Study on biological variation of haemostatic parameters in clinically healthy dogs

Thromboelastography (TEG) may be a valuable supplement to the coagulation assays activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT), fibrinogen, antithrombin (AT) and D-Dimer currently used in most clinical pathology laboratories. Allowable imprecision and bias reference limits for analytical tests can be calculated based on measurements of biological variation. No studies to date have examined the effect of biological variation on these haemostasis parameters in the same group of dogs. Plasma samples were collected after a set protocol once weekly for five consecutive weeks from eight healthy dogs (four males and four females) and stored at -80 degrees C until analysis. Randomized duplicate coagulation tests and TEG analyses were performed on all plasma samples within one run. The data were analyzed for outliers and subsequently subjected to nested analysis of variance to obtain the coefficient of analytical, intra-individual and inter-individual variation. From these objective analytical performance standards for imprecision, critical difference, total error and the index of individuality were calculated to assess the utility of conventional population-based reference ranges. All the clotting times (aPTT, PT and TT), fibrinogen, AT and D-Dimer showed a degree of individuality, which may make the use of population-based reference ranges alone an insensitive interpretation criterion, whereas a population-based reference interval seems to be sensitive for interpreting all TEG parameters. Analytical performance standards for imprecision were only met for one of the coagulation assays, whereas all TEG parameters except the alpha angle, alpha achieved this analytical goal.     

Periparturition alterations to liver ultrasonographic echo-texture and fat mobilization parameters in clinically healthy Holstein cows

The objective of present study was to record the sequential alterations in liver echo-texture through digital analyzing of the B-mode ultrasonography in three groups of under-conditioned (UC), moderate-conditioned (MC), and over-conditioned (OC) clinically healthy Holstein cows from 30 days to calving until 30 days in milk. Furthermore, to compare their changes in association with the changes of fat mobilization parameters of non-esterified fatty acids (NEFA), betahydroxybutyric acid (BHBA), and body condition score (BCS). Although the cows lost significant (P < 0.05) BCS from calving and the NEFA values showed an increasing trend near calving and the BHBA values significantly inclined postparturition, the mean grey scale histogram (MGSH) of liver images did not reveal significant fluctuations unless a significant decrease on calving day (P < 0.05). The MGSH drop was predicted to be the result of anatomical changes in abdominal cavity, related to delivery and liver’s blood flow. OC cows had higher NEFA on day +20 than UC and MC cows (P < 0.05). UC cows showed higher MGSH values on day −30 than MC cows and again on day −10 comparing to MC and OC cows (P < 0.05). MGSH values correlated with BCS values (r _UC = −0.186; r _MC = −0.283; r _OC = −0.158). It was concluded that the studied cows did not show significant alterations in textural changes in their liver ultrasound whilst going through fat mobilization. As quantitative ultrasonography has shown the potential to detect cases of fatty liver, it could gain the attention to become a feasible device for liver health monitoring on a herd basis.     

Platelet aggregation responses in clinically healthy adult llamas

Background: Limited information exists regarding hemostasis in camelids despite the importance of platelet function testing in the accurate identification of platelet disorders. As further importation of llamas to North America is restricted, variability in breeding stock will continue to decrease, potentially leading to an increase in heritable bleeding disorders. Objective: The objective of this study was to measure platelet aggregation responses in clinically healthy llamas and provide baseline data to which abnormal platelet function may be compared in the future. Methods: Blood samples were collected from 39 healthy adult llamas, citrated, and centrifuged to produce platelet‐rich plasma (PRP). Within 4 hours of the blood draw, 20 μL of each agonist reagent were added to 180 μL of PRP. Final concentrations of agonists were 2 × 10^?5 M ADP, 0.19 mg collagen/mL PRP, 1 × 10^?4 M epinephrine, and 500 μg arachidonic acid/mL PRP. Results: Llama platelets were most responsive to ADP and collagen, with a maximum percent aggregation (mean±SD) of 71.3±18.6% and 55.8±19% and aggregation rates of 9.5±3.9 and 6.7±3.7 cm/min, respectively. Llama platelet aggregation in response to epinephrine and arachidonic acid was minimal to absent. Conclusions: This study is the first of its kind to establish baseline values for platelet aggregation in healthy adult llamas.     

