Objectives A prospective experimental study was performed in nine young healthy cats to investiga... more Objectives A prospective experimental study was performed in nine young healthy cats to investigate a pharmacokinetic profile and the clinical relevance of rectally administered buprenorphine. Rectal pH value was measured in all nine cats. Methods Blood was collected 15, 30, 60, 90, 120, 240 and 480 mins and 24 h after the rectal administration of a suppository and a gel at doses between 0.02 mg/kg and 0.1 mg/kg buprenorphine to determine the plasma concentration of buprenorphine. Rectal pH was measured with pH paper. Results Upon pharmacokinetic non-compartment analysis of high-dose buprenorphine (0.1 mg/kg), average maximal plasma concentration was found to be 1.13 ng/ml, time to maximal plasma concentration was 45 mins and area under the plasma concentration–time curve was 94.19 ng*min/ml, representing low but potential bioavailability. Mean residual time was 152.2 mins and the half-life was 92.6 mins. A wide range of plasma concentrations within the cohort was measured and two o...
The aim of this study was to establish heart rate as a measure of energy expenditure in large act... more The aim of this study was to establish heart rate as a measure of energy expenditure in large active kennel dogs (28 AE 3 kg bw). Therefore, the heart rate (HR)-oxygen consumption ( _ VO 2 ) relationship was analysed in Foxhound-Boxer-Ingelheim-Labrador cross-breds (FBI dogs) at rest and graded levels of exercise on a treadmill up to 60-65% of maximal aerobic capacity. To test for effects of training, HR and _ VO 2 were measured in female dogs, before and after a training period, and after an adjacent training pause to test for reversibility of potential effects. Least squares regression was applied to describe the relationship between HR and _ VO 2 . The applied training had no statistically significant effect on the HR-_ VO 2 regression. A general regression line from all data collected was prepared to establish a general predictive equation for energy expenditure from HR in FBI dogs. The regression equation established in this study enables fast estimation of energy requirement for running activity. The equation is valid for large dogs weighing around 30 kg that run at ground level up to 15 km/h with a heart rate maximum of 190 bpm irrespective of the training level.
ABSTRACT Background Hypothyroidism and dilated cardiomyopathy (DCM) are both common diseases in D... more ABSTRACT Background Hypothyroidism and dilated cardiomyopathy (DCM) are both common diseases in Doberman Pinschers. A possible influence of hypothyroidism on the etiology and progression of DCM is controversial.Objectives Evaluation of the role of hypothyroidism in etiology and progression of DCM.AnimalsA total of 175 Doberman Pinschers.Methods In this longitudinal prospective study, echocardiography and 24-hour ambulatory ECG recordings were performed in all dogs as screening tests for DCM. Total thyroxine (TT4) and thyroid ultrasonography served as initial screening tests for hypothyroidism and low TT4 values were followed up by a thyroid stimulating hormone (TSH) test or free total thyroxine (fT4)/cTSH measurements. Additionally, a follow-up study of dogs affected by both DCM and hypothyroidism under optimal treatment for hypothyroidism was conducted.ResultsA total of 107 dogs were healthy, 45 dogs had DCM, 11 hypothyroidism, and 12 dogs had both DCM and hypothyroidism. TT4 values as well as the thyroid volumes were equivalent in the healthy dogs and in those with DCM. Neither ventricular premature complexes nor echocardiographic parameters differed between healthy and hypothyroid dogs. Dogs with DCM had a 2.26-fold (CI0.95 = 1.1–4.8) higher risk of also being affected by hypothyroidism. Despite optimal thyroid treatment of dogs with hypothyroidism and DCM, there was a progression of the heart disease.Conclusions and Clinical ImportanceThis study did not confirm a role of hypothyroidism in the etiology or progression of DCM. Treatment of hypothyroidism did not improve the clinical outcome.
The aim of the study was to compare the efficacy and compatibility of a separate or combined vacc... more The aim of the study was to compare the efficacy and compatibility of a separate or combined vaccination against the porcine reproductive and respiratory syndrome (PRRS) and Haemophilus (H.) parasuis. The study was conducted in a 1200 head nursery farm. A total of 360 piglets at an age of 26 days were randomized into three groups. Group A was vaccinated separately against H. parasuis (Porcilis(®)Glässer) and PRRS (Porcilis(®)PRRS), group B was vaccinated with a combined vaccine of both vaccines and group C remained unvaccinated as control group. The compatibility was evaluated by measurement of the body temperature and a palpation score of the injection site 0, 4, 24 and 72h after vaccination. During the nursery and the fattening period the average daily weight gain (ADWG), the number of runts and the mortality was evaluated. Additionally blood samples were taken every 2 weeks during the nursery period to perform an OppA-ELISA and a PCR for PRRS virus. No significant difference coul...
