Characteristics of Staphylococcus intermedius isolates from diseased and healthy dogs

Staphylococcus intermedius isolates from diseased and healthy dogs were examined for production of extracellular enzymes and toxins, and phage patterns. There were no significant differences between the two groups of isolates in the production rates of DNase, protease, lipase, gelatinase, hyaluronidase, hemolysins, protein A, and TSST-1, or in phage patterns. But the production rate of enterotoxins in isolates from diseased dogs was significantly higher than that in isolates from healthy dogs. PFGE analysis was performed with isolates from different body sites in individual dogs. In 3 of 6 healthy dogs, identical PFGE patterns were seen in isolates from the nares, external auditory meatus or skin. The remaining 3 dogs yielded isolates of different patterns. In 4 of 6 diseased dogs, identical patterns were seen in isolates from lesions as well as from the other normal sites.     

Frequency of yeasts and dermatophytes from healthy and diseased dogs.

The aim of this study was to investigate the presence of dermatophytes and yeasts in healthy and diseased dogs. A total of 633 samples were collected from 26 healthy animals (104 samples), 131 with dermatitis (343 samples), 74 with otitis (148 samples), and 19 with ocular diseases (38 samples). Cultures from healthy animals were positive for Malassezia pachydermatis in 13.5% (7/52) of samples from skin, 42.3% (11/26) from ear, and 3.8% (1/26) from eye. Fungal growth was observed in 20.4% (70/343) samples from animals with dermatitis. Microsporum canis was the most isolated fungus (n = 39), followed by M. pachydermatis (n = 30) and Malassezia sp. (n = 3). Of the 148 samples from dogs with otitis, 90 (60.8%) were positive for M. pachydermatis, and of the clinical specimens from the conjunctiva of animals with ophthalmic disease, 2.6% (1/38) presented positive cultures for M. pachydermatis. Only 14.3% (2/14) of the positive cultures for M. pachydermatis and 40.9% (9/22) of those for M. canis were positive in the direct exam. Direct exams were positive in 84.3% (70/83) of the culture positive samples from affected ears of dogs with otitis. Malassezia pachydermatis may act as an aggravating factor in the occurrence of cutaneous diseases, or the isolation of M. canis may be associated with the onset of dermatophytosis. Fungal culture, rather than microscopic examination, should be used as the definitive diagnostic test for dermatomycoses and otitis.     

Thrombin‐activatable fibrinolysis inhibitor activity in healthy and diseased dogs

Background: In people, increased thrombin‐activatable fibrinolysis inhibitor (TAFI) antigen has been associated with increased risk of thrombosis, and decreased TAFI may contribute to bleeding diathesis. TAFI activity in dogs has been described in experimental models, but not in dogs with spontaneous disease. Objective: The aim of this study was to compare TAFI activity in healthy dogs with TAFI activity in dogs with spontaneous disease. Methods: Plasma samples from 20 clinically healthy Beagles and from 35 dogs with various diseases were analyzed using a commercial chromogenic assay that measured TAFI activity relative to activity in standardized pooled human plasma. Results: Median TAFI activity for the 20 Beagles was 46.1% (range 32.2–70.8%) compared with 62.6% (29.1–250%) for the 35 diseased dogs, and 14/35 (40%) had TAFI activities >the upper limit for controls. The highest individual activities (>225%) were in 3 dogs with malignant neoplasms and 1 dog with thrombocytopenia. For data grouped by diagnosis, median TAFI activity was 61.7% for benign neoplasia (n=5), 64.9% for malignant neoplasia (n=8), 75.5% for Angiostrongylus vasorum infection (n=4), 68.8% for bacterial sepsis (n=7), and 58.7% for miscellaneous diseases (n=11). Compared with TAFI activity in control dogs, median TAFI activity was significantly increased only in the group of dogs with bacterial sepsis. Conclusion: Bacterial sepsis was associated with significantly increased TAFI activity, and individual dogs with increased TAFI activities were found in all disease groups. The role of TAFI in the pathogenesis of hemostatic disorders in dogs and its value as a prognostic indicator deserve further investigation.     

