The effect of doxycycline on canine neutrophil functions.

Doxycycline is a broad-spectrum tetracycline-class antibiotic that is frequently used to treat bacterial infections. Its use has also been described in immune-mediated diseases due to its immunomodulatory properties. The aim of this study was to evaluate the immunomodulatory effect of doxycycline on canine neutrophil functions. Therefore, the release of reactive oxygen species (ROS) and the formation of neutrophil extracellular traps (NETs) were determined after incubation of canine PMNs with doxycycline in three different concentrations (4 µg/mL, 20 µg/mL and 200 µg/mL) for one and three hours, respectively. Additionally, a neutrophil killing assay with a doxycycline-resistant Staphylococcus aureus was performed to determine the bactericidal effect of doxycycline treated PMNs in presence of plasma. Doxycycline significantly diminished the production of ROS. However, doxycycline concentrations of 4 µg/mL and 20 µg/mL significantly induced NETs. A synergistic bacteriostatic effect of PMNs and doxycycline on a doxycycline-resistant Staphylococcus aureus isolate was detectable. However, already PMNs and especially doxycycline alone inhibited the growth. In summary, doxycycline showed a concentration-dependent immunomodulatory property in canine PMNs with a reduced ROS production and increased NET-induction. This immunomodulatory effect resulted in a slightly increased elimination of a doxycycline-resistant Staphylococcus aureus by the doxycycline plasma concentrations achieved in dogs.

[Polyendocrine syndromes in dogs]. / Polyendokrine Syndrome beim Hund.

The autoimmune polyendocrine syndrome (APS) refers to a combination of autoimmune endocrine disorders. It is rarely described in dogs. The most common combinations are hypoadrenocorticism and hypothyroidism, followed by diabetes mellitus, and less often hypoparathyroidism and orchitis. The diagnosis of the APS is based on the diagnosis of each endocrinopathy, as is the therapy, which involves the substitution of deficient hormones. If a patient was previously stable under treatment and is showing further signs (e.g. polyuria, polydipsia, or weight loss), the development of additional endocrinopathies like hypoadrenocorticism or diabetes mellitus should be considered. The diagnosis of the initially diagnosed endocrinopathy should also be critically questioned. This article summarizes some cases of our own animal hospital and selected cases published in the available literature.

A qualitative analysis of the impact of canine hypoadrenocorticism on the quality of life of owners.

BACKGROUND: Canine hypoadrenocorticism is a rare chronic disease, which demands intense dog-owner interaction, as its treatment requires to be individualised. The aim of this study was a qualitative analysis of the challenges owners face when dealing with the disease, especially regarding its management and how this affects quality of life. By promoting an online discussion between owners, we transcribed and summarised their experiential knowledge in dealing with the disease. METHODS: Owners were recruited for the online seminars via social media. After a theoretical introduction, participants were free to share experiences and ask questions. The recorded events were retrospectively analysed. RESULTS: Twenty-four owners of 22 Addisonian dogs took part in four events. Owners felt most "traumatised" when experiencing their dog's acute adrenal crisis. The initial adjustment phase and distinguishing the non-specific symptoms of hypoadrenocorticism from those of other diseases were also challenging. Overall, owners were well informed on the disease and committed to its long-term adjustment. CONCLUSIONS: Adrenal crisis and the initial adjustment phase may be more burdening to owners than expected. Understanding what their clients' concerns are, can help veterinarians provide better care and reduce the negative impacts of canine hypoadrenocorticism. Promoting peer to peer support, as well as providing a framework for participative communication might also help.

Correlation between Targeted qPCR Assays and Untargeted DNA Shotgun Metagenomic Sequencing for Assessing the Fecal Microbiota in Dogs.

DNA shotgun sequencing is an untargeted approach for identifying changes in relative abundances, while qPCR allows reproducible quantification of specific bacteria. The canine dysbiosis index (DI) assesses the canine fecal microbiota by using a mathematical algorithm based on qPCR results. We evaluated the correlation between qPCR and shotgun sequencing using fecal samples from 296 dogs with different clinical phenotypes. While significant correlations were found between qPCR and sequencing, certain taxa were only detectable by qPCR and not by sequencing. Based on sequencing, less than 2% of bacterial species (17/1190) were consistently present in all healthy dogs (n = 76). Dogs with an abnormal DI had lower alpha-diversity compared to dogs with normal DI. Increases in the DI correctly predicted the gradual shifts in microbiota observed by sequencing: minor changes (R = 0.19, DI < 0 with any targeted taxa outside the reference interval, RI), mild-moderate changes (R = 0.24, 0 < DI < 2), and significant dysbiosis (R = 0.54, 0.73, and 0.91 for DI > 2, DI > 5, and DI > 8, respectively), compared to dogs with a normal DI (DI < 0, all targets within the RI), as higher R-values indicated larger dissimilarities. In conclusion, the qPCR-based DI is an effective indicator of overall microbiota shifts observed by shotgun sequencing in dogs.

