Evaluation and establishment of reference intervals using the i-STAT1 blood chemistry analyzer in turkeys

In veterinary medicine, point-of-care testing techniques have become popular, since they provide immediate results and only small amounts of blood are needed. The handheld i-STAT1 blood analyzer is used by poultry researchers and veterinarians; however, no studies have evaluated the accuracy of this analyzer determined reference intervals in turkey blood. The objectives of this study were to 1) investigate the effect of storage time on turkey blood analytes, 2) compare the results obtained by the i-STAT1 analyzer to those obtained by the GEM Premier 3000, a conventional laboratory analyzer, and 3) establish reference intervals for blood gases and chemistry analytes in growing turkeys using the i-Stat. For the first and second objectives, we used the CG8+ i-STAT1 cartridges to test blood from 30 healthy turkeys in triplicate and once with the conventional analyzer. To establish the reference intervals, we tested a total 330 blood samples from healthy turkeys from 6 independent flocks during a 3-yr period. Blood samples were then divided into brooder (<1 wk) and growing (1-12 wk of age). Friedman's test demonstrated significant time-dependent changes in blood gas analytes, but not for electrolytes. Bland-Altman analysis revealed that there was agreement between the i-STAT1 and the GEM Premier 300 for most of the analytes. However, Passing-Bablok regression analysis identified constant and proportional biases in the measurement of multiple analytes. Tukey's test revealed significant differences in the whole blood analytes between the means of brooding and growing birds. The data presented in the present study provide a basis for measuring and interpreting blood analytes in the brooding and growing stages of the turkey lifecycle, offering a new approach to health monitoring in growing turkeys.

Interventions and observations associated with survival of orphaned shelter kittens undergoing treatment for diarrhea

OBJECTIVES

The objective of this study was to identify significant associations between treatment interventions and survival of orphaned shelter kittens with diarrhea.

METHODS

Orphaned kittens admitted to a large open-intake municipal animal shelter and entering a volunteer foster care provider network between April 2016 and July 2017 were studied. Individual orphaned kittens for which the care provider sought examination by shelter veterinarians because of clinical signs of diarrhea were included. Treatments administered were recorded and their association with kitten survival to adoption or transfer to a rescue partner was statistically examined.

RESULTS

A total of 1718 orphaned kittens were fostered, among which 220 kittens (12.8%) from 118 different litters were presented for evaluation of diarrhea. A total of 172 (78.2%) kittens underwent treatment for their diarrhea, among which 153 (89.0%) survived to adoption or transfer to a rescue partner and 19 (11.0%) died or were humanely euthanized. Kittens with diarrhea that were ⩾4 weeks of age were 24.8 times more likely to survive (95% confidence interval [CI] 6.8-89.8; P <0.0001). While controlling for age, kittens that received a vitamin and mineral supplement were 12.8 times more likely to survive (95% CI 3.1-52.5; P = 0.0004) than kittens with diarrhea that did not receive the supplement. Treatment with subcutaneous fluids, penicillin G, tube feeding, a probiotic containing Enterococcus faecium SF68, ponazuril or metronidazole did not statistically significantly increase the survival of kittens with diarrhea.

CONCLUSIONS AND RELEVANCE

Age ⩾4 weeks and treatment of diarrhea with a vitamin and mineral supplement favorably improves survival of orphaned kittens to adoption. Application of these findings are likely to improve the health and welfare of this population and contribute to a refinement in use of shelter resources.

Association of Gallbladder Mucocele Histologic Diagnosis with Selected Drug Use in Dogs: A Matched Case-Control Study

Background

The cause of gallbladder mucocele (GBM) formation in dogs currently is unknown. Many available drugs represent a newer generation of xenobiotics that may predispose dogs to GBM formation.

Objective

To determine if there is an association between the histologic diagnosis of GBM in dogs and administration of selected drugs.

Animals

Eighty‐one dogs with a histologic diagnosis of GBM and 162 breed, age, and admission date‐matched control dogs from a single referral institution.

Methods

Medical records of dogs with GBM and control dogs from 2001 to 2011 were reviewed. Owner verification of drug history was sought by a standard questionnaire. Reported use of heartworm, flea, and tick preventatives as well as nonsteroidal anti‐inflammatory drugs, analgesics, corticosteroids, or medications for treatment of osteoarthritis was recorded.

Results

Dogs with GBM were 2.2 times as likely to have had reported use of thyroxine (as a proxy for the diagnosis of hypothyroidism) as control dogs (95% confidence interval [CI], 0.949–5.051), 3.6 times as likely to have had reported treatment for Cushing's disease (95% CI, 1.228–10.612), and 2.3 times as likely to have had reported use of products containing imidacloprid (95% CI, 1.094–4.723). Analysis of a data subset containing only Shetland sheepdogs (23 GBM and 46 control) indicated that Shetland sheepdogs with GBM formation were 9.3 times as likely to have had reported use of imidacloprid as were control Shetland sheepdogs (95% CI, 1.103–78.239).

Conclusions and Clinical Importance

This study provides evidence for an association between selected drug use and GBM formation in dogs. A larger epidemiologic study of Shetland sheepdogs with GBM formation and exposure to imidacloprid is warranted.

