dogs, and to establish the minimal electrocautery dose needed to affect thermal necrosis of the germinal chondrocytes of the immature canine pubis. STUDY DESIGN--A randomized, controlled, prospective study. ANIMALS--Twelve puppies, 15 to 17 weeks of age. METHODS--Each treated puppy was randomly selected to receive 3 of 33 possible doses of electrical current applied at uniform intervals along the pelvic symphysis. Three treatment sites were sham-operated controls. All treatment zones were biopsied 7 days after application of electrocautery. Confocal laser microscopy with calcein green and ethidium homodimer red stains were used to determine cell type and viability within treatment and control zones. The physeal diameter and thermal necrosis zone were measured. Thermal necrosis zone and dose, and temperature and dose were compared using regression analysis. Prediction equation analysis was used to establish dose recommendations. RESULTS--Doses of 40 W produced a highly significant linear relationship (R(2) =.88, P <.01) with thermal necrosis zone, and a significant linear relationship (R(2) =.76, P <.02) with maximal temperature. CONCLUSIONS--The thermal necrosis zone within the pelvic symphysis and maximal temperature achieved can be reliably predicted using electrocautery doses of 40 W. For application of electrocautery to induce pubic symphysiodesis, doses should be chosen based on measured or estimated physeal size. Using prediction equation analysis, the surgeon can plan mean thermal necrosis zone with acceptable variance. CLINICAL RELEVANCE--Unipolar needle electrocautery can be used to reliably achieve symphyseal necrosis. Prediction equation analysis can be used to determine 40-W doses.     

Canine symmetrical lupoid onychodystrophy: a retrospective study with particular reference to management

The records of six dogs in which a diagnosis of symmetrical lupoid onychodystrophy (SLO) had been made were examined retrospectively. The age at onset ranged from six months to eight years. All the dogs had been presented with onycholysis, onychomadesis, onychalgia and onychodystrophy. The diagnosis of SLO was confirmed in all cases by histological examination. Histological features were similar in all cases and included hydropic degeneration of the basal cell layer, pigmentary incontinence and a cell-rich interface dermatitis. Response (defined as good, partial or failure) to various therapies was compared. Treatments (as initial therapy or following previous treatment failure) included essential fatty acids (EFA) (three cases), a combination of tetracycline and nicotinamide (four cases) and azathioprine and/or prednisolone (one case each). EFA therapy resulted in one good response, one partial and one failure, tetracycline and nicotinamide in two good responses, one partial and one failure, and azathioprine and/or prednisolone in one good and one partial response. Although all treatments were successful in some cases, none was universally effective.     

The immune response to equine arteritis virus: potential lessons for other arteriviruses

The members of the family Arteriviridae, genus Arterivirus, include equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), lactate dehydrogenase-elevating virus (LDV) of mice, and simian hemorrhagic fever virus (SHFV). PRRSV is the newest member of the family (first isolated in North America and Europe in the early 1990s), whereas the other three viruses were recognized earlier (EAV in 1953, LDV in 1960, and SHFV in 1964). Although arterivirus infections are strictly species-specific, the causative agents share many biological and molecular properties, including their virion morphology, replication strategy, unique properties of their structural proteins, and their ability to establish distinctive persistent infections in their natural hosts. The arteriviruses are each antigenically distinct and cause different disease syndromes in their natural hosts. Similarly, the mechanism(s) responsible for the prolonged and/or persistent infections that characterize infections with each arterivirus in their natural hosts are remarkably different. The objective of this review is to compare and contrast the immune response to EAV with that to the other three arteriviruses, and emphasize the potential relevance of apparent similarities and differences in the neutralization characteristics of each virus.     

Canine adiponectin: cDNA structure, mRNA expression in adipose tissues and reduced plasma levels in obesity

Adiponectin is a protein synthesized and secreted by adipocytes. Decreased adiponectin is responsible for insulin resistance and atherosclerosis associated with human obesity. We obtained a cDNA clone corresponding to canine adiponectin, whose nucleotide and deduced amino acid sequences were highly identical to those of other species. Adiponectin mRNA was detected in adipose tissues, but not in other tissues, of dogs. When 22 adult beagles were given a high-energy diet for 14 weeks, they became obese, showing heavier body weights, higher plasma leptin concentrations, but lower plasma adiponectin concentrations. The adiponectin concentrations of plasma samples collected from 71 dogs visiting veterinary practices were negatively correlated to plasma leptin concentrations, being lower in obese than non-obese dogs. These results are compatible with those reported in other species, and suggest that adiponectin is an index of adiposity and a target molecule for studies on diseases associated with obesity in dogs.     