Seroprevalence of tick-borne encephalitis virus in wild and domestic animals in northern Germany.

Tick-borne encephalitis virus (TBEV) is a tick-transmitted flavivirus, which can infect humans and animals, sometimes even with a fatal outcome. Since many decades, TBEV is endemic in southern Germany, while only sporadic occurrence has been noted in northern parts of the country so far. Nevertheless, autochthonous human clinical cases are increasing in the federal state of Lower Saxony in north-western Germany, and several natural foci of TBEV transmission have recently been detected in this federal state. In order to shed more light on the current distribution of TBEV in Lower Saxony, the present study examined blood samples from wild and domestic animals for antibodies against TBEV. Overall, samples from 4,085 animals were tested by ELISA, including wild boar (N = 1,208), roe deer (N = 149), red deer (N = 61), fallow deer (N = 18), red foxes (N = 9), nutria (N = 9), raccoon dogs (N = 3), raccoons (N = 3), badgers (N = 1), European pine martens (N = 1), horses (N = 574), sheep (N = 266), goats (N = 67), dogs (N = 1,317) and cats (N = 399). Samples with an ELISA result of ≥60 Vienna units (VIEU)/ml were subjected to confirmatory serum neutralization tests (SNT). In total, 343 of 4,085 (8.4%) animals tested positive for anti-TBEV-IgG by ELISA, of which 60 samples were confirmed by SNT. Samples of 89 animals showed a cytotoxic effect in the SNT and were excluded from seroprevalence calculation, resulting in an overall seroprevalence of 1.5% (60/3,996). Seroprevalence was higher among wild animals (wild boar: 2.9% [34/1,190], roe deer: 2.7% [4/149], red deer: 1.7% [1/60], fallow deer: 5.6% [1/18]) than among domestic animals (dogs: 1.1% [15/1,317], horses: 0.8% [4/505], sheep: 0.4% [1/266]). No anti-TBEV-antibodies were detected in the other wild animal species as well as goats and cats. A notable clustering of positive samples was observed in districts where TBEV transmission foci have been described. Further clusters in other districts suggest the existence of so far undetected transmission foci, underlining the fact that both wild and domestic animals are useful sentinels for monitoring the spread of TBEV.

Effect of long-term management of hypoadrenocorticism on the quality of life of affected dogs and their owners.

BACKGROUND: The treatment of canine adrenal insufficiency consists of hormone substitution and requires high owner compliance and intense human-dog interaction. This might affect the quality of life (QoL) of owners and their pets. The aim of the study was to evaluate the impact of hypoadrenocorticism and its treatment on the QoL of dogs and their owners. METHODS: Owners completed a web-based survey that contained items concerning signalment, owner QoL, dog QoL and long-term therapy. RESULTS: Three hundred and twenty-two owners participated. Most owners feared an adrenal crisis. Approximately half of the participants reported that the bond between them and their pet increased after diagnosis. Although many participants felt that their own QoL was not affected by their dog's disease, worries about costs and leaving their dog unsupervised were frequently reported. Half of the study participants increased their dog's glucocorticoid doses when a stressful situation was foreseeable ('boosting' of therapy). Some administered hydrocortisone, mostly switched from prednisolone, resulting in a reduction in side effects. CONCLUSIONS: Special attention should be given to glucocorticoid therapy and owner's QoL. The overall worry of an adrenal crisis might increase caregivers' burden, reducing their overall QoL. Hydrocortisone might be a safe alternative to prednisolone, but further research is necessary to evaluate its long-term efficacy and safety in dogs.

Methylprednisolone Induces Extracellular Trap Formation and Enhances Bactericidal Effect of Canine Neutrophils.

Methylprednisolone is a glucocorticoid and can negatively influence immune defense mechanisms. During bacterial infections in the dog, neutrophils infiltrate infected tissue and mediate antimicrobial effects with different mechanisms such as phagocytosis and neutrophil extracellular trap (NET) formation. Here, we investigated the influence of methylprednisolone on canine NET formation and neutrophil killing efficiency of Gram positive and Gram negative bacteria. Therefore, canine blood derived neutrophils were treated with different concentrations of methylprednisolone over time. The survival factor of Staphylococcus pseudintermedius, Streptococcus canis or Escherichia coli was determined in presence of stimulated neutrophils. Additionally, free DNA and nucleosomes as NET marker were analyzed in supernatants and neutrophils were assessed for NET formation by immunofluorescence microscopy. Methylprednisolone concentrations of 62.5 and 625 µg/mL enhanced the neutrophil killing of Gram positive bacteria, whereas no significant influence was detected for the Gram negative Escherichia coli. Interestingly, higher amounts of free DNA were detected under methylprednisolone stimulation in a concentration dependency and in the presence of Streptococcus canis and Escherichia coli. The nucleosome release by neutrophils is induced by bacterial infection and differs depending on the concentration of methylprednisolone. Furthermore, immunofluorescence microscopy analysis identified methylprednisolone at a concentration of 62.5 µg/mL as a NET inducer. In summary, methylprednisolone enhances NET-formation and time-dependent and concentration-dependent the bactericidal effect of canine neutrophils on Gram positive bacteria.

