Electroretinographic findings in day-blind dogs

Cone degeneration (cd; day blindness) is one of the inherited retinal diseases of dogs. Its diagnosis is based on vision testing, fundoscopy, electroretinography (ERG) and, for some breeds, on genetic tests. Typical signs of the disease are day blindness and cone dysfunction during ERG while fundoscopy does not show any abnormalities. The aim of this study was to compare behavioural findings, fundoscopic lesions and electroretinographic alterations in 12 cd-affected dogs (Alaskan Malamute, Labrador Retriever, German Shepherd, Dachshund, Yorkshire Terrier, Shih Tzu, Siberian Husky and crossbreeds) examined at our clinic. None of the examined dogs had any fundoscopic lesions, and all of them had normal scotopic vision with strongly impaired or absent photopic vision. Light-adapted transient, cone-mediated and steady-state, 31-Hz cone flicker ERGs were much below the 5th percentile limits of normality or even unrecordable, while the rod-driven ERGs were within normal values. Vision test and ERG results corresponded to each other and, combined with the results of fundoscopy, were typical of cd. To date, our research is one of the few studies in the world presenting ERG alterations compared with vision test findings and fundoscopic results in the course of cd

The effects of environmental parameters on the microbial activity in peat-bog lakes.

Microbiological activity is an important parameter for understanding the functioning of different environments. Therefore, the purpose of this study was to estimate the quantity and contribution of metabolically active at the single-cell level bacteria in the microbial community in peat-bog lakes. To determine different aspects of the metabolic activity of bacteria, four fluorescent staining methods (Dehydrogenase/Electron Transport System Activity -CTC+, Nucleoid Containing Cells- NuCC+, Active Bacteria with Intact Ribosome Structures- RIB+ and Active Bacteria With an Intact Membrane-MEM+) were applied. We identified four natural peat-bog lakes in Northern Europe to determine which factors-community (bacterial factors) or environment (hydrochemical and physical factors)-have a significant influence on the quantitative dynamics of metabolically active microorganisms, in terms of seasonal and habitat changes. The results show that change in the amount of abiotic components such as DOC, TN, and TOC can result in stress, which may limit a function but does not lead to losing all other metabolic functions in the community-forming bacteria. In nutrient-poor peat bog lakes, nutrients and organic carbon are factors which regulate the overall activity of the community

Prokaryotic Community Composition Affected by Seasonal Changes in Physicochemical Properties of Water in Peat Bog Lakes

Based on a three-year study on the prokaryotic community composition in peat bog lakes surrounded by a floating mat of Sphagnum sp. moss in the conditions of Northeast Poland (Central Europe), we verified the relationship between 20 water parameters and main Eubacteria and Archaea phyla for specific sites: the subsurface (pelagic zone), near-bottom (benthic zone), and the Sphagnum mat (ecotone zone). Abundance and composition of the main aquatic bacteria phyla (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, Actinobacteria, and Cytophaga-Flavobacteria) and Archaea were associated with different combinations of physico-chemical parameters of water, and followed temporal variations of temperature, dissolved organic carbon (DOC), aromaticity, and water color. Redundancy analysis (RDA) showed that water acidity is a less significant predictor of bacterial activity; however, we have found Betaproteobacteria negatively correlated (r = −0.49, p = 0.01), while Actinobacteria positively correlated (r = 0.21, p = 0.05) to pH. This relation was the most significant in the ecotone zone. In the overall bacteria community structure Betaproteobacteria dominated (18.3%) regardless of site or season, except for winter when, at low temperatures and DOC concentrations, Actinobacteria increased to 22.9%. The Archaea fraction was uniform (11%) in seasons and sites and showed no specific preferences to physico-chemical predictors. Although the water parameters from the Sphagnum mat did not differ significantly from pelagic water, its role as a source of allochthonous organic matter is crucial for bacteria activity. The relations between peat bog lake attributes and seasonal changes in bacterial diversity demonstrated a distinct divergent pattern for each prokaryote. Obtaining results will provide support for any future evaluation of the effects of environmental variables on prokaryotic community structures in peat bog lakes

Therapeutic efficacy of botulinum toxin in the treatment of urinary incontinence in female dogs

Urinary incontinence in animals poses a growing therapeutic problem. Satisfactory results in the treatment of incontinence are not reported despite the wide availability of pharmaceuticals addressing the problem. The growing number of side effects and the need for sustained pharmacotherapy have prompted a search for new treatment methods. The experiment described in this study was performed on 11 bitches with clinical symptoms of urinary incontinence. The dogs underwent cystoscopy during which botulinum toxin solution was injected into the wall of the urinary bladder (50–100 botulinum toxin units were given per animal in 10 injections), causing changes in its innervation. Positive therapeutic effects lasting for 5 months in average were noted in 70% of the treated animals

Patterns of salinity regime in coastal lakes based on structure of benthic invertebrates.

The macrozoobenthic diversity patterns along a brackish-freshwater salinity gradient have been identified, considering effects of differences in the level of hydrological connection of coastal lakes with the sea on the structure of benthic invertebrate communities. The study is based on samples from six coastal lakes located along the southern coast of the Baltic Sea in Poland. The analysis of environmental and biological data confirmed the existence of stable phases (brackish water vs. freshwater), but as a result of periodical intrusion of seawater, adaptation of animal communities takes place, which was reflected in low values of the predictors describing them (number of taxa, density and diversity). Redundancy analysis indicates that values of conductivity and salinity are the major factors that determine the abundance of dominant groups of benthic fauna. The gradient of hydrological connection of the lakes with the sea accounted for 50% of the variance in biological data, physico-chemical variables for 25%, trophic variables for 15%, and only 9% of the variance was unexplained. The major implication of our results is that coastal lakes that differ only slightly in salinity can have alternative, regional patterns of diversity of structure of benthic fauna. Periodical inflow of brackish waters initiates adaptive cycles of benthic fauna, and their frequency is strongly linked with the hydrological regime. The rhythm of the inflow of seawater is variable, so that management and protection of coastal lakes are extremely complicated

Environmental Factors Structuring Fish Communities in Floodplain Lakes of the Undisturbed System of the Biebrza River

We evaluated the influence of habitat connectivity and local environmental factors on the distribution and abundance of functional fish groups in 10 floodplain lakes in the Biebrza River, northeastern Poland. Fish were sampled by electrofishing, and 15 physico-chemical parameters were recorded at three sampling sites at each lake in the period of 2011–2013. A total of 18,399 specimens, belonging to 23 species and six families, were captured. The relationships between environmental factors and fish communities were explored with the use of canonical correspondence analysis (CCA). Sampling sites were grouped based on fish communities using a hierarchical cluster analysis (HCA). Along a lateral connectivity gradient from lotic to lentic habitats (parapotamic–plesiopotamic–paleopotamic), the proportions of rheophilic species were determined as 10:5:1, whereas the proportion of limnophilic species was determined as 1:2:5. The predominant species were the roach (Rutilus rutilus), and pike (Esox lucius) in parapotamic lakes, rudd (Scardinius erythropthalmus) and pike in plesiopotamic lakes, and sunbleak (Leucaspius delineates) and Prussian carp (Carassius auratus gibelio) in paleopotamic lakes. The findings indicated that the composition and abundance of fish communities are determined by lake isolation gradient, physico-chemical parameters and water stage. Although intact riverine ecosystems may promote fish biodiversity, our findings suggest that lateral connectivity between the main channel and floodplain lakes is of utmost importance. Thus, the conservation of fish biodiversity requires the preservation of this connectivity