Background: Recurrent airway obstruction (RAO), an asthma-like disease, is 1 of the most common a... more Background: Recurrent airway obstruction (RAO), an asthma-like disease, is 1 of the most common allergic diseases in horses in the northern hemisphere. Hypersensitivity reactions to environmental antigens cause an allergic inflammatory response in the equine airways. Cytosine-phosphate-guanosine-oligodeoxynucleotides (CpG-ODN) are known to direct the immune system toward a Th1-pathway, and away from the pro-allergic Th2-line (Th2/Th1-shift). Gelatin nanoparticles (GNPs) are biocompatible and biodegradable immunological inert drug delivery systems that protect CpG-ODN against nuclease degeneration. Preliminary studies on the inhalation of GNP-bound CpG-ODN in RAO-affected horses have shown promising results.
Journal of applied animal welfare science : JAAWS, Jan 20, 2015
Sheep and goats are frequently used in nonhuman animal-assisted activities on city farms. There a... more Sheep and goats are frequently used in nonhuman animal-assisted activities on city farms. There are few data available on this type of usage of small ruminants. Health evaluations, behavioral observations (feeding, resting, comfort, explorative and social behaviors), behavioral tests (human approach tests and touch test), and measurements of fecal cortisol metabolites and heart rate were performed to assess stress levels in 25 sheep and 32 goats on 7 city farms and 2 activity playgrounds in Germany. No evidence was found that the animals suffered from major distress. Health evaluations, behavioral observations, and behavioral tests proved to be the methods of stress assessment most suitable for routine on-farm checks in these settings.
Veterinary and comparative orthopaedics and traumatology : V.C.O.T, Jan 12, 2015
To evaluate negative pressure wound therapy (NPWT) for treatment of complicated wounds in dogs. R... more To evaluate negative pressure wound therapy (NPWT) for treatment of complicated wounds in dogs. Retrospective multicentre study. Dogs (n = 50) undergoing open wound treatment were classified according to treatment method used: bandage (Group A, n = 7), NPWT (Group B, n = 18), and foam dressing (Group C, n = 25). Pairs of patients matched based on wound conformation, localization, and underlying cause were compared between Group A and C (n = 7 pairs) and between groups B and C (n = 18 pairs) in terms of duration of previous treatment, time to closure, and complications. Signalment, antibiotic medications, antiseptic treatment, and bacterial status of wounds were comparable between groups. The duration of previous treatment was significantly higher in patients assigned to Group B (p = 0.04) compared to Group C, while no significant difference was found between groups A and B. Total time to wound closure was significantly shorter in Group C compared to Group A (p = 0.02) and in Group B...
Investigations of the pathophysiology of ocular diseases require a detailed knowledge of the micr... more Investigations of the pathophysiology of ocular diseases require a detailed knowledge of the microanatomy of the eye. The available information is still inadequate for the equine retina despite the importance of eye diseases in equine medicine. Here we provide a comprehensive analysis of the histologic features of the horse eye as a reference for future studies. Thirty normal eyes of 15 healthy horses were examined immediately after slaughter. The retina of the horse differs considerably in the degree and quantity of neurons and glial elements as well as in vascular patterns compared to the retina of other domestic animals. Morphometric analysis revealed that the thickness of the retina varies between 80 µ m at the ora serrata and 250 µ m medial to the optic disc. Approximately 90% of the equine retina is comparatively thin (< 130 µ m). This is a physiologic response to the distance that oxygen can diffuse in avascular retina. Ganglion cells form a single layer in all parts of the retina. The majority of ganglion cells are very large Nissl-positive cells. Small Nissl-negative ganglion cells are less abundant. A high ganglion cell density is found only in the central area. Vascularization is virtually absent from the retina with the exception of a narrow strip around the disc of the optic nerve, as revealed by lectin histochemistry. Light microscopy of the eyes of older horses repeatedly revealed cystoid degenerations in the retina adjacent to the pars plana of the ciliary body, as well as a destruction of the regular layering of the peripheral region of the retina.