Transmission of MRSA between companion animals and infected human patients presenting to outpatient medical care facilities

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in both human and veterinary medicine. The importance of companion animals as reservoirs of human infections is currently unknown. The companion animals of 49 MRSA-infected outpatients (cases) were screened for MRSA carriage, and their bacterial isolates were compared with those of the infected patients using Pulsed-Field Gel Electrophoresis (PFGE). Rates of MRSA among the companion animals of MRSA-infected patients were compared to rates of MRSA among companion animals of pet guardians attending a “veterinary wellness clinic” (controls). MRSA was isolated from at least one companion animal in 4/49 (8.2%) households of MRSA-infected outpatients vs. none of the pets of the 50 uninfected human controls. Using PFGE, patient-pets MRSA isolates were identical for three pairs and discordant for one pair (suggested MRSA inter-specie transmission p-value = 0.1175). These results suggest that companion animals of MRSA-infected patients can be culture-positive for MRSA, representing a potential source of infection or re-infection for humans. Further studies are required to better understand the epidemiology of MRSA human-animal inter-specie transmission.

Fresh cow mastitis monitoring on day 3 postpartum and its relationship to subsequent milk production

The purpose was to determine the association of milk California Mastitis Test (CMT), somatic cell concentration (SCC), and milk differential cell count results on day 3 postcalving with subsequent lactation production and health events. On d 3 postcalving, the CMT was performed and quarter milk samples were collected from 130 dairy cows. Quarter SCC and milk differential cell counts were determined. Microbiology on duplicate quarter milk samples was used to determine the presence of intramammary infection by major or minor pathogens. Production measures obtained using Dairy Herd Improvement Association testing were 150-d standardized and summit milks. Milk culture results on a cow basis included 82 (63.1%) samples with no growth, 31 (23.9%) with major pathogens, and 17 (13.1%) with minor pathogens. Milk culture results comparing cows with no growth to those with any growth (major or minor pathogens) were not associated with statistically significant differences in milk production. Milk culture results comparing cows with major pathogens to those with no growth and minor pathogens combined were associated with statistically significant differences in 150 d milk. Milk production did not differ for cows with CMT results above and below a cut-off of trace, and for SCC results above and below cut-offs of 200,000, 300,000, and 400,000/mL, respectively. Statistically significant differences in milk production were found for cows above and below cut-offs for percentage neutrophils in milk and for absolute neutrophil counts. Associations were found for milk production and number of quarters (0, 1, 2, or 3 and 4 combined) above respective cut-offs for SCC, percentage neutrophils in milk, and absolute numbers of neutrophils in milk, but not for CMT. Milk production differed for cows experiencing any health event versus those with no health event. The most commonly recorded health event was clinical mastitis. Statistically significant associations were detected between health events and milk culture results, SCC, neutrophil percentage, and neutrophil absolute counts. Results of the present investigation indicate that milk monitoring on d 3 of lactation using milk neutrophil percentage or neutrophil absolute counts may be useful as an indication of subsequent milk production.

North Carolina Hispanic farmworkers and intestinal parasitism: a pilot study of prevalence and health-related practices, and potential means of foodborne transmission

Migrant and seasonal farmworkers provide much of the necessary labor to harvest and process agricultural commodities desired by consumers. Little is known about the health status (especially the parasitic burden) of farm laborers, who handpick agricultural items such as fruits and vegetables, despite being implicated as a means of foodborne pathogen transmission. The goal of this research was to develop a framework to investigate enteric parasitic infections among Hispanic farmworkers in Eastern North Carolina. Seventy-one interviews were conducted, 16 stool samples were collected, and two parasite-positive workers were found. In addition, some potentially harmful health practices (e.g., self-medication) were identified. Further research is necessary to fully understand the scope of farmworker health issues and the potential risk of disseminating foodborne pathogens to humans. The study model presented provides a geographically expandable format to allow for various types of health investigations including the prevalence of other pathogens.

Detection and molecular characterization of swine hepatitis E virus in North Carolina swine herds and their faecal wastes

Recent findings of almost genetically indistinguishable swine and human strains, have suggested swine play a role in the transmission of hepatitis E virus (HEV). The extent to which HEV may be present and persist in the faecal waste generated from intensive swine operations is largely unknown. The fate of swine waste liquid is often land application, possibly resulting in unintentional seepage into groundwater or run-off into surface waters, hence validating concerns of human exposure risks. Freshly passed swine faeces, barn flush liquid waste, and lagoon liquid from production sites in North Carolina were surveyed periodically for HEV using RT-PCR primers located in ORF2. On three farms where HEV RNA was detected in swine faeces, it was also found in stored liquid waste on several occasions. HEV presence was related to swine age but not to animal management and waste management procedures, which varied amongst the farms. Seasonal patterns of HEV prevalence could not be established as viral RNA was isolated at all time points from two farms. Phylogenetic analysis of 212 bases of the genomic RNA indicated that isolates resembled the known US swine and human strains (percentage nucleic acid homology 91 to 94%), with one amino acid substitution.

