Heterobilharzia americana infection in dogs: A retrospective study of 60 cases (2010-2019).

BACKGROUND: The trematode Heterobilharzia americana (HA) causes granulomatous gastrointestinal and hepatic disease in dogs. Before 2008, diagnosis relied on saline fecal sedimentation or histopathology, and earlier reports primarily described dogs with advanced disease or cases diagnosed incidentally at necropsy. The advent of a fecal PCR test has facilitated the diagnosis of HA and provided insights into manifestations and response to treatment. OBJECTIVES: Describe the clinical findings, response to treatment, and outcome for dogs infected with HA. ANIMALS: Sixty dogs diagnosed with HA between 2010 and 2019. METHODS: Retrospective study. Medical records were searched for dogs diagnosed with HA by fecal PCR testing, identification of ova in feces, or histopathology. RESULTS: Mean age was 7.5 (±4.1) years and weight was 23.2 (±10.18) kg. Clinical signs included diarrhea (55.8%), vomiting (46.2%), and weight loss with or without anorexia (15.4%). Laboratory abnormalities included hyperglobulinemia (42.6%) and increased liver enzyme activities (30%). More than 40% of dogs had an eosinophil count >500/µL. Hypercalcemia attributable to HA was identified in only 4 dogs. Pinpoint hyperechoic foci were noted in intestines, liver, or mesenteric lymph nodes during transabdominal ultrasonography in 64.4% of dogs. Survival data was available for 34 dogs, of which 73.5% (25) were alive 6 months after diagnosis. CONCLUSIONS AND CLINICAL IMPORTANCE: Hyperglobulinemia, high eosinophil count, and ultrasonographic evidence of visceral mineralization were suggestive of infection. Hypercalcemia was uncommon. Combination treatment with praziquantel and fenbendazole was variably effective, and 17.6% of treated dogs with known outcome died as a result of HA infection.

Sequence analysis of the coding regions of the apolipoprotein C2 (APOC2) gene in Miniature Schnauzers with idiopathic hypertriglyceridemia.

It has been hypothesized that idiopathic hypertriglyceridemia in Miniature Schnauzers is hereditary, but the gene responsible has yet to be identified. The objective of this study was to determine if there were coding variants in the apolipoprotein C2 (APOC2) gene in Miniature Schnauzers with idiopathic hypertriglyceridemia. Blood samples from 12 Miniature Schnauzers with idiopathic hypertriglyceridemia were analyzed. Genomic DNA was extracted from whole blood, and the three coding exons of APOC2 were amplified by PCR. The PCR amplicons were sequenced and analyzed for variants relative to the canine reference genome (CanFam3.1 assembly). A second objective was to determine the extent of variation in coding exons of APOC2 in a large and diverse canine population using the Dog Biomedical Variant Database Consortium variant catalog, comprised of whole genome sequencing variant calls from 582 dogs of 126 breeds and eight wolves. There were no variants detected in the coding exons of APOC2 for any of the 12 Miniature Schnauzers with idiopathic hypertriglyceridemia. Variants in the coding exons of APOC2 were also rare in the Dog Biomedical Variant Database Consortium variant catalog; a single synonymous variant was identified in a heterozygous state in a Tibetan Mastiff. Thus, we concluded that coding variants in APOC2 are unlikely to be a major cause of idiopathic hypertriglyceridemia in North American Miniature Schnauzers and furthermore, that such coding variants are rare in the canine population.

Untargeted metabolomic profiling of serum from dogs with chronic hepatic disease.