The integrity of gamete transport, fertilization, and early embryonic development in the oviduct ... more The integrity of gamete transport, fertilization, and early embryonic development in the oviduct are essential prerequisites for successful reproduction. Although the basic mechanisms of gamete transport, gamete interaction, and early embryogenesis are known in most mammals, the interactions between gametes and oviductal epithelium as well as the communication between the early embryo and the female reproductive tract remain to be elucidated. Recent techniques of live cell imaging such as digital videomicroscopy and confocal fluorescence microscopy are valuable tools that provide actual new insights into these interactions. By applying these techniques, the mechanisms of sperm transport, sperm storage, oocyte transport, gamete interaction, and early embryo-maternal crosstalk can be analyzed under in vivo or in situ conditions. Detailed knowledge of these very early and important processes creates the basis to develop new therapeutic concepts for subfertility and infertility and to improve the techniques of assisted reproduction. The current review will focus on a short description of recent techniques of live cell imaging in the reproductive tract followed by an overview of actual observations during the early events of reproduction.
Journal of Animal Physiology and Animal Nutrition, 2014
The welfare of an animal is ensured if it is able to fully satisfy its essential species-typical ... more The welfare of an animal is ensured if it is able to fully satisfy its essential species-typical needs in all functional aspects of behaviour. In mink, stereotypies and apathy, internal and/or external injuries as well as increased susceptibility to disease have been known to occur as a result of chronic stress. The non-invasive method of analysing faecal cortisol metabolites (FCM) allows conclusions to be drawn about the stress level in the respective housing system. The objective of this study is to find out how the cortisol metabolites content in the faecal changes with increasing age of the mink under semi-natural housing conditions. Thus, 40 American mink (Neovison vison) were housed in two outdoor enclosures imitating natural conditions. Throughout the entire study (13th to 32nd week of life), faecal samples were collected to measure cortisol metabolites. No differences in FCM concentrations between the two outdoor enclosures were found. In the young mink lower, less fluctuating FCM levels were found than in older animals. After the first faecal collection in the 13th/14th week of life, the level of metabolites decreased slightly (p = 0.032; 17th/18th week). From the 22nd/23rd week onwards until the 30th/31st week, shortly before the animals were pelted, continuously increasing concentrations were then measured. Increasing FCM levels with advancing age of the animals are probably attributable to the onset of sexual maturity and/or the respective season. This has to be taken into account in future studies using this method for assessing welfare and when comparing different mink housing systems.
Journal of Animal Physiology and Animal Nutrition, 2013
Different head-neck positions (HNPs) are used in equestrian sports and are regarded as desirable ... more Different head-neck positions (HNPs) are used in equestrian sports and are regarded as desirable for training and competition by riders, judges and trainers. Even though some studies have been indicative of hyperflexion having negative effects on horses, this unnatural position is frequently used. In the present study, the influence of different HNPs on physical and psychological stress parameters in the ridden horse was investigated. Heart rate (HR), heart rate variability (HRV) and blood cortisol levels were measured in 18 horses. Low frequency (LF) and high frequency (HF) are power components in the frequency domain measurement of HRV which show the activity of the sympathetic and parasympathetic nervous system. Values were recorded at rest, while riding with a working HNP and while riding with hyperflexion of the horse&amp;amp;#39;s head, neck and poll. In addition, rideability and behaviour during the different investigation stages were evaluated by the rider and by an observer. Neither the HR nor the HRV showed a significant difference between working HNP (HR = 105 ± 22/min; LF/HF = 3.89 ± 5.68; LF = 37.28 ± 10.77%) and hyperflexion (HR = 110 ± 18; LF/HF = 1.94 ± 2.21; LF = 38.39 ± 13.01%). Blood cortisol levels revealed a significant increase comparing working HNP (158 ± 60 nm) and hyperflexion (176 ± 64 nm, p = 0.01). The evaluation of rider and observer resulted in clear changes of rideability and behavioural changes for the worse in all parameters collected between a working HNP and hyperflexion. In conclusion, changes of the cortisol blood level as a physical parameter led to the assumption that hyperflexion of head, neck and poll effects a stress reaction in the horse, and observation of the behaviour illustrates adverse effects on the well-being of horses during hyperflexion.
To investigate the uveitogenic potential of retinal S-antigen (S-Ag) in horses. METHODS. Horses w... more To investigate the uveitogenic potential of retinal S-antigen (S-Ag) in horses. METHODS. Horses were immunized subcutaneously with S-Ag or BSA as control antigen, emulsified in complete Freund's adjuvant. Simultaneously, Bordetella pertussis was given intravenously. Antigen specific T-and B-cell responses were analyzed in a 3-day interval. Disease development was judged clinically and histopathologically. Two identical booster immunizations were given every 4 weeks to test induction of recurrences. RESULTS. T-and B-cell responses specific for S-Ag were observed in all immunized horses but were absent in control animals. However, uveitis developed in only one of five animals. Reimmunization with S-Ag did not lead to a uveitic relapse in this horse. All other horses of the S-Ag-and BSA-treated groups neither showed any signs of uveitis, nor had inflammatory infiltrates of the inner eye. CONCLUSIONS. In contrast to interphotoreceptor retinoid-binding protein (IRBP), S-Ag is a weak autoantigen in horses. Even though S-Ag immunization leads to the activation of autoreactive T-and B-cells, infiltration of the inner eye and induction of uveitis are controlled in most horses. (Invest Ophthalmol Vis Sci.