Antimicrobial susceptibility of Staphylococcus intermedius isolated from healthy and diseased dogs

A total of 90 strains of Staphylococcus intermedius isolated from dogs were examined for antimicrobial susceptibility. There were no significant differences in the distribution patterns of MICs between strains from 1982 to 1985 and those from 1999, and between strains from healthy dogs and those from diseased dogs. All of the strains were susceptible to ABPC, DMPPC, CEX, TDM, ERFX, BFLX, and FF at concentrations of 0.05 to 6.25 microg/ml. The MICs of OTC, KM, EM, AIV-TS, and LCM were distributed in a broad range of 0.1 to >100 microg/ml, indicating the existence of resistant as well as susceptible populations of S. intermedius. Thirty-three strains (36.7%) were resistant to one or more anitmicrobial agents such as OTC (n=32), KM (n=9), EM (n=7), AIV-TS (n=7), and LCM (n=7).     

The genital Mycoplasma and Ureaplasma flora of healthy and diseased dogs.

The genital mycoplasma and ureaplasma flora was compared in 136 dogs with varied reproductive histories. Mycoplasmas were recovered from 88% of vulvovaginal swabs, 85% preputial swabs and 72% semen samples. Isolation rates were slightly higher from dogs that were infertile or had evidence of genital disease but the differences from those that were fertile or clinically normal were statistically significant only in the male. Ureaplasmas were recovered from half the females sampled. Higher, but not statistically significant isolation rates (75%) were made from infertile females with purulent vulvar discharge versus those that were clinically normal and fertile (40%). In the male dog there was a significantly higher incidence of ureaplasmas in the prepuce of infertile animals (69%) than those that were fertile (0%) (p less than or equal to 0.05). Semen isolations although not significantly higher in infertile males, were all made from ejaculates, with subnormal motility, low sperm counts and/or a high percentage of midpiece and tail abnormalities (bent or tightly coiled).     

Immunohistochemical investigation of Foxp3 expression in the intestine in healthy and diseased dogs

ABSTRACT: Intestinal immune regulation including development of oral tolerance is of great importance for the maintenance of intestinal homeostasis. Concerning this, regulatory T cells (Tregs) occupy a pivotal role in cell-mediated immunosuppression. Dysregulation of mucosal immunology leading to an abnormal interaction with commensal bacteria is suggested to play a key role in the pathogenesis of Inflammatory Bowel Disease (IBD) in men and dogs. The aim of this study was to characterise the expression of Foxp3 in the normal canine gut of 18 dogs (mean age: 6.03 years), in 16 dogs suffering from IBD (mean age: 5.05 years), and of 6 dogs with intestinal nematode infection (mean age: 0.87 years) using immunohistochemistry. In the duodenum, Tregs in healthy dogs declined from villi (median: 10.67/62 500 μm2) to crypts (median: 1.89/62 500 μm2). Tregs were further increased in the villi of middle-aged dogs (median: 18.92/62 500 μm2) in contrast to juvenile (median: 3.50/62 500 μm2) and old (median: 9.56/62 500 μm2) individuals. Compared to healthy controls, animals suffering from IBD revealed reduced numbers of Tregs in duodenal villi (median: 4.13/62 500 μm2). Dogs with intestinal nematode infection displayed increased numbers of Tregs (median: 21.06/62 500 μm2) compared to healthy animals.Age-related changes indicate a progressive establishment of oral tolerance and immunosenescence in the canine elderly. The results further suggest that a defect in Treg homeostasis may be involved in the pathogenesis of canine IBD. In contrast, increased numbers of Tregs in the duodenum may be due to nematode infection.     

Diseased dogs isoamylases in clinically normal and diseased dogs

Isoamylases in normal canine sera were separated on cellulose acetate membranes using a discontinuous buffer system without EDTA. Four peaks of amylase activity were present in 17 of 24 sera. Normal values were established. The majority of activity was present in Peak 4 (cathodal isoamylase). Tissue extracts of pancreas, duodenum, kidney, lung, testis, spleen and uterus-ovaries contained Peak 4 isoamylase. Liver and salivary gland lacked all isoamylase activity. Pancreas contained Peak 3 in addition to Peak 4 isoamylase. A tissue origin for Peaks 1 and 2 was not identified. An overall lack of resolution resulted from the inclusion of EDTA in the electrophoresis buffer system. This may account for previous findings suggesting that pancreatic amylase is not present in normal canine serum. An increase in the Peak 3 isoamylase was present in dogs with pancreatitis while dogs with pancreatic atrophy had a decrease in all isoamylases. Total amylase activity was significantly (p < 0.05) decreased in dogs with pancreatic atrophy.     

