Detection of Mykobacterium avium subspecies paratuberculosis in Swiss dairy cattle by culture and serology

Es wurden Kotproben von 186 Milchkühen aus 10 verschiedenen Milchviehbeständen mit sporadischem Auftreten klinischer Paratuberkulose (Gruppe A) und Kotproben von 100 Milchkühen aus verschiedenen Paratuberkulose-freien Herden (Gruppe B) auf das Vorhandensein von Mycobacterium avium ssp. paratuberculosis (MAP) untersucht. Für den kulturellen Erregernachweis wurden die Kotproben mit zwei verschiedenen Methoden dekontaminiert: a) Dekontamination mit NaOH und Oxalsäure; b) Dekontamination mit 0,75% Hexadecylpyridinumchlorid (HPC). Die aufbereiteten Proben wurden auf Löwenstein-Jensen-Medium mit und ohne Mycobactin verimpft und für 16 Wochen inkubiert. Die Klassifizierung säurefester Stäbchen als MAP erfolgte sowohl auf der Basis des Mycobactin-abhängigen Wachstums als auch durch eine PCR-gekoppelte Restriktionsenzymanalyse des IS1311-Insertionselementes von M. avium. MAP konnte aus 15 von 186 Proben (8.1%) der Gruppe A isoliert werden. Der kulturelle Nachweis von MAP in der Gruppe B fiel negativ aus. Im Vergleich zu HPC-behandelten Proben war die Nachweisrate von MAP bei den Proben signifikant höher (8.1% vs. 1.6%) und die Kontaminationsrate signifikant geringer (17.6% vs. 21,5%), die mit der NaOH/Oxalsäure-Methode dekontaminiert wurden. Atypische Mykobakterien, welche aus 46.8% der NaOH/Oxalsäure-behandelten Proben isoliert wurden, konnten aus keiner der HPC-behandelten Proben isoliert werden. Serologische Untersuchungen der Seren aller Tiere wurden mit einem kommerziellen ELISA durchgeführt, in welchem MAP-Lipoarabinomannan (LAM) als Antigen verwendet wird. Insgesamt reagierten 16.8% der Tiere im ELISA positiv. Die Korrelation zwischen Antikörpernachweis und kulturellem Nachweis von MAP war mit 15.4% eher gering. Die ELISA-Werte von Tieren mit einem mikroskopischen Nachweis von säurefesten Stäbchen und einem kulturellen Nachweis von atypischen Mykobakterien (n=31) unterschieden sich nicht signifikant von den Werten der Tiere, bei denen weder mikroskopisch säurefeste Stäbchen noch kulturell atypische Mykobakterien nachgewiesen werden konnten (n=26; p=0.157, Mann-Whitney Test). Dies spricht für die Validität der positiven ELISA-Reaktionen bei den Tieren mit negativen MAP-Kulturen. Fecal samples from 186 dairy cows representing ten commercial dairy herds with sporadic clinical paratuberculosis (group A), and from 100 dairy cows from herds without a history of paratuberculosis (group B) were cultured for Mycobacterium avium subspecies paratuberculosis (MAP). Two different decontamination methods, a NaOH/oxalic acid method and treatment with 0.75% hexadecylpyridinium chloride (HPC) were performed prior to inoculation of Loewenstein-Jensen agar slants with and without mycobactin. Cultures were incubated for 16 weeks. Acid-fast staining bacteria (AFB) were identified as MAP on the basis of mycobactin dependency and by PCR-coupled RFLP analysis of the IS1311-insertion element of M. avium. MAP was grown from 15 of 186 group A animals (8.1%) whereas fecal culture for MAP was consistently negative in group B. In comparison with HPC-treated fecal samples, the growth rate of MAP was significantly higher (8.1% vs. 1.6%) and the contamination rate of cultures was significantly lower (17.6% vs. 21.5%) in fecal samples decontaminated with NaOH/oxalic acid (p<0.01, McNemar's test). Atypical mycobacteria which were grown from 46.8% of NaOH/oxalic acid treated specimens were not obtained from any of the HPC-treated samples. A commercial ELISA with MAP-lipoarabinomannan (LAM) as antigen was used to detect MAP-antibodies in unabsorbed sera from all animals. The percentage of ELISA- positive cows was 16.8%. The overall agreement between antibody detection and MAP-positive fecal culture was only poor with 15.4%. The validity of positive ELISA reactivities in MAP-culture negative animals is suggested since ELISA values of animals with both, a positive AFB microscopy and growth of atypical mycobacteria (n=31), were consistently negative and did not differ significantly from corresponding values of animals with negative AFB microscopy as well as negative mycobacterial culture (n=26; p=0.157, Mann-Whitney test)

