Oxidative hemolytic crises in a dog due to fragrance products: clinical insights and treatment approaches.

IMPORTANCE: This is the first reported case of fragrance products-induced recurrent oxidative hemolytic anemia in a dog, detailing the successful therapeutic approach employed. CASE PRESENTATION: A 4-year-old intact female Pomeranian dog presented with brown tongue, pigmenturia, peripheral edema, and vomiting. Blood smears revealed a high count of eccentrocytes and Heinz bodies, along with a precipitous decline in packed cell volume and an increase in blood methemoglobin levels, suggesting an oxidative hemolytic crisis. This clinicopathological pattern recurred several times after the patient returned home. Antioxidants, methylene blue, hyperbaric oxygen (HBO) therapy, and blood transfusion were successfully employed to address recurrent hemolytic anemia; however, oxidative hemolytic crises recurred. After the owner removed exposure to various home remedies and fragrances, the clinical signs and hemolytic crises did not recur. CONCLUSION AND RELEVANCE: Recurring oxidative hemolytic crises should raise suspicions of environmental toxicity, which, although harmless in small quantities to humans, can be devastating to small-breed dogs. In addition to removing the causative agents, methylene blue and other antioxidants, along with HBO, may be beneficial in the acute management of oxidative hemolytic anemia.

CMAH Coding Sequence Variants in 15 Non-Domestic Felid Species Related to ABC Blood Group System.

Different blood group systems have been characterized in people and other mammals. In domestic cats, the ABC blood group system plays the most important clinical role and has been investigated extensively-from the phenotype to the molecular genetics. In non-domestic felids, phenotypic ABC blood typing has been performed by different methods to detect the antigens, but the four informative CMAH markers in domestic cats were not able to identify types B and C (AB) in non-domestic cats. In this study, 138 blood samples from 15 non-domestic (wild) felid species were investigated by CMAH exonic sequencing and genotyping for putative variants causing type B or C (AB) and correlation to the respective ABC blood phenotype. A total of 58 CMAH variants were found, including 15 missense and 43 synonymous CMAH variants. One variant (c.635G>C) was concordant with blood type B (and C) in cheetahs and type B in cougars, compared to blood type A in all other felid species (lion, tiger, Canada lynx, snow leopard, clouded leopard, serval, jaguar, fishing cat, Pallas cat, bobcat, black footed cat, leopard, and sand cat). Since cheetahs and cougars belong to the genera puma, it could not be determined if the common CMAH variant is either a marker for type B (or C) or is just common in pumas.

Comparison of a robotic surgery program for rectal cancer: short- and long-term results from a comparative, retrospective study between two laparoscopic and robotic reference centers.

BACKGROUND: It is assumed that robotic-assisted surgery (RAS) may facilitate complex pelvic dissection for rectal cancer compared to the laparoscopic-assisted resection (LAR). The aim of this study was to compare perioperative morbidity, short- and long-term oncologic, and functional outcomes between the RAS and LAR approaches. METHODS: Between 2015 and 2021, all rectal cancers operated on by (LAR) or (RAS) were retrospectively reviewed in two colorectal surgery centers. RESULTS: A total of 197 patients were included in the study, with 70% in the LAR group and 30% in the RAS group. The tumor location and stage were identical in both groups (not significant = NS). The overall postoperative mortality rate was not significantly different between the two groups. (0% LAR; 0.5% RAS; NS). The postoperative morbidity was similar between the two groups (60% LAR vs 57% RAS; NS). The number of early surgical re-interventions within the first 30 days was similar (10% for the LAR group and 3% for the RAS group; NS). The rate of complete TME was similar (88% for the LAR group and 94% for the RAS group; NS). However, the rate of circumferential R1 was significantly higher in the LAR group (13%) compared to the RAS group (2%) (p = 0.009). The 3-year recurrence rate did not differ between the two groups (77% for both groups; NS). After a mean follow-up of three years, the incidence of anterior resection syndrome was significantly lower in the LAR group compared to the RAS group (54 vs 76%; p = 0.030). CONCLUSIONS: The use of a RAS was found to be reliable for oncologic outcomes and morbidity. However, the expected benefits for functional outcomes were not observed. Therefore, the added value of RAS for rectal cancer needs to be reassessed in light of new laparoscopic technologies and patient management options.