Hematology and plasma chemistry reference intervals for mature laboratory pine voles (Microtus pinetorum) as determined by using the nonparametric rank percentile method

Plasma biochemical and hematologic values are important parameters for assessing animal health and experimental results. Although normal reference values for many rodent species have been published, there is a dearth of similar information for the genus Microtus. In addition, most studies use a mean and standard deviation to establish reference intervals, but doing so is not the recommendation of the Clinical and Laboratory Standards Institute (formerly the National Committee on Clinical Laboratory Standards) or the International Federation of Clinical Chemistry and Laboratory Medicine. The purpose of this study was to establish normal reference parameters for plasma biochemistry and hematology in mature pine voles (Microtus pinetorum) by using the nonparametric rank percentile method as recommended by the 2 laboratory medicine organizations mentioned. Samples of cardiac blood from a closed colony of pine voles were collected at euthanasia and evaluated under rodent settings on 2 automated hematology analyzers from 2 different manufacturers and on the same type of automated biochemistry analyzer. There were no sex-associated clinically significant differences between the sexes; younger animals had a lower hematocrit, higher mean corpuscular volume, and lower mean corpuscular hemoglobin concentration than did older animals. Only platelet counts differed when comparing hematologic values from different analyzers. Relative to rats and mice, pine voles have a lower mean corpuscular volume and higher red blood cell count, higher blood urea nitrogen, much higher alanine aminotransferase, and lower glucose and phosphorous concentrations. Hematology and plasma biochemical results obtained in this study are considered representative for healthy adult laboratory pine voles under similar environmental conditions.

Isolation, detection and characterization of swine hepatitis E virus from herds in Costa Rica

Although swine HEV isolates from North America, Europe, and Asia have been genetically characterized, little is known about the strains presumed to be circulating in Latin America. In this study, seven commercial swine production sites in Costa Rica were surveyed for HEV. Using RT-PCR, with primers located in ORF2, 19/52 fecal samples produced a product of the expected size following two rounds of amplification. Most positive samples were from swine between the ages of 1.5 and 4 months. This study provides documented evidence for the endemicity of HE infections in swine residing in Central America. Through nucleic acid sequencing, isolates were found to be genetically similar, if not identical, with no amino acid substitutions. By comparison of swine and human HEV strains representing all four genotypes and phylogenetic analysis, our isolates closely resembled the US swine and human and other Genotype III strains, with 85-93% nucleic acid identity.

Use of basal serum or plasma cortisol concentrations to rule out a diagnosis of hypoadrenocorticism in dogs: 123 cases (2000-2005)

OBJECTIVE

To determine whether basal serum or plasma cortisol concentration can be used as a screening test to rule out hypoadrenocorticism in dogs.

DESIGN

Retrospective case-control study.

ANIMALS

110 dogs with nonadrenal gland illnesses and 13 dogs with hypoadrenocorticism.

PROCEDURES

Sensitivity and specificity of basal serum or plasma cortisol concentrations of either <or= 1 microg/dL or <or= 2 microg/dL to detect dogs with hypoadrenocorticism were estimated by use of the ACTH stimulation test as the gold standard.

RESULTS

Basal cortisol concentrations of <or= 1 microg/dL had excellent sensitivity (100%) and specificity (98.2%) for detecting dogs with hypoadrenocorticism. For basal cortisol concentrations of <or= 2 microg/dL, sensitivity was 100% but specificity was 78.2%.

CONCLUSIONS AND CLINICAL RELEVANCE

On the basis of sensitivity and specificity, basal serum or plasma cortisol concentrations had high negative predictive values over a wide range of prevalence rates and can be used to rule out a diagnosis of hypoadrenocorticism. Dogs with basal cortisol concentrations > 2 microg/dL that are not receiving corticosteroids, mitotane, or ketoconazole are highly unlikely to have hypoadrenocorticism. However, if the basal cortisol concentration is <or= 2 microg/dL, little to no information regarding adrenal gland function can be obtained and an ACTH stimulation test should be performed.

The dog as a sentinel for human infection: prevalence of Borrelia burgdorferi C6 antibodies in dogs from southeastern and mid-Atlantic States

Lyme disease is the most frequently reported human vector-associated disease in the United States. Infection occurs after the bite of an Ixodid tick that is infected with Borrelia burgdorferi. Dogs have often been reported to serve as effective sentinel animals to assess the risk of human B. burgdorferi infection. Based on published data of human Lyme disease case numbers and our clinical impressions, we hypothesized that canine exposure to B. burgdorferi would be lower in North Carolina when compared to the exposure in Virginia, Maryland, and Pennsylvania. To address this hypothesis, we evaluated B. burgdorferi exposure status utilizing a specific and sensitive C6 peptide-based enzyme-linked immunosorbent assay. Our convenience sample included 1,666 canine serum samples submitted to the Vector-Borne Disease Diagnostic Laboratory from North Carolina (n = 987), Virginia (n = 472), Maryland (n = 167), and Pennsylvania (n = 40). Comparisons among states were made using the Chisquare test or the Fisher's exact test; p-values were adjusted for multiple comparisons using the Bonferroni correction. A Chi-square test for trend was used to determine if there was an increase in the frequency of seroreactors associated with the geographical origin of the samples. The proportion of seroreactive dogs in North Carolina was markedly lower (p < 0.008) than that observed in dogs from Virginia, Maryland, and Pennsylvania. These results support the hypothesis that B. burgdorferi transmission seems to occur infrequently in North Carolina dogs as compared to dogs residing in other southeastern and mid-Atlantic states. Furthermore, they support the utility of dogs as a sentinel to characterize the risk of B. burgdorferi transmission to humans in a defined geographical location.

