Veterinary Clinical Pathology Laboratory Research Articles

Breed distributions for diabetes mellitus and hypothyroidism in Norwegian dogs

BackgroundDiabetes mellitus (DM) and hypothyroidism are common canine endocrinopathies. Both canine DM and primary hypothyroidism are assumed to originate from autoimmune destruction of the respective endocrine glands and have been associated with the major histocompatibility complex (MHC) gene region. This study aims to investigate breed distributions for DM and hypothyroidism in the Norwegian canine population by calculating odds ratios (OR) from two different comparator groups.MethodsResults from canine serum samples submitted from 2001 to 2018 to the Veterinary Clinical Pathology Laboratory (VCPL) at the Faculty of Veterinary Medicine, Norwegian University of Life Sciences for analysis of fructosamine and thyroid hormones in serum were used as cases in a retrospective bivariate analysis of canine breeds. The ORs were calculated as a measure of risk for the included breeds, where all the submitted blood samples to the VCPL and dogs registered in the Norwegian Kennel Club (NKK), the national organization for dog owners, were used as two comparator groups.ResultsSignificant differences in disease prevalence between breeds were discovered using both comparator groups. Australian terrier, Swedish lapphund, Samoyed, and Schipperke were at highest risk for DM. German Shepherd, Golden retriever, German pointing dog, and Collie presented as the breeds with lowest risk for DM. For hypothyroidism, Schnauzer, Eurasier, Dunker, and English setter were at highest risk for developing the disease. The breeds at lowest risk of developing hypothyroidism were Rottweiler, Dachshund, German shepherd, and Border collie. The results from the different comparator groups gave different ORs and ranks, but the breeds with highest and lowest odds showed the same susceptibility using both comparators.ConclusionsThese findings support that there are breeds more and less prone to develop DM and hypothyroidism. A strong genetic predisposition involved in the aetiology of these two diseases is therefore likely. Interestingly, there also appeared to be an inverse relationship of odds for the two diseases for some of the breeds since some breeds that had a high OR for DM or hypothyroidism had a lower OR for the other disease. This indicates that there may be different risk alleles/haplotypes for the two diseases. The possible aetiological relationship between canine DM and hypothyroidism should be further investigated.

Age- and sex-associated differences in hematology and biochemistry parameters of Dunkin Hartley guinea pigs (Cavia porcellus).

The Dunkin Hartley is the most common guinea pig strain used in biomedical research, particularly for studies of asthma, allergy, infectious disease, reproduction, and osteoarthritis. Minimally invasive blood tests, such as complete blood counts and serum biochemistry profiles, are often collected for diagnostics and laboratory analyses. However, reference intervals for these assays have not yet been well-documented in this strain. The purpose of this study was to establish reference intervals for hematologic and biochemical parameters of Dunkin Hartley guinea pigs and determine age- and sex-related differences. Hematologic and biochemical parameters were retrospectively obtained from 145 male and 68 female guinea pigs between 2 and 15 months of age. All blood parameters were analyzed by a veterinary clinical pathology laboratory. Reference intervals were established according to the American Society for Veterinary Clinical Pathology guidelines. Age- and sex-related differences were determined using unpaired t-tests or nonparametric Mann-Whitney tests. Hematocrit, red blood cell distribution width, mean platelet volume, white blood cell count, heterophils, monocytes, eosinophils, glucose, blood urea nitrogen, creatinine, calcium, magnesium, total protein, albumin, globulin, cholesterol, aspartate aminotransferase, gamma glutamyl transferase, and bicarbonate increased with age. Mean corpuscular hemoglobin concentration, cellular hemoglobin concentration mean, platelets, lymphocytes, phosphorus, albumin/globulin ratio, alkaline phosphatase, anion gap, and calculated osmolality decreased with age. Males had higher hemoglobin, hematocrit, red blood cell count, mean corpuscular hemoglobin concentration, white blood cell count, heterophils, Foa-Kurloff cells, alanine aminotransferase, and bicarbonate and lower mean corpuscular volume, red blood cell distribution width, platelets, mean platelet volume, eosinophils, total protein, albumin, globulin, cholesterol, potassium, anion gap, calculated osmolality, and iron compared to females. Establishing age and sex differences in hematologic and biochemical parameters of Dunkin Hartley guinea pigs provides valuable insight into their physiology to better evaluate diagnostics and experimental results.

