Spontaneous acute and chronic spinal cord injuries in paraplegic dogs: a comparative study of in vivo diffusion tensor imaging.

STUDY DESIGN: Prospective observational-analytical study. OBJECTIVES: Description of diffusion tensor imaging (DTI) metrics obtained from the spinal cord (SC) of dogs with severe acute or chronic spontaneous, non-experimentally induced spinal cord injury (SCI) and correlation of DTI values with lesion extent of SCI measured in T2-weighted (T2W) magnetic resonance imaging sequences. SETTING: Hannover, Germany. METHODS: Forty-seven paraplegic dogs, 32 with acute and 15 with chronic SCI, and 6 disease controls were included. T2W and DTI sequences of the thoracolumbar spinal cord were performed. Values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were obtained from the epicentre of the lesion and one SC segment cranially and caudally and compared between groups. Pearson's correlation coefficient was calculated between DTI and T2W metrics. RESULTS: During acute SCI, FA values were increased (P=0.0065) and ADC values were decreased (P=0.0099) at epicentres compared to disease controls. FA values obtained from dogs with chronic SCI were lower (P<0.0001 epicentres and caudally; P=0.0002 cranially) and ADC showed no differences compared to disease control values. Dogs with chronic SCI revealed lower FA and higher ADC compared to dogs with acute SCI (P<0.0001 for both values at all localisations). FA values from epicentre and cranially to the lesion during chronic SCI correlated with extent of lesion (r=0.5517; P=0.0052 epicentres and r=0.6810; P=0.0408 cranially). CONCLUSION: Using DTI, differences between acute and chronic stages of spontaneous canine SCI were detected and correlations between T2W and DTI sequences were found in chronic SCI, supporting canine SCI as a useful large animal model.

Use of density centrifugation for delayed cryopreservation of stallion sperm: perform sperm selection directly after collection or after storage?

Equipment for cryopreservation of stallion sperm is not always available. In such cases, diluted semen can be shipped to a facility for later cryopreservation. The aim of this study was to evaluate if selection of sperm via density centrifugation yields higher survival rates when cryopreservation is to be delayed (i.e. carried out after 1 day of storage at 5°C). Two-layer iodixanol as well as single-layer Androcoll density centrifugation were tested and compared with samples prepared with standard centrifugation. Special emphasis was placed on comparing centrifugation on the day of semen collection with centrifugation after 1-day refrigerated storage. Sperm morphology and motility as well as membrane and chromatin integrity were evaluated before and after centrifugation. Sperm motility and membrane integrity were also assessed after cryopreservation. It was found that both two- and single-layer density centrifugation processing resulted in higher percentages of morphologically normal and motile sperm with higher membrane and chromatin integrity, as compared to standard centrifugation or diluted samples. Differences were only in the order of magnitude of 5%. Recovery rates after density centrifugation were only approximately 30-40%. When cryopreservation was carried out after 1-day refrigerated storage, centrifugation processing of sperm directly after semen collection resulted in higher percentages of plasma membrane intact sperm post-thaw as compared to performing centrifugation processing of stored sperm just prior to cryopreservation. No significant differences in progressively motile sperm post-thaw were seen. Taken together, for delayed cryopreservation, it is best to perform density centrifugation directly after collection rather than immediately prior to cryopreservation.

Contrast-enhanced ultrasonography of the thyroid gland in healthy dogs, hypothyroid dogs and dogs with non-thyroidal illness.

Diagnosis of canine hypothyroidism remains challenging, as non-thyroidal illness (NTI)-syndrome and medical treatment can influence thyroid hormone concentrations. Conventional ultrasound may give additional hints, however high interobserver variability has been described. Contrast-enhanced ultrasound (CEUS) allows detection of changes in tissue perfusion. The purpose of the present study was to assess the possible diagnostic value of CEUS regarding diagnosis of hypothyroidism. CEUS of the thyroid gland was performed in 52 healthy dogs, 16 hypothyroid dogs, and 20 NTI patients. The following perfusion parameters were calculated: Thyroid/carotid artery (TG/CA) ratios for peak enhancement (PE) and area under the curve (AUC), time to peak (TTP) and wash-in and wash-out rates (WiR, WoR) of the thyroid gland. Impact of sedation on perfusion parameters was investigated in 8 calm healthy dogs which were examined before and after sedation using midazolam and butorphanol. Significantly higher median TG/CA ratios for PE were detected for the left and right thyroid lobe in dogs with hypothyroidism (0.97/0.96) compared to healthy dogs (0.85/0.85) and dogs with NTI (0.84/0.84). AUCs were also significantly increased in hypothyroid dogs when compared to other groups. Dogs with NTI showed significantly lower WiR and WoR compared to other groups. Values for TTP were not significantly different between groups. Sedation had only impact on results of TTP which was significantly prolonged in sedated dogs. In conclusion, CEUS of the thyroid gland can provide an additional tool for diagnosis of hypothyroidism in dogs and support its differentiation from NTI. Sedation has limited impact on CEUS results.