Increased susceptibility to Mycobacterium avium complex infection in miniature Schnauzer dogs caused by a codon deletion in CARD9.

Mammals are generally resistant to Mycobacterium avium complex (MAC) infections. We report here on a primary immunodeficiency disorder causing increased susceptibility to MAC infections in a canine breed. Adult Miniature Schnauzers developing progressive systemic MAC infections were related to a common founder, and pedigree analysis was consistent with an autosomal recessive trait. A genome-wide association study and homozygosity mapping using 8 infected, 9 non-infected relatives, and 160 control Miniature Schnauzers detected an associated region on chromosome 9. Whole genome sequencing of 2 MAC-infected dogs identified a codon deletion in the CARD9 gene (c.493_495del; p.Lys165del). Genotyping of Miniature Schnauzers revealed the presence of this mutant CARD9 allele worldwide, and all tested MAC-infected dogs were homozygous mutants. Peripheral blood mononuclear cells from a dog homozygous for the CARD9 variant exhibited a dysfunctional CARD9 protein with impaired TNF-α production upon stimulation with the fungal polysaccharide ß-glucan that activates the CARD9-coupled C-type lectin receptor, Dectin-1. While CARD9-deficient knockout mice are susceptible to experimental challenges by fungi and mycobacteria, Miniature Schnauzer dogs with systemic MAC susceptibility represent the first spontaneous animal model of CARD9 deficiency, which will help to further elucidate host defense mechanisms against mycobacteria and fungi and assess potential therapies for animals and humans.

NONDOMESTIC FELID ABC BLOOD PHENOTYPING, GENOTYPING, AND CROSSMATCHING.

Based upon previous clinical experience with domestic cats (Felis catus), the ability to assess ABC blood types and blood (in-)compatibilities of nondomestic felids, and adequately consider and plan for blood transfusions, may be important. Although nondomestic felids appear to have an ABC blood group system similar to domestic cats, typing with point-of-care kits and by CMAH genotyping for domestic cats have not been reported. In this study, 162 blood samples from 18 different nondomestic felid species (cheetah [Acinonyx jubatus, n = 42], lion [Panthera leo, n = 33], tiger [Panthera tigris, n = 23], Canada lynx [Lynx canadensis, n = 11], snow leopard [Uncia uncia, n = 10], puma [Puma concolor, n = 7], clouded leopard [Neofelis nebulosa, n = 6], serval [Leptailurus serval, n = 5], jaguar [Panthera onca, n = 5], fishing cat [Prionailurus viverrinus, n = 4], Pallas cat [Felis manul, n = 3], bobcat [Lynx rufus, n = 3], ocelot [Leopardus pardalis, n = 3], black footed cat [Felis nigripes, n = 2], leopard [Panthera pardus, n = 2], African wildcat [Felis lybica, n = 1], caracal [Caracal caracal, n = 1], and sand cat [Felis margarita, n = 1]) were ABC blood typed by laboratory and point-of-care tests, genotyped for four known CMAH variants for type B and type C (AB) phenotypes, and crossmatched with one another and domestic type A cats. Traditional tube typing identified blood type A (n = 106), type B (n = 8), type C (n = 43), and no discernible ABC type (n = 4). Several discrepancies were found between point-of-care and traditional typing test results. None of the tested felids possessed the four CMAH variants responsible for type B and C (AB) in domestic cats. Crossmatch incompatibilities (≥2+ agglutination) were identified within and between nondomestic felid species and beyond ABC incompatibilities. Of 26 crossmatches performed between domestic cats and various nondomestic felids, only 7 (27%) were compatible. In conclusion, point-of-care typing kits and CMAH genotyping, successfully used in domestic cats, may not identify the correct ABC blood type in nondomestic felids. Prior crossmatching is recommended to increase the likelihood of compatible transfusions between any nondomestic felids.

Extreme erythrocytosis in a cat reverts after short-term treatment with hydroxyurea and the cat remains healthy for years.