Muscle characteristics and plasma lactate and ammonia response after racing in Standardbred trotters: relation to performance

Blood samples from the jugular vein and muscle biopsies (gluteus medius) in 25 Standardbred trotters were obtained 5-10 min after racing. The biopsies were analysed for fibre type composition and enzymatic profile and blood samples for plasma lactate and ammonia concentrations. Muscle characteristics, plasma lactate and ammonia concentrations after racing were compared with each horse's individual performance index (IPI). The IPI is calculated annually from the individual horse's racing performance (% placing 1, 2 or 3, total annual earnings, average earning per start, and best racing record), respectively, converted to and expressed as a percentage deviation from the average record of the same sex and age group. The IPI values were 100-116. Plasma lactate concentrations were 15.0-42.7 mmol/l (mean 31.3 mmol/l) and ammonia concentrations 65-210 micromol/l (mean 141 micromol/l) after racing. Fibre type composition varied among horses (range 9-27% for Type I, 32-54% for Type IIA, and 27-46% for Type IIB). Fibre type composition, enzyme activities, plasma lactate and ammonia responses to racing were not correlated to IPI. Ten of the horses also performed a submaximal test on the track, consisting of 5 incremental 1000 m heats at approximate speeds of 9.1, 9.5, 10.0, 10.5, and 11.1 m/s. Immediately after each heat a blood sample was drawn from the jugular vein for plasma lactate analysis. Plasma lactate response to exercise differed between horses, but no correlation was seen with IPI. Muscle characteristics, plasma lactate and ammonia concentrations after racing and lactate response to a submaximal track test did not correlate with current race performance expressed as IPI in a group of horses with average or better performance capacity at the time of testing. Analysis of lactate and ammonia in blood after racing is not a valuable tool to predict an individual performance index.     

Canine pleural and mediastinal effusions: a retrospective study of 81 cases

Eighty-one cases of canine pleural and/or mediastinal effusions were identified from radiography and ultrasonography records reviewed between 1992 and 2000 at the Queen's Veterinary School Hospital, University of Cambridge. All cases had a follow-up period of at least 12 months. Twenty-eight underlying disease processes were associated with pleural and/or mediastinal effusions. The most common disease was pyothorax (13 cases). Other common diseases identified were idiopathic pericardial effusion, cranial mediastinal mass, idiopathic chylothorax, secondary lung metastases and dilated cardiomyopathy. Approximately one-quarter of all cases recovered completely after initial treatment and one-third of all cases either died during, or were euthanased immediately after, completion of the initial investigations.     

Canine extraskeletal osteosarcoma and chondrosarcoma: a clinicopathologic study of 14 cases

Canine extraskeletal osteosarcomas are extremely rare tumors. Over a period of 25 years at the Animal Medical Center, approximately 1,000 cases of skeletal osteosarcomas have been diagnosed. During the same period 11 cases of extraskeletal osteosarcomas and three extraskeletal chondrosarcomas were diagnosed. Tumors of the mammary gland were excluded. Extraskeletal osteosarcomas were found in the adrenal gland, eye, gastric ligament, ileum, kidney, liver, spleen, testicle, and vagina. The chondrosarcomas were found in the mitral valves, lungs, and omentum. The mean age of the dogs with extraskeletal osteosarcoma was 11 years, and the mean age of the dogs with extraskeletal chondrosarcoma was 14 years. The The sizes of the tumors ranged from 3 cubic centimeters to 8,315 cubic centimeters. Osteoblastic osteosarcomas were the most common histologic type (7/11, 63.6%); there was a single case of each of the following: fibroblastic, fibrous histiocytic, chondroblastic, and mixed osteo-chondroblastic osteosarcoma. Two of the dogs with chondrosarcomas had mesenchymal chondrosarcomas involving the lungs and omentum. The remaining dog had a regular chondrosarcoma involving the mitral valve. Distant metastases were present in seven of 11 dogs with extraskeletal osteosarcoma and in none of the dogs with chondrosarcoma. In contrast to human beings, in which most extraskeletal osteosarcomas occur in the soft tissues and the extremities, most canine extraskeletal osteosarcomas develop in the visceral organs.