Improved Survival Associated With Postoperative Wound Infection in Dogs Treated With Limb-Salvage Surgery for Osteosarcoma

BACKGROUND

Limb-salvage surgery and adjuvant chemotherapy are performed as a treatment of appendicular osteosarcoma in dogs. Approximately 50% of dogs that undergo limb-salvage surgery develop postoperative surgical wound infections. Postoperative surgical infections may affect survival in cancer patients. The purposes of this study were to examine the effect of surgical wound infection on survival, local recurrence, and metastasis in relation to other prognostic factors for dogs with spontaneous osteosarcoma treated with limb-salvage surgery.

METHODS

Forty-seven client-owned dogs with osteosarcoma of the distal radius were treated with limb-salvage surgery and adjuvant chemotherapy--either carboplatin or carboplatin and doxorubicin. Hazard ratios were estimated by using the Cox proportional hazard model, and survival functions were estimated by using the Kaplan-Meier product-limit life-table method.

RESULTS

Of the 47 dogs in this study, 32 (68%) developed a postoperative wound infection. Infection, dog weight, and extent of the primary tumor (percentage of length) significantly affected survival, and infection and percentage of length significantly affected time to metastasis. None of the variables considered in this study affected local recurrence. Dogs that were diagnosed with an infection were less likely to die (hazard ratio, .446), and dogs with greater body weight and greater percentage length involvement were more likely to die (hazard ratios of 3.37 and 3.66, respectively).

CONCLUSIONS

In dogs with osteosarcoma treated with limb-salvage surgery, infection has a positive influence on survival, as does a smaller initial length of radius involved and lower body weight.

Geographic distribution of babesiosis among dogs in the United States and association with dog bites: 150 cases (2000-2003)

OBJECTIVE

To identify the geographic distribution of babesiosis among dogs in the United States and determine, for dogs other than American Pit Bull Terriers (APBTs), whether infection was associated with a recent dog bite.

DESIGN

Retrospective study.

ANIMALS

150 dogs.

PROCEDURE

Canine blood samples submitted to the North Carolina State University Vector-Borne Disease Diagnostic Laboratory between May 2000 and October 2003 for which results of a Babesia-specific polymerase chain reaction assay were positive were identified, and breed and geographic origin of dogs from which samples were obtained were recorded. History and hematologic abnormalities for dogs that were not APBTs were recorded, and possible associations with a recent dog bite were examined.

RESULTS

Dogs positive for Babesia DNA were located in 29 states and 1 Canadian province (Ontario). Babesia gibsoni was the most commonly detected species, with B gibsoni DNA detected in blood samples from 131 of 144 (91%) dogs. Of the 131 dogs positive for B gibsoni DNA, 122 (93%) were APBTs. Of the 10 dogs positive for Babesia canis vogeli DNA, 6 were Greyhounds. In dogs other than APBTs, there was an association between having recently been bitten by another dog, particularly an APBT, and infection with B gibsoni.

CONCLUSIONS AND CLINICAL RELEVANCE

Results document an expansion of the known geographic range for babesiosis among dogs in the United States. Testing for babesiosis should be pursued in dogs with clinicopathologic abnormalities consistent with immune-mediated hemolytic anemia or thrombocytopenia, particularly if there is a history of a recent dog bite.

The dog as a sentinel for human infection: prevalence of Borrelia burgdorferi C6 antibodies in dogs from southeastern and mid-Atlantic states

Lyme disease is the most frequently reported human vector-associated disease in the United States. Infection occurs after the bite of an Ixodid tick that is infected with Borrelia burgdorferi. Dogs have often been reported to serve as effective sentinel animals to assess the risk of human B. burgdorferi infection. Based on published data of human Lyme disease case numbers and our clinical impressions, we hypothesized that canine exposure to B. burgdorferi would be lower in North Carolina when compared to the exposure in Virginia, Maryland, and Pennsylvania. To address this hypothesis, we evaluated B. burgdorferi exposure status utilizing a specific and sensitive C6 peptide-based enzyme-linked immunosorbent assay. Our convenience sample included 1,666 canine serum samples submitted to the Vector Borne Disease Diagnostic Laboratory from North Carolina (n = 987), Virginia (n = 472), Maryland (n = 167), and Pennsylvania (n = 40). Comparisons among states were made using the Chi-square test or the Fisher's exact test; p-values were adjusted for multiple comparisons using the Bonferroni correction. A Chi-square test for trend was used to determine if there was an increase in the frequency of seroreactors associated with the geographical origin of the samples. The proportion of seroreactive dogs in North Carolina was markedly lower (p < 0.008) than that observed in dogs from Virginia, Maryland, and Pennsylvania. These results support the hypothesis that B. burgdorferi transmission seems to occur infrequently in North Carolina dogs as compared to dogs residing in other southeastern and mid-Atlantic states. Furthermore, they support the utility of dogs as a sentinel to characterize the risk of B. burgdorferi transmission to humans in a defined geographical location.