OBJECTIVE: This case report describes a cat with severe erythrocytosis (Hct, 80%), which after initial treatment with hydroxyurea has gone into remission for over 3 years. ANIMAL: A 1-year-old neutered male American Maine Coon crossbred cat. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: A 1-year-old neutered male American Maine Coon crossbred domestic cat was presented with acute neurologic signs, systolic heart murmur, and extreme erythrocytosis (Hct, 80%; normal interval, 30% to 48%). There were no clinical signs of dehydration, and several diagnostic tests for absolute erythrocytosis did not identify an underlying cause. A presumptive diagnosis of primary erythrocytosis (polycythemia vera [P vera], a myeloproliferative disease) was made. TREATMENT AND OUTCOME: Repeated phlebotomies were declined by the owner, and thus the cat was treated with oral hydroxyurea. The neurologic signs, heart murmur, and erythrocytosis resolved within 2 months (Hct, 41%). Treatment with hydroxyurea was continued for 2 years and then discontinued. The Hct remained in the normal range (between 37% and 44%) during a 3-year observation period. CLINICAL RELEVANCE: This case illustrates the challenges of determining a precise cause of erythrocytosis. The extreme erythrocytosis reverted after treatment with hydroxyurea and did not recur even after drug withdrawal, suggesting an undefined singular or multifactorial cause of the erythrocytosis rather than a primary absolute erythrocytosis, such as P vera. The reversibility of this cat's erythrocytosis suggested that in select cases the discontinuation of treatment is warranted.

Discordance between ABC blood phenotype and genotype in a domestic short-haired cat.

An adult domestic short-haired feline leukemia virus-infected cat was referred for kidney failure and worsening anemia requiring transfusions. ABC blood typing was performed with an immunochromatographic strip assay at different occasions. Gel column systems were used for the major and minor crossmatching tests, and anti-A and anti-B titers were determined. No discrete A or B bands appeared on the immunochromatographic strips at any time point for the recipient cat. The recipient's plasma agglutinated RBCs from tested type A and B cats. The recipient's RBCs appeared compatible with plasma from 1 type A and 2 B donors, and incompatible with plasma from another type A cat. Genotyping of recipient blood revealed a single homozygous c.179G>T CMAH variant predicting a blood type B. These studies suggest an unusual weak type B or missing all ABC antigens. The latter resembles the exceedingly rare Bombay phenotype in the human ABO blood group system.

Impact of the first wave of COVID-19 epidemy on the surgical management of sigmoid diverticular disease in France: National French retrospective study.

OBJECTIVE: To analyze the surgical management of sigmoid diverticular disease (SDD) before, during, and after the first containment rules (CR) for the first wave of COVID-19. METHODS: From the French Surgical Association multicenter series, this study included all patients operated on between January 2018 and September 2021. Three groups were compared: A (before CR period: 01/01/18-03/16/20), B (CR period: 03/17/20-05/03/20), and C (post CR period: 05/04/20-09/30/21). RESULTS: A total of 1965 patients (A n = 1517, B n = 52, C n = 396) were included. The A group had significantly more previous SDD compared to the two other groups (p = 0.007), especially complicated (p = 0.0004). The rate of peritonitis was significantly higher in the B (46.1%) and C (38.4%) groups compared to the A group (31.7%) (p = 0.034 and p = 0.014). As regards surgical treatment, Hartmann's procedure was more often performed in the B group (44.2%, vs A 25.5% and C 26.8%, p = 0.01). Mortality at 90 days was significantly higher in the B group (9.6%, vs A 4% and C 6.3%, p = 0.034). This difference was also significant between the A and B groups (p = 0.048), as well as between the A and C groups (p = 0.05). There was no significant difference between the three groups in terms of postoperative morbidity. CONCLUSION: This study shows that the management of SDD was impacted by COVID-19 at CR, but also after and until September 2021, both on the initial clinical presentation and on postoperative mortality.

The Indirect Antiglobulin (Coombs') Test Is Specific but Less Sensitive Than the Direct Antiglobulin Test for Detecting Anti-Erythrocytic Autoantibodies and Thereby Immune-Mediated Hemolytic Anemia in Dogs.