BACKGROUND: Chronic hepatopathies present a diagnostic challenge, with different diseases being associated with similar clinical and laboratory findings. Characterization of dogs with chronic hepatopathies can be difficult and require costly diagnostic procedures such as acquisition of a liver biopsy specimen. Noninvasive and inexpensive biomarkers that reliably characterize chronic hepatopathies such as chronic hepatitis or a congenital portosystemic vascular anomaly may decrease the need for costly or invasive diagnostic testing and guide novel therapeutic interventions. OBJECTIVE: To investigate differences in the serum metabolome among healthy dogs, dogs with congenital portosystemic shunts, and dogs with chronic hepatitis. ANIMALS: Stored serum samples from 12 healthy dogs, 10 dogs with congenital portosystemic shunts, and 6 dogs with chronic hepatitis were analyzed. METHODS: The serum metabolome was analyzed with an untargeted metabolomics approach using gas chromatography-quadrupole time of flight mass spectrometry. RESULTS: Principal component analysis and heat dendrogram plots of the metabolomics data showed clustering among individuals in each group. Random forest analysis showed differences in the abundance of various metabolites including increased aromatic amino acids and xylitol in dogs with congenital portosystemic shunts. Based on the univariate statistics, 50 metabolites were significantly different among groups. CONCLUSIONS AND CLINICAL IMPORTANCE: The serum metabolome varies among healthy dogs, dogs with congenital portosystemic shunts, and dogs with chronic hepatitis. Statistical analysis identified several metabolites that differentiated healthy dogs from dogs with vascular or parenchymal liver disease. Further targeted assessment of these metabolites is needed to confirm their diagnostic reliability.

Collaborating genomic, transcriptomic and microbiomic alterations lead to canine extreme intestinal polyposis.

Extreme intestinal polyposis in pet dogs has not yet been reported in literature. We identified a dog patient who developed numerous intestinal polyps, with the severity resembling human classic familial adenomatous polyposis (FAP), except the jejunum-ileum junction being the most polyp-dense. We investigated this dog, in comparison with 22 other dogs with spontaneous intestinal tumors but no severe polyposis, and with numerous published human cancers. We found, not APC mutation, but three other alteration pathways as likely reasons of this canine extreme polyposis. First, somatic truncation mutation W411X of FBXW7, a component of an E3 ubiquitin ligase, over-activates MYC and cell cycle-promoting network, accelerating crypt cell proliferation. Second, genes of protein trafficking and localization are downregulated, likely associated with germline mutation G406D of STAMBPL1, a K63-deubiquitinase, and MYC network activation. This inhibits epithelial apical-basolateral polarity establishment, preventing crypt cell differentiation. Third, Bacteroides uniformis, a commensal gut anaerobe, thrives and expresses abundantly thioredoxin and nitroreductase. These bacterial products could reduce oxidative stress linked to host germline mutation R51X of CYB5RL, a cytochrome b5 reductase homologue, decreasing cell death. Our work emphasizes the close collaboration of alterations across the genome, transcriptome and microbiome in promoting tumorigenesis.

Agreement between microscopic examination and bacterial culture of bile samples for detection of bactibilia in dogs and cats with hepatobiliary disease.

OBJECTIVE To evaluate the agreement between results of microscopic examination and bacterial culture of bile samples from dogs and cats with hepatobiliary disease for detection of bactibilia. DESIGN Cross-sectional study. ANIMALS 31 dogs and 21 cats with hepatobiliary disease for which subsequent microscopic examination and bacterial culture of bile samples was performed from 2004 through 2014. PROCEDURES Electronic medical records of included dogs and cats were reviewed to extract data regarding diagnosis, antimicrobials administered, and results of microscopic examination and bacterial culture of bile samples. Agreement between these 2 diagnostic tests was assessed by calculation of the Cohen κ value. RESULTS 17 (33%) dogs and cats had bactibilia identified by microscopic examination of bile samples, and 11 (21%) had bactibilia identified via bacterial culture. Agreement between these 2 tests was substantial (percentage agreement [positive and negative results], 85%; κ = 0.62; 95% confidence interval, 0.38 to 0.89) and improved to almost perfect when calculated for only animals that received no antimicrobials within 24 hours prior to sample collection (percentage agreement, 94%; κ = 0.84; 95% confidence interval, 0.61 to 1.00). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that agreement between microscopic examination and bacterial culture of bile samples for detection of bactibilia is optimized when dogs and cats are not receiving antimicrobials at the time of sample collection. Concurrent bacterial culture and microscopic examination of bile samples are recommended for all cats and dogs evaluated for hepatobiliary disease.