The effects of oral magnesium hydroxide administration on rumen fluid in cattle

This study was conducted to determine the effects of oral magnesium hydroxide administration on rumen fluid in cattle. Six lactating Holstein cows (4-7 years of age) with rumen fistulas were studied. Cattle were randomly assigned to receive boluses of magnesium hydroxide (162 g) or a powdered form (450 g dissolved in 3.5 L of water) PO daily for 3 days. Analysis of rumen fluid, blood gas tensions, and pH and measurement of serum magnesium concentrations were conducted daily. The study was discontinued after 72 hours, or sooner if rumen pH exceeded 8.0. After at least 3 weeks, the study was repeated with each cow receiving the other form of magnesium hydroxide (powder or bolus). Compared with baseline rumen pH (mean +/- SD: 6.22 +/- 0.28), magnesium hydroxide boluses caused a significant increase (P < .05) in rumen pH after 48 (7.27 +/- 0.11) and 72 (8.01 +/- 0.16) hours of administration, whereas the powdered form caused a significant increase (P < .05) in rumen pH after 24 (7.54 +/- 0.19) and 48 (8.43 +/- 0.22) hours of administration. Both the powdered and bolus forms of magnesium hydroxide decreased rumen protozoal numbers and increased methylene blue reduction times compared with baseline values. There was no change in blood pH, bicarbonate, or base excess values. Serum magnesium concentrations were significantly increased (P < .05) in cows that received the magnesium hydroxide powder. The results of this study indicate that magnesium hydroxide has a potent alkalinizing effect on rumen pH and significantly decreases rumen microbial activity.

Sensitivity, specificity, and predictive values of reagent test strip estimations of blood urea nitrogen

Azostix-reagent-tests(R) strips (Ames, Miles, Inc., Diagnostic Division, Elkhart, IN) were used to measure blood urea nitrogen values in blood samples from 125 dogs and cats at the North Carolina State University, College of Veterinary Medicine. Results of the tests were compared with standard serum urea nitrogen results. Sensitivity, specificity, and negative predictive values were high (86.4, 90.3, and 96.5%, respectively). Positive predictive value was low, 65.5% of the dogs and cats with elevated blood urea nitrogen values were correctly classified as abnormal The test performs well when the prevalence of abnormal values is near 50%.

Antibody levels to hepatitis E virus in North Carolina swine workers, non-swine workers, swine, and murids

In a cross-sectional serosurvey, eastern North Carolina swine workers (n = 165) were compared with non-swine workers (127) for the presence of antibodies to hepatitis E virus as measured by a quantitative immunoglobulin enzyme-linked immunosorbent assay. Using a cutoff of 20 Walter Reed U/ml, swine-exposed subjects had a 4.5-fold higher antibody prevalence (10.9%) than unexposed subjects (2.4%). No evidence of past clinical hepatitis E or unexplained jaundice could be elicited. Swine (84) and mice (61), from farm sites in the same region as exposed subjects, were also tested. Antibody prevalence in swine (overall = 34.5%) varied widely (10.0-91.7%) according to site, but no antibody was detected in mice. Our data contribute to the accumulating evidence that hepatitis E may be a zoonosis and specifically to the concept of it as an occupational infection of livestock workers.

Volatile constituents of Chinese chive (Allium tuberosum Rottl. ex Sprengel) and rakkyo (Allium chinense G. Don)

Volatile components were isolated from Chinese chive and rakkyo by simultaneous steam distillation-solvent extraction and analyzed by GC and GC-MS. Sulfur compounds account for 88 and 94% of the total volatiles in the isolated extract of Chinese chive and rakkyo, respectively. In addition to the sulfur compounds commonly reported in the genus Allium, 27 novel volatile sulfur-containing components were found in the isolated extracts of both species. Among them were a sulfide, disulfides, trisulfides, and tetrasulfides with ethyl, butyl, and pentyl groups.

[Analysis of fatty acids from strains of Mycobacterium habana and Mycobacterium simiae]

A comparative analysis of mycobacterial fatty acid fractions of Mycobacteriun habana and Mycobacterium sineae strains was made. This study used the gas-liquid chromatography coupled with mass spectrometry. Chromatographic profiles obtained from this technique were exposed and compared. This technique proves to be valuable as an alternative element in mycobacterial characterization and makes it possible to analyze the possible differences that may exist among mycobacterial species and to identify the present fatty acid fractions. The outcome proved that the studied strains had quantifiable quantities of over 20 C atom chain fatty acids. There are small differences among the strains in terms of these organic components. It was confirmed that each of then describes a characteristic chromatographic pattern although the composition of present fatty acids is very similar in both studied species.

Effects of sample storage and delayed secondary enrichment on detection of Salmonella spp in swine feces

OBJECTIVE

To determine effects of fecal sample storage and delayed secondary enrichment (DSE) on detection of Salmonella spp in swine feces. Sample Population-Fecal samples obtained from 84 pigs in a commercial herd.