The immunodiagnostic assessment of dogs suspected of having immune-mediated hemolytic anemia (IMHA) is based on persistent autoagglutination of erythrocytes (after three saline washes), marked spherocytosis, and a positive direct antiglobulin (Coombs') test (DAT). However, the value of using the indirect antiglobulin test (IAT) for the detection of anti-erythrocytic autoantibodies in serum from dogs suspected of having IMHA is unclear. To evaluate the IAT, leftover serum samples from a large cohort of 94 dogs suspected of having IMHA and for which DAT results were known were incubated with DAT- erythrocytes, and five IAT techniques were performed (in part with different reagents and temperatures): microtiter plate (MICRO), microcapillary, laboratory gel column, gel minitube kit (GEL KIT), and immunochromatographic strip kit. Two IAT techniques (MICRO at 37 °C and GEL KIT with rabbit anti-dog polyvalent reagent) detected autoantibodies against erythrocytes in serum from 53% and 57% of DAT+ dogs, respectively, while other IATs performed less well. Moreover, while the analytic specificity of the IAT methods compared to the DAT ranged from 96-100%, the sensitivity range was only 9-57%. Thus, we still recommend DAT for diagnosis and monitoring of IMHA in dogs but conclude that a positive IAT result may aid diagnostically when serum is available, but fresh red blood cells are not.

Methemoglobinemia, Increased Deformability and Reduced Membrane Stability of Red Blood Cells in a Cat with a CYB5R3 Splice Defect.

Methemoglobinemia is an acquired or inherited condition resulting from oxidative stress or dysfunction of the NADH-cytochrome b5 reductase or associated pathways. This study describes the clinical, pathophysiological, and molecular genetic features of a cat with hereditary methemoglobinemia. Whole genome sequencing and mRNA transcript analyses were performed in affected and control cats. Co-oximetry, ektacytometry, Ellman's assay for reduced glutathione concentrations, and CYB5R activity were assessed. A young adult European domestic shorthair cat decompensated at induction of anesthesia and was found to have persistent methemoglobinemia of 39 ± 8% (reference range < 3%) of total hemoglobin which could be reversed upon intravenous methylene blue injection. The erythrocytic CYB5R activity was 20 ± 6% of normal. Genetic analyses revealed a single homozygous base exchange at the beginning of intron 3 of the CYB5R3 gene, c.226+5G>A. Subsequent mRNA studies confirmed a splice defect and demonstrated expression of two mutant CYB5R3 transcripts. Erythrocytic glutathione levels were twice that of controls. Mild microcytosis, echinocytes, and multiple Ca2+-filled vesicles were found in the affected cat. Erythrocytes were unstable at high osmolarities although highly deformable as follows from the changes in elongation index and maximal-tolerated osmolarity. Clinicopathological presentation of this cat was similar to other cats with CYB5R3 deficiency. We found that methemoglobinemia is associated with an increase in red blood cell fragility and deformability, glutathione overload, and morphological alterations typical for stress erythropoiesis.

Dystrophin (DMD) Missense Variant in Cats with Becker-Type Muscular Dystrophy.

Muscular dystrophy due to dystrophin deficiency in humans is phenotypically divided into a severe Duchenne and milder Becker type. Dystrophin deficiency has also been described in a few animal species, and few DMD gene variants have been identified in animals. Here, we characterize the clinical, histopathological, and molecular genetic aspects of a family of Maine Coon crossbred cats with clinically mild and slowly progressive muscular dystrophy. Two young adult male littermate cats exhibited abnormal gait and muscular hypertrophy with macroglossia. Serum creatine kinase activities were highly increased. Histopathologically, dystrophic skeletal muscle exhibited marked structural changes including atrophic, hypertrophic, and necrotic muscle fibers. Immunohistochemistry showed irregularly reduced expression of dystrophin but the staining of other muscle proteins such as ß- and γ-sarcoglycans as well as desmin was also diminished. Whole genome sequencing of one affected cat and genotyping of the littermate found both to be hemizygous mutant at a single DMD missense variant (c.4186C>T). No other protein-changing variants in candidate genes for muscular dystrophy were detected. In addition, one clinically healthy male littermate was hemizygous wildtype, while the queen and one female littermate were clinically healthy, but heterozygous. The predicted amino acid exchange (p.His1396Tyr) resides in a conserved central rod spectrin domain of dystrophin. Various protein modeling programs did not predict major disruption of the dystrophin protein by this substitution, but the altered charge of the region may still affect protein function. This study represents the first genotype-to-phenotype correlation of Becker-type dystrophin deficiency in companion animals.

EHBP1L1 Frameshift Deletion in English Springer Spaniel Dogs with Dyserythropoietic Anemia and Myopathy Syndrome (DAMS) or Neonatal Losses.