Hippocampal expression of the cannabinoid receptor type 1 in canine epilepsy.

Canine drug-resistant epilepsy is a prevailing issue in veterinary neurology. Alternative or additional treatment with cannabinoids is showing promising results in seizure management. A crucial component of the endocannabinoid system, cannabinoid receptor type 1 (CB1R), is heavily involved in the control of neurotransmitter release. Knowledge of its distribution in the epileptic brain would serve a better understanding of disease pathology and application of cannabinoids in dogs with epilepsy. CB1R distribution was assessed in sub-regions of hippocampus of dogs with idiopathic epilepsy, structural epilepsy and without cerebral pathology. In dogs with idiopathic epilepsy, significantly decreased CB1R expression compared to control animals was observed in CA1. In dogs with structural epilepsy, a significant increase in CB1R signal intensity in comparison to controls was observed. CB1R expression was higher in the structural group as compared to the idiopathic. Double immunofluorescence showed co-localization between CB1R and an astrocytic marker in about 50% of cells, regardless of the diagnosis. In summary, CB1R expression in canine hippocampus undergoes modification by the epileptic process and the direction of this change depends on the etiology of the disease. The distinct disease-associated CB1R expression needs to be considered in new treatment development for dogs with epilepsy.

Influences of increased levels of biotin, zinc or mannan-oligosaccharides in the diet on foot pad dermatitis in growing turkeys housed on dry and wet litter.

Foot pad dermatitis (FPD) is very common in turkeys and it is an animal health and welfare issue affecting not only performance and walking ability but also the carcass quality. Thus, there is a great need to find out the preventive measures against this problem. The potential roles of extra dietary biotin, Zn and mannan-oligosaccharides (MOS) in preventing the development of FPD were assessed in this study which was conducted on 2-week-old female turkeys over a period of 4 weeks. The birds were allotted to four groups, with 29 each, and housed on dry wood shavings in floor pens. The turkeys were fed a control (300 µg biotin and 50 mg Zn/kg), high biotin (2000 µg/kg), high Zn (150 mg/kg) or MOS (1%) diet. Half of the turkeys in each group were additionally exposed to wet litter (27% DM) for 8 h daily in adjacent separate boxes. Foot pads of the birds were examined on days 0, 7, 14, 21 and 28 and assessed macroscopically and histopathologically for foot pad lesions. High dietary levels of biotin or Zn significantly reduced the severity of FPD on dry litter (score 1 vs. 2 in control) but not on wet litter. However, MOS did not affect the severity of foot pad lesions either on dry or wet litter. In addition, the severity was overall substantially higher on wet (approximately three times) than on dry litter. The present results suggest that adding high levels of biotin or Zn to the diet could reduce the development and severity of FPD on dry litter but without having any preventive effects on wet litter. Finally, the high litter moisture appears to be the major factor resulting in FPD. Therefore, the litter should be maintained dry to minimize the prevalence and severity of FPD in turkeys.

Measurement of canine Th17 cells by flow cytometry.