PROCEDURE

Each fecal sample underwent 3 storage treatments: no storage (ie, processed on the day of collection), storage at 4 C for 6 days, and storage at -15 C for 14 days. After assigned storage treatments, all samples were enriched in Rappaport-Vassiladias (RV) broth (single enrichment) and plated on XLT4 agar. Delayed secondary enrichment was performed, using single enrichment broths that were stored for 4 days at room temperature.

RESULTS

Of 504 cultures, 186 (36.9%) were Salmonella positive. A difference in proportions of samples with positive results was not found between same-day processing and storage at 4 C for 6 days. Compared with use of single enrichment for 24 hours (34% positive), use of DSE resulted in a greater proportion (40%; P < 0.001) of samples with positive results. Estimated relative sensitivities for the storage methods were 0.90, 0.85, and 0.71 for same-day processing, storage at 4 C for 6 days, and storage at -15 C for 14 days, respectively.

CONCLUSIONS

Where practical, processing of fecal samples on the day of collection is recommended, although storage at 4 C for several days does not result in marked loss of sensitivity. Improved detection associated with DSE warrants further investigation and optimization.

Abnormalities of the thoracic bellows: stress fractures of the ribs and hiatal hernia

The thoracic bellows mechanism consists of the rib cage and the diaphragm. The purpose of this study was to determine if nontraumatically acquired lesions of the bellows were secondary to underlying disease. Abnormalities of the bellows, specifically stress fractures of the ribs and hiatal hernia, were found in 21 dogs and cats with underlying cardiopulmonary disease, neuromuscular disease, or metabolic disease. A case-control study of Bulldogs demonstrated that hiatal hernia was associated with the more severe manifestations of brachycephalic syndrome. Stress fractures occurred mostly in females and in cats, and involved multiple ribs. Fractures were usually related to severe respiratory effort, but also occurred in association with metabolic disease. Hiatal hernia was also associated with severe respiratory effort, but may be exacerbated if a neuromuscular disorder affecting the diaphragm is present. Abnormalities of the thoracic bellows, such as rib stress fractures and hiatal hernia, may be signs of underlying disease, rather than being primary causes of disease.

Epidemiologic evaluation of the risk factors associated with exposure and seroreactivity to Bartonella vinsonii in dogs

OBJECTIVES

To determine seroprevalence to Bartonella vinsonii subsp berkhoffii in a population of sick dogs from North Carolina and Virginia and to evaluate potential risk factors associated with increased likelihood of exposure to the organism.

SAMPLE POPULATION

Serum samples from 1,920 sick dogs.

PROCEDURE

An indirect fluorescent antibody assay was performed on each sample, and the end-point antibody titer was recorded. A case (seropositive) was defined as a dog with reciprocal titer > or = 64, and a control (seronegative) was defined as a dog with reciprocal titer < 16 that was referred within 0 to 3 days of referral of a corresponding case. From this population, 207 dogs (69 cases and 138 controls) were included in a case-control seroepidemiologic study.

RESULTS

3.6% (69/1,920) of the dogs were seropositive to B vinsonii subsp berkhoffii. Results of the case-control study indicated that seropositive dogs were more likely to live in rural environments, frequently on a farm, were free to roam the neighborhood, and were considered to be predominantly outdoor dogs. Moreover, seropositive dogs were 14 times more likely to have a history of heavy tick exposure. After analysis of the case-control study, a more detailed examination of banked sera from dogs with known tick exposure was performed. High correlation was found between sero-reactivity to B vinsonii and seroreactivity to E canis or B canis (36.0 and 57.1%, respectively). Sera derived from dogs experimentally infected with E canis or R rickettsii did not cross react with B vinsonii antigen.

CONCLUSIONS AND CLINICAL RELEVANCE

Several potential risk factors are associated with canine exposure to B vinsonii. Rhipicephalus sanguineus, the tick vector for E canis and B canis, may be involved in B vinsonii transmission among dogs.

Histopathology and epidemiology of condemnations due to squamous cell carcinoma in broiler chickens in North Carolina

Squamous cell carcinoma (SCC) lesions were confirmed by histopathology in 94% of 176 carcasses condemned for SCC during 8-hour shifts at four different processing plants. Lesions in the remaining carcasses were diagnosed as focal ulcerative dermatitis. SCC lesions were confined to the skin; no metastasis or invasion of underlying muscle was present. Monthly prevalence of SCC condemnations at processing was obtained from two plants for a 1-year period and from two additional plants for 3-year periods. Overall study prevalence of SCC varied between 0.03% and 0.09% of total condemnations. Servicemen were found not to have an effect on SCC condemnations for the only company that had these data available. Chronological trends were evaluated for SCC condemnations. A trigonometric model predicted 6-month cycles for one processing plant over a 3-year period. The same model was used to describe 6-month cycles present in the last 12 months of a 3-year observation period in a different processing plant. Chronologic trends were evaluated qualitatively for the two other processing plants.