Feline primary erythrocytosis: a multicentre case series of 18 cats

A retrospective multicentre case series of feline primary erythrocytosis (PE) was evaluated. The aim was to gain better understanding of disease presentation and progression to guide management and prognostication. Case records were assessed for evidence of increased packed cell volume (PCV; >48%), sufficient investigation to rule out relative and secondary erythrocytosis, and follow-up data for at least 12 months or until death. Eighteen cats were included in the case series. No significant trends in signalment were noted. Seizures and mentation changes were the most common presenting signs (both n = 10). Median PCV was 70% (median total protein concentration of 76 g/l) with no other consistent haematological changes. Sixteen cats survived to discharge. Phlebotomy was performed initially in 15/16 surviving animals and performed after discharge in 10/16. Hydroxyurea was the most common adjunctive therapy, used in 10/16 cats. Of the 16 patients surviving to discharge, 14 patients were still alive at the conclusion of the study (survival time >17 months post-discharge), with the two non-survivors having lived for 5 years or more after diagnosis. PCV, when stabilised, did not correlate with resolution of clinical signs

Cross-sectional study of approaches to diagnosis and management of dogs with immune-mediated haemolytic anaemia in primary care and referral veterinary practices in the United Kingdom.

ObjectivesTo determine whether veterinarians in primary care practices (PCPs) and board-certified clinicians (BCCs) approach treatment of dogs with immune-mediated haemolytic anaemia (IMHA) similarly, and whether practitioners with more experience treat similarly to those with less experience. We hypothesised those in PCPs would show more variation in their approach to similar cases than BCCs.MethodsA cross-sectional study was conducted by distributing a questionnaire to BCCs and veterinarians in PCPs. The questionnaire included direct questions and a number of clinical scenarios intended to capture approaches to common treatment problems.ResultsQuestionnaire responses were received from 241 veterinarians, including 216 in PCPs and 25 BCCs. Veterinarians in both settings used similar tests for diagnosis of IMHA, but BCCs performed more tests to exclude underlying causes of 'associative' disease. All veterinarians reported use of similar initial dosages of glucocorticoids (median 2 mg/kg per day in both groups, p = 0.92) but those used by more experienced practitioners were higher than those with less experience. Most veterinarians made allowances for the weight of dogs, using lower prednisolone dosages in a clinical scenario involving a 40 kg dog compared to a 9 kg dog (p = 0.025 for PCP, p = 0.002 for BCC). BCCs reported greater use of combinations of immunosuppressive drugs (pConclusionsApproaches to treatment of dogs with IMHA differ between BCCs and those in PCP. These differences may affect design and implementation of future research studies and clinical guidelines

Suspected congenital hyperinsulinism in a Shiba Inu dog

A 3-month-old male intact Shiba Inu dog was evaluated for a seizure disorder initially deemed idiopathic in origin. Seizure frequency remained unchanged despite thera- peutic serum phenobarbital concentration and use of levetiracetam. The dog was documented to be markedly hypoglycemic during a seizure episode on reevaluation at 6 months of age. Serum insulin concentrations during hypoglycemia were 41 U/μL (reference range, 10-29 U/μL). The dog was transitioned to 4 times per day feeding, diazoxide was started at 3.5 mg/kg PO q8h, and antiepileptic drugs were discon- tinued. No clinically relevant abnormalities were identified on bicavitary arterial and venous phase contrast computed tomographic imaging. The dog remained seizure- free and clinically normal at 3years of age while receiving 5.5 mg/kg diazoxide PO q12h and twice daily feeding. Seizures later occurred approximately twice per year and after exertion, with or without vomiting of a diazoxide dose. Blood glucose curves and interstitial glucose monitoring were used to titrate diazoxide dose and dosing interval. Congenital hyperinsulinism is well recognized in people but has not been reported in veterinary medicine

