Three dogs reared on a dairy farm with a high incidence for Brucella abortus were serologically positive for B. abortus and no other Brucella spp. The identity of the organism was confirmed to be B. abortus by AMOS (abortus melitensis ovis suis)-polymerase chain reaction with specific primers for B. canis. One hundred percent homology of the canine isolate and the bovine pathogen isolated from the farm was demonstrated. The only possible source of infection was infected cattle on the same farm. It is suggested that dogs be routinely included in brucellosis surveillance and eradication programs.

Objective-To determine the effects of endotoxin administration on thyroid function test results and serum tumor necrosis factor-alpha (TNF-alpha) activity in healthy dogs. Animals-6 healthy adult male dogs. Procedures-Serum concentrations of thyroxine (T4), 3,5,3'-triiodothyronine (T3), 3,3'5'-triiodothyronine (rT3), free T4 (fT4), and endogenous canine thyroid stimulating hormone (TSH), and TNF-alpha activity were measured before (day-1; baseline), during (days 0 to 3), and after (days 4 to 24) IV administration of endotoxin every 12 hours for 84 hours. Results-Compared with baseline values, serum T3 concentration decreased significantly, whereas rT3 concentration increased significantly 8 hours after initial endotoxin administration. Serum T4 concentration decreased significantly at 8 and 12 hours after initiating endotoxin administration. Serum T4 concentration returned to reference range limits, then decreased significantly on days 6 to 12 and 16 to 20. Serum fT4 concentration increased significantly at 12, 24, and 48 hours after cessation of endotoxin treatment, compared with baseline values. Serum rT3 concentration returned to reference range, then decreased significantly days 5 and 7 after stopping endotoxin treatment. Serum TNF-alpha activity was significantly increased only 4 hours after initial endotoxin treatment, compared with baseline activity. Conclusions and Clinical Relevance-Endotoxin administration modeled alterations in thyroid function test results found in dogs with spontaneous nonthyroidal illness syndrome. A decrease in serum T4 and T3 concentrations and increase in serum rT3 concentration indicate impaired secretion and metabolism of thyroid hormones. The persistent decrease in serum T4 concentration indicates that caution should be used in interpreting serum T4 concentrations after resolution of an illness in dogs.

The purpose of this study was to investigate the relationship between swine health status and the concentration of the serum acute phase proteins, haptoglobin (HP), and C-reactive protein (CRP). A total of 378 clinically healthy pigs from farms A and B, plus 20 pigs culled from farm A due to poor growth, were used in this experiment. Each pig was examined and blood samples were collected during slaughter. The HP concentration was measured by using an HP-hemoglobin binding assay. The CRP concentration was measured by using a CRP enzyme immunoassay. Gross and histopathological lesions were examined and recorded at slaughter. Representative samples were then collected in order to isolate pathogens. Swine enzootic pneumonia, found in 47.7% of the pigs, was the most common lesion. Other lesions included pleuropneumonia (32.7%), suppurative pneumonia (10.3%), fibrinous pericardititis (4.3%), Ascaris migration in the liver (33.9%), and intestinal serositis (3.0%). On farm A, the percentage of pigs with 1 or more lesions was 88.2%. For culled pigs from farm A, the mean serum concentrations of HP and CRP were 2.23 +/- 0.14 mg/mL and 252.93 +/- 11.62 μg/mL, which were significantly higher than concentrations in clinically normal pigs (1.42 +/- 0.02 mg/mL and 84.88 +/- 2.61 μg/mL, respectively, P < 0.01). Moreover, among clinically normal farm A pigs, the mean HP concentration in pigs with lesions (1.43 +/- 0.02 mg/mL) was significantly higher than in pigs without lesions (1.32 +/- 0.07 mg/mL) (P < 0.05). However, the mean serum CRP concentrations in these animals were not significantly different. On farm B, the percentage of pigs with one or more lesions was 50.0%. Interestingly, the mean serum HP concentration in clinically normal pigs with lesions was significantly lower in farm B pigs (1.23 +/- 0.07 mg/mL) than in the farm A pigs (1.43 +/- 0.02 mg/mL; P < 0.01). However, serum CRP concentrations in farm A and B pigs were not significantly different. Serum HP concentration, which is a better indicator of inflammatory reactions in pig herds than serum CRP concentration, provides an important marker for swine health status.

