[Vigilance for veterinary medicinal products: Reports of adverse reactions in the year 2017]

INTRODUCTION

A total of 306 reports of adverse reactions to veterinary medicinal products were received during the year 2017 representing an increase of 21% compared to the previous year. The majority of these reports described reactions concerning companion animals (180 dogs and 59 cats) as well as cattle (38 reports) and horses (14 reports). Most of the reported reactions were linked to the use of antiparasitics (158 reports), hormone products (30 reports) and anti-inflammatory products (25 reports). 40 reports were generated from consultations with Tox Info Suisse in Zürich and mainly involved the excessive intake of flavoured tablets and, in some cases, the use of products under the cascade regulation (applied to another species than that authorized). Nine signals were identified from the reports, resulting in revisions of the product information in the sections addressing contra-indications or adverse reactions.

[Online information system for -phytotherapy in animals]

INTRODUCTION

Phytotherapy becomes increasingly popular in veterinary medicine. To fully exploit the therapeutic potential of medicinal plants and ensure their safe use, knowledge about the effective plant parts and preparations is required. Improper use and overdosage of medicinal plants can be toxic. With www.phytoarznei.ch, we provide an online decision support aid that allows for the retrieval of currently available information on medicinal plants and their use in domestic animals. This decision support system is based on the available literature in the field, which after critical evaluation has been incorporated into a structured database. For each medicinal plant or drug, we have listed therapeutic indications, different application types, organoleptic properties, plant ingredients, pharmacological effects, dosages, duration of treatment, toxicity, legal frame for use in livestock and relevance for doping. A user-friendly access to all data is achieved by means of two search programs, either by entering the plant name or name of the drug in a search field or by selecting the desired animal species and therapeutic application from respective drop-down lists. This database on medicinal plant applications in animals is linked to the poisonous plant database of the University of Zurich and, for marketed preparations, to the Swiss compendium of veterinary medicinal products as well as to an index of related veterinary products.

[Vigilance for veterinary medicinal products: Reports of adverse reactions in the year 2016]

INTRODUCTION

A total of 253 reports of adverse reactions to veterinary medicinal products were received during the year 2016 representing a decrease of 13% compared to the previous year (292 reports). The majority of the reports described reactions affecting companion animals (178 dogs and 32 cats) as well as cattle (17 reports) and horses (10 reports). Most of the reactions reported were linked to the use of antiparasitics (145 reports), hormone products (26 reports) and antiinfectives (10 reports). 32 reports were generated from consultations with Tox Info Suisse in Zürich and involved mainly the excessive intake of flavoured tablets and, in some cases, the use of reconverted products (applied to another species than that authorized). Five signals were identified from the reports, which resulted in revisions of the product information in the sections addressing contraindications or adverse reactions.

[Vigilance for veterinary medicinal products: Reports of adverse reactions in the year 2015]

INTRODUCTION

A total of 292 adverse reactions to veterinary medicinal products were reported during the year 2015. This represents an increase of 9% compared to the previous year (268 reports). Similar to previous years, most of the reactions reported were linked to the use of antiparasitics (55.1%), non-steroidal anti-inflammatory products (8.9%) or antiinfectives (9.3%). The affected animal species were primarily dogs (198 reports) and cats (42 reports), followed by cattle (31 reports) and horses (8 reports). Additional 42 reports were provided within the frame of consultations with Tox Info Suisse in Zürich and involved mainly the excessive intake of flavored tablets. Eight signals were identified from the reports received or the periodic safety update reports. They resulted in revisions of the product information in sections addressing contraindications, adverse reactions or withdrawal times.

[Vigilance of veterinary medicinal products: Reports of adverse reactions in the year 2014]

During the year 2014, a total of 268 adverse reactions due to Swissmedic-authorized veterinary medicinal products were reported representing an increase of 7% compared to the previous year. Similar to previous years, most of the reactions reported were linked to the use of antiparasitic products (47.8%) or antiinfectives (9.3%). In 10.8% of the reports, reactions were described after the use of products acting on the hormonal system. The affected animal species were primarily dogs (182 reports), cats (58 reports), and cattle (16 reports). Additionally, 33 reports were provided within the frame of consultations with the toxicological information centre in Zurich (Tox Info Suisse). We present a short overview of the safety of COX-2 inhibitors and a series of reactions following the use of a parenteral buprenorphine solution. Finally, the vaccinovigilance program received 124 declarations following the application of various vaccines, but no detailed analysis of those reports is available.