Correlation between thromboelastography and traditional coagulation test parameters in hospitalized dogs.

A hospital-based, prospective cross-sectional study was used to compare kaolin-activated thromboelastography (TEG) parameters with traditional coagulation tests in 29 hospitalized dogs. Cases were included if the attending clinician requested coagulation testing. Blood was obtained from each dog and coagulation (prothrombin time, partial thromboplastin time, antithrombin activity, d-dimer concentration, and fibrinogen concentration) and TEG analyses were performed. Hematocrit (Hct) was also measured. Traditional coagulation results were evaluated for correlation with those from kaolin-activated TEG. Spearman's correlation was used to calculate correlation coefficients. Fibrinogen was positively correlated with maximum amplitude (Pearson r=0.72, P<0.001) and global clot strength (Pearson r=0.72, P<0.001). There was no correlation between any of the remaining coagulation variables, TEG parameters, or Hct. Results of kaolin-activated TEG and traditional coagulation tests are not interchangeable means of monitoring coagulation derangements in this intensive care unit patient population. Determination of a true outcome measure is necessary to establish TEG's clinical relevance to veterinary medicine.

Effects of processing delay, temperature, and transport tube type on results of quantitative bacterial culture of canine urine.

OBJECTIVE: To determine the impact of processing delay, temperature, and transport tube type on results of quantitative bacterial culture (QBC) of canine urine. DESIGN: Diagnostic test evaluation. SAMPLE: 60 mL of pooled urine from 4 dogs, divided into six 10-mL aliquots. PROCEDURES: Urine aliquots were spiked with bacteria from 1 of 6 independent Escherichia coli cultures to achieve a target bacterial concentration of 10(5) CFUs/mL. One milliliter from each aliquot was transferred into 5 silicone-coated clot tubes (SCTs) and 5 urine transport tubes (UTTs). Samples were stored at 4°C (39°F) and 25°C (77°F) for 0, 8, and 24 hours, and then standard QBCs were performed. RESULTS: Median bacterial concentration for urine samples stored in a UTT for 24 hours at 4°C was lower than that for samples stored in an SCT under the same conditions. Conversely, a substantial decrease in median bacterial concentration was identified for samples stored for 24 hours in an SCT at 25°C, compared with the median concentration for samples stored in a UTT under the same conditions. Median bacterial concentration in samples stored in an SCT at 25°C for 24 hours (275 CFUs/mL) was less than the cutoff typically used to define clinically important bacteriuria by use of urine samples obtained via cystocentesis (ie, > 1,000 CFUs/mL). CONCLUSIONS AND CLINICAL RELEVANCE: Canine urine samples submitted for immediate QBC should be transported in plain sterile tubes such as SCTs. When prolonged (24-hour) storage at room temperature is anticipated, urine samples should be transported in UTTs.

Stability of hemostatic proteins in canine fresh-frozen plasma thawed with a modified commercial microwave warmer or warm water bath.