Th17 cells are T helper cells which play an important role during inflammation and autoimmune disease. To investigate the role of these cells in diseases in dogs in a clinical setting, methods for fast identification had to be established. Th17 cells are a rare cell population, for their measurement stimulation is recommended. To examine more samples simultaneously and to receive a relatively high purity of cell population of CD3 + CD4+ cells, different methods on various levels of preselection of cells as well as the possibility of storing blood overnight for measuring Th17 cells by flow cytometry were investigated. Firstly, to receive a high number of mononuclear cells, two different density gradients were compared and analysed. Furthermore, the enrichment of CD3 + CD4+ cells via depletion of CD8alpha+, CD11b + and CD21+ cells by cell sorting (autoMACS Pro Separator) was tested. It was also investigated whether stimulation processes led to better interpretation of results and whether there was a significant difference in measurement of directly processed blood samples and samples that had been stored overnight. In conclusion, the use of the density gradient (Lymph24+ Spin Medium) resulted in a purer cell population through a significant decrease in polymorphonuclear cells (*p = 0.01). After cell sorting, a significant difference in cell population purity was detected. Within the target fraction (containing mainly CD3 + CD4+ cells), CD8alpha+, CD21+, CD11b + cell percentages were significantly lower (***p < 0.001, *p < 0.02, ***p < .0001, respectively), and CD3 + CD4+ cell percentage was significantly higher (***p < .0001). There was a significant difference in Th17 cell percentage between unstimulated and stimulated cell populations (***p < .0001), but no significant difference in the percentage of unstimulated Th17 cells (p = 0.29) or stimulated Th17 cells (p = 0.71) in stored blood in comparison to directly processed EDTA blood samples. Finally, a modified protocol that offers an efficient way to investigate samples that were stored overnight by means of flow cytometry was evolved to research the role of Th17 cells in dogs with different diseases or in healthy populations.

Effects of litter quality (moisture, ammonia, uric acid) on development and severity of foot pad dermatitis in growing turkeys.

High dietary protein is thought to increase the incidence of foot pad dermatitis (FPD) as a result of increased uric acid and secondary ammonia production in the excreta or litter. This study was conducted on female turkeys over a period of 3 wk to test the effects of water alone, and also of these end products of protein metabolism, independent of the presence of excreta, on the development and severity of FPD. The animals were allocated into four groups, with 20 birds in each, and housed in floor pens on dry, clean wood shavings (changed daily) throughout the experiment. The control group was housed continuously in its pen, whereas the other groups were additionally exposed daily (for 8 hr) to experimentally treated wood shavings, in adjacent separate boxes, enriched with water alone or water with NH4Cl or uric acid. NH4Cl and uric acid were added via water to the litter to achieve the concentrations of ammonia and uric acid in the litter as found in the excreta of turkeys (about 0.50 g ammonia and 20 g uric acid/kg). The wet litter was kept clean by removing the excreta twice daily and by changing the litter twice a week. The foot pads of all birds were examined on days 0, 7, 14, and 21 and scored externally (macroscopically). Three birds were selected from each group on days 0, 7, and 14, while the remaining 11 birds/group were sacrificed on day 21 for histopathologic assessment of foot pads. The severity of FPD was found to be markedly higher (about 3 times) on wet than on dry litter. There were no negative effects of ammonia and uric acid on foot pad lesions. The results indicate that high litter moisture is the most likely factor causing FPD in turkeys. A focus on nitrogenous irritants in the litter was not substantiated. Exposure of birds to wet litter (in the absence of excreta) for only 8 hr/day was sufficient to develop foot pad lesions. The present results suggest that a focus on the protein content of the diet as a cause of FPD may be misplaced, but all dietary factors which increase excreta or litter moisture, or both, should be considered. The prevalence and severity of FPD can be reduced by maintaining dry litter.

Endoparasite control management on horse farms--lessons from worm prevalence and questionnaire data.

REASONS FOR PERFORMING STUDY: Increasing prevalence of anthelmintic resistance in equine nematodes calls for a reexamination of current parasite control programmes to identify factors influencing control efficacy and development of resistance. OBJECTIVES: To investigate if associations occur between prevalence of parasitic nematodes and management practices. METHODS: German horse farms (n = 76) were investigated in 2003 and 2004. Information on farm and pasture management with respect to endoparasite control measures obtained using a questionnaire survey. Faecal examinations were performed in parallel. RESULTS: Horses (n = 2000) were examined by faecal nematode egg counts, grouped into foals, yearlings and mature individuals for statistical analyses. Farms were categorised into 3 types, riding, stud farms and small holdings. Count regression models were used to analyse strongyle faecal egg count data. Following dichotomisation of faecal egg count (FEC) data, prevalence of strongyle and Parascaris equorum infections were assessed by logistic regression models as a function from various management factors. Yearlings on stud farms showed a 2-fold higher risk of being positive for strongyle FEC, higher (i.e. > or =3 per year) anthelmintic drug treatment frequencies were associated with reduced strongyle infection rates only in mature individuals but not in foals or yearlings, foals on farms fertilising pastures with horse manure had a significantly higher risk of being P. equorum FEC positive and yearlings on stud farms were more often showing incomplete FECR following anthelmintic treatment compared to yearlings on other farm types. The mean yearly treatment frequencies per age group were: foals 4.52, yearlings 3.26 and mature horses 2.72 times, respectively. CONCLUSION AND POTENTIAL RELEVANCE: To delay the development of anthelmintic, resistance management should include additional nonchemotherapeutic parasite control strategies, FEC-monitoring, controlled quarantine treatment of new arrivals and control of efficacy by the faecal egg count reduction test on a regular basis.