[Vigilance for veterinary medicinal products: reports of adverse reactions in the year 2012]

197 adverse reactions of Swissmedic-authorized veterinary medicinal products were reported during the year 2012 (2011: 167). Species and drug classes remain unchanged over the years: most of the reports related to reactions following the use of antiparasitic products (37.6 %), antiinfectives (15.7 %) or non-steroidal antiinflammatory drugs (11.7 %) in companion animals (94 dogs and 53 cats) followed by cattle/calves (29). Additionally, 45 cases transmitted by the Swiss Toxicological Information Centre in Zürich were processed. We discuss a paradoxical reaction under the potential influence of acepromazine as well as a modified protocol for treating permethrin intoxication in cats. Finally, the vaccinovigilance program received 95 declarations following the application of various vaccines, mainly to dogs or cats.

Behandlung einer chronischen Kupfervergiftung mit oralem Ammoniummolybdat und Natriumsulfat bei Milchschafen

Four weeks after the introduction of a new ration, a herd of sheep in the Swiss midland area was affected by depression, anorexia, decreased milk production, anemia, hemoglobinuria and frequent recumbency. Seventeen ewes died within a few days. A diagnosis of chronic copper poisoning was based on the results of feed analysis, histopathological findings and the toxicological examination of liver tissue. The remaining sheep were treated with oral ammonium molybdate and sodium sulfate, which together provide an inexpensive alternative to the chelator D-penicillamine.This combination not only prevents further copper intake, but also supports its elimination from the hepatocellular storage compartments. Serum copper levels have been determined to monitor the mobilization of copper following this antidote therapy.

Bromadiolon-Vergiftung bei Füchsen

Bromadiolone is an anticoagulant rodenticide that inhibits the reactivation of vitamin K1 by the enzyme vitamin K1-epoxide reductase. The present case report originated from the application of bromadiolone against water voles (Arvicola terrestris) in northeastern Switzerland. At least 40 foxes (Vulpes vulpes) were found dead after the inappropriate use of a bait that contained 0.02 % bromadiolone. Anticoagulant rodenticide poisoning was suspected on the basis of the postmortem examination and subsequently confirmed by the detection ofbromadiolone both in the blood and in samples from thoracic and abdominal fluids.

[Vigilance for veterinary medicinal products: reports of adverse reactions in the year 2011]

167 adverse reactions of Swissmedic-authorized veterinary medicinal products were reported during the year 2011 (2010: 160). Species and drug classes remain comparable with previous years: most of the reactions occurred following the use of antiparasitic products (39 %), antiinfectives (20 %) or non-steroidal antiinflammatory drugs (11 %) in companion animals (85 dogs and 27 cats) followed by cattle/calves (37). We received 15 cases of adverse reactions following reconverted use, 8 of them in treated cats. Additionally the Swiss Toxicological Information Centre in Zürich processed 84 enquiries and transmitted them to Swissmedic. One case of a successful new therapy to treat ivermectin poisoning in a pony is presented. Finally, the vaccinovigilance program received 60 declarations following the application of various vaccines, mainly to dogs or cats.

Distribution of polychlorinated biphenyls and polybrominated diphenyl ethers in birds of prey from Switzerland

Polychlorinated biphenyls (PCBs) and the structurally related polybrominated diphenyl ethers (PBDEs) have been associated with chronic neurotoxicity involving reduced motor activity and impaired attentiveness. Such neurobehavioral effects indicate that the central nervous system may represent an important target organ for the action of these persistent contaminants in wildlife. As a consequence, the brain of different terrestrial and aquatic birds collected in Switzerland was analysed for PCBs and PBDEs. In parallel, the same contaminants were examined in the accompanying adipose tissue. After clean-up by means of glass columns containing acidified silica, deactivated alumina and anhydrous sodium sulphate, the samples were analysed by high resolution gas chromatography/tandem mass spectrometry (HRGC-MS/MS). Median PCB concentrations in the brain (sum of PCB 28, PCB 52, PCB 101, PCB 118, PCB 138, PCB 153 and PCB 180) ranged between 13 ng g(-1) wet weight (ww) in blackbirds (Turdus merula) and 428 ng g(-1) ww in sparrow hawks (Accipiter nisus). Median PBDE concentrations in the brain (sum of BDE 28, BDE 47, BDE 99, BDE 100, BDE 153, BDE 154 and BDE 183) ranged from below the decision limit in buzzards (Buteo buteo) and blackbirds, to 14 ng g(-1) ww in sparrow hawks. After correction for the respective lipid content, higher PCB or PBDE concentrations in brain compared to adipose tissue, were found in three sparrow hawks, four buzzards and in all investigated blackbirds. These results suggest that a deficit in the neuroprotective function of the blood-brain barrier may cause unexpected levels of PCBs and PBDEs in the central nervous system.