Growth hormone (GH) has recently been shown to promote the development of preimplantation embryos... more Growth hormone (GH) has recently been shown to promote the development of preimplantation embryos. The aim of our study was therefore to analyze the effects of GH on the morphology and ultrastructure of the cells of bovine preimplantation embryos produced by in vitro fertilization (IVF). In order to determine the physiologically optimal morphology of blastocysts, ex vivo embryos obtained by uterine flushing were also included in the study. As shown by transmission electron microscopy, treatment with GH induced the elimination of glycogen storage in cells of the inner cell mass of 7-day-old embryos. GH also stimulated the exocytosis of lipid vesicles in the inner cell mass and trophectoderm cells of these embryos. Quantitative analysis of micrographs demonstrated a higher volume density of embryonic mitochondria in 7-day-old embryos cultured with GH than in control embryos. Treatment with GH regularly resulted in an improvement of the ultrastructural features of embryos produced in vitro, thus resembling the morphology of ex vivo embryos. Scanning electronmicroscopy studies demonstrated that GH altered the structure and the pore size of the zona pellucida of blastocysts. Our studies imply that GH can modulate carbohydrate, lipid, and energy metabolism and influence transportation processes in the early IVF embryo.
Using a digital videomicroscopic analysis system in the bovine, we showed that the mechanisms of ... more Using a digital videomicroscopic analysis system in the bovine, we showed that the mechanisms of transport caused by ciliary beating are distinctly different in ampulla and isthmus of the oviduct. The average particle transport speed (PTS) in the oviduct (mean, 133 microm/sec) does not differ in the cycle (metestrus) and during pregnancy after implantation, but it is locally modulated at the site of the embryo. Using videomicroscopy, we were able to document that after entering the ampulla, the cumulus-oocyte complex (COC) is not transported by ciliary beating down the oviduct, but firmly attaches to the ampullar epithelium. This attachment is mediated by the cumulus cells. However, when a COC is degenerated, it is floating in the oviductal lumen. As soon as a vital COC is in the ampulla, the sperm bound in the sperm reservoir of the ampullar isthmic junction leave the reservoir and hurry to the oocyte. When a sperm has penetrated the zona pellucida, the COC detaches and continues its migration. Quantitative measurements showed that the early embryo is able to locally downregulate PTS during its migration down the oviduct. It locally changes the pattern of vascularization and induces the formation of secretory cells. Our studies imply that the oviductal epithelium is able to select vital oocytes. The early embryo is able to induce the formation of secretory cells, modify vascularization, and downregulate speed of transport, thus creating the prerequisite for the first embryo-maternal communication in the oviduct.
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C, 1992
ABSTRACT Lectin-histochemical study of the equine epidermis of skin and hoofCarbohydrate moieties... more ABSTRACT Lectin-histochemical study of the equine epidermis of skin and hoofCarbohydrate moieties of cell membranes in the epidermis of equine skin and hoof were investigated using lectin-histochemistry. The loss of desmosomes during keratinization leads to a reduced lectin affinity. Lectin binding capacity of the intercellular matrix in the stratum corneum of the epidermis is weak compared to that of the intercellular kitt of the hoof. Qualitative differences in lectin binding of the intercellular kitt of different hoof segments correlate with the quality of the horn in the respective areas.
To evaluate the effect of UV-blocking soft contact lenses in treatment for chronic superficial ke... more To evaluate the effect of UV-blocking soft contact lenses in treatment for chronic superficial keratitus (CSK). Twenty six dogs with CSK were treated continuously with UV-blocking contact lenses for 6 months. A contact lens was placed on one eye of each dog; the other eye remained without a lens as a control eye. After this primary study, five of the dogs were further treated and they wore then contact lenses in both eyes. Continuously, all patients were concurrently treated topically with cyclosporine. The contact lenses were changed every 4 weeks and an ophthalmic examination performed. Evaluation criteria included corneal alterations as pigmentation, edema, pannus and vascularization. To determine the transmittance characteristics of the contact lenses before and after use, 32 contact lenses were measured with a UV-vis-NIR spectrophotometer. Pigmentation increased in eyes wearing lenses and in control eyes over the evaluation period of 6 months. Corneal edema increased in the eye...