Management factors influencing the occurrence of cellulitis in broiler chickens.

One of the main reasons for condemning fattening broiler chickens during meat inspection is cellulitis, which demonstrates the great economic issue concerning this topic. The aim of this epidemiological study was therefore to identify risk factors in order to draw conclusions on how to prevent the occurrence of cellulitis in broilers by implementing management changes. The data were collected between April and November 2018 on conventional broiler farms (n = 100) in the north of Germany with one to fourteen poultry houses per farm. In total, data were collected from 199 broiler flocks with a total of 5,332,767 broilers. Data on the type of management (feeding- and drinking management, housing, lighting management, litter type and animal health) were collected via a questionnaire, with additional data on condemnation rates being provided by the abattoirs. It was found that litter additives like fennel, eucalyptus and probiotics as well as a moist litter quality were associated with lower cellulitis condemnation rates. Flocks fattened in windowless barns, but with relatively higher lux-values as well as those broilers examined in a lower number of housing inspections had significantly lower cellulitis condemnation rates compared to other husbandry systems. In addition, lower cellulitis rates were seen when housing capacities were smaller, regardless of stocking density. The source of the breeders and hatchery also had a significant influence on the occurrence of cellulitis. No correlation was found between the condemnation rates due to cellulitis and the performance of thinning, the water source used, the use of drinking additives, observational skills and number of herd managers monitoring the broilers, participation in an animal welfare programme, the technique of heating and ventilation systems used, the feed supplier, litter material, the broiler breed, the length of darkness periods and chick losses during the first seven days. We concluded that management decisions that lead to stress reduction in the broiler flocks are beneficial in terms of chicken welfare and occurrence of cellulitis.

Molecular detection of benzimidazole resistance in Haemonchus contortus using real-time PCR and pyrosequencing.

Benzimidazoles (BZ) are widely used to treat parasitic nematode infections of humans and animals, but resistance is widespread in veterinary parasites. Several polymorphisms in beta-tubulin genes have been associated with BZ-resistance. In the present study, we investigated beta-tubulin isotype 1 sequences of 18 Haemonchus contortus isolates with varying levels of resistance to thiabendazole. The only polymorphism whose frequency was significantly increased in the resistant isolates was TTC to TAC at codon 200. Real-time PCR (using DNA from 100 third-stage larvae, L3s) and pyrosequencing (from DNA from 1000-10 000 L3s) were used to measure allele frequencies at codon 200 of these isolates, producing similar results; drug sensitivity decreased with increasing TAC frequency. Pyrosequencing was also used to measure allele frequencies at positions 167 and 198. We showed that such measurements are sufficient to assess the BZ-resistance status of most H. contortus isolates. The concordance between real-time PCR and pyrosequencing results carried out in different laboratories indicated that these tools are suitable for the routine diagnosis of BZ-resistance in H. contortus. The molecular methods were more sensitive than the 'egg hatch test', and less time-consuming than current in vivo- or in vitro-anthelmintic resistance detection methods. Thus, they provide a realistic option for routine molecular resistance testing on farms.

Comparison of two beta-tricalcium phosphate composite grafts used for reconstruction of mandibular critical size bone defects.

OBJECTIVE: The aim was to compare osseointegration of blood perfused beta-tricalcium phosphate cylinders (beta-TCPB) with similar composites that were additionally loaded with cancellous bone and bone marrow (beta-TCPB/BM/CB) for mandibular reconstruction. METHODS: Twelve German Black-Headed sheep with an average weight of 72.5 +/- 10 kg underwent segmental resection of the right hemi-mandible. The animals that were assigned to group A (n = 6) were reconstructed using beta-TCPB while the sheep that were assigned to group B received beta-TCPB/BM/CB grafts. Tissue quality was histologically assessed and bone-, scaffold-, cartilage- and fibrous-tissue area were estimated using semiautomated histomorphometrical software. RESULTS: Composite grafts that were loaded with bone marrow and cancellous bone (beta-TCPB/BM/CB) exhibited significant (p<0.01) higher amounts of bone formation than beta-TCPB. The patients that were assigned to group B achieved defect union and a high grade of bone maturation. Residual ceramic remnants were rare and disconnected. Bone maturity within group A was inferior and none of the specimens showed defect union. The defect centre was still occupied by a ceramic core. CLINICAL SIGNIFICANCE: Bone and bone marrow augmented beta-tricalcium phosphate composites may qualify as a promising alternative to autograft bone for mandibular reconstruction in human and veterinary medicine.