[CliniTox: the computer-based information system for poisoning in farm animals]

Poisonings can cause reduced performance and severe economic loss in farm animals. A swift and targeted action is required from veterinarians. We have established a computer-based decision support system for poisonings in ruminants and pigs. The system offers access to the most recent information available in clinical toxicology of farm animals. Towards this goal, relevant reports from the peer-reviewed literature were evaluated and organised according to the requirements of a structured database. The information provided for each toxic substance includes a summary of its chemical and physical properties, sources, commercial uses or natural occurrences, toxicokinetic data, mechanisms of action, threshold doses, clinical symptoms with brief case reports, sampling and analytical results, post-mortem abnormalities, differential diagnoses, therapeutic guidelines and references to the literature. This decision support system has been programmed with two user-friendly search functions: a search tool that allows the choice of clinical and pathological findings, and another function that serves to find a substance using its chemical name, the class of compounds to wich it belongs, a possible source or one of its main applications. CliniTox can be accessed directly via our webserver (http://www.clinitox.ch).

[Computer-based information system (CliniTox) for the management of poisoning in small animals]

Because cases of poisoning are observed rarely, veterinary practitioners have only limited knowledge of clinical toxicology and may face considerable problems in handling toxicological emergencies. In this report, we describe a novel decision support system for the management of poisonings in companion animals that provides rapid access to the current knowledge of clinical toxicology. For that purpose, relevant reports from the peer-reviewed literature were evaluated and organised according to the requirements of a structured database. The information provided for each toxic substance includes a summary of its chemical and physical properties, sources, commercial uses or natural occurrences, toxicokinetic data, mechanisms of action, threshold doses, clinical symptoms with brief case reports, sampling and analytical results, post-mortem findings, differential diagnoses, therapeutic guidelines and references to the literature. This decision support system has been programmed with two user-friendly search functions: a search tool that allows to choose clinical symptoms, and another function that serves to find a substance using its chemical name, the class of compounds to wich it belongs, a possible source or one of its main applications. CliniTox can be accessed directly via our webserver (http://www.clinitox.ch).

Functional expression of GFP-tagged Kv1.3 and Kv1.4 channels in HEK 293 cells

Various types of voltage gated potassium channels (Kv) are responsible for setting the resting potential and shaping the membrane potential waveform in the subcellular domains of neurons. In order to visualize the expression behaviour of recombinant Kv channels, we have fused green fluorescent protein (GFP) to the N-terminal of the alpha subunits Kv1.3 and Kv1.4. In transiently transfected HEK 293 cells the GFP-Kv chimeras localize to the plasma membrane. Whole-cell voltage clamp recordings demonstrate that they form functional potassium channels. Kinetic analysis reveals that the gating kinetics of GFP-Kv1.3 are virtually indistinguishable from those displayed by its wild-type correlate. For GFP-Kv1.4 channels we find that their gating is modified in an expected manner. In response to short depolarizing voltage pulses they do not inactivate, indicating that the attached GFP interferes with the fast N-type inactivation mechanism present in wild type Kv1.4 channels. We suggest that GFP tagging of Kv channels might be a useful tool to monitor the spatiotemporal distribution of recombinant potassium channels expressed in living neurons.

[Imported hepatozoonosis in the dog: 3 cases]

Canine hepatozoonosis is presented with 3 cases. The most common signs are: fever, anorexia, weight loss, diarrhea and vomiting, muscle weakness, lymphadenopathy, anemia and purulent discharge from the nose and the eyes. Because an infection with H. canis in the dog is often associated with other infectious diseases such as leishmaniasis, ehrlichiosis and babesiosis, the clinical picture may be dominated by these diseases. The diagnosis is made with the typical inclusions in neutrophilic granulocytes and monocytes. Only short remissions may be obtained with the presently available medications.