OBJECTIVE: To compare stability of hemostatic proteins in canine fresh-frozen plasma (FFP) thawed with a modified commercial microwave warmer (MCM) or warm water bath (37°C; WWB) or at room temperature (22°C). SAMPLE: Fresh-frozen plasma obtained from 8 canine donors of a commercial blood bank. PROCEDURES: A commercial microwave warmer was modified with a thermocouple to measure surface temperature of bags containing plasma. The MCM and a WWB were each used to concurrently thaw a 60-mL bag of plasma obtained from the same donor. Two 3-mL control aliquots of FFP from each donor were thawed to room temperature without use of a heating device. Concentrations of hemostatic proteins, albumin, and D-dimers; prothrombin time (PT); and activated partial thromboplastin time (aPTT) were determined for all samples. RESULTS: Significant decreases in concentrations of factors II, IX, X, XI, fibrinogen, von Willebrand factor, antithrombin, protein C, and albumin and significant increases in PT and aPTT were detected for plasma thawed with the MCM, compared with results for samples thawed with the WWB. Concentrations of factors VII, VIII, and XII were not significantly different between plasma thawed with the MCM and WWB. Concentrations of D-dimers were above the reference range for all thawed samples regardless of thawing method. No significant differences in factor concentrations were detected between control and WWB-thawed samples. CONCLUSIONS AND CLINICAL RELEVANCE: Significant differences in hemostatic protein concentrations and coagulation times were detected for plasma thawed with an MCM but not between control and WWB-thawed samples. Clinical importance of these changes should be investigated.

Evaluation of serum thyroid hormones in dogs with systemic inflammatory response syndrome or sepsis.

OBJECTIVE: To determine whether dogs with systemic inflammatory response syndrome (SIRS) or sepsis have derangements in serum thyroid hormone concentrations and to evaluate whether such derangements relate to illness severity or outcome. DESIGN: Prospective observational study. Dogs hospitalized with SIRS or sepsis between May and December 2010 were included. Serum thyroid hormone concentrations were measured in all dogs. Data obtained on admission were used to calculate the Acute Patient Physiologic and Laboratory Evaluation (APPLE) scores. SETTING: University teaching hospital. ANIMALS: Twenty-two consecutive client-owned dogs hospitalized with SIRS or sepsis were enrolled; 18 dogs completed the study and 4 dogs were excluded for incomplete data. Forty-nine healthy dogs owned by volunteers were used as controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Decreased total thyroxine (TT4) concentrations were documented in all septic and 7/9 dogs with SIRS. Free T4 concentrations were decreased, but were within the reference interval in 12/18 dogs with SIRS or sepsis compared to control dogs (P < 0.001). Dogs with increased APPLE(fast) scores were less likely to survive (P = 0.017). CONCLUSIONS: Dogs with SIRS or sepsis have derangements in measured serum thyroid hormones. No relationships were identified between thyroid hormone concentrations and survival. The APPLE(fast) score was the only variable predictive of poor outcome.

Multicenter evaluation of the administration of crotalid antivenom in cats: 115 cases (2000-2011).

OBJECTIVE: To evaluate use of crotalid antivenom, frequency of hypersensitivity reactions, and risk factors for hypersensitivity reactions and death in envenomed cats. DESIGN: Retrospective multicenter case series. ANIMALS: 115 envenomed cats treated with antivenom and 177 envenomed cats treated without antivenom. Procedures-Medical records from 5 institutions were searched by means of a multiple-choice survey with standardized answers for patient data including signalment, diagnosis, antivenom administration criteria, premedication, product, dose, administration rate, hypersensitivity reactions, and mortality rate. RESULTS: 95 of 115 (82.6%) cats received whole IgG antivenom, 11 (9.57%) received F(ab')2 antivenom, and 4 (3.48%) received Fab antivenom. The majority (101/115 [878%]) of cats received 1 vial of antivenom. In all cats, the median dilution of antivenom was 1:60 (range, 1:10 to 1:250) administered over a median period of 2.0 hours (range, 0.3 to 9.0 hours). There was no mortality rate difference between cats that did (6.67%) or did not (5.08%) receive antivenom. A type I hypersensitivity reaction was diagnosed in 26 of 115 (22.6%) cats. The use of premedications did not decrease type I hypersensitivity or improve mortality rate. Cats that had a type I hypersensitivity reaction were 10 times as likely to die as were those that did not have such a reaction. CONCLUSIONS AND CLINICAL RELEVANCE: The mortality rate of cats treated with antivenom was low. The administration of premedications did not improve mortality rate or prevent hypersensitivity reactions. The only variable associated with mortality rate was development of a type I hypersensitivity reaction. The rate of antivenom administration should be further evaluated as a possible risk factor for type I hypersensitivity reactions.