Objectives A prospective experimental study was performed in nine young healthy cats to investiga... more Objectives A prospective experimental study was performed in nine young healthy cats to investigate a pharmacokinetic profile and the clinical relevance of rectally administered buprenorphine. Rectal pH value was measured in all nine cats. Methods Blood was collected 15, 30, 60, 90, 120, 240 and 480 mins and 24 h after the rectal administration of a suppository and a gel at doses between 0.02 mg/kg and 0.1 mg/kg buprenorphine to determine the plasma concentration of buprenorphine. Rectal pH was measured with pH paper. Results Upon pharmacokinetic non-compartment analysis of high-dose buprenorphine (0.1 mg/kg), average maximal plasma concentration was found to be 1.13 ng/ml, time to maximal plasma concentration was 45 mins and area under the plasma concentration–time curve was 94.19 ng*min/ml, representing low but potential bioavailability. Mean residual time was 152.2 mins and the half-life was 92.6 mins. A wide range of plasma concentrations within the cohort was measured and two o...
The aim of this study was to establish heart rate as a measure of energy expenditure in large act... more The aim of this study was to establish heart rate as a measure of energy expenditure in large active kennel dogs (28 AE 3 kg bw). Therefore, the heart rate (HR)-oxygen consumption ( _ VO 2 ) relationship was analysed in Foxhound-Boxer-Ingelheim-Labrador cross-breds (FBI dogs) at rest and graded levels of exercise on a treadmill up to 60-65% of maximal aerobic capacity. To test for effects of training, HR and _ VO 2 were measured in female dogs, before and after a training period, and after an adjacent training pause to test for reversibility of potential effects. Least squares regression was applied to describe the relationship between HR and _ VO 2 . The applied training had no statistically significant effect on the HR-_ VO 2 regression. A general regression line from all data collected was prepared to establish a general predictive equation for energy expenditure from HR in FBI dogs. The regression equation established in this study enables fast estimation of energy requirement for running activity. The equation is valid for large dogs weighing around 30 kg that run at ground level up to 15 km/h with a heart rate maximum of 190 bpm irrespective of the training level.
ABSTRACT Background Hypothyroidism and dilated cardiomyopathy (DCM) are both common diseases in D... more ABSTRACT Background Hypothyroidism and dilated cardiomyopathy (DCM) are both common diseases in Doberman Pinschers. A possible influence of hypothyroidism on the etiology and progression of DCM is controversial.Objectives Evaluation of the role of hypothyroidism in etiology and progression of DCM.AnimalsA total of 175 Doberman Pinschers.Methods In this longitudinal prospective study, echocardiography and 24-hour ambulatory ECG recordings were performed in all dogs as screening tests for DCM. Total thyroxine (TT4) and thyroid ultrasonography served as initial screening tests for hypothyroidism and low TT4 values were followed up by a thyroid stimulating hormone (TSH) test or free total thyroxine (fT4)/cTSH measurements. Additionally, a follow-up study of dogs affected by both DCM and hypothyroidism under optimal treatment for hypothyroidism was conducted.ResultsA total of 107 dogs were healthy, 45 dogs had DCM, 11 hypothyroidism, and 12 dogs had both DCM and hypothyroidism. TT4 values as well as the thyroid volumes were equivalent in the healthy dogs and in those with DCM. Neither ventricular premature complexes nor echocardiographic parameters differed between healthy and hypothyroid dogs. Dogs with DCM had a 2.26-fold (CI0.95 = 1.1–4.8) higher risk of also being affected by hypothyroidism. Despite optimal thyroid treatment of dogs with hypothyroidism and DCM, there was a progression of the heart disease.Conclusions and Clinical ImportanceThis study did not confirm a role of hypothyroidism in the etiology or progression of DCM. Treatment of hypothyroidism did not improve the clinical outcome.
The aim of the study was to compare the efficacy and compatibility of a separate or combined vacc... more The aim of the study was to compare the efficacy and compatibility of a separate or combined vaccination against the porcine reproductive and respiratory syndrome (PRRS) and Haemophilus (H.) parasuis. The study was conducted in a 1200 head nursery farm. A total of 360 piglets at an age of 26 days were randomized into three groups. Group A was vaccinated separately against H. parasuis (Porcilis(®)Glässer) and PRRS (Porcilis(®)PRRS), group B was vaccinated with a combined vaccine of both vaccines and group C remained unvaccinated as control group. The compatibility was evaluated by measurement of the body temperature and a palpation score of the injection site 0, 4, 24 and 72h after vaccination. During the nursery and the fattening period the average daily weight gain (ADWG), the number of runts and the mortality was evaluated. Additionally blood samples were taken every 2 weeks during the nursery period to perform an OppA-ELISA and a PCR for PRRS virus. No significant difference coul...