Reduced NK-Cell Activity in Patients with Metastatic Colon Cancer

Natural killer cells (NK-cells) are believed to play an essential role in the immune surveillance against tumors and infectious diseases. The role of NK-cells in colon cancer remains obscure, since increased as well as decreased percentages and/or activity of NK-cells in comparison to control patients have been reported. Percentage and cytolytic activity of NKcells in the peripheral blood were analyzed in 42 patients with colon cancer before surgery and one year thereafter in comparison to control patients with non-malignant diseases. Patients without distant metastasis at the time of diagnosis displayed a significantly increased percentage of NK-cells as well as sustained NK-cell activity in the peripheral blood prior to surgery when compared to control patients. In contrast, patients with metastatic disease at the time of diagnosis displayed significantly decreased NK-cell activity in the peripheral blood when compared to control patients. One year after surgery, patients who remained free of metastasis still displayed sustained NK-cell activity, whereas patients who developed metastasis presented with profoundly decreased levels of NK-cell activity. Further analysis of these patients revealed that patients who developed metastasis within the first year after surgery already displayed reduced NK-cell activity prior to curative colorectal surgery. These observations indicate that metastatic spread of colorectal cancer is associated with decreased NK-cell activity. It remains speculative whether decreased NK-cell activity precedes the development of metastasis and thus may help to identify patients with a high risk of rapid tumor progression following curative colorectal surgery

Characterisation of the Immunophenotype of Dogs with Primary Immune-Mediated Haemolytic Anaemia

Immune-mediated haemolytic anaemia (IMHA) is reported to be the most common autoimmune disease of dogs, resulting in significant morbidity and mortality in affected animals. Haemolysis is caused by the action of autoantibodies, but the immunological changes that result in their production have not been elucidated.To investigate the frequency of regulatory T cells (Tregs) and other lymphocyte subsets and to measure serum concentrations of cytokines and peripheral blood mononuclear cell expression of cytokine genes in dogs with IMHA, healthy dogs and dogs with inflammatory diseases.19 dogs with primary IMHA, 22 dogs with inflammatory diseases and 32 healthy control dogs.Residual EDTA-anti-coagulated blood samples were stained with fluorophore-conjugated monoclonal antibodies and analysed by flow cytometry to identify Tregs and other lymphocyte subsets. Total RNA was also extracted from peripheral blood mononuclear cells to investigate cytokine gene expression, and concentrations of serum cytokines (interleukins 2, 6 10, CXCL-8 and tumour necrosis factor α) were measured using enhanced chemiluminescent assays. Principal component analysis was used to investigate latent variables that might explain variability in the entire dataset.There was no difference in the frequency or absolute numbers of Tregs among groups, nor in the proportions of other lymphocyte subsets. The concentrations of pro-inflammatory cytokines were greater in dogs with IMHA compared to healthy controls, but the concentration of IL-10 and the expression of cytokine genes did not differ between groups. Principal component analysis identified four components that explained the majority of the variability in the dataset, which seemed to correspond to different aspects of the immune response.The immunophenotype of dogs with IMHA differed from that of dogs with inflammatory diseases and from healthy control dogs; some of these changes could suggest abnormalities in peripheral tolerance that permit development of autoimmune disease. The frequency of Tregs did not differ between groups, suggesting that deficiency in the number of these cells is not responsible for development of IMHA

Causes of thrombocytopenia in dogs in the United Kingdom: A retrospective study of 762 cases