Serum antibodies against human albumin in critically ill and healthy dogs

OBJECTIVE: To characterize the magnitude and duration of the antibody response against human albumin (HA) in critically ill and healthy dogs. DESIGN: Cohort and cross-sectional study. ANIMALS: Fourteen critically ill dogs that received 25% HA as part of their treatment protocol, 2 healthy dogs with no known previous exposure to HA that received 2 infusions of 25% HA (positive control dogs), and 47 healthy dogs and 21 critically ill dogs with no known exposure to HA (negative control dogs). PROCEDURES: An ELISA to detect IgG against HA was developed. Serum samples were obtained from the critically ill dogs prior to infusion of HA, at the time of hospital discharge, and 4 to 6 weeks and 6 months after HA administration. Serum samples were obtained at 2- to 4-week intervals from both positive control dogs for 101 weeks. A single serum sample was obtained from each of the negative control dogs. RESULTS: All 14 critically ill dogs developed serum IgG against HA. Peak antibody response was detected 4 to 6 weeks after HA administration. In both positive control dogs, IgG against HA was detected 10 days after HA administration and continued past 97 weeks. The peak antibody response was detected at 3 weeks in 1 dog and at 9 weeks in the other. Five of the 68 (7%) negative control dogs had a positive antibody response. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that dogs developed a pronounced IgG response following exposure to HA and that some dogs with no history of HA administration were positive for anti-HA IgG.     

High occurrence of multi-antimicrobial resistance in Staphylococcus intermedius isolates from healthy and diseased dogs and domesticated pigeons

Staphylococcus intermedius isolates (n = 106), including 44 dog isolates and 62 pigeon isolates, were examined for their susceptibility to ampicillin, cephalexin, erythromycin, gentamicin, kanamycin, lincomycin, norfloxacin, oxacillin, tetracycline, and vancomycin by standard disk-diffusion test. The frequencies of resistance to ampicillin, kanamycin, and tetracycline were significantly higher in dog isolates than pigeon isolates (95.5% vs. 0%, 31.8% vs. 0%, and 45.5% vs. 9.7%, respectively; P < 0.01). Antimicrobial resistance patterns of dog isolates and pigeon isolates were categorized respectively into nine and five distinct profiles. Significantly higher occurrence of resistance to two or more antimicrobials was observed in dog isolates than pigeon isolates (54.5% vs. 12.9%; P < 0.01) and also in domesticated pigeon isolates than non-domesticated pigeon isolates (53.3% vs. 0%; P < 0.01).     

High occurrence of multi-antimicrobial resistance in Staphylococcus intermedius isolates from healthy and diseased dogs and domesticated pigeons

Staphylococcus intermedius isolates (n=106), including 44 dog isolates and 62 pigeon isolates, were examined for their susceptibility to ampicillin, cephalexin, erythromycin, gentamicin, kanamycin, lincomycin, norfloxacin, oxacillin, tetracycline, and vancomycin by standard disk-diffusion test. The frequencies of resistance to ampicillin, kanamycin, and tetracycline were significantly higher in dog isolates than pigeon isolates (95.5% vs. 0%, 31.8% vs. 0%, and 45.5% vs. 9.7%, respectively; P<0.01). Antimicrobial resistance patterns of dog isolates and pigeon isolates were categorized respectively into nine and five distinct profiles. Significantly higher occurrence of resistance to two or more antimicrobials was observed in dog isolates than pigeon isolates (54.5% vs. 12.9%; P<0.01) and also in domesticated pigeon isolates than non-domesticated pigeon isolates (53.3% vs. 0%; P<0.01).     

Prevalence of serum antibodies against six Leptospira serovars in healthy dogs

OBJECTIVE: To determine the prevalence of antibodies against 6 Leptospira serovars and determine risk factors associated with positive Leptospira titers in healthy client-owned dogs in Michigan. DESIGN: Cross-sectional study. ANIMALS: 1,241 healthy dogs at least 4 months of age. PROCEDURES: Dogs were examined by veterinarians at private practices. Vaccinated and unvaccinated dogs were enrolled in the study, which occurred prior to the availability of a 4-serovar (Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona) Leptospira vaccine. Sera were tested by use of the microscopic agglutination test to determine antibody titers against Leptospira serovars Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. A questionnaire was used to collect demographic information about each dog to identify risk factors associated with seropositive status. RESULTS: 309 of 1,241 (24.9%) dogs had antibody titers against at least 1 of the 6 Leptospira serovars, which suggested exposure to Leptospira spp. Prevalence of antibodies was highest to serovar Grippotyphosa, followed by Bratislava, Canicola, Icterohaemorrhagiae, and Pomona. Age, travel outside Michigan, exercise outside fenced yards, and exposure to livestock and wildlife were significant risk factors for positive titers. CONCLUSIONS AND CLINICAL RELEVANCE: Among healthy dogs from the lower peninsula of Michigan, > 20% have antibodies against leptospiral serovars historically considered uncommon but more recently incriminated as causing clinical canine leptospirosis. Wildlife and livestock may be of increasing importance as reservoirs for canine leptospirosis as urbanization continues to occur. Expanded vaccination strategies may partially mitigate these trends.     