Internal Mg2+ block of recombinant NMDA channels mutated within the selectivity filter and expressed in Xenopus oocytes

1. The NMDA receptor channel is blocked by both external and internal Mg2+ ions, which are assumed to bind inside the channel on each side of a central barrier. We have analysed the internal Mg2+ block in recombinant NR1-NR2A NMDA receptors expressed in Xenopus oocytes. We have determined the effects of mutations of two asparagines that line the selectivity filter of the channel, one located within the NR1 subunit (N598) and the other within the NR2A subunit (N596). 2. The whole-cell current-voltage relation of wild-type NMDA channels shows inward rectification that reflects the voltage-dependent block produced by the internal Mg2+ of the oocyte. This inward rectification is slightly reduced in the NR2 mutant (N596S) but is abolished in the NR1 mutants (N598Q and N598S). This suggests that the NR1 asparagine plays a larger role than the NR2 asparagine in controlling the internal Mg2+ block. 3. Single-channel current-voltage relations confirm that the internal Mg2+ block is reduced in both the NR1 and NR2 mutants. However, the reduction is small and is similar for the two families of mutants. 4. The discrepancy between whole-cell and single-channel data is partly due to differential effects of internal Mg2+ on the open probabilities of the two conductance states present in NR1 mutant channels. 5. The results suggest that mutations of NR1 and NR2 asparagines lower the central barrier to Mg2+. An additional contribution of the NR2 asparagine to the external Mg2+ binding site (and possibly to the external barrier that controls access to this site) may account for the marked relief of external Mg2+ block produced by the NR2 mutation.

Probing the pore region of recombinant N-methyl-D-aspartate channels using external and internal magnesium block

Mg2+ ions block N-methyl-D-aspartate (NMDA) channels by entering the pore from either the extracellular or the cytoplasmic side of the membrane in a voltage-dependent manner. We have used these two different block phenomena to probe the structure of the subunits forming NMDA channels. We have made several amino acid substitutions downstream of the Q/R/N site in the TMII region of both NR1 and NR2A subunits. Mutant NR1 subunits were coexpressed with wild-type NR2A subunits and vice versa in Xenopus oocytes. We found that individually mutating the first two amino acid residues downstream to the Q/R/N site affects mostly the block by external Mg2+. Mutations of residues five to seven positions downstream of the Q/R/N site do not influence the external Mg2+ block, but clearly influence the block by internal Mg2+. These data add support to the hypothesis that there are two separate binding sites for external and internal Mg2+ block. They also indicate that the C-terminal end of TMII contributes to the inner vestibule of the pore of NMDA channels and thus provide additional evidence that TMII forms a loop that reemerges toward the cytoplasmic side of the membrane.

Intracellular and extracellular amino acids that influence C-type inactivation and its modulation in a voltage-dependent potassium channel

The rate of C-type inactivation of the cloned voltage-gated potassium channel, Kv1.3, measured in membrane patches from Xenopus oocytes, increases when the patch is detached from the cell; the structural basis for this on-cell/off-cell change was examined. First, four serine and threonine residues, that are putative sites for phosphorylation by protein kinases A and C, were mutated to alanines. Mutating any one of these residues, or two or three of them simultaneously, does not eliminate the change in C-type inactivation. However, the basal rate of C-type inactivation in the cell-attached patch is markedly slower in the triple phosphorylation site mutant. Second, a homologous potassium channel, Kv 1.6, does not exhibit the on-cell/off-cell change. When an extracellular histidine at position 401 of Kv1.3 is replaced with tyrosine, the residue at the equivalent position (430) in Kv1.6, the resulting Kv1.3 H401Y mutant channel does not undergo the on-cell/off-cell change. The results indicate that several potentially phosphorylatable intracellular amino acids influence the basal rate of C-type inactivation, but are not essential for the on-cell/off-cell change in inactivation kinetics. In contrast, an extracellular amino acid is critical for this on-cell/off-cell change.