Background: Thrombocytopenia is a common laboratory abnormality in dogs, and numerous diseases have been associated with its development. Estimates for the sensitivity and specificity of the degree of reduction of platelet concentration for the diagnosis of primary immune‐mediated thrombocytopenia (pITP) have not been reported. Objectives: To report the prevalence of different causes of thrombocytopenia in dogs in the United Kingdom and to investigate the utility of platelet concentration to differentiate causes of thrombocytopenia. Methods: Medical records of 762 dogs with thrombocytopenia presented to seven referral hospitals from January 2017 to December 2018 were retrospectively reviewed. Cases were assigned into the following categories: pITP, infectious diseases, neoplasia, inflammatory/other immune‐mediated disorders and miscellaneous causes. The prevalence of the different categories was estimated, and platelet concentrations were compared. Receiver‐operating characteristic (ROC) curves were used to investigate the utility of platelet concentration to differentiate between causes of thrombocytopenia. Results: The most common disease category associated with thrombocytopenia was neoplasia (27.3%), followed by miscellaneous causes (26.9%), pITP (18.8%), inflammatory/immune‐mediated disorders (14.4%) and infectious diseases (12.6%). Dogs with pITP had significantly lower platelet concentrations (median 8 × 109/L, range: 0–70 × 109/L) than dogs in the other four categories. Platelet concentration was useful for distinguishing pITP from other causes of thrombocytopenia (area under ROC curve = 0.89, 95% confidence interval 0.87, 0.92), with a platelet concentration ≤12 × 109/L being 60% sensitive and 90% specific. Conclusions: Severe thrombocytopenia was highly specific for a diagnosis of pITP, which was more prevalent in this UK population of thrombocytopenic dogs compared with previous epidemiological studies. Conversely, the proportion of dogs with infectious diseases was lower than in previous reports from other locations

Clinical and clinicopathological features and outcomes of cats with suspected dietary induced pancytopenia

Background: After a strong epidemiological link to diet was established in an outbreak of pancytopenia in cats in spring 2021 in the United Kingdom, 3 dry diets were recalled. Concentrations of the hemato- and myelotoxic mycotoxins T-2, HT-2 and diacetoxyscirpenol (DAS) greater than the European Commission guidance for dry cat foods were detected in the recalled diets. Objectives: To describe clinical and clinicopathological findings in cats diagnosed with suspected diet induced pancytopenia. Animals: Fifty cats presenting with pancytopenia after exposure to a recalled diet. Methods: Multicenter retrospective case series study. Cats with known exposure to 1 of the recalled diets were included if presented with bi- or pancytopenia and underwent bone marrow examination. Results: Case fatality rate was 78%. Bone marrow aspirates and biopsy examination results were available in 23 cats; 19 cats had a bone marrow aspirate, and 8 cats had a biopsy core, available for examination. Bone marrow hypo to aplasia—often affecting all cell lines—was the main feature in all 31 available core specimens. A disproportionately pronounced effect on myeloid and megakaryocytic cells was observed in 19 cats. Myelofibrosis or bone marrow necrosis was not a feature. Conclusion and Clinical Importance: Mycotoxin induced pancytopenia should be considered as differential diagnosis in otherwise healthy cats presenting with bi- or pancytopenia and bone marrow hypo- to aplasia

Comparison of timing of relapse in dogs with nonassociative immune‐mediated hemolytic anemia, thrombocytopenia, or polyarthritis

Abstract Background Relapse is a clinical concern in dogs diagnosed with immune‐mediated hemolytic anemia (IMHA), thrombocytopenia (ITP), or polyarthritis (IMPA). The average time to relapse is unknown, and evidence that vaccination is associated with disease relapse is lacking. Hypothesis/Objectives Compare the incidence of relapse in groups of dogs with IMHA, ITP, or IMPA over a 24‐month period after diagnosis and compare proportions of dogs that received vaccines in those dogs that did and did not relapse. Animals One hundred sixty client‐owned dogs (73 with IMHA, 55 with ITP, 32 with IMPA). Methods Medical records of dogs were reviewed with the goal of following cases for a minimum of 2 years. Incidence of relapse was calculated for each disease, and relapse rates in dogs that were or were not vaccinated after diagnosis were compared. Results Relapse rates at 12 months differed significantly among disease groups (P = .02), with a higher rate for IMPA (35%) compared to IMHA (11%) or ITP (11%). Relapse rate at 24 months was 41% for IMPA, 18% for IMHA, and 23% for ITP. Ninety percent of IMPA relapses occurred in the first 12 months after diagnosis, compared with 56% for IMHA and 50% for ITP. Vaccine administration after diagnosis was not associated with relapse (P = .78). Conclusions and Clinical Importance Risk of disease relapse in IMPA is highest in the first year after diagnosis, with a higher relapse rate compared with IMHA and ITP. The role of vaccination in disease relapse remains unclear