Hereditary myopathies are well documented in dogs, whereas hereditary dyserythropoietic anemias are rarely seen. The aim of this study was to further characterize the clinical and clinicopathological features of and to identify the causative genetic variant for a dyserythropoietic anemia and myopathy syndrome (DAMS) in English springer spaniel dogs (ESSPs). Twenty-six ESSPs, including five dogs with DAMS and two puppies that died perinatally, were studied. Progressive weakness, muscle atrophy-particularly of the temporal and pelvic muscles-trismus, dysphagia, and regurgitation due to megaesophagus were observed at all ages. Affected dogs had a non-regenerative, microcytic hypochromic anemia with metarubricytosis, target cells, and acanthocytes. Marked erythroid hyperplasia and dyserythropoiesis with non-orderly maturation of erythrocytes and inappropriate microcytic metarubricytosis were present. Muscle biopsies showed centralized nuclei, central pallor, lipocyte infiltrates, and fibrosis, which was consistent with centronuclear myopathy. The genome sequencing of two affected dogs was compared to 782 genomes of different canine breeds. A homozygous frameshift single-base deletion in EHBP1L1 was identified; this gene was not previously associated with DAMS. Pedigree analysis confirmed that the affected ESSPs were related. Variant genotyping showed appropriate complete segregation in the family, which was consistent with an autosomal recessive mode of inheritance. This study expands the known genotype-phenotype correlation of EHBP1L1 and the list of potential causative genes in dyserythropoietic anemias and myopathies in humans. EHBP1L1 deficiency was previously reported as perinatally lethal in humans and knockout mice. Our findings enable the genetic testing of ESSP dogs for early diagnosis and disease prevention through targeted breeding strategies.

A Common Missense Variant Causing Factor XI Deficiency and Increased Bleeding Tendency in Maine Coon Cats.

Hereditary factor XI (FXI) deficiency is characterized as an autosomal mild to moderate coagulopathy in humans and domestic animals. Coagulation testing revealed FXI deficiency in a core family of Maine Coon cats (MCCs) in the United States. Factor XI-deficient MCCs were homozygous for a guanine to adenine transition resulting in a methionine substitution for the highly conserved valine-516 in the FXI catalytic domain. Immunoblots detected FXI of normal size and quantity in plasmas of MCCs homozygous for V516M. Some FXI-deficient MCCs experienced excessive post-operative/traumatic bleeding. Screening of 263 MCCs in Europe revealed a mutant allele frequency of 0.232 (23.2%). However, V516M was not found among 100 cats of other breeds. Recombinant feline FXI-M516 (fFXI-M516) expressed ~4% of the activity of wild-type fFXI-V516 in plasma clotting assays. Furthermore, fFXIa-M516 cleaved the chromogenic substrate S-2366 with ~4.3-fold lower catalytic efficacy (kcat/Km) than fFXIa-V516, supporting a conformational alteration of the protease active site. The rate of FIX activation by fFXIa-M516 was reduced >3-fold compared with fFXIa-V516. The common missense variant FXI-V516M causes a cross-reactive material positive FXI deficiency in MCCs that is associated with mild-moderate bleeding tendencies. Given the prevalence of the variant in MCCs, genotyping is recommended prior to invasive procedures or breeding.

Metabolomic Abnormalities in Serum from Untreated and Treated Dogs with Hyper- and Hypoadrenocorticism.

The adrenal glands play a major role in metabolic processes, and both excess and insufficient serum cortisol concentrations can lead to serious metabolic consequences. Hyper- and hypoadrenocorticism represent a diagnostic and therapeutic challenge. Serum samples from dogs with untreated hyperadrenocorticism (n = 27), hyperadrenocorticism undergoing treatment (n = 28), as well as with untreated (n = 35) and treated hypoadrenocorticism (n = 23) were analyzed and compared to apparently healthy dogs (n = 40). A validated targeted proton nuclear magnetic resonance (1H NMR) platform was used to quantify 123 parameters. Principal component analysis separated the untreated endocrinopathies. The serum samples of dogs with untreated endocrinopathies showed various metabolic abnormalities with often contrasting results particularly in serum concentrations of fatty acids, and high- and low-density lipoproteins and their constituents, which were predominantly increased in hyperadrenocorticism and decreased in hypoadrenocorticism, while amino acid concentrations changed in various directions. Many observed serum metabolic abnormalities tended to normalize with medical treatment, but normalization was incomplete when compared to levels in apparently healthy dogs. Application of machine learning models based on the metabolomics data showed good classification, with misclassifications primarily observed in treated groups. Characterization of metabolic changes enhances our understanding of these endocrinopathies. Further assessment of the recognized incomplete reversal of metabolic alterations during medical treatment may improve disease management.