Main biosafety measures for veterinary clinical pathology laboratories and the importance of their knowledge

Biosafety is a set of measures that aim to prevent, minimize, or eliminate risks intrinsic to professional practice, thus ensuring the preservation of the environment, the health of man and animals. Veterinarians, as well as other health professionals, must know and apply these measures, protecting themselves from the risks inherent to their profession and, consequently, protecting the population. In the veterinary clinical pathology lab, numerous activities with a potential capacity to generate accidents are observed, from occupational risks knowing as occupational diseases to exposure to chemical and biological agents, putting the health of these professionals and the environment integrity daily at risk. Therefore, suitable biosafety measures must be taken to minimize these risks. Thus, this work aims to make a bibliographic review on the main biosafety measures applicable to the area, alerting veterinarians about the importance of its application in their work environment.

An analysis of time trends for canine heartworm disease in Grenada and its associated risk factors based on veterinary clinical pathology laboratory data base records between 2003 and 2015

Canine heartworm (CHW) disease is a common parasitic infection in dogs in the Caribbean islands. However, studies on temporal trends and risk factors are limited for this region. This study represents the time trends in laboratory prevalence and risk factors of canine heartworm infections between 2003 and 2015.In this case series, 662 cases of laboratory-diagnosed heartworm were compared to 662 dogs without a laboratory diagnosis of heartworm (controls). One hundred and seventy two frozen serum positive samples were later analyzed for heartworm antigens using Heska solo® Step CH, and all 172 cases of microfilariae were confirmed as Dirofilaria immitis. Annual prevalence, linear trends and odds ratios (OR) for CHW were estimated using EPIINFO version 7 at a significance level of α = 0.05. Logistic regression was used to assess the association of CHW with variables showing a statistically significant univariate relationship.Laboratory prevalence of CHW decreased from 72 cases per 1000 dogs per year in 2003 to 15 cases per 1000 dogs per year in 2015 [X2 for linear trend = 151.8, p < 0.0001], with the occurrence of an epidemic of CHW between 2008 and 2010.The odds of CHW were higher among adult dogs [(OR) = 3.9 (95% CI, 2.9–7.0)] and geriatric dogs [OR = 2.1 (95% CI, 1.1–4.3)] compared to puppies. The odds of CHW were higher [OR = 1.3 (95% CI, 1.1–1.6)] among male dogs than female dogs, but the odds for CHW were lower among neutered dogs [OR = 0.4 (95% CI, 0.2 – 0.6)] compared to intact dogs. The odds of a dog being diagnosed with CHW were elevated [OR = 4.1 (95% CI, 3.2–5.2)] during the dry season compared to the rainy season.Our findings show that canine heartworm is extensive in laboratory submissions in Grenada. However, the laboratory prevalence of CHW decreased between 2003 and 2015, with an epidemic occurring between 2008 and 2010. Age of the dog, sex, neutered status, and seasonality of diagnosis were significantly associated CHW in Grenada.

Mechanisms of β-lactam resistance of Streptococcus uberis isolated from bovine mastitis cases

A number of veterinary clinical pathology laboratories in New Zealand have been reporting emergence of increased minimum in inhibitory concentrations for β-lactams in the common clinical bovine mastitis pathogen Streptococcus uberis. The objective of this study was to determine the genetic basis of this increase in MIC for β-lactams amongst S. uberis. Illumina sequencing and determination of oxacillin MIC was performed on 265 clinical isolates. Published sequences of the five penicillin binding proteins pbp1a, pbp1b, pbp2a, pbp2b, and pbp2x were used to identify, extract and align these sequences from the study isolates. Amino acid substitutions resulting from single nucleotide polymorphisms (SNP) within these genes were analysed for associations with elevated (≥ 0.5 mg/L) oxacillin MIC together with a genome wide association study. The population structure of the study isolates was approximated using a phylogenetic tree generated from an alignment of the core genome. A total of 53 % of isolates had MIC ≥ 0.5 mg/L for oxacillin. A total of 101 substitutions within the five pbp were identified, of which 11 were statistically associated with an MIC ≥ 0.5 mg/L. All 140 isolates which exhibited an increased β-lactam MIC had SNPs leading to pbp2x E381K and Q554E substitutions. The phylogenetic tree indicated that the genotype and phenotype associated with the increased MIC for oxacillin were present in several different lineages suggesting that acquisition of this increased β-lactam MIC had occurred in multiple geographically distinct regions. Reanalysis of the data from the intervention studies from which the isolates were originally drawn found a tendency for the pbp2x E381K substitution to be associated with lower cure rates. It is concluded that there is geographically and genetically widespread presence of pbp substitutions associated with reduced susceptibility to β-lactam antimicrobials. Additionally, presence of pbp substitutions tended to be associated with poorer cure rate outcomes following antimicrobial therapy for clinical mastitis.