Effect of fentanyl on thermal and mechanical nociceptive thresholds in horses and estimation of anti-nociceptive plasma concentration.

There are few investigations relating anti-nociception to plasma concentrations of fentanyl in horses. The study objective was to evaluate analgesic efficacy and duration in horses and determine the minimum anti-nociceptive plasma concentrations. Eight horses were treated with saline (P) and fentanyl (F2.5=2.5µg/kg; F5=5µg/kg; F10=10µg/kg) given IV over 5min, with a wash-out period of 10 days. To evaluate thermal (°C) and mechanical (N) nociceptive threshold single stimulations were applied prior to (baseline) and 10, 30, 60, 90, 120, 180, 240, 300, 360, 420, 540min and 22.5h after treatment. Plasma fentanyl concentrations were measured at specific time points. Locomotor activity, heart rate, respiratory rate and gastrointestinal sounds were recorded. Two-way repeated measures ANOVA and pairwise comparisons were used for data analysis (P<0.05). With treatment F10, there was a significant increase in thermal threshold above baseline (47.2ö4.1°C) at t10 (53.7ö4.2°C) and t30 (52.1ö5.6°C), whereas mechanical threshold increased considerably above baseline (3.7ö1.3N) only at t10 (6.6ö3.6N). Estimated mean minimum anti-nociceptive plasma concentration determined by thermal stimulation was 6.1-6.8ng/mL. Dose-dependent increased locomotion occurred, but no significant changes in heart rate, respiratory rate and gastrointestinal sounds were observed. Fentanyl IV at 10µg/kg produced anti-nociception for 10-30min and fentanyl plasma concentrations of ≥6.1-6.8ng/mL appear necessary to induce thermal anti-nociception. Dose-dependent increased locomotion was the main side effect observed.

Pulmonary dysfunction and skeletal muscle changes in horses with RAO.

BACKGROUND: Chronic pulmonary diseases (recurrent airway obstruction [RAO]) have been reported to alter skeletal muscle cells in humans. The purpose of this study was to evaluate a potential relationship between pulmonary and muscle variables in horses with a clinical diagnosis of RAO. Muscle biopsies from healthy horses and from horses with RAO were investigated and the relationship between the severity of lung disease and the degree of muscular changes was determined. HYPOTHESIS: We hypothesized that chronic pulmonary disease can lead to changes of the skeletal muscle in horses. ANIMALS: Fifteen healthy horses (control) and 50 horses with RAO were examined. METHODS: In a prospective clinical trial, a complete lung examination was performed in all horses. In all horses, muscle enzyme activity at rest and after exercise and muscle biopsies from the M. gluteus medius were examined. RESULTS: None of the horses had clinical or histologic signs of primary or neurogenic myopathies. According to the clinical, endoscopic, and radiographic findings and with a scoring system, the horses with RAO were grouped according to the severity of pulmonary findings (15 horses mild, 24 horses moderate, 11 horses severe RAO). Pathologic changes of the skeletal muscle (fiber atrophy or fiber hypertrophy, myofibrillar degeneration, hyperplasia of mitochondria, and ragged-red-like fibers) were identified in most horses with RAO but in only a few individual control horses. In addition, a marked depletion of muscle glycogen storage was evident in the RAO horses but not in the control group. Other pathologic changes of skeletal muscle such as centralized nuclei and regenerating fibers were rare, but were more frequent in horses with lung diseases than in the control group. The degree of muscle cell changes was also graded with a scoring system and correlated with the severity of pulmonary disease (r= 0.55). CONCLUSION: Chronic pulmonary disease in horses is associated with structural changes in skeletal muscle. CLINICAL IMPORTANCE: Because chronic pulmonary disease may affect muscles, early and effective therapy may prevent these changes. This finding could be of clinical importance but requires further studies.

Effects of dobutamine, dopamine, phenylephrine and noradrenaline on systemic haemodynamics and intestinal perfusion in isoflurane anaesthetised horses.