Echocardiographic measurements in clinically healthy ferrets anesthetized with isoflurane

Two-dimensional, M4-mode, and color flow Doppler echocardiography was performed in 29 (18 females, 11 males) clinically healthy ferrets anesthetized with isoflurane. M-mode measurements of the left ventricle, left atrial appendage diameter (LAAD), and aorta (Ao) were obtained. The fractional shortening and LAAD/Ao ratio were calculated. The values of the M-mode measurements were compared between the male and female ferrets using a Student's t-test. No significant differences were found. The difference in body weight between the male and female ferrets was highly significant (P<0.001), but no significant correlation was found between body weight and M-mode measurements. Color flow Doppler examinations of the mitral, tricuspid, aortic, and pulmonary valves were recorded and there was minor valvular regurgitation in five ferrets, which was considered nonsignificant.     

Respiratory disease in the donkey

The donkey suffers from a similar range of respiratory diseases as the horse; however, there are a number of subtle variations, knowledge of which can influence the success of treatment. As an animal adapted to a semi‐arid terrain, there are variations in physiology, anatomy and disease susceptibility. The nonathletic nature of the donkey means that delayed presentation is common with many diseases and, while there may be enhanced resistance to some transboundary and parasitic diseases, there may be equal or increased severity of illness to some endemic diseases, e.g. equine influenza. Donkeys frequently live to geriatric ages and the clinician should be aware of the increased risk of conditions such as tracheal collapse, fibrosing pneumonia and neoplasia in this age group. As with any condition that causes stress and inappetance, respiratory disease in the donkey may be complicated by hyperlipaemia and good nursing care is an essential component of treatment.     

Common dental disorders in the donkey

Normal dental anatomy and the range of dental disorders found in donkeys are largely similar to those described in horses. Recent studies have shown dental disease to have a high prevalence in donkeys. Some dental disorders, such as diastemata, displaced teeth and wave mouth can have serious clinical consequences by causing oral pain and weight loss and even predispose to colic. Many of these signs can be prevented by regular dental treatment that can slow down or even prevent the progression of these disorders.     

Electrocardiographic evaluation of the degree of sedation and the isolated use of methadone in healthy dogs

ObjectiveThe present study aimed to investigate the influence of methadone on cardiorespiratory parameters, electrocardiogram and clinical sedation in dogs. Further possible side effects are reported.Study designProspective experimental cross-over study.DogsEight, 1–4-year-old, various breeds of dogs of both genders weighing 9–36 kg.MethodsEach dog was treated three times: methadone 0.3 mg kg^?1 (M0.3), 0.5 mg kg^?1 (M0.5) and 1.0 mg kg^?1 (M1.0) intramuscularly. Respiratory rate, heart rate and arterial blood pressure were recorded as well as electrocardiographic evaluation of lead II. Clinical sedation in each treatment received a score (0–3) after drug administration and at 30 minute intervals until scores and measurements returned to baseline values.ResultsA significant decrease in heart rate was seen with each dose of methadone and bradycardia (HR<60 bpm) was noted in a few dogs at each dose. A clinically significant arrhythmia occurred in one dog at 1 mg kg^?1 that required reversal with butorphanol. There was no significant difference in SAP, MAP and DAP between treatments. Some side effects such as salivation, defecation, vocalization and panting, after administration of methadone were observed. There were no differences in mean values of heart rate, P-wave and QRS complex duration and QT interval between treatments.Conclusion and clinical relevanceMethadone administration was associated with panting and a decrease in heart rate at all doses tested in this study. The cardiac rhythm should be monitored carefully in dogs when methadone is administered on its own, especially at higher doses.     