Objective-To determine pharmacokinetics and tissue concentrations of azithromycin in ball pythons ( Python regius ) after IV or oral administration of a single dose. Animals-2 male and 5 female ball pythons. Procedures-Using a crossover design, each snake was given a single dose of azithromycin (10 mg/kg) IV. After a 4-week washout period, each snake was given a single dose of azithromycin (10 mg/kg) orally. Blood samples were collected prior to dose administration and 1, 3, 6, 12, 24, 48, 72, and 96 hours after azithromycin administration. Azithromycin was quantitated by use of liquid chromatography-mass spectrometry. Results-After IV administration, azithromycin had an apparent volume of distribution of 5.69 L/kg and a plasma clearance of 0.19 L/h/kg. Harmonic means for the terminal half-life were 17 hours following IV administration and 51 hours following oral administration. Mean residence times were 37 and 94 hours following IV and oral administration, respectively. Following oral administration, azithromycin had a peak plasma concentration (Cmax) of 1.04 micrograms/mL, a time to Cmax of 8.4 hours, and a prolonged mean absorption time of 57 hours. Mean oral bioavailability was 77%. Tissue concentrations ranged from 4 to 140 times the corresponding plasma concentration at 24 and 72 hours after azithromycin administration. Conclusions and Clinical Relevance-Azithromycin is well absorbed and tolerated by ball pythons. On the basis of plasma pharmacokinetics and tissue concentration data, we suggest an azithromycin dosage in ball pythons of 10 mg/kg, orally, every 2 to 7 days, depending upon the site of infection and susceptibil ity of the infective organism.

Objective-To evaluate the association between airway reactivity and age, sex, body weight, and radiographic findings in cats. Animals-32 mature cats that constituted 2 age groups (17 young cats that were 1 to 2 years old and 15 old cats that were 12 to 13 years old). Procedure-Cats were placed in the chamber of a barometric whole-body plethysmograph (volume, 38 L), and box pressure was measured at baseline and after aerosol administration of increasing concentrations of carbachol. Airway reactivity was assessed by monitoring increases in enhanced pause (PENH), a unitless variable that measures bronchoconstriction as derived from dose-response curves. The endpoint chosen was the provocative concentration of carbachol that increased PENH to 300% of the baseline value (PCPENH300). Results-We did not find a correlation between PCPENH300 and sex, body weight, number of eosinophils, PENH before bronchoconstriction, respiratory frequency, tidal volume, or minute ventilation. Airway reactivity was significantly less in the old cats (mean +/- SD PCPENH300, 0.578 +/- 0.051%), compared with the value for the young cats (0.053 +/- 0.006%). Radiographic patterns differed significantly between groups of cats; a greater proportion of old cats (12/15) had bronchointerstitial patterns, compared with the proportion of young cats (4/17). Conclusion and Clinical Relevance-These data support the notion that age exerts a strong influence on airway reactivity in adult cats, and radiographic differences suggest that structural changes in older cats may contribute to this effect. These findings have important implications for interpretation of results of airway reactivity tests in cats.

Objective-To determine the effects of immersion in warm springwater (38° to 40°C) on autonomic nervous activity in horses. Animals-10 male Thoroughbreds. Procedure-Electrocardiograms were recorded from horses for 15 minutes during a warm springwater bath after being recorded for 15 minutes during stall rest. Variations in heart rate (HR) were evaluated from the power spectrum in terms of low frequency (LF, 0.01 to 0.07 Hz) power and high frequency (HF, 0.07 to 0.6 Hz) power as indices of autonomic nervous activity. Results-Mean (+/-SE) HR during stall rest and immersion in warm springwater was 31.1 +/- 1.7 and 30.3 +/- 1.0 beat/min, respectively. No significant difference was found between the HR recorded during stall rest and that recorded during immersion in warm springwater. The HF power significantly increased from 1,361 +/- 466 milliseconds2 during stall rest to 2,344 +/- 720 milliseconds2 during immersion in warm springwater. The LF power during stall rest and immersion in warm springwater was 3,847 +/- 663 and 5,120 +/- 1,094 milliseconds2, respectively, and were not significantly different from each other. Similarly, the LF:HF ratio did not change during immersion in warm springwater. The frequency of second-degree atrioventricular block, which was observed in 2 horses, increased during immersion in warm springwater, compared with during stall rest. Conclusions and Clinical Relevance-Increases in HF power indicates that the parasympathetic nervous activity in horses increases during immersion in warm springwater. Thus, immersion in warm springwater may provide a means of relaxation for horses.

Objective-To quantitate the density of Dermatophagoides farinae and D pteronyssinus and concentrations of house dust mite (HDM) allergens (Der f 1, Der p 1, and Group 2 allergens) in the indoor microenvironment of dogs. Sample Population-50 homes in Columbus, Ohio. Procedure-In each home, samples of dust were collected from 3 locations in which dogs spent most time. Whenever possible, the species of mites collected was identified. Mite density (mites/g of dust) was assessed, and allergen concentrations were assayed by standardized ELISAs. Relative humidity and temperature in each home were monitored during a 5-day period. Characteristics of homes and sample sources were evaluated. Results-Dust samples from all 50 homes contained greater than 1 HDM allergen; Der f 1 and Der p 1 were detected in 100 and 74% of homes, respectively. Fifteen homes had HDMs; compared with D pteronyssinus, D farinae was found more commonly (14/15 homes) and at a higher density. Basements, homes without central air-conditioning, and dog beds that were greater than 1 year old had high HDM allergen concentrations. Homes with greater than 2 micrograms of Der f 1 or Group 2 allergens/g of dust or greater than 100 mites/g of dust were significantly more likely to have a maximum relative humidity greater than 75%. Conclusions and Clinical Relevance-Results indicated the presence of HDMs and HDM allergens in the specific microenvironment of dogs in homes. Factors associated with high levels of exposure were identified, which may be associated with increased risk for sensitization and development of atopic diseases.