Detection of antibodies against Sarcocystis neurona, Neospora caninum and Toxoplasma gondii in horses, dogs and cat

The occurrence and distribution of antibodies against Sarcocystis neurona, Neospora caninum and Toxoplasma gondii was investigated in horses, dogs and cats from Curitiba, Paraná state, Brazil. Serum samples were selected from 100 horses, 100 dogs and 100 cats from the routine of the Veterinary Clinical Pathology Laboratory in the Veterinary Hospital of the University of Paraná (UFPR). The 100 dog samples were divided into two groups: 35 samples from dogs with neurological sign (convulsion) and 65 samples from dogs without neurological signs. The animals were adults of different breeds, males and females. Samples were analyzed by indirect fluorescent antibody test (IFAT) for protozoa S. neurona, N. caninum andT. gondii at the following cut-off dilutions: horses: 1:50, 1:50 and 1:16; dogs: 1:50, 1:50 and 1:16; cats: 1:50, 1:50 and 1:50, respectively. The obtained results were 42% of horses, 7% of dogs and 5% of cats seropositive for S. neurona; 58% of horses, 68% of dogs and 42% of cats seropositive to N. caninum, and 36% of horses, 20% of dogs and 21% of cats seropositive for T. gondii. Among the dogs with neurological signs, 8.6%, 68.6% and 25.7% were seropositive for S. neurona, N. caninum and T. gondii, respectively. Among the dogs without neurological signs, 6.2% 67.7% and 16.9% were seropositive for S. neurona, N. caninum and T. gondii, respectively. No statistical difference was found between groups of seropositive dogs for the three protozoa with neurological signs and without neurological signs. Co-infection and high antibody titers were detected. The antibodies against Sarcocystis neurona, Neospora caninum and Toxoplasma gondii were found widely distributed among horses, dogs and cats in the region of Curitiba, state of Paraná, Brazil. &#x0D;

Use of Six Sigma Worksheets for assessment of internal and external failure costs associated with candidate quality control rules for an ADVIA 120 hematology analyzer.

Quality control (QC) validation is an essential tool in total quality management of a veterinary clinical pathology laboratory. Cost-analysis can be a valuable technique to help identify an appropriate QC procedure for the laboratory, although this has never been reported in veterinary medicine. The aim of this study was to determine the applicability of the Six Sigma Quality Cost Worksheets in the evaluation of possible candidate QC rules identified by QC validation. Three months of internal QC records were analyzed. EZ Rules 3 software was used to evaluate candidate QC procedures, and the costs associated with the application of different QC rules were calculated using the Six Sigma Quality Cost Worksheets. The costs associated with the current and the candidate QC rules were compared, and the amount of cost savings was calculated. There was a significant saving when the candidate 1-2.5s, n = 3 rule was applied instead of the currently utilized 1-2s, n = 3 rule. The savings were 75% per year (£ 8232.5) based on re-evaluating all of the patient samples in addition to the controls, and 72% per year (£ 822.4) based on re-analyzing only the control materials. The savings were also shown to change accordingly with the number of samples analyzed and with the number of daily QC procedures performed. These calculations demonstrated the importance of the selection of an appropriate QC procedure, and the usefulness of the Six Sigma Costs Worksheet in determining the most cost-effective rule(s) when several candidate rules are identified by QC validation.

Feline reference intervals for the Sysmex XT-2000iV and the ProCyte DX haematology analysers in EDTA and CTAD blood specimens.