The effects of cyclosporine versus standard care in dogs with naturally occurring glomerulonephritis

Glomerulonephritis (GN) is a leading cause of chronic renal failure in dogs. However, little is known about the efficacy of available treatment options for GN in this species. The purpose of this study was to determine the effects of cyclosporine (Cy) administration on the outcome of naturally occurring GN in dogs. Thirteen dogs from 4 institutions were included in the study. Randomization of dogs into placebo-versus Cy-treated groups was stratified according to initial morphological diagnosis and contributing institution. Seven and 6 dogs were assigned to be given placebo or Cy, respectively. The initial Cy dose of 10 mg/kg every 24 hours was adjusted to maintain 24-hour trough, whole blood Cy concentrations between 250 and 400 ng/mL. There were no statistically significant differences between placebo- and Cy-treated groups with respect to serum total protein, albumin, urea nitrogen and creatinine, and plasma protein concentrations; platelet count; urine protein-creatinine ratio; endogenous creatinine clearance; 24-hour urine protein concentrations; or 24-hour urine protein-endogenous creatinine clearance ratio. However, PCV was significantly lower in the Cy-treated group. Decreased appetite, diarrhea, vomiting, weight loss, involuntary shaking, and thrombocytopenia were noted in both treatment groups; however, clinical signs in Cy-treated dogs subjectively were more severe. One Cy-treated dog developed gingival hyperplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival of pseudorabies virus on swabs maintained under standard field sample shipping conditions

Pseudorabies virus survival was compared using three different types of applicator swabs in Eagle's minimum essential medium held under shipping conditions (packed with frozen gel packs) for up to 96 hours. Virus titer decay rates for dacron-tipped applicators were not statistically different from those of controls. Titer decay rates were statistically different from controls for cotton- and calcium alginate-tipped applicators. With the lowest input virus titer, virus was detectable up to 96, 72, or 24 hours after inoculation for dacron-, cotton-, and calcium alginate-tipped applicators, respectively. Dacron-tipped applicators were chosen to evaluate pseudorabies virus survival on tonsil swabs collected from experimentally challenged or contact control pigs to simulate field sampling and shipping conditions. Virus was still detectable in 20 of 24 swab samples after 72 hours in cell culture medium under shipping conditions.

Effects of calving season and milk yield on pregnancy risk and income in North Carolina Holstein cows

Effects of season of calving and milk yield and their potential interaction on days from calving to last breeding were investigated using survival analysis and an economic model in 2000 Holstein cows that calved during 1989 and 1990. The final Cox proportional hazards model included lactation number, calving season, and herdmate deviation FCM. The interval from calving to last breeding ranged from 40 to 570 d. Compared with cows that calved in fall, cows that calved in summer were two-thirds as likely to become pregnant. Conversely, cows calving in winter or spring were more likely to become pregnant. Milk yields beyond approximately 8025 kg lowered the risk of pregnancy. The interaction of season and yield was nonsignificant, suggesting that these factors may act independently to affect reproduction. Lower pregnancy rates associated with high yield were detected earlier postpartum than were lower rates associated with calving in summer. Within each season, higher yield offset the lower income over feed costs associated with poorer reproductive performance. Nevertheless, summer calving lowered income over feed costs per cow per year by $98, $2, $176, and $68 for low, medium to low, medium to high, and high yielding cows, respectively.

Heterogeneity of sulfated microdomains within basement membranes of pulmonary airway epithelium

The purpose of this study was to determine whether the cytochemically defined distribution of sulfated macromolecules is significantly different in microdomains of basement membranes (BMs) associated with different levels of pulmonary airways. The high iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) technique, which is highly specific for sulfate esters of glycosaminoglycans and some glycoproteins, was used as a probe to compare the BM of trachea, bronchi, and three different sizes of bronchioles. When HID-reactive sites were counted and statistically compared, significant differences were found between the three known anatomically distinct layers of the BM--lamina lucida (LL), lamina densa (LD), and lamina reticularis (LR)--relative to the airway level. The highest concentration of HID reactivity in trachea, bronchi, and large bronchiole was found in LR and the lowest in LD. By comparison, HID-reactive sites were found to be more concentrated in the LL in medium and small bronchioles. HID reactivity was consistently low in LD as compared with LL and LR in all five locations. The overall degree of HID reactivity in BMs was clearly highest in large bronchioles and lowest in medium and small bronchioles. This cytochemically detectable heterogeneity in the distribution of HID reactivity in BM microdomains may represent specific compositional differences in pulmonary BMs which are important determinants of epithelial cell function and might be expected to impact key biologic processes in normal and pathologic states.

Risk factors for downer cow syndrome

A nested case-control study to detect risk factors for the development of the downer cow syndrome 30 d postpartum was conducted. Records from 2705 lactations from 12 Holstein dairy herds in the vicinity of Cornell University were collected prospectively between March 1981 and April 1985. Logistic regression was used to model the risk factors for downer cow syndrome. No confounding or modification effect by season of calving and parity was detected. The cumulative postpartum incidence rate for downer cow syndrome was 1.1%. Clinical hypocalcemia and stillbirth increased the risk of downer cow syndrome fivefold. An interaction term existed between dystocia and retained placenta.