Background: Recurrent airway obstruction (RAO), an asthma-like disease, is 1 of the most common a... more Background: Recurrent airway obstruction (RAO), an asthma-like disease, is 1 of the most common allergic diseases in horses in the northern hemisphere. Hypersensitivity reactions to environmental antigens cause an allergic inflammatory response in the equine airways. Cytosine-phosphate-guanosine-oligodeoxynucleotides (CpG-ODN) are known to direct the immune system toward a Th1-pathway, and away from the pro-allergic Th2-line (Th2/Th1-shift). Gelatin nanoparticles (GNPs) are biocompatible and biodegradable immunological inert drug delivery systems that protect CpG-ODN against nuclease degeneration. Preliminary studies on the inhalation of GNP-bound CpG-ODN in RAO-affected horses have shown promising results.
Journal of applied animal welfare science : JAAWS, Jan 20, 2015
Sheep and goats are frequently used in nonhuman animal-assisted activities on city farms. There a... more Sheep and goats are frequently used in nonhuman animal-assisted activities on city farms. There are few data available on this type of usage of small ruminants. Health evaluations, behavioral observations (feeding, resting, comfort, explorative and social behaviors), behavioral tests (human approach tests and touch test), and measurements of fecal cortisol metabolites and heart rate were performed to assess stress levels in 25 sheep and 32 goats on 7 city farms and 2 activity playgrounds in Germany. No evidence was found that the animals suffered from major distress. Health evaluations, behavioral observations, and behavioral tests proved to be the methods of stress assessment most suitable for routine on-farm checks in these settings.
Veterinary and comparative orthopaedics and traumatology : V.C.O.T, Jan 12, 2015
To evaluate negative pressure wound therapy (NPWT) for treatment of complicated wounds in dogs. R... more To evaluate negative pressure wound therapy (NPWT) for treatment of complicated wounds in dogs. Retrospective multicentre study. Dogs (n = 50) undergoing open wound treatment were classified according to treatment method used: bandage (Group A, n = 7), NPWT (Group B, n = 18), and foam dressing (Group C, n = 25). Pairs of patients matched based on wound conformation, localization, and underlying cause were compared between Group A and C (n = 7 pairs) and between groups B and C (n = 18 pairs) in terms of duration of previous treatment, time to closure, and complications. Signalment, antibiotic medications, antiseptic treatment, and bacterial status of wounds were comparable between groups. The duration of previous treatment was significantly higher in patients assigned to Group B (p = 0.04) compared to Group C, while no significant difference was found between groups A and B. Total time to wound closure was significantly shorter in Group C compared to Group A (p = 0.02) and in Group B...
Investigations of the pathophysiology of ocular diseases require a detailed knowledge of the micr... more Investigations of the pathophysiology of ocular diseases require a detailed knowledge of the microanatomy of the eye. The available information is still inadequate for the equine retina despite the importance of eye diseases in equine medicine. Here we provide a comprehensive analysis of the histologic features of the horse eye as a reference for future studies. Thirty normal eyes of 15 healthy horses were examined immediately after slaughter. The retina of the horse differs considerably in the degree and quantity of neurons and glial elements as well as in vascular patterns compared to the retina of other domestic animals. Morphometric analysis revealed that the thickness of the retina varies between 80 µ m at the ora serrata and 250 µ m medial to the optic disc. Approximately 90% of the equine retina is comparatively thin (< 130 µ m). This is a physiologic response to the distance that oxygen can diffuse in avascular retina. Ganglion cells form a single layer in all parts of the retina. The majority of ganglion cells are very large Nissl-positive cells. Small Nissl-negative ganglion cells are less abundant. A high ganglion cell density is found only in the central area. Vascularization is virtually absent from the retina with the exception of a narrow strip around the disc of the optic nerve, as revealed by lectin histochemistry. Light microscopy of the eyes of older horses repeatedly revealed cystoid degenerations in the retina adjacent to the pars plana of the ciliary body, as well as a destruction of the regular layering of the peripheral region of the retina.