Four different experimental models for Streptococcus suis-induced disease were compared to find a model that closely mimics naturally occurring disease in conventional pigs. Fourteen, 2-week old pigs free of S. suis type 2 were used in 2 experiments. In experiment 1, 3 pigs were inoculated intravenously (IV) and 3 pigs intranasally (IN) with S. suis. Two out of 3 of the IV-inoculated pigs exhibited signs of severe central nervous system disease (CNS) and were euthanized. Streptococcus suis type 2 was isolated from whole blood, joints, and serosal surfaces of both pigs. No clinical signs and no growth of S. suis were detected in the IN-inoculated pigs. In experiment 2, 4 pigs were inoculated IV and another 4 were inoculated IN with the same isolate as in experiment 1. One hour before inoculation the IN-inoculated pigs were given 5 mL of 1% acetic acid intranasally (IN-AA). All the IV-inoculated pigs showed CNS disease and lameness, and 2 of the pigs became severely affected and were euthanized. All the IN-AA inoculated pigs exhibited roughened hair coats and 2 pigs developed severe CNS disease and were euthanized. Streptococcus suis was isolated from the joints and blood of 3 pigs in the IV-inoculated group. Streptococcus suis was isolated from blood of 2 pigs, meninges of 3 pigs, and joints of 1 pig in the IN-AA inoculated group. Natural exposure to S. suis most likely occurs by the intranasal route. The IN-AA model should serve as a good model for S. suis-induced disease, because the natural route of exposure is intranasal and the IN-AA model was effective in inducing disease that mimics what is observed in the field.

Objective-To compare aesthesiometer-determined corneal sensitivity between diabetic and nondiabetic dogs and to investigate the correlation between corneal sensitivity and duration of diabetes or status of glycemic control, as estimated by use of glycated blood protein concentrations. Animals-23 diabetic and 29 nondiabetic normoglycemic dogs. Procedure-A Cochet-Bonnet aesthesiometer was used to measure corneal touch threshold (CTT) in 5 corneal regions of each dog. At the time of ocular examination, duration of diabetes mellitus was estimated from the history, and blood was drawn for assessment of blood glycosylated hemoglobin and serum fructosamine concentrations. Results-Median CTT for central, nasal, dorsal, temporal, and ventral corneal regions in nondiabetic dogs (1.6, 2.3, 2.8, 2.8, and 5.1 g/mm2, respectively) was significantly lower than in diabetic dogs (2.8, 4.0, 5.1, 5.1, and 6.6 g/mm2, respectively). Median regional CTT in diabetic dogs was not significantly correlated with estimated duration of diabetes mellitus or blood glycated protein concentrations. No significant difference was found in regional CTT between eyes of normoglycemic dogs with unilateral cataracts. Conclusion and Clinical Relevance-Diabetic dogs have significantly reduced corneal sensitivity in all regions, compared with nondiabetic normoglycemic dogs. Regional variation in corneal sensitivity is similar in diabetic and normoglycemic dogs. Neither glycemic control nor duration of diabetes, as estimated, is significantly correlated with corneal hyposensitivity. Corneal nerve dysfunction may be associated with recurrent or nonhealing ulcers in diabetic dogs for which no other underlying cause can be found.

Objective-To use transient and stable transfection of Chinese hamster ovary cells to clone the gene encoding feline erythropoietin (feEPO) protein, characterize the expressed protein, and assess its biological activity. Sample Population-Cultures of Chinese hamster ovary or TF-1 cells. Procedure-The gene encoding feEPO was cloned into a eukaryotic expression plasmid. Chinese hamster ovary cells were transiently or stably transfected with the plasmid. Expressed recombinant feEPO (rfeEPO) protein was purified from transiently transfected cells. The protein was characterized by use of SDS gel electrophoresis and western blot analysis. Biological activity was assessed by measuring thymidine incorporation by TF-1 erythroleukemic cells. Results-Purified rfeEPO from supernatants of transiently transfected cells was determined to be 34 to 40 kilodaltons (kd) by use of SDS gel electrophoresis, whereas the molecular weight predicted from the amino acid sequence was 21.5 kd. The banding pattern and high molecular weight suggested the protein was glycosylated. The rfeEPO proteins derived from transient or stable transfections subsequently were determined to be biologically active in vitro. Conclusions and Clinical Relevance-The gene encoding feEPO can be transfected into eukaryotic cells, and the expressed rfeEPO protein is biologically active in vitro. Cats with chronic renal failure often are anemic as a result of reduced expression of erythropoietin (EPO). Treatment with human-derived EPO stimulates RBCs in anemic cats; however, treatment is often limited by the development of antibodies directed against the recombinant human protein, which can then cross-react with endogenous feEPO. Recombinant feEPO may prove beneficial for use in cats with chronic renal failure.