Path analysis for seven postpartum disorders of Holstein cows

Path analysis and multiple logistic regression with an extrabinomial variation error term (to account for herd) were used to model seven postpartum clinical disorders of dairy cows and factors related to the calf. Data were from 7761 lactation records from 34 commercial herds in the vicinity of Cornell University. Stillbirth increased the odds of developing metritis and retained placenta. The odds of developing dystocia and mastitis were lower when the sex of the calf was female. However, cows that twinned had increased odds of developing dystocia and retained placenta. Dystocia was related to an increase in the odds of retained placenta. Milk fever, dystocia, and ketosis each increased the odds of developing left-displaced abomasum. Postpartum periods with dystocia, retained placenta, or ketosis had increased odds of metritis. Two interaction terms involved parity: stillbirth for milk fever and retained placenta for ketosis. The extrabinomial variation error term contributed to the fit in all models.

A nested case-control study of uterine prolapse

A nested case-control study was conducted to detect risk factors for periparturient uterine prolapse. Records from 4173 lactations were collected for 5 years from 17 Holstein dairies in the vicinity of Cornell University. Logistic regression was used to model the risk factors for uterine prolapse. Milk fever, dystocia, sex of the calf, and stillbirth were examined as potential risk factors. There was no confounding or effect modification by season of calving and parity. The incidence rate for uterine prolapse was 0.6%. Dystocia and milk fever increased the risk of uterine prolapse five and three times, respectively.

Factors associated with the development of equine degenerative myeloencephalopathy

A case-control study was done to identify factors associated with the development of equine degenerative myeloencephalopathy (EDM). Questionnaires were mailed to the owners of 146 horses admitted to the New York State College of Veterinary Medicine between November 1978 and June 1987 and diagnosed as having EDM by histologic examination. Questionnaires also were sent to owners of 402 clinically normal horses admitted to the college during the same period. Data were compared between the EDM-affected and control groups (56 and 179 questionnaires returned, respectively). Risk factors identified included the use of insecticide applied to foals, exposure of foals to wood preservatives, and foals frequently spending time on dirt lots while outside. Foals spending time outside on green pastures was a protective factor. Foals from dams that had had an EDM-affected foal were at higher risk of developing EDM than were foals from other dams.

An ecological analysis of risk factors for postpartum disorders of Holstein-Friesian cows from thirty-two New York farms

Path analysis and multiple logistic-normal regression were used to model the interrelationships between stated herd management practices and herd 30-d postpartum incidence rates of dystocia, retained placenta, and clinical postpartum metritis, cystic ovary, milk fever, ketosis, left displaced abomasum, and mastitis. Management risk factors were obtained from a personal interview questionnaire. Data were from 2141 multiparous Holstein calvings from May 1981 through April 1982 in 32 commercial herds in the vicinity of Cornell University. Farms where the stated policy was to administer low calcium diets to the dry cows experienced more dystocia and retained placenta. More dystocia was experienced on farms where the stated policy was to administer extra vitamin D to dry cows, where dry cows were housed with the milking cows, or where calving occurred in maternity pens rather than stanchions. There was an increased likelihood of milk fever and left displaced abomasum on farms on which the stated policy was to lead feed. Farms where dairy farmers treated cases of retained placenta had more retained placenta than farms on which the treatment was done by the veterinarian. Farms reporting the practice of feeding the cows to increase their weight during the dry period had increased odds of ketosis.

Effects of age, sex, and body size on serum concentrations of thyroid and adrenocortical hormones in dogs

Thyroxine (T4), 3,5,3'-triiodothyronine (T3), and cortisol frequently are quantified in canine serum or plasma samples to aid in the diagnosis of hypothyroidism, hypoadrenocorticism, and hyperadrenocorticism. Many laboratories have established reliable references values for concentrations of these hormones in blood of clinically normal animals. However, nonpathologic factors that affect thyroidal and adrenocortical secretion may lead to misinterpretation of test results when values for individual animals are compared with reference values. The objective of the study reported here was to identify effects of age, sex, and body size (ie, breed) on serum concentrations of T3, T4, and cortisol in dogs. Blood samples were collected from 1,074 healthy dogs, and serum concentrations of the iodothyronines and cortisol were evaluated for effects of breed/size, sex, and age. Mean (+/- SEM) serum concentration of T4 was greater in small (2.45 +/- 0.06 micrograms/dl)- than in medium (1.94 +/- 0.04 micrograms/dl)- or large (2.03 +/- 0.03 micrograms/dl)-breed dogs, the same in females (2.11 +/- 0.04 micrograms/dl) and males (2.08 +/- 0.04 micrograms/dl), and greater in nursing pups (3.04 +/- 0.05 micrograms/dl) than in weanling pups (1.94 +/- 0.05 micrograms/dl), rapidly growing dogs (1.95 +/- 0.04 micrograms/dl), and young adult (1.90 +/- 0.06 micrograms/dl), middle-aged adult (1.72 +/- 0.05 micrograms/dl), or old adult (1.50 +/- 0.05 micrograms/dl) dogs. Dogs greater than 6 years old had lower mean serum T4 concentration than did dogs of all other ages, except middle-aged adults. Mean serum T3 concentration in medium-sized dogs (1.00 +/- 0.01 ng/ml) was greater than that in small (0.90 +/- 0.01 ng/ml)- and large (0.88 +/- 0.01 ng/ml)-breed dogs.(ABSTRACT TRUNCATED AT 250 WORDS)