Characterization of certain inflammatory variables in the peripheral blood of clinically healthy dogs

Many laboratory techniques have been developed to study and quantify the inflammatory response, including the release of acid hydrolase enzymes, leukotriene B(4) (LTB(4)) production, reactive oxygen species (ROS) production and complement conversion studies. Although extensively studied in human health and disease, the relevance of such tests in the dog is largely unknown. After isolation of the peripheral blood mononuclear cell (PBMC) and polymorphonuclear cell (PMN) fractions from the peripheral blood of 38 clinically healthy dogs, values for ROS production were similar for both cell fractions when measured by luminol-enhanced chemiluminescence (17,853+/-9,695 U/10(6) cells versus 19,138+/-14,569 U/10(6) cells for the PBMC (n=38) and PMN (n=18) fractions, respectively). However, the mean time taken to reach maximum chemiluminescence was noticeably shorter in the PBMC fraction (5.1+/-3.3 versus 10.7+/-2.5 min for PBMCs (n=36) and PMNs (n=18), respectively). Intracellular concentrations of beta-glucuronidase, beta-galactosidase and N-acetyl-beta-glucosaminidase were assayed by spectrofluorometry. Mean values for all three enzymes were higher in PBMCs (n=31-35) than in PMNs (n=10-14). Both cell fractions released 20% of the intracellular enzyme concentration when stimulated with opsonized zymosan. Following incubation with A23187 (1 microM), mean LTB(4) production was higher in PBMCs (4.45+/-2.92 ng/10(6) cells; n=27) than in PMNs (0.96+/-2.22 ng/10(6) cells; n=13) using a validated high performance liquid chromatography (HPLC) assay. Immunoprecipitation studies revealed that the mean percentage conversion of C3 to C3b following stimulation with opsonized zymosan was 57.3+/-13.4% (n=36). The results provide normal values for clinically healthy dogs that may subsequently be used in future studies investigating dogs with various inflammatory disorders.     

Serum bile acids concentrations in healthy and clinically ill neonatal foals

BACKGROUND: Reference ranges for serum bile acids (SBA) concentration are well established in healthy adult horses. Increased values are indicative of hepatic disease. HYPOTHESES: SBA concentrations are significantly greater in the neonatal period compared with mature horses, and illness in the neonatal period will further increase SBA. ANIMALS: Ten healthy mature horses, 12 healthy foals, and 31 clinically ill foals. METHODS: Prospective cross-sectional study. Blood samples were obtained once from the mature horses, from healthy foals immediately after birth, at 2 days, and at 1, 2, 3, 4, and 6 weeks of age; and from ill foals less than 1 month of age at the time of admission to the Veterinary Teaching Hospital. SBA concentrations were determined enzymatically and by radioimmunoassay. Total and direct bilirubin and triglyceride concentrations were measured, as well as sorbitol dehydrogenase (SDH) and gamma-glutamyltransferase (GGT) activities. RESULTS: There was a significant negative correlation between age and SBA concentration. Compared with mature horses, SBA concentrations were significantly greater in healthy foals at each collection time over the first 6 weeks of life. Radioimmunoassay values were lower than enzymatic SBA values, with increasing bias as the mean difference between values increased. When comparing age-matched values between healthy and ill foals, there were no significant differences in SBA. None of the ill foals had a primary diagnosis of hepatic disease. There was no significant correlation between the SBA concentration and the bilirubin or triglyceride concentrations or the GGT activity. There was a significant direct correlation between increased SBA and serum SDH activity in healthy foals only. CONCLUSION AND CLINICAL IMPORTANCE: SBA concentrations in foals are significantly higher in the early neonatal period, underscoring the importance of using age-matched references when evaluating clinical pathology values during the neonatal period.     