BACKGROUND: In the horse, effects of cardiovascular-active drugs on local perfusion of the gastrointestinal tract are poorly understood. OBJECTIVES: To determine the effect of drugs commonly used to support blood pressure, on local intestinal blood flow and tissue oxygenation under isoflurane anaesthesia. STUDY DESIGN: In vivo randomised crossover experiment. METHODS: Ten horses were anaesthetised with isoflurane. After 90 min of equilibration three doses (µg/kg bwt/min) of dobutamine (DOB 0.5/1/3), dopamine (DA 1/2/5), noradrenaline (NA 0.1/0.2/0.5) and phenylephrine (PHE 0.5/1/3) were infused for 15 min, in a randomised order, with a 45 min washout-period. Blood flow and tissue oxygenation (sO2 ) of jejunum, colon and stomach were measured using white light remission spectrophotometry and laser doppler flowmetry; heart rate (HR), mean arterial blood pressure (MAP), cardiac output (CO) were measured and systemic vascular resistance (SVR) calculated. RESULTS: Compared to baseline high dose dobutamine significantly increased CO, HR, MAP (P<0.001) and blood flow to the jejunum (+47 ± 26%, P = 0.001) and colon (+29 ± 15%, P<0.001) (mean ± s.d.). Dopamine (DA5) increased CO but decreased colonic blood flow (-39 ± 21% from baseline, P<0.001), as well as SVR and MAP compared to baseline (P<0.001). Noradrenaline had no significant influence on intestinal perfusion, but increased MAP and SVR from baseline (P<0.001). Phenylephrine (PHE3) caused a significant decrease in blood flow and sO2 , most profoundly at the colon compared to baseline (flow -44 ± 21%; sO2 -16 ± 3%, P<0.001), while MAP and SVR increased and CO and HR decreased (P<0.001). MAIN LIMITATIONS: The measurement technique only allows for flow measurements in arbitrary units, which can limit comparability to other techniques. CONCLUSION: At the investigated doses dobutamine improved systemic and peripheral haemodynamics, while dopamine decreased MAP and peripheral perfusion. Noradrenaline increased MAP and SVR while peripheral blood flow was maintained, phenylephrine increased MAP, but reduced both local and systemic perfusion.

Cases of reduced cyathostomin egg-reappearance period and failure of Parascaris equorum egg count reduction following ivermectin treatment as well as survey on pyrantel efficacy on German horse farms.

In 2003 and 2004, on a total of 63 different German horse farms, a survey using the faecal egg count reduction (FECR) test was performed to investigate the efficacy of ivermectin (IVM, Ivomec) and pyrantel (PYR, Banminth) treatment against gastro-intestinal nematodes in a total of 767 horses. IVM treatment resulted in 100% reduction of the cyathostomin egg production 14 and 21 days post-treatment (d.p.t.) on 37 farms. On the remaining five farms, the mean faecal egg count reduction ranged between 97.7 and 99.9%. The mean cyathostomin FECR following PYR treatment ranged between 92.2 and 100% on the 25 farms tested. Therefore, based on the 90% FECR threshold suggested for detection of anthelmintic resistance in horses, neither IVM nor PYR anthelmintic resistance was detected. However, if the thresholds recommended for the detection of resistance in small ruminants were applied, on one and four farms signs of reduced IVM and PYR efficacy, respectively, were observed. In 2005, to further investigate these findings, the cyathostomin egg-reappearance period (ERP) following IVM treatment was examined on six selected farms, two of which were found to show less than 99.8% FECR in the previous survey. On these two latter farms, the ERP was less than 5 weeks, while on the other four it was at least 8 weeks. Earlier investigations described IVM cyathostomin ERP of at least 9 weeks. The efficacy of IVM to reduce Parascaris equorum egg excretion was also studied. On one farm in 2 consecutive years, IVM treatment did not lead to a significant reduction in P. equorum faecal egg counts in one and five young horses, respectively.

Comparison of Preoperative Quantitative Magnetic Resonance Imaging and Clinical Assessment of Deep Pain Perception as Prognostic Tools for Early Recovery of Motor Function in Paraplegic Dogs with Intervertebral Disk Herniations.