[Hypothyroidism in dogs: an overview]. / Hypothyreose beim Hund: eine Übersicht.

Hypothyroidism is one of the most common endocrinopathies in dogs. In rare cases, it may be associated with further endocrinopathies. The most common combination is the con-currence of hypothyroidism and hypoadrenocorticism. The diagnosis of hypothyroidism is based on the measurement of thyroid hormones (T4/fT4) and thyroid stimulating hormone (TSH). As thyroid hormone concentrations in the blood are influenced by various factors (e. g. systemic diseases or drugs), test results must be interpreted in conjunction with complaints demonstrated by the patient. In cases when diagnosis is not definite, stimulating tests or diagnostic imaging techniques (ultrasound, scintigraphy) are advisable. Dogs with hypothyroidism should be diagnosed and treated with thyroid hormones. When addiditional clinical signs are not consistent with hypothyroidism, co-existing additional endocrinopathies need to be considered. Furthermore, when treatment fails to result in the expected clinical response, the diagnosis of hypothyroidism must be subject to critical re-evaluation. This article provides an overview of the current diagnostic and treatment methods in canine hypothyroidism.

[Immunosuppressive therapy in dogs and cats. Properties of drugs and their use in various immune-mediated diseases]. / Immunsuppressive Therapie bei Hunden und Katzen. Eigenschaften von Wirkstoffen und ihre Anwendung bei verschiedenen immunvermittelten Erkrankungen.

Veterinarians are regularly faced with the diagnosis and therapy of immune-mediated diseases. More frequently occurring immune-mediated diseases are immune-mediated hemolytic anemia, immunemediated thrombocytopenia and polyarthritis. Glucocorticoids are commonly used as first-line treatment because of their availability, efficacy and rapid action. Nevertheless, some patients do not respond to glucocorticoid therapy alone. Others require a rapid dose reduction because of severe side effects from glucocorticoid treatment. These patients benefit from adjuvant therapies. Ciclosporin preparations are licensed for use in veterinary medicine. The use of azathioprine, mycophenolate mofetil and human immunoglobulin therapy has also been documented. This article describes the mode of action of certain immunosuppressive agents and their use in selected diseases from recent literature.

[Comparison of clinical immunohistochemical findings in keratocystic odontogenic tumours and ameloblastomas considering their risk of recurrence]. / Vergleichende klinische und immunhistochemische Charakterisierung keratozystischer odontogener Tumoren und Ameloblastome im Hinblick auf das Rezidivrisiko.

BACKGROUND: With the new term "keratocystic odontogenic tumour" (KCOT) keratocyts are even in the nomenclature a close differential diagnosis to ameloblastomas (A). PURPOSE: Recurrence of KCOT and A were retrospectively compared with regard to treatment and immunohistochemical markers of cell cycle and migration and cell architecture. PATIENTS AND METHODS: Biopsies harvested over a period of 22 years of 101 patients (86 KCOT, 15 A) were examined. The histopathological slides were stained with H&E and with the immunohistochemical markers: Cyclin D1, Collagen IV, p16, Cox-2-Laminin-5 and Tenascin-C. RESULTS: Mean age KCOT 47 years (range 14-80 years), A 41 years (range 16-79 years). Gender KCOT: m:f =2:1; A: m:f = 3:2. Region of origin mandible with predilection of the angle and the ramus: KCOT: 76; A: 12. Maxilla: KCOT: 18; A: 3. Multiple lesions were found in 5 KCOT patients. Treatment primary KCOT: cystectomy (46), cystostomy (6), cystectomy and curettage (17), cystectomy and marginal ostectomy (14), resection (11). A: resection (10), enucleation (5). Recurrence rate KCOT: 11,7% after 5,5 years. Recurrence after: cystostomy (4), cystectomy (6), cystectomy and curettage (3), cystectomy and marginal ostectomy (2). A: no recurrences. Immunohistochemistry Cell cycle associated and extracellular matrix proteins did not differ in quantity in KCOT and A, and did also not differ in recurrent and non-recurrent KCOT. CONCLUSIONS: 1. KCOT are in the own cohort more likely recurrent than A. 2. Recurrence rate of KCOT can not be predicted by the used (most common) markers of cell cycle, migration and modulation of architecture. 3. Higher recurrence rate of KCOT in the patients examined is proposed due to less extensive resection.