The flagellar bundle of Halobacterium salinarium is inserted into a distinct polar cap structure

Flagellated envelopes of Halobacterium salinarium cells were prepared by lysis with taurodeoxycholate. After solubilization of the envelopes with Triton X-100 at high ionic strength, flagella and round patches from which numerous flagella emerged were isolated by gel filtration chromatography. We conclude that the flagellar bundle of H. salinarium is inserted into a differentiated polar cap structure.

Na(+)-activated K+ channels are widely distributed in rat CNS and in Xenopus oocytes

We recorded the activity of K+ channels activated by sodium (KNa channels) in two widely used preparations, primary cell cultures prepared from neocortex, cerebellum, midbrain, brainstem and spinal cord, and Xenopus oocytes. KNa channels from all regions shared an absolute dependence on [Na+], had conductances of 140-170 pS in symmetrical 150 mM K+ and exhibited characteristic substates. The role of this channel must now be considered in terms of its widespread distribution.

Properties and rundown of sodium-activated potassium channels in rat olfactory bulb neurons

We have used single-channel recording techniques to investigate the properties of sodium-activated potassium channels (KNa channels) in cultured rat olfactory bulb neurons, and in large neurons in the mitral cell layer of thin slices of olfactory bulb. Ion channels highly selective for potassium over sodium and chloride, and requiring 10-180 mM internal sodium (Nai) for their activation, were present in approximately 75% of inside-out membrane patches detached from cultured olfactory bulb neurons. Most of these patches contained several KNa channels. KNa channels were seen in cell-attached patches only when Nai was raised by including veratridine in the extracellular medium. Preincubation of the cell in TTX or removal of extracellular sodium prevented this effect of veratridine, confirming that the channels observed under these conditions were indeed KNa channels. Lithium did not substitute for Nai in activating these channels. With 150 mM potassium on both sides of the membrane, KNa channels had a single-channel conductance of 172 pS, and at least two subconducting states were observed in addition to this fully open state. Under these ionic conditions, the channels exhibited linear fully open channel current-voltage curves over the potential range of -100 to 0 mV. At voltages more positive than the potassium equilibrium potential, the single-channel currents exhibited inward rectification as a result of sodium block of outward potassium current. The channels opened in bursts, during which they fluctuated between the fully open and closed states, and the substates. Between bursts they sometimes entered a long-lived inactive state that could last for up to several minutes. In addition, KNa channels in the detached patches exhibited rundown, a progressive irreversible loss in activity, over a time course that varied from less than 1 min to longer than 1 hr. Rundown of KNa channel activity in cell-attached patches (in the presence of veratridine) did not occur, suggesting that some intracellular factor necessary for KNa channel activity is lost when the membrane patch is detached from the cell.

Basal-body-associated disks are additional structural elements of the flagellar apparatus isolated from Wolinella succinogenes

The intact flagella of Wolinella succinogenes, a gram-negative, anaerobic bacterium with a single polar flagellum, were obtained by an improved procedure, introduced recently by Aizawa et al. (S.-J. Aizawa, G. E. Dean, C. J. Jones, R. M. Macnab, and S. Yamaguchi, J. Bacteriol. 161:836-849, 1985) for the flagellum of Salmonella typhimurium. Disks with a diameter of 130 +/- 30 nm, which were attached to the basal body of the isolated intact flagella, could be identified by electron microscopy as additional structural elements of the bacterial flagellar apparatus. In freeze-dried and metal-shadowed samples, two rings of the basal body were detected on one side and a terminal knob was located on the other side of the disks. Suspension of the flagellar apparatus in acidic solution dissociated the flagellar filaments, yielding hook-basal body complexes with and without the associated disks. If whole cells were subjected to low pH, double disks of the same diameter and with a central hole of about 13 nm could be isolated. Similar parallel disks could be seen also in negatively stained whole cells. When uranyl acetate was used for negative staining of the intact flagella, concentric rings were detected on the disks, similar to the concentric membrane rings found by Coulton and Murray (J. W. Coulton and R. G. E. Murray, J. Bacteriol. 136:1037-1049, 1978) on platelike arrays of proteins in outer membrane preparations of Aquaspirillum serpens. Because the disks of W. succinogenes can be isolated together with the flagellar hook-basal body complex, they appear to be basal-body-rather than secondary membrane-associated structures. It is possible that these disks are the bearing or stator of this rotary device.