Serum immunoglobulin A concentrations in normal and diseased dogs

The normal level of serum IgA in Western Australian dogs was defined by single radial immunodiffusion using sera from 100 healthy randomly selected adult crossbred animals. Serum IgA values of 185 animals from six breeds were also determined. The mean and variance of serum IgA of these groups were similar to the crossbred dogs with the exception of German shepherd dogs where these values were statistically greater. In addition, 210 dogs with a range of chronic diseases (autoimmune, hypersensitivity, pyoderma, neoplasia, demodecosis, disseminated aspergillosis) were assayed and low values recorded in five cases. In all disease groups the mean serum IgA value was significantly greater than in the crossbred group and the variance significantly greater in most of these groups. The German shepherd group were the only normal dogs with a mean and variance similar to those of the clinical series suggesting that this breed may have a primary defect in IgA metabolism.     

α1-acid glycoprotein and serum binding of drugs in healthy and diseased dogs

Inter-individual variation in drug serum protein binding was studied in healthy dogs and in dogs with inflammatory diseases for lidocaine, oxprenolol and propranolol, which bind mainly to alpha 1-acid glycoprotein (alpha 1-AGP), and for diazepam, digitoxin and phenytoin, which bind mainly to albumin. For the drugs mostly bound to alpha 1-AGP, in both groups of dogs binding varied considerably, and it was markedly higher in dogs with inflammatory disease. For the other drugs, the variation in binding was smaller and did not differ between the two groups of dogs. In both groups of dogs, the alpha 1-AGP concentration varied widely; it was higher in the serum of the dogs with inflammation, while the concentration of albumin was lower in these animals. There was a significant negative correlation between percentage free lidocaine, oxprenolol or propranolol and alpha 1-AGP concentration, suggesting that the inter-individual variation in binding of these drugs is due to the variation in alpha 1-AGP concentration. There was a marked intra-individual variation in lidocaine binding and in serum alpha 1-AGP concentration, studied over a period of 3 weeks in healthy dogs; a significant negative correlation between percentage free lidocaine and alpha 1-AGP concentration was obtained.     

Pharmacokinetics and tissue residues of kitasamycin in healthy and diseased broilers

The pharmacokinetics of kitasamycin after intravenous and oral administration in a dose of 300 mg/kg b.wt. was studied in 18 healthy and 18 Salmonella gallinarum naturally infected chickens. The tissue residue of the studied antibiotic was estimated in 36 normal chickens when it was given orally for 7 successive days. Therapeutic level of kitasamycin was achieved after 15 minutes and persisted for 20-22 hours after its oral administration. Higher serum kitasamycin concentrations were recorded in Salmonella gallinarum infected chickens. The elimination half-life of kitasamycin calculated after single intravenous injection was 9.03 hours in diseased chickens corresponding to 3.74 hours in healthy birds. The body clearance was significantly reduced in diseased chickens (23.86 ml/kg/min) when compared to that in normal ones (62.03 ml/kg/min). Kitasamycin treated broilers should not be slaughtered before 3 days from the last dose as it was detected only in bile and caecum at that time but not in edible tissues.     

The apo-enzyme content of aminotransferases in healthy and diseased domestic animals

We investigated the apo-enzyme content of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in clinically normal and ill canine, feline, equine and bovine patients. Aminotransferase activity was measured with and without the addition of exogenous pyridoxal-5'-phosphate (P5P). The amount of apo-enzyme was expressed as the percentage change in aminotransferase activity with the inclusion of P5P. The results of aminotransferase assays without P5P (holo-enzyme activity) were highly correlated to the results obtained with P5P (total enzyme activity) in all four species (Spearman rank correlations > 0.980). The median apo-aminotransferase percentage in clinically normal patients was: 11% ALT and 0% AST in 115 dogs, 7% ALT and -5% AST in 50 cats, 6% AST in 46 horses and 9% AST in 50 cattle. The amount of apo-enzyme did not increase as holo-enzyme activity increased in any of the species. The apo-aminotransferase content was not significantly different in canine, feline and equine patients with diseases affecting the liver, kidney or musculature compared to clinically normal animals. The apo-enzyme content did not differ significantly between specific liver diseases in canine and feline patients.