The integrity of gamete transport, fertilization, and early embryonic development in the oviduct ... more The integrity of gamete transport, fertilization, and early embryonic development in the oviduct are essential prerequisites for successful reproduction. Although the basic mechanisms of gamete transport, gamete interaction, and early embryogenesis are known in most mammals, the interactions between gametes and oviductal epithelium as well as the communication between the early embryo and the female reproductive tract remain to be elucidated. Recent techniques of live cell imaging such as digital videomicroscopy and confocal fluorescence microscopy are valuable tools that provide actual new insights into these interactions. By applying these techniques, the mechanisms of sperm transport, sperm storage, oocyte transport, gamete interaction, and early embryo-maternal crosstalk can be analyzed under in vivo or in situ conditions. Detailed knowledge of these very early and important processes creates the basis to develop new therapeutic concepts for subfertility and infertility and to improve the techniques of assisted reproduction. The current review will focus on a short description of recent techniques of live cell imaging in the reproductive tract followed by an overview of actual observations during the early events of reproduction.
Journal of Animal Physiology and Animal Nutrition, 2014
The welfare of an animal is ensured if it is able to fully satisfy its essential species-typical ... more The welfare of an animal is ensured if it is able to fully satisfy its essential species-typical needs in all functional aspects of behaviour. In mink, stereotypies and apathy, internal and/or external injuries as well as increased susceptibility to disease have been known to occur as a result of chronic stress. The non-invasive method of analysing faecal cortisol metabolites (FCM) allows conclusions to be drawn about the stress level in the respective housing system. The objective of this study is to find out how the cortisol metabolites content in the faecal changes with increasing age of the mink under semi-natural housing conditions. Thus, 40 American mink (Neovison vison) were housed in two outdoor enclosures imitating natural conditions. Throughout the entire study (13th to 32nd week of life), faecal samples were collected to measure cortisol metabolites. No differences in FCM concentrations between the two outdoor enclosures were found. In the young mink lower, less fluctuating FCM levels were found than in older animals. After the first faecal collection in the 13th/14th week of life, the level of metabolites decreased slightly (p = 0.032; 17th/18th week). From the 22nd/23rd week onwards until the 30th/31st week, shortly before the animals were pelted, continuously increasing concentrations were then measured. Increasing FCM levels with advancing age of the animals are probably attributable to the onset of sexual maturity and/or the respective season. This has to be taken into account in future studies using this method for assessing welfare and when comparing different mink housing systems.
Journal of Animal Physiology and Animal Nutrition, 2013
Different head-neck positions (HNPs) are used in equestrian sports and are regarded as desirable ... more Different head-neck positions (HNPs) are used in equestrian sports and are regarded as desirable for training and competition by riders, judges and trainers. Even though some studies have been indicative of hyperflexion having negative effects on horses, this unnatural position is frequently used. In the present study, the influence of different HNPs on physical and psychological stress parameters in the ridden horse was investigated. Heart rate (HR), heart rate variability (HRV) and blood cortisol levels were measured in 18 horses. Low frequency (LF) and high frequency (HF) are power components in the frequency domain measurement of HRV which show the activity of the sympathetic and parasympathetic nervous system. Values were recorded at rest, while riding with a working HNP and while riding with hyperflexion of the horse&amp;amp;#39;s head, neck and poll. In addition, rideability and behaviour during the different investigation stages were evaluated by the rider and by an observer. Neither the HR nor the HRV showed a significant difference between working HNP (HR = 105 ± 22/min; LF/HF = 3.89 ± 5.68; LF = 37.28 ± 10.77%) and hyperflexion (HR = 110 ± 18; LF/HF = 1.94 ± 2.21; LF = 38.39 ± 13.01%). Blood cortisol levels revealed a significant increase comparing working HNP (158 ± 60 nm) and hyperflexion (176 ± 64 nm, p = 0.01). The evaluation of rider and observer resulted in clear changes of rideability and behavioural changes for the worse in all parameters collected between a working HNP and hyperflexion. In conclusion, changes of the cortisol blood level as a physical parameter led to the assumption that hyperflexion of head, neck and poll effects a stress reaction in the horse, and observation of the behaviour illustrates adverse effects on the well-being of horses during hyperflexion.
To investigate the uveitogenic potential of retinal S-antigen (S-Ag) in horses. METHODS. Horses w... more To investigate the uveitogenic potential of retinal S-antigen (S-Ag) in horses. METHODS. Horses were immunized subcutaneously with S-Ag or BSA as control antigen, emulsified in complete Freund's adjuvant. Simultaneously, Bordetella pertussis was given intravenously. Antigen specific T-and B-cell responses were analyzed in a 3-day interval. Disease development was judged clinically and histopathologically. Two identical booster immunizations were given every 4 weeks to test induction of recurrences. RESULTS. T-and B-cell responses specific for S-Ag were observed in all immunized horses but were absent in control animals. However, uveitis developed in only one of five animals. Reimmunization with S-Ag did not lead to a uveitic relapse in this horse. All other horses of the S-Ag-and BSA-treated groups neither showed any signs of uveitis, nor had inflammatory infiltrates of the inner eye. CONCLUSIONS. In contrast to interphotoreceptor retinoid-binding protein (IRBP), S-Ag is a weak autoantigen in horses. Even though S-Ag immunization leads to the activation of autoreactive T-and B-cells, infiltration of the inner eye and induction of uveitis are controlled in most horses. (Invest Ophthalmol Vis Sci.