BACKGROUND: Prognostic tools to predict early postoperative motor function recovery (MFR) after thoracolumbar intervertebral disk herniation (IVDH) in paraplegic dogs represent an opportunity to timely implement novel therapies that could shorten recovery times and diminish permanent neurological dysfunctions. HYPOTHESIS: Fractional anisotropy (FA) values obtained using diffusion tensor imaging have a higher prognostic value than a lesion extension ratio in T2-weighted images (T2W-LER) and clinical assessment of deep pain perception (DPP) for MFR. ANIMALS: Thirty-five paraplegic dogs with diagnosis of acute or subacute thoracolumbar IVDH. METHODS: Prospective, descriptive observational study. At admission, absence or presence of DPP, T2W-LER, and FA values was evaluated. MFR was assessed within 4 weeks after decompressive surgery. Values of T2W-LER and FA of dogs with and without MFR were compared using t-tests. All 3 methods were evaluated for their sensitivity and specificity as a prognostic factor. RESULTS: No differences were found between groups regarding T2W-LER. FA values differed statistically when measured caudally of lesion epicenter being higher in dogs without MFR compared to dogs with MFR (P = .023). Logistic regression analysis revealed significance in FA values measured caudally of the lesion epicenter (P = .033, area under the curve = 0.72). Using a cutoff value of FA = 0.660, the technique had a sensitivity of 80% and a specificity of 55%. Evaluation of DPP had a sensitivity of 73.3% and specificity of 75% (P = .007). CONCLUSIONS AND CLINICAL IMPORTANCE: Evaluation of DPP showed a similar sensitivity and a better specificity predicting early MFR than quantitative magnetic resonance imaging.

Correlation between severity of clinical signs and transcranial magnetic motor evoked potentials in dogs with intervertebral disc herniation.

Transcranial magnetic motor evoked potentials (TMMEPs) can assess the functional integrity of the spinal cord descending motor pathways. In intervertebral disc herniation (IVDH), these pathways are compromised to varying degrees reflected by the severity of neurological deficits. The hypotheses of this study were as follows: (1) TMMEPs differ in dogs with IVDH and healthy control dogs; (2) TMMEPs reflect different severities of neurological signs; and (3) TMMEPs can document functional motor improvement and therefore monitor recovery of function. TMMEPs were recorded in 50 dogs with thoracolumbar IVDH. Clinical signs ranged from spinal hyperesthesia to non-ambulatory paraparesis in 19 dogs and paraplegia with/without deep pain sensation in 31 dogs. In these 31 paraplegic dogs, transcranial magnetic stimulation (TMS) was repeated during follow-up examinations. Ten healthy Beagle dogs served as controls. There was a significant increase in onset latency and decrease in peak-to-peak amplitude in the pelvic limb TMMEPs of dogs with spinal hyperesthesia to severe paraparesis compared to control dogs. Waveforms in dogs with IVDH were predominantly polyphasic in contrast to the biphasic waveforms of the control dogs. TMMEPs could not be generated in the pelvic limbs of paraplegic dogs. However, TMMEPs with markedly increased onset latencies and decreased peak-to-peak amplitudes reappeared in the pelvic limbs of dogs that were paraplegic before surgery and showed functional motor improvement during follow-up. The severity of neurological deficits was reflected by TMMEP findings, which could be used to document functional motor recovery in IVDH. TMS could therefore be used as an ancillary test to monitor response to therapy in dogs during rehabilitation.

Frequency-specific electric response audiometry (ERA) and its clinical application in the diagnosis of hearing defects in the dog.

Reference values were established for frequency-specific electric response audiometry (ERA) in dogs on the basis of the results of ERA examinations of 200 animals with normal hearing. Air-conducting acoustic tubes with foam stoppers were used in the determination of the following: the latencies of waves I, III and V; interpeak latencies (IPL) I-III, III-V and I-V; amplitudes I and V; and the amplitude difference I-V. A frequency-specific stimulus (tone pip) was used for frequency-specific examination (1 to 4 kHz) over the entire frequency range indicated. These reference values were then used for the clinical examination of 50 dogs with hearing defects. A frequency-specific ERA was conducted and the results evaluated. These findings made it possible to draw objective conclusions about the degree, type and site of the hearing defects. Frequency-specific electric response audiometry was shown to be an important diagnostic tool for the detection of partial high- and low-frequency hearing loss and for the characterisation of hearing defects of otological, otoneurological and neurological origin.

[Pulmonary artery wedge pressure and heart rate measurement during pharmacological stress induction for left cardial function diagnosis in horses with and without heart disease]. / Lungenkapillardruck- und Herzfrequenzmessung unter medikamenteller Stressinduktion zur links- kardialen Funktionsdiagnostik bei Pferden mit und ohne Herzerkrankungen.

