BackgroundLiterature on the seroprevalence of antibodies to the causative agents of equine protozoal myeloencephalitis (EPM) in Canada is limited.Hypothesis/ObjectivesTo determine the prevalence of serum antibodies against Sarcocystis neurona and Neospora hughesi in apparently healthy horses without signs of neurologic disease which have always resided in Alberta, Canada, using commercially available immunodiagnostic tests.AnimalsSamples from 116 healthy horses were obtained from a biobank containing horse serum collected across Alberta in 2021 and 2022. Samples were selected based on owner survey responses, and only horses that had always resided in Alberta were included in the study.MethodsThis cross-sectional study analyzed serum samples for anti-S neurona (SarcoFluor and rSnSAG2/4/3 ELISA) and N hughesi (NeoFluor and NhSAG1 ELISA) antibodies. A subset of 30 samples underwent additional testing by S neurona western blot.ResultsFor anti-S neurona antibodies, 26/116 horses were positive on indirect fluorescent antibody test (IFAT), 4/116 on ELISA, and 5/30 on western blot; however, none of the horses were positive on all 3 of the tests. For anti-N hughesi antibodies, 18/116 were positive on IFAT and 2/116 on ELISA, with no horses positive on both tests.Conclusions and clinical importanceThese findings suggest possible exposure of Alberta horses to S neurona and N hughesi. However, the commercially available tests had low sensitivities and poor agreement in this study group of apparently healthy horses.

BackgroundNairobi sheep disease virus (NSDV), a highly pathogenic tick-borne orthonairovirus affecting ruminants, represents an emerging zoonotic threat. While endemic to East Africa, recent reports confirm its presence in Asia. Hypothesis/ObjectivesThis study investigated NSDV circulation in the eastern Shandong Peninsula.AnimalsA total of 745 Haemaphysalis longicornis ticks (grouped into 139 pools) and 246 ruminant serum samples were collected during 2021 field surveillance in Weifang and Yantai regions.MethodsMolecular detection employed quantitative reverse transcription PCR and nested PCR assays, with genomic characterization through complete and partial segment sequencing. Serological analysis used ELISA and immunofluorescence assays (IFAs). Phylogenetic reconstruction was performed using maximum-likelihood methods.ResultsNairobi sheep disease virus RNA was detected in 9 tick pools (minimum infection rate: 1.2%). Genomic analysis revealed one complete genome (L: 11 999 bp; M: 5013 bp; and S: 1469 bp) and 4 partial S segment sequences (975 bp) showing > 98% nucleotide identity with Chinese reference strains and 100% identity among themselves. Phylogenetically, Shandong isolates clustered with other Chinese NSDV variants, indicating local evolutionary adaptation. Seroprevalence reached 5.7% (14/246) among ruminants, suggesting local virus exposure.Conclusions and clinical importanceThis molecular and serological evidence of NSDV in eastern Shandong suggests the potential presence of the virus beyond its historical range. The close genetic relationship with other Chinese strains suggests regional spread rather than independent introductions. These findings underscore the need for enhanced surveillance in tick-ruminant systems and the development of control strategies to mitigate economic and zoonotic risks.