Laser-based haematology analysers are routinely used in veterinary clinical pathology laboratories, and are available to practitioners. However, feline haematological reference intervals (RIs) determined according to international recommendations are, to our knowledge, not available. Furthermore, platelet count RI is difficult to establish in cats because of the frequent occurrence of platelet aggregation in blood specimens. The purpose of this study was to establish feline haematological RIs with the Sysmex XT-2000iV and ProCyte DX analysers, in ethylenediamine tetra-acetic acid (EDTA) and in citrate, theophylline, adenosine and dipyridamole (CTAD), which is a combination of anticoagulants limiting platelet aggregation. Blood specimens from 120 healthy cats were analysed in duplicate, and the degree of platelet aggregation was assessed on blood smears. After exclusion of inadequate specimens, 81 sets of results (from 44 males and 37 females, aged from 6 to 116 months) were available for the determination of RIs by the non-parametric method. The effects of the anticoagulant, analyser and aggregation score were assessed. When the aggregation effect was significant, the RIs were determined using the subgroup of blood specimens with no or little aggregation. The effects of sex, age and weight were also investigated, but were moderate. The different RIs obtained with the Sysmex XT-2000iV and ProCyte DX analysers, and the two anticoagulants, were very similar to previous RIs established in EDTA with the ADVIA 120, another laser-based analyser, except for the platelet count in CTAD specimens. Its lower reference limit was higher in CTAD vs EDTA specimens, which confirms the interest in this anticoagulant in cats.

Canine reference intervals for the Sysmex XT‐2000iV hematology analyzer

The laser-based Sysmex XT-2000iV hematology analyzer is increasingly used in veterinary clinical pathology laboratories, and instrument-specific reference intervals for dogs are not available. The purpose of this study was to establish canine hematologic reference intervals according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the Sysmex XT-2000iV hematology analyzer. Blood samples from 132 healthy purebred dogs from France, selected to represent the most prevalent canine breeds in France, were analyzed. Blood smears were scored for platelet (PLT) aggregates. Reference intervals were established using the nonparametric method. PLT and RBC counts obtained by impedance and optical methods were compared. Effects of sex and age on reference intervals were determined. The correlation between impedance (I) and optical (O) measurements of RBC and PLT counts was excellent (Pearson r=.99 and .98, respectively); however, there were significant differences between the 2 methods (Student's paired t-test, P<.0001). Differences between sexes were not significant except for HCT, PLT-I, and PLT-O. WBC, lymphocyte, and neutrophil counts decreased significantly with age (ANOVA, P<.05). Median eosinophil counts were higher in Brittany Spaniels (1.87 × 10(9) /L), Rottweilers (1.41 × 10(9) /L), and German Shepherd dogs (1.38 × 10(9) /L) than in the overall population (0.9 × 10(9) /L). PLT aggregates were responsible for lower PLT counts by the impedance, but not the optical, method. Reference intervals for hematologic analytes and indices were determined under controlled preanalytical and analytical conditions for a well-characterized population of dogs according to international recommendations.

Appearance of granulated cells in blood films stained by automated aqueous versus methanolic Romanowsky methods

Romanowsky stains are used routinely by veterinary clinical pathology laboratories for cytologic and blood film evaluations. Automated stainers are available for both aqueous and methanolic Romanowsky stains. Mast cell granules and canine distemper virus inclusions are known to stain differently by these 2 methods, but we have noticed differences in the staining characteristics of other granulated cells. The aim of this study was to investigate and document the variable appearance of basophils and large granular lymphocytes in blood films stained using aqueous and methanolic Romanowsky methods. Cytologic preparations from 1 canine mast cell tumor and blood films from 8 dogs, 1 cat, 1 rabbit, and 1 ostrich were stained using an automated aqueous stain (Aerospray 7120, with and without a predip fixative) and an automated methanolic stain (Hematek). Staining quality and intensity of the cytoplasmic granules in mast cells, basophils, and large granular lymphocytes was evaluated subjectively. Cytoplasmic granules of mast cells, basophils, and large granular lymphocytes stained poorly or not at all with the automated aqueous stain but stained prominently and were readily identified with the automated methanolic stain. Use of the predip fixative with the Aerospray method improved the visibility of basophil granules but not mast cell granules, and had a variable affect on the visibility of granules in large granular lymphocytes. Clinical pathologists should be aware of the staining methodology used on the slides they evaluate to avoid incorrect interpretation of granulated cell populations.