In 18 horses, the pulmonary artery wedge pressure and the heart rate were measured during pharmacological stress load. 12 horses were healthy (4 trained, 8 untrained) and 6 horses had a heart disease (3 trained, 3 untrained). Pharmacological stress induction was carried out with the sympathomimetic drug dobutamine at a dosage rate of 7.5 microg/kg/min over 10 minutes of infusion. At the fourth minute, the parasympatholytic drug atropine was administered (5 microg/kg bw), and the heart rate and the pulmonary artery wedge pressure were continuously measured over 26 minutes. During sole dobutamine infusion, a significant decrease in heart rate and a significant increase in pulmonary artery wedge pressure were observed. After the application of atropine in the fourth minute, a significant increase in heart rate (from 35.7 +/- 6 up to 106 +/- 38/ min) and in pulmonary artery wedge pressure (from 15.7 +/- 3 up to 24 +/- 8.6 mmHg) were visible in the group of healthy horses. The horses with heart diseases had a significantly higher increase in both parameters (heart rate and pulmonary artery wedge pressure) with a significantly positive correlation (r = 0.7). The heart rate increased in the horses with heart diseases from 35.2 +/- 2,8 beats/min up to 132 +/- 45.7 beats/min and the pulmonary artery wedge pressure increased from 17.3 +/- 3,2 mmHg up to 32.7 +/- 13 mmHg. The cardiac status (healthy or heart disease) as well as the training level of the horses (untrained or trained) had a significant influence on the heart rate and the pulmonary artery wedge pressure. The untrained horses (healthy and heart disease) showed significantly higher values over a longer period of time than did the trained horses with the same cardiac status. Additionally the influence of pharmacological stress induction on echocardiographic parameters was investigated. The left atrial size (p = 0.015) and left ventricular diameter were significanly different in the systole (p = 0.008) and in the diastole (p = 0.001) between healthy horses and horses with heart diseases. All horses showed a positive correlation between the pulmonary artery wedge pressure and the left atrial size (r = 0.8), as well as between the left ventricular systolic (r = 0.6) and the diastolic diameter (r = 0.6). The correlation between the pulmonary artery wedge pressure and the left atrial size was nearly the same in the healthy horses (r = 0.74) and in the horses with heart diseases (r = 0.76). Regarding the training level, all untrained horses had a significantly higher correlation between the pulmonary artery wedge pressure and the left atrial size (r = 0.87) in comparison to the trained horses (r = 0.74). Particularly in the untrained horses with heart diseases, this correlation was remarcable (r = 0.99).

Noninvasive color Doppler sonography of uterine blood flow throughout pregnancy in sheep and goats.

In contrast to cattle or horses, uterine blood flow in small ruminants has been investigated predominantly after surgical intervention and chronic instrumentation. The objective of the present study was to investigate the clinical applicability of noninvasive color Doppler sonography to characterize blood flow in the maternal uterine artery of sheep, n = 11 (18 pregnancies) and goats, n = 11 (20 pregnancies). The following parameters were measured transrectally or transabdominally: blood flow volume, time-averaged maximum velocity (TAMV), resistance index (RI), pulsatility index (PI), Time-averaged mean velocity, impedance of blood flow (AB or systolic/diastolic [S/D] velocity ratio), peak velocity of blood flow and blood flow acceleration. Examinations started 2 weeks after breeding and continued at 2-week intervals until parturition. Outcomes for sheep and goats were similar and will be discussed together. Based on noninvasive color Doppler sonography, blood flow volume increased (approximately 60-fold, P < 0.0001) until the end of pregnancy, with a rapid increase early in gestation, and a slow increase after week 18. Time-averaged maximum velocity in the uterine artery increased (approximately 4-fold; P < 0.0001) throughout pregnancy in sheep and goats. Furthermore, for uterine artery blood flow, there was an effect of stage of pregnancy on PI and RI (P < 0.001 and P < 0.0001, respectively), both indices decreased until the end of gestation. Time-averaged mean velocity decreased from week 18 to 20 in both species. The blood flow acceleration increased (P < 0.0001) until week 16 and week 14 in sheep and goats, respectively, and then decreased until parturition. Similar to PI and RI, vascular impedance of the uterine decreased (P < 0.0001) throughout pregnancy. This is apparently the first study using noninvasive color Doppler sonography of uterine blood flow throughout physiological pregnancy in small ruminants. Clearly, this technology facilitates repeated, noninvasive assessments, with great potential for future studies.