Platelet surface-associated immunoglobulin (PSAIG) occurs in thrombocytopenic dogs with vector-borne diseases and immune thrombocytopenia (ITP) and may be associated with thrombocytopenia severity and inflammatory markers, including neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios (NLR, PLR). Assess associations between PSAIG positivity, hematologic parameters, thrombocytopenia severity, and vector-borne status in thrombocytopenic dogs. Sixty-nine client-owned thrombocytopenic dogs (<200×103/μL) were enrolled between June 2022 and June 2023. Dogs were prospectively enrolled. Platelet surface-associated immunoglobulin was measured using flow cytometry. Vector-borne pathogens were assessed by serology (Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi, Dirofilaria immitis) and PCR for Ehrlichia canis. Hematologic parameters were compared between PSAIG groups (Mann-Whitney U), and associations tested by univariable logistic regression. Dogs positive for PSAIG (n=16) had lower median automated platelet counts (16.5×103/μL; interquartile range [IQR]: 8.25-40.75) than PSAIG-negative dogs (n=53; 64×103/μL; IQR: 25.0-92.5; P=.001), with similarly lower manual platelet counts (48×103/μL; IQR: 20-86 vs 96×103/μL; IQR: 55-138; P=.01) and automated PLR (7.14; IQR: 3.30-15.28 vs 21.82; IQR: 9.42-38.99; P=.01). In logistic regression, PSAIG positivity was associated with lower platelet counts and automated PLR, E. canis PCR positivity, and Anaplasma seropositivity, with the strongest association for concurrent E. canis PCR and Anaplasma seropositivity (odds ratio [OR]; 15.3; 95% confidence interval [CI]: 2.69-86.99; P=.002). Lower platelet counts and automated PLR were associated with PSAIG positivity in thrombocytopenic dogs. Associations between PSAIG, E. canis infection, and co-exposure to Anaplasma spp. support immune-mediated platelet destruction in infected dogs.

Vaccination is implicated in development of human immune-mediated diseases, but studies in dogs yielded conflicting results for immune-mediated hemolytic anemia (IMHA) and thrombocytopenia (ITP). To investigate temporal relationships between onset of IMHA or ITP and vaccination in dogs. Client-owned dogs with nonassociative IMHA (n=295) and ITP (n=163) at 4 referral hospitals, alongside control dogs (n=1180 for IMHA, 652 for ITP) presented contemporaneously. Multicenter retrospective case-control study, with meta-analysis of published studies. Proportions vaccinated ≤ 30days before disease onset were compared to controls, along with times since last vaccine. Proportion of dogs vaccinated ≤ 30days of disease onset was significantly higher in the IMHA group (35/295, 11.9%) compared with controls (72/1180, 6.1%; P=.0015). Dogs with IMHA vaccinated ≤ 30days of disease onset were more likely to have received a L2 vaccine (Leptospira serovars Canicola and Icterohemorrhagiae) in their last dose than those vaccinated > 30days before onset (P=.04). Meta-analysis indicated dogs with IMHA were 2.48 times (95% CI, 1.69-3.63) more likely to have been vaccinated in the past month than controls, but with high heterogeneity across this and 2 other studies. There was no difference in proportion of ITP dogs and controls vaccinated ≤ 30days of disease onset, and meta-analysis with 1 other study showed no temporal association, though both analyses were likely underpowered. These results support a possible temporal association between vaccination and onset of IMHA in dogs. Our results do not establish a causal relationship between vaccination and IMHA.

Pimobendan might affect mitral annular dynamics (MAD) in dogs with myxomatous mitral valve disease (MMVD); in humans, alterations in MAD are known to increase the severity of mitral regurgitation (MR). To investigate the short-term effect of pimobendan on MAD, severity of MR, and systemic arterial compliance in dogs with MMVD. Twenty dogs with newly diagnosed ACVIM stage B2 MMVD. Prospective, open-label, longitudinal study. All dogs underwent echocardiographic and cardiac computed tomographic (CCT) examinations before and 2 weeks after oral administration of pimobendan. Changes in MAD, leaflet-to-annulus index, left heart volumes, regurgitant volume/fraction, and aortic distensibility index were evaluated on CCT. All dogs completed the study without major adverse events. Pimobendan decreased normalized end-systolic mitral annular area (mean difference of 1.38cm2/m2; 95% CI, 0.79-1.97cm2/m2; P<.001), aortoparietal distance (mean difference of 1.03mm/kg1/3; 95% CI, 0.54-1.53mm/kg1/3; P<.001), and intercommissural distance (mean difference of 0.75mm/kg1/3; 95% CI, 0.44-1.06mm/kg1/3; P<.001). Mean leaflet-to-annulus index increased (mean difference of 0.06; 95% CI, 0.02-0.09; P=.002). Changes in left ventricular end-diastolic and end-systolic volumes, left atrial end-diastolic and end-systolic volumes, regurgitant volume (mean reduction of 0.31mL/kg; 95% CI, 0.13-0.5mL/kg), and regurgitant fraction (mean reduction of 9.8%; 95% CI, 5.2%-14.3%) were detected (all P<.05) with administration of pimobendan. There was no detectable difference in aortic distensibility index (P=.6). Short-term pimobendan administration decreases MR severity by augmenting systolic contraction of the mitral annulus. The study provides new insight into the mechanism of action of pimobendan in dogs with MMVD.