Quality Documentation Challenges for Veterinary Clinical Pathology Laboratories

An increasing number of veterinary laboratories worldwide have obtained or are seeking certification based on international standards, such as the International Organization for Standardization/International Electrotechnical Commission 17025. Compliance with any certification standard or quality management system requires quality documentation, an activity that may present several unique challenges in the case of veterinary laboratories. Research specifically addressing quality documentation is conspicuously absent in the veterinary literature. This article provides an overview of the quality system documentation needed to comply with a quality management system with an emphasis on preparing written standard operating procedures specific for veterinary laboratories. In addition, the quality documentation challenges that are unique to veterinary clinical pathology laboratories are critically evaluated against the existing quality standards and discussed with respect to possible solutions and/or recommended courses of action. Documentation challenges include the establishment of quality requirements for veterinary tests, the use or modification of human analytic methods for animal samples, the limited availability of quality control materials satisfactory for veterinary clinical pathology laboratories, the limited availability of veterinary proficiency programs, and the complications in establishing species-specific reference intervals.

Analysis of mouse, rat, dog, marmoset, and human serum proteins by capillary electrophoresis: comparison with agarose gel electrophoresis

Serum protein analysis in both humans and experimental animal species has so far been carried out by labor-intensive techniques, such as agarose gel electrophoresis (AGE). The objective of this study was to evaluate capillary electrophoresis (CE) as an alternative technique to AGE for the analysis of serum proteins from healthy animals. Blood samples were collected into tubes without anticoagulant from 6 fasted healthy male mice, rats, dogs, marmosets, and humans. Serum proteins were separated by CE using a technique standardized for the analysis of human proteins, and the results (efficiency, resolution, and precision) were compared with those obtained through AGE. Compared with AGE, CE resulted in narrower peaks and more peaks. The efficiency of protein separation by CE was significantly higher for all species, and resolution (R) was significantly higher in samples from dogs. Using rat serum, intraday reproducibility was lower for all protein fractions, and interday reproducibility was lower for most peaks, compared with AGE. We conclude that CE is a viable alternative to AGE for the determination of protein electrophoresis in a routine veterinary clinical pathology laboratory. The minimal sample requirement (2 microL), complete automation, and quantitative results make CE an especially valuable technique for protein analysis in experimental animal models.

Evaluation of an automated tabletop blood biochemical analyzer for the veterinary clinical pathology laboratory

Summary The importance of accurate quantitative blood biochemical analysis for the diagnosis and management of disease is recognized by most veterinarians. In recent years, several biochemical analyzers have become available for the veterinary market. One of these analyzers was evaluated for its suitability in measuring several biochemical variables—alkaline phosphatase, urea nitrogen, creatinine, glucose, alanine transaminase (dog and cat only), and aspartate transaminase (horse only)—in dogs, cats, and horses. Instrument within-day precision ranged from 1.0 to 7.1%, and between-day precision ranged from 1.6 to 7.4%. During the 6-month period of the study, the analyzer required recalibration for only 1 analyte (creatinine). Concentrations of individual analytes were similar when blood (collected in anticoagulant), plasma, and serum were assayed in parallel. The accuracy of the analyzer, as measured by correlation to a reference method, ranged from 0.861 for creatinine in horses to &gt; 0.950 for each of the other analytes in the 3 species. Mean values for each analyte were similar, except for alkaline phosphatase, which had consistently lower values by use of the analyzer method. A data base was established for reference values in each species.

Plasma ammonia concentration in dogs using ion-exchange method of analysis.

Laboratory methods for measuring plasma ammonia concentration were reviewed. The ion-exchange method of analysis was evaluated using canine plasma from 15 clinically normal dogs and five dogs with portosystemic shunts. Mean and standard deviation was 40.3 +/- 8.1 microgram NH(3)/dl in normal dogs, and values ranged from 125 to 200 microgram NH(3)/dl in dogs with portosystemic shunts. Handling of blood samples properly for accurate results was found to require pre-chilled collection tubes, chilling the samples in an ice bath, immediate separation of plasma from red blood cells and immediate analysis for ammonia concentration. The ion exchange method was determined to be sufficiently accurate for clinical use and is suggested for any veterinary clinical pathology laboratory.