Growth hormone (GH) has recently been shown to promote the development of preimplantation embryos... more Growth hormone (GH) has recently been shown to promote the development of preimplantation embryos. The aim of our study was therefore to analyze the effects of GH on the morphology and ultrastructure of the cells of bovine preimplantation embryos produced by in vitro fertilization (IVF). In order to determine the physiologically optimal morphology of blastocysts, ex vivo embryos obtained by uterine flushing were also included in the study. As shown by transmission electron microscopy, treatment with GH induced the elimination of glycogen storage in cells of the inner cell mass of 7-day-old embryos. GH also stimulated the exocytosis of lipid vesicles in the inner cell mass and trophectoderm cells of these embryos. Quantitative analysis of micrographs demonstrated a higher volume density of embryonic mitochondria in 7-day-old embryos cultured with GH than in control embryos. Treatment with GH regularly resulted in an improvement of the ultrastructural features of embryos produced in vitro, thus resembling the morphology of ex vivo embryos. Scanning electronmicroscopy studies demonstrated that GH altered the structure and the pore size of the zona pellucida of blastocysts. Our studies imply that GH can modulate carbohydrate, lipid, and energy metabolism and influence transportation processes in the early IVF embryo.
Using a digital videomicroscopic analysis system in the bovine, we showed that the mechanisms of ... more Using a digital videomicroscopic analysis system in the bovine, we showed that the mechanisms of transport caused by ciliary beating are distinctly different in ampulla and isthmus of the oviduct. The average particle transport speed (PTS) in the oviduct (mean, 133 microm/sec) does not differ in the cycle (metestrus) and during pregnancy after implantation, but it is locally modulated at the site of the embryo. Using videomicroscopy, we were able to document that after entering the ampulla, the cumulus-oocyte complex (COC) is not transported by ciliary beating down the oviduct, but firmly attaches to the ampullar epithelium. This attachment is mediated by the cumulus cells. However, when a COC is degenerated, it is floating in the oviductal lumen. As soon as a vital COC is in the ampulla, the sperm bound in the sperm reservoir of the ampullar isthmic junction leave the reservoir and hurry to the oocyte. When a sperm has penetrated the zona pellucida, the COC detaches and continues its migration. Quantitative measurements showed that the early embryo is able to locally downregulate PTS during its migration down the oviduct. It locally changes the pattern of vascularization and induces the formation of secretory cells. Our studies imply that the oviductal epithelium is able to select vital oocytes. The early embryo is able to induce the formation of secretory cells, modify vascularization, and downregulate speed of transport, thus creating the prerequisite for the first embryo-maternal communication in the oviduct.
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C, 1992
ABSTRACT Lectin-histochemical study of the equine epidermis of skin and hoofCarbohydrate moieties... more ABSTRACT Lectin-histochemical study of the equine epidermis of skin and hoofCarbohydrate moieties of cell membranes in the epidermis of equine skin and hoof were investigated using lectin-histochemistry. The loss of desmosomes during keratinization leads to a reduced lectin affinity. Lectin binding capacity of the intercellular matrix in the stratum corneum of the epidermis is weak compared to that of the intercellular kitt of the hoof. Qualitative differences in lectin binding of the intercellular kitt of different hoof segments correlate with the quality of the horn in the respective areas.
To evaluate the effect of UV-blocking soft contact lenses in treatment for chronic superficial ke... more To evaluate the effect of UV-blocking soft contact lenses in treatment for chronic superficial keratitus (CSK). Twenty six dogs with CSK were treated continuously with UV-blocking contact lenses for 6 months. A contact lens was placed on one eye of each dog; the other eye remained without a lens as a control eye. After this primary study, five of the dogs were further treated and they wore then contact lenses in both eyes. Continuously, all patients were concurrently treated topically with cyclosporine. The contact lenses were changed every 4 weeks and an ophthalmic examination performed. Evaluation criteria included corneal alterations as pigmentation, edema, pannus and vascularization. To determine the transmittance characteristics of the contact lenses before and after use, 32 contact lenses were measured with a UV-vis-NIR spectrophotometer. Pigmentation increased in eyes wearing lenses and in control eyes over the evaluation period of 6 months. Corneal edema increased in the eye...
Uploads
Papers by Sven Reese