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Preclinical testing of novel therapeutics for chronic hepatitis B (CHB) requires suitable animal models. Equids host homologs of hepatitis C virus (HCV). Because coinfections of hepatitis B virus (HBV) and HCV occur in humans, we screened 2,917 specimens from equids from five continents for HBV. We discovered a distinct HBV species (Equid HBV, EqHBV) in 3.2% of donkeys and zebras by PCR and antibodies against EqHBV in 5.4% of donkeys and zebras. Molecular, histopathological, and biochemical analyses revealed that infection patterns of EqHBV resembled those of HBV in humans, including hepatotropism, moderate liver damage, evolutionary stasis, and potential horizontal virus transmission. Naturally infected donkeys showed chronic infections resembling CHB with high viral loads of up to 2.6 × 10(9) mean copies per milliliter serum for >6 mo and weak antibody responses. Antibodies against Equid HCV were codetected in 26.5% of donkeys seropositive for EqHBV, corroborating susceptibility to both hepatitis viruses. Deltavirus pseudotypes carrying EqHBV surface proteins were unable to infect human cells via the HBV receptor NTCP (Na(+)/taurocholate cotransporting polypeptide), suggesting alternative viral entry mechanisms. Both HBV and EqHBV deltavirus pseudotypes infected primary horse hepatocytes in vitro, supporting a broad host range for EqHBV among equids and suggesting that horses might be suitable for EqHBV and HBV infections in vivo. Evolutionary analyses suggested that EqHBV originated in Africa several thousand years ago, commensurate with the domestication of donkeys. In sum, EqHBV naturally infects diverse equids and mimics HBV infection patterns. Equids provide a unique opportunity for preclinical testing of novel therapeutics for CHB and to investigate HBV/HCV interplay upon coinfection.

Donkeys have been used as working animals for transport and farm activities worldwide. Recently, in European countries, there has been an increasing interest in donkeys due to their use as pets, onotherapy or milk production. During 2014–2016, a countrywide survey was conducted to determine prevalence and risk factors of principal helminth infections in 1775 donkeys in 77 Italian farms. A questionnaire on management and parasite control practices was filled out for each farm. Faecal samples were examined using a modified McMaster technique, a centrifugation/flotation method and a sedimentation technique. Pooled coprocultures were performed for differentiation of strongylid eggs. Strongyles were the most common parasites detected (84.9%), followed by Dictyocaulus arnfieldi (6.9%), Oxyuris equi (5.8%), Parascaris spp. (3.6%), Anoplocephala spp. (1.0%), Strongyloides westeri (0.3%). Coprocultures revealed an omnipresence of cyathostomins (100%), followed by Strongylus vulgaris (31.0%), Poteriostomum spp. (25.0%), Triodontophorus spp. (9.0%), Strongylus edentatus (7.0%), Strongylus equinus (5.0%). Logistic regression analysis identified breed, co-pasture with horses, living area, herd size and number of treatments as significantly associated with strongyles. Sex, age, living area and herd size were significantly associated with Parascaris spp. Dictyocaulus arnfieldi was significantly associated with sex, grass, co-pasture with horses, living area and herd size. Strongylus vulgaris was significantly associated with living area and herd size. The mean number of anthelmintic treatments/year was 1.4; most of the donkeys (71.8%) were dewormed using an ivermectin drug. It is important to design parasite programs to specifically address both D. arnfieldi and S. vulgaris in donkeys, and this is especially important if donkeys co-graze with horses.

Mebendazole (MBZ) has been licensed for use in horses and donkeys, however there are no data available in the literature regarding its pharmacokinetic disposition and efficacy in donkeys. This study was designed to determine the plasma disposition, milk excretion and anthelmintic efficacy of MBZ in donkeys naturally infected by Cyathostominae. The animals were allocated to three groups, each of six donkeys. One group was untreated control (C-group) and the others were treated using a paste formulation of MBZ administered per os at the manufacturer's recommended horse dosage of 10 mg/kg body weight (MBZ 1) and at the double horse dosage 20 mg/kg body weight (MBZ 2). Blood and milk samples were collected at various times between 1 h and 120 h post treatment and analyzed by high performance liquid chromatography with photodiode array detector. Individual FECs (Faecal Egg Counts) were performed on each animal before the treatment (day-3) and weekly from day 7 until day 56 post treatment using a modified McMaster technique. The plasma concentrations and systemic exposure of MBZ in donkeys were relatively lower compared with the other methylcarbamate benzimidazoles. Dose-dependent plasma dispositions of MBZ were observed at the increased dosage (10 mg/kg vs 20 mg/kg) in donkeys. MBZ was not detected in any milk samples at a dosage of 10 mg/kg. However, the parent drug reached 0.01 μg/ml peak milk concentration at 10.66 h and AUCmilk/AUCplasma value was 0.18 ± 0.02 at a dosage of 20 mg/kg bodyweight. This study indicated that per os administration of MBZ has a minimal disposition rate into the milk and may be used in lactating donkeys with zero milk-withdrawal period. The results of FECRT for both MBZ dosages were efficient (>95% efficacy) until day 28. This trial demonstrates that MBZ oral paste at horse dosage (10 mg/kg B.W.) was effective and safety for the treatment of Cyathostominae in donkeys. Therefore, similar dosage regimens of MBZ could be used for horses and donkeys.

Collective evidence indicates that motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is non-cell-autonomous and requires the interaction with the neighboring astrocytes. Recently, we reported that a subpopulation of spinal cord astrocytes degenerates in the microenvironment of motor neurons in the hSOD1 G93A mouse model of ALS. Mechanistic studies in vitro identified a role for the excitatory amino acid glutamate in the gliodegenerative process via the activation of its inositol 1,4,5-triphosphate (IP 3)-generating metabotropic receptor 5 (mGluR5). Since non-physiological formation of IP 3 can prompt IP 3 receptor (IP 3R)-mediated Ca 2+ release from the intracellular stores and trigger various forms of cell death, here we investigated the intracellular Ca 2+ signaling that occurs downstream of mGluR5 in hSOD1 G93A-expressing astrocytes. Contrary to wild-type cells, stimulation of mGluR5 causes aberrant and persistent elevations of intracellular Ca 2+ concentrations ([Ca 2+] i) in the absence of spontaneous oscillations. The interaction of IP 3Rs with the anti-apoptotic protein Bcl-X L was previously described to prevent cell death by modulating intracellular Ca 2+ signals. In mutant SOD1-expressing astrocytes, we found that the sole BH4 domain of Bcl-X L, fused to the protein transduction domain of the HIV-1 TAT protein (TAT-BH4), is sufficient to restore sustained Ca 2+ oscillations and cell death resistance. Furthermore, chronic treatment of hSOD1 G93A mice with the TAT-BH4 peptide reduces focal degeneration of astrocytes, slightly delays the onset of the disease and improves both motor performance and animal lifespan. Our results point at TAT-BH4 as a novel glioprotective agent with a therapeutic potential for ALS. © The Author 2011. Published by Oxford University Press. All rights reserved