Evaluation of the MYC_CANFA gene in Chinese Shar Peis with cobalamin deficiency.

BACKGROUND: A recent genome-wide scan using the canine minimal screening set 2 (MSS-2) showed that cobalamin deficiency appears to be hereditary in Chinese Shar Peis and is linked to the microsatellite markers DTR13.6 and REN13N11 on canine chromosome 13. OBJECTIVE: The goal of this study was to evaluate the MYC_CANFA gene, which is the closest known gene with a distance of approximately 0.06 megabases (Mb) to the microsatellite marker DTR13.6, for any mutations in this breed. METHODS: Microsatellite markers (Myc and G15987) for genotyping and primers for sequencing were used to evaluate the MYC_CANFA gene. The genotype and gene sequence were compared between cobalamin-deficient Shar Peis, Shar Peis with normal serum cobalamin concentrations, and the DNA sequences published as part of the Ensemble Genomic map. RESULTS: Neither the microsatellite markers (Myc and G15987) nor the sequences of the MYC_CANFA gene showed a significant difference among both groups of Shar Peis and the published canine DNA sequence. CONCLUSIONS: The data presented here suggest that cobalamin deficiency in Shar Peis is not related to any mutations of the MYC_CANFA gene according to the genotyping and sequencing results in this study. Further investigations are warranted to find a potential genomic locus in proximity to DTR13.6 and REN13N11 that shows mutations in cobalamin-deficient Shar Peis.

Partial characterization of cobalamin deficiency in Chinese Shar Peis.

A total of 22,462 serum sample results from dogs being evaluated for gastrointestinal disease at the Gastrointestinal Laboratory, College of Veterinary Medicine, Texas A&M University were evaluated retrospectively. The proportion of dogs with serum cobalamin concentrations below the reference interval and median serum concentrations were compared between Shar Peis and other dog breeds. Serum samples were also obtained prospectively from 22 healthy and 32 Shar Peis with chronic gastrointestinal disease and 59 healthy dogs of other breeds, and serum concentrations of cobalamin, folate, and methylmalonic acid were determined and compared. Overall, 64.0% (89/139) of serum samples from Shar Peis showed serum cobalamin concentrations below the limit of the reference interval and 38.1% (53/139) of these were below the detectable limit for the assay. The median serum cobalamin concentration in Shar Peis was significantly lower than in other breeds. Shar Peis with gastrointestinal disease had significantly lower serum cobalamin and higher serum methylmalonic acid concentrations compared to healthy Shar Peis. Healthy Shar Peis had significantly increased serum methylmalonic acid concentrations compared to healthy dogs of other breeds. There were no meaningful differences in folate concentrations between groups. In conclusion, Shar Peis have a high prevalence of cobalamin deficiency compared to other breeds and healthy Shar Peis may have subclinical cobalamin deficiency.

Identification of variants of the SPINK1 gene and their association with pancreatitis in Miniature Schnauzers.

OBJECTIVE: To evaluate the serine protease inhibitor, Kazal type 1 (SPINK1) gene for variants and to determine their possible association with pancreatitis in Miniature Schnauzers. ANIMALS: 39 Miniature Schnauzers with pancreatitis, 25 healthy Miniature Schnauzers, and 23 healthy dogs of other breeds. PROCEDURES: The entire canine SPINK1 gene with its intron-exon boundaries was initially sequenced in 22 Miniature Schnauzers. Then, 2 regions of the gene were sequenced in 65 additional canine DNA samples at the locations of variants identified in the initial sequencing of the entire SPINK1 gene. RESULTS: Analysis of the SPINK1 gene in Miniature Schnauzers revealed 3 closely associated variants in healthy Miniature Schnauzers and Miniature Schnauzers with pancreatitis. These variants consisted of 2 missense mutations in the second exon (N20K and N25T) and a poly T insertion in the third intron that was near the boundary of exon 3 (IVS3+26-27ins(T)33-39,15_61dup11). Pancreatitis was significantly associated with homozygous alleles for these 3 variants in Miniature Schnauzers. In healthy dogs of other breeds, only the 2 exon variants were identified. CONCLUSIONS AND CLINICAL RELEVANCE: Variants of the SPINK1 gene may be associated with the development of pancreatitis in Miniature Schnauzers.