Simultaneous or staged resection for synchronous liver metastasis and primary rectal cancer: a propensity score matching analysis.

BACKGROUND: Colorectal cancer is the third most common cancer in France and by the time of the diagnosis, 15-25% of patients will suffer from synchronous liver metastases. Surgery associated to neoadjuvant treatment can cure these patients, but few studies focus only on rectal cancer. This study was meant to compare the outcomes of patients who underwent a simultaneous resection to those who underwent a staged resection (rectum first or liver first) in the University Hospital of Tours, France. METHODS: We assessed retrospectively a prospective maintained data base about the clinical, pathological and survival outcomes of patients who underwent a simultaneous or a staged resection in our center between 2010 and 2018. A propensity score matching was used, considering the initial characteristics of our groups. RESULTS: There were 70 patients (55/15 males, female respectively) with median age 60 (54-68) years. After matching 48 (69%) of them underwent a staged approach and 22 (31%) a simultaneous approach were compared. After PSM, there were 22 patients in each group. No differences were found in terms of morbidity (p = 0.210), overall survival (p = 0.517) and disease-free survival (p = 0.691) at 3 years after matching. There were significantly less recurrences in the simultaneous group (50% vs 81.8%, p = 0.026). CONCLUSIONS: Simultaneous resection of the rectal primary cancer and synchronous liver metastases is safe and feasible with no difference in terms of survival.

Metabolomic serum abnormalities in dogs with hepatopathies.

Hepatopathies can cause major metabolic abnormalities in humans and animals. This study examined differences in serum metabolomic parameters and patterns in left-over serum samples from dogs with either congenital portosystemic shunts (cPSS, n = 24) or high serum liver enzyme activities (HLEA, n = 25) compared to control dogs (n = 64). A validated targeted proton nuclear magnetic resonance spectroscopy platform was used to assess 123 parameters. Principal component analysis of the serum metabolome demonstrated distinct clustering among individuals in each group, with the cluster of HLEA being broader compared to the other groups, presumably due to the wider spectrum of hepatic diseases represented in these samples. While younger and older adult control dogs had very similar metabolomic patterns and clusters, there were changes in many metabolites in the hepatopathy groups. Higher phenylalanine and tyrosine concentrations, lower branched-chained amino acids (BCAAs) concentrations, and altered fatty acid parameters were seen in cPSS dogs compared to controls. In contrast, dogs with HLEA had increased concentrations of BCAAs, phenylalanine, and various lipoproteins. Machine learning based solely on the metabolomics data showed excellent group classification, potentially identifying a novel tool to differentiate hepatopathies. The observed changes in metabolic parameters could provide invaluable insight into the pathophysiology, diagnosis, and prognosis of hepatopathies.

A Single Base Insertion in F9 Causing Hemophilia B in a Family of Newfoundland-Parti Standard Poodle Hybrid Dogs.

Hemophilia B is an x-linked recessive hereditary coagulopathy that has been reported in various species. We describe a male Newfoundland-Parti Standard Poodle hybrid puppy and its family with hemophilia B from clinical manifestations to the molecular genetic defect. The index case presented for dyspnea was found to have a mediastinal hematoma, while surgical removal and transfusion support brought some relief, progressive hematoma formations led to humane euthanasia. Sequencing the F9 exons revealed a single nucleotide insertion resulting in a frameshift in the last exon (NM_001003323.2:c.821_822insA), predicted to result in a premature stop codon (NP_001003323.1:p.Asn274LysfsTer23) with a loss of 178 of 459 amino acids. The unexpected high residual plasma factor IX activity (3% to 11% of control) was likely erroneous, but no further studies were performed. Both the purebred Newfoundland dam and her sister were heterozygous for the insertion. Five additional male offspring developed severe hemorrhage and were hemizygous for the F9 variant and/or had a prolonged aPTT. In contrast, other male littermates had normal aPTTs and no evidence of bleeding. While they are related to a common Newfoundland granddam, the prevalence of the pathogenic variant in the Newfoundland breed is currently unknown. These clinical to molecular genetic studies illustrate that precision medicine is achievable in clinical companion animal practice.