The association of plasma cortisol concentration with prognosis for dogs with congestive heart failure (CHF) is unknown. To determine whether higher plasma cortisol concentration was independently associated with greater risk of cardiac mortality in dogs with CHF. Additional study aims were to evaluate the associations between other clinical, neurohormonal, and echocardiographic indices and cardiac mortality. Thirty-one client-owned dogs with CHF secondary to myxomatous mitral valve disease (MMVD). Prospective cohort observational study. Plasma cortisol measurement, urine cortisol-to-creatinine ratio, renal function test results, serum electrolytes, biomarkers of the renin-angiotensin-aldosterone system, N-terminal pro-B-type natriuretic peptide, and echocardiography were performed in dogs with MMVD at first onset of CHF. Plasma cortisol was repeated 7-14days later. Association between plasma cortisol and other covariates with survival was determined using a proportional hazards regression model. Plasma cortisol concentration was not associated with cardiac (P=.112; hazard ratio [HR] 1.01; 95% CI, 0.998-1.02) or all-cause mortality (P=.143; HR 1.01; 95% CI, 0.998-1.02). Treatment with angiotensin-converting enzyme inhibitors (P=.021; HR 0.058; 95% CI, 0.0052-0.66) was associated with longer survival to cardiac mortality. Treatment with spironolactone (P=.038; HR 0.36; 95% CI, 0.14-0.94), percent fractional shortening (P=.034; HR 0.0018; 95% CI, 5.44 × 10-6 to 0.61), and lower serum potassium (P=.048; HR 2.07; 95% CI, 1.01-4.27) at diagnosis were associated with longer survival to all-cause mortality. Spironolactone treatment at baseline was associated with all-cause mortality on multivariable regression analysis. Plasma cortisol concentrations were not associated with cardiac mortality in this sample of dogs with CHF.

Therapeutic strategies are needed to treat immune-mediated diseases in dogs. Human intravenous immunoglobulin (hIVIG), approved to treat inflammatory diseases in humans, has been used in dogs with some success in some immune-mediated hematologic and dermatologic disorders. However, cost, supply issues, and safety concerns have limited studies in dogs. Evaluate the feasibility of swine immunoglobulin G (SwIgG) in healthy dogs as a replacement for hIVIG. Three healthy female beagles. Swine IgG purified by column chromatography and injected SC into beagle dogs with or without intradermal injections at predetermined time points. The dogs were observed for up to 3weeks with blood collected for clinical chemistry, hematology, and cytokine analysis. Clinical monitoring included heart rate, temperature, and respiratory rate. Injection of 1 dose (1g/kg) of SwIgG resulted in vomiting after injection that resolved with treatment; no other clinical signs were observed over the 3-week period. One beagle that received a single dose of 0.2g/kg SwIgG had a reaction and was removed from the second trial. The third beagle received 3 serial doses of 0.5g/kg SwIgG with no adverse reaction throughout the 3-week period. Clinical chemistry in all dogs indicated slight increase in creatine kinase activity, C-reactive protein concentration, and aspartate aminotransferase activity which returned to normal by day 7 postinjection. It is feasible to use SwIgG in dogs and additional studies to investigate its use as an adjunctive treatment for immune-mediated disorders are warranted.