Use of biomarkers of collagen types I and III fibrosis metabolism to detect cardiovascular and renal disease in chimpanzees (Pan troglodytes).

Cardiovascular disease is the leading cause of morbidity and mortality among captive chimpanzees. The most prevalent form of cardiovascular disease among chimpanzees is sudden cardiac death. Myocardial fibrosis was the only significant pathologic lesion observed in affected animals at necropsy. We previously showed an association between myocardial fibrosis and sudden cardiac death. The presumed pathogenesis was interstitial myocardial fibrosis that led to decreased myocardial contractility and interrupted signal propagation in the heart, leading to fibrillation and resulting in sudden cardiac death. In this pilot study, we assayed 5 biomarkers of collagen types I and III metabolism and fibrogenesis and studied their association with CVD in chimpanzees. The biomarker MMP1 did not crossreact in chimpanzee sera and could not be studied further. Two biomarkers (TIMP1 and PINP) and their difference showed no significant association with CVD in chimpanzees. The biomarkers ICTP and PIIINP were significantly increased in cases of CVD with concurrent renal disease. Furthermore, both biomarkers showed a significant trend to increase with disease severity. We conclude that ICTP and PIIINP warrant further study for antemortem detection of renal and myocardial fibrosis in chimpanzees.

Association study of cobalamin deficiency in the Chinese Shar Pei.

Cobalamin deficiency is a common disorder in Chinese Shar Peis (Shar Peis) and is thus suspected to be hereditary. The objective of this study was to identify a genomic region or locus that cosegregates with the phenotype of cobalamin deficiency in Shar Peis. Serum cobalamin concentrations were measured, and blood for genomic DNA extraction was collected from 14 cobalamin-deficient Shar Peis and 28 Shar Peis with a serum cobalamin concentration in the reference range. The 327 microsatellite markers from the canine minimal screening set 2 and 4 additional markers were amplified by polymerase chain reaction and genotyped by automated capillary electrophoresis. Two microsatellite markers, DTR13.6 (P = 1.4 x 10(-6)) and REN13N11 (P = 1.5 x 10(-5)), both on canine chromosome 13, showed evidence of linkage disequilibrium. These findings indicate that the region of chromosome 13 near these markers should be mapped and closely examined for potential mutations associated with this disease in Shar Peis.

Evaluation of the cationic trypsinogen gene for potential mutations in miniature schnauzers with pancreatitis.

The purpose of this study was to evaluate the cationic trypsinogen gene in miniature schnauzers for possible mutations. Genetic mutations have been linked with hereditary pancreatitis in humans. Four miniature schnauzers were selected on the basis of a clinical history of pancreatitis. One healthy miniature schnauzer and 1 healthy mixed breed canine were enrolled as controls. DNA was extracted from these canines using a commercial kit. Primers were designed to amplify the entire canine cationic trypsinogen cDNA sequence. A polymerase chain reaction (PCR) was performed and products were purified and sequenced. All sequences were then compared. The healthy control canine, a healthy miniature schnauzer, and the 4 miniature schnauzers with pancreatitis showed identical sequences of the cationic trypsinogen gene to the published sequence. We conclude that, in contrast to humans with hereditary pancreatitis, mutations of the cationic trypsinogen gene do not play a major role in the genesis of pancreatitis in the miniature schnauzer.