Effect of chiropractic manipulations on the kinematics of back and limbs in horses with clinically diagnosed back problems

REASON FOR PERFORMING STUDY: Although there is anecdotal evidence of clinical effectiveness of chiropractic in treatment of equine back pain, little scientific work has been reported on the subject. OBJECTIVES: To quantify the effect of chiropractic manipulations on back and limb kinematics in horse locomotion. METHODS: Kinematics of 10 Warmblood horses were measured over ground at walk and trot at their own, preferred speed before, and one hour and 3 weeks after chiropractic treatment that consisted of manipulations of the back, neck and pelvic area. Speed was the same during all measurements for each horse. RESULTS: Chiropractic manipulations resulted in increased flexion-extension range of motion (ROM) (P<0.05) at trot in the vertebral angular segments: T10-T13-T17 (0.3 degrees ) and T13-T17-L1 (0.8 degrees ) one hour after treatment, but decreased ROM after 3 weeks. The angular motion patterns (AMPs) of the same segments showed increased flexion at both gaits one hour after treatment (both angles 0.2 degrees at walk and 0.3 degrees at trot, P<0.05) and 3 weeks after treatment (1.0 degrees and 2.4 degrees at walk and 1.9 degrees and 2.9 degrees at trot, P<0.05). The lumbar (L3 and L5) area showed increased flexion after one hour (both angles 0.3 degrees at walk and 0.4 degrees at trot P<0.05), but increased extension after 3 weeks (1.4 degrees and 1.2 degrees , at trot only, P<0.05). There were no detectable changes in lateral bending AMPs. The inclination of the pelvis was reduced at trot one hour (1.6 degrees ) and 3 weeks (3 degrees ) after treatment (P<0.05). The mean axial rotation of the pelvis was more symmetrical 3 weeks after the treatment at both gaits (P<0.05). There were no changes in limb angles at walk and almost no changes at trot. CONCLUSIONS: The main overall effect of the chiropractic manipulations was a less extended thoracic back, a reduced inclination of the pelvis and improvement of the symmetry of the pelvic motion pattern. POTENTIAL RELEVANCE: Chiropractic manipulations elicit slight but significant changes in thoracolumbar and pelvic kinematics. Some of the changes are likely to be beneficial, but clinical trials with increased numbers of horses and longer follow-up are needed.     

Long term ECG recording with Holter monitoring in clinically healthy horses.

The electrocardiogram of 9 horses was continuously recorded for 24 h with Holter monitoring to examine the variations in heart rate and rhythm during daily routine procedures and at night. Three horses had transient sinus bradycardia, and 3 had periods of sinus tachycardia. Heart blocks were detected in 3 horses, and all horses had periods of sinus arrhythmia. These changes in the heart rate and rhythm were apparently caused by variations in autonomic nervous system tone and they are probably "normal" findings in resting, undisturbed horses. Ventricular premature depolarisations were not observed in any horse, but some single supraventricular premature contractions were detected. There was preliminary evidence that in order to register the real resting heart rate and rhythm of a horse the ECG should be recorded over a long period, and also at night and without the presence of the investigator.     

Doppler velocimetric parameters of the testicular artery in healthy dogs

This study aimed to examine the Doppler velocimetric pattern of the testicular artery of small dogs in two different locations. Testes of 21 dogs were evaluated by two-dimensional ultrasonography to measure testicular volume and by Doppler ultrasonography to record the velocimetric patterns of the testicular artery in the spermatic cord and marginal location. The volume of left testes (4.70 ± 1.22 cm³) was significantly higher than the volume of the right testes (4.45 ± 1.17 cm³). Peak systolic velocity (PSV) of the left spermatic cord was significantly higher than the right side. End-diastolic velocity was significantly higher in the marginal artery than the spermatic cord on both sides; however, resistance and pulsatility indexes were significantly lower in the marginal artery. Results demonstrate the viability of Doppler ultrasonography for characterization of the testicular artery in small dogs and Doppler velocimetric values vary according to the location of measurement along the artery.