Insulinoma is the most commonly diagnosed endocrine tumor of the pancreas in dogs. Current literature has predominately focused on referral management of insulinoma in dogs. To describe clinical signs, management, and survival and to explore risk factors associated with clinical management undertaken for insulinoma in dogs under primary veterinary care in the United Kingdom. Two hundred seventy-eight insulinoma cases identified from 2250741 VetCompass study dogs within the United Kingdom in 2019. Nested cohort study. Insulinoma cases were identified by manual review of electronic health records. Multivariable logistic regression was used to identify risk factors associated with clinical management. The Kaplan-Meier method with log rank test and multivariable Cox regression were used to identify risk factors associated with survival. Epileptiform seizures, weakness, collapse/syncope, and muscle fasciculations were the most commonly reported clinical signs. Spaniel breed dogs (OR 2.43, 95% CI 1.02-5.79), dogs with epileptiform seizures (OR 2.15, 95% CI 1.15-4.02) and referred dogs (OR 4.85, 95% CI 2.42-9.72) had increased odds of undergoing surgery, compared to non-spaniel breed dogs, dogs without epileptiform seizures, and non-referred dogs. Compared to dogs treated solely medically, dogs treated surgically had a lower hazard (HR 0.49, 95% CI 0.32-0.77) of dying. Referred dogs had a longer median survival time (673 days, IQR 221-1139) than non-referred dogs (275 days, IQR 55-735) (P<.001). This study identified that referral and surgical treatment are associated with improved clinical outcomes for dogs with insulinoma presenting to primary veterinary care.

Septic arthritis (SA) in camelids is infrequently reported in the literature. The purpose of this study was to describe the clinical presentation, etiologies, diagnostics, treatment and short- and long-term outcome in neonatal and juvenile New World camelids (NWCs) with SA. Two neonatal alpaca crias were diagnosed with SA associated with failure of transfer of passive immunity and neonatal sepsis. Three juvenile camelids, 1 alpaca, and 2 llamas were presented with an infection of a single joint with associated lameness. All animals were treated with systemic and intra-articular antimicrobials. Surgical treatment including joint lavage was performed in 4 cases. Four (80%) NWCs survived to discharge. Three were sound at the time of discharge and 1 was discharged with mild lameness. One neonatal cria was euthanized. Septic arthritis in neonatal and juvenile NWC appears to have a favorable prognosis for discharge and guarded prognosis for long-term outcome with appropriate treatment.

BackgroundC-reactive protein (CRP) concentration in serum or plasma is high in humans during adrenal crisis due to multiple mechanisms, however, the frequency and clinical relevance of high CRP concentrations in dogs with hypoadrenocorticism are unknown.Hypothesis/ObjectivesTo determine the frequency of high CRP concentrations in serum or plasma of dogs with hypoadrenocorticism. We hypothesized that CRP concentrations are commonly above reference limit in dogs with hypoadrenocorticism with and without inflammatory comorbidities.AnimalsFifty-one dogs with hypoadrenocorticism presented to 2 referral centers between 2017 and 2023.MethodsMedical records were retrospectively reviewed for dogs diagnosed with and presenting for illness due to hypoadrenocorticism. Dogs were grouped according to identification of a concurrent inflammatory disease at the time of diagnosis, and whether electrolyte abnormalities were present. C-reactive protein concentrations were compared between groups.ResultsFifty-one dogs were included. C-reactive protein concentration in serum or plasma was above 10 mg/L in 38 of 51 (75%) cases. Median CRP concentration was 52.5 mg/L (range 8-191.4); this was not significantly different between dogs with (n = 14) or without (n = 37) a known inflammatory comorbidity (54.25 [8.0-191.4] and 44.0 [8-180.8] mg/L, respectively, P = .35), or between dogs with (n = 32) or without (n = 13) electrolyte abnormalities (48.25 [8.0-180.8] and 63.0 [8.0-191.4] mg/L, respectively, P = .51).Conclusions and clinical importanceHigh CRP concentrations in serum or plasma were frequently identified in dogs with hypoadrenocorticism, including dogs without recognized inflammatory comorbidities. Hypoadrenocorticism should be considered as a differential diagnosis in cases with high CRP concentrations and vague clinical signs. Extensive investigations for high CRP concentrations in dogs with hypoadrenocorticism might not be necessary without other supporting evidence of an inflammatory comorbidity.