Influence of aging on adrenal responsiveness in a population of eleven healthy beagles

The present study aimed at investigating the effects of aging on the adrenal cortex response of cortisol and aldosterone in dogs.A population of healthy adult Beagles was evaluated twice at a five-year interval. At each evaluation, plasma basal cortisol and aldosterone, cortisol and aldosterone following ACTH-stimulation, sodium, and potassium concentrations and arterial blood pressure were measured. We observed significantly (p < 0.05) greater sodium, urea and creatinine concentrations with aging. Nevertheless urea and creatinine remained within our laboratory reference ranges. This study showed a highly significant age-related elevation of basal cortisol (p < 0.01). Inversely, both aldosterone following ACTH-stimulation levels and difference between aldosterone following ACTH-stimulation and basal aldosterone values plummeted significantly (p < 0.01) with aging. In conclusion, the evaluation of the adrenal cortex function in dogs should take in consideration the age of the individuals.     

Serum cortisol and progestin concentrations in pregnant and non-pregnant Asian elephants (Elephas maximus)

Blood samples were collected during the estrous cycle (n=3), throughout gestation (n=3), and during the periparturient period (n=11) to assess serum concentrations of cortisol in pregnant and non-pregnant Asian elephants whose reproductive status was being monitored by serum progestin determination. While serum cortisol concentrations remained constant throughout gestation, progestin concentrations decreased significantly (p<0.05) in the second half of pregnancy, declining to undetectable levels by 3 days before calving. During the non-luteal phase of the estrous cycle serum progestins varied from undetectable levels to 100pg/ml (53+/-10.7pg/ml) then increased steadily during the luteal phase (322+/-207.5pg/ml). There were no significant differences between serum cortisol concentrations during the luteal and those of the non-luteal phase (p>0.05). The mean cortisol concentration during the estrous cycle was about twice that during pregnancy (p>0.05). No substantial changes in maternal cortisol were found during the course of pregnancy or the periparturient period.     

Effect of fluoxetine on blood concentrations of serotonin, cortisol and dehydroepiandrosterone in canine aggression

Canine aggression directed towards people is the most frequent reason for referral to behaviour practices. The serotonergic system and the hypothalamic-pituitary-adrenal (HPA) axis are believed to play an important role in controlling aggression. The selective serotonin reuptake inhibitor fluoxetine is the most commonly used drug in canine aggression. The aim of the present study was to assess the effect of a 30-day-long fluoxetine treatment on the peripheral serotonergic system and the HPA axis in canine aggression. To this end, the concentrations of serum serotonin (5-HT) and plasma cortisol and dehydroepiandrosterone (DHEA) were analysed in a group of aggressive (n = 22) and nonaggressive dogs (n = 9) during pre- (day 0) and posttreatment (day 30) conditions. Treatment caused a significant decrease in 5-HT concentrations (46% in the aggressive group and 32% in the control group). There was a trend towards a rise of DHEA/cortisol ratio values after treatment both in the aggressive and the control group. The determination of blood 5-HT and the DHEA/cortisol ratio could have important clinical applications in the future for deciding which animals might benefit from a given treatment as well as for monitoring the response. Further large-scale studies with this aim should be carried out to obtain sound conclusions.     

观察饲料添加剂二次蓄积对幼犬性激素水平的影响

本试验旨在研究分析市场上正在广泛使用的饲料添加剂,探讨二次饲喂雄性幼犬后饲料添加剂蓄积对其生长、生殖发育的影响研究。选用12只1月龄犬,随机分为试验组和对照组,对照组犬饲喂正常日粮和大鼠鼠肉,试验组犬饲喂正常日粮和高剂量组大鼠鼠肉,喂养幼犬直至成熟,检测食用饲料添加剂高剂量组大鼠鼠肉是否对雄性犬的生长、生殖发育产生影响。采用酶联免疫试剂盒的方法来检测犬血清激素指标水平。结果显示：试验组雌二醇、促卵泡激素含量明显升高（P＜0.01）,而睾酮含量明显降低,有显著性差异（P＜0.01）,饲料添加剂高剂量组对犬血清中的促黄体生成未见显著变化。雄性幼犬食用试验大鼠后可导致雄性幼犬青春期体内内分泌激素含量异常,即青春期11月龄测定的雌二醇以及促卵泡激素水平增高,睾酮的水平降低。提示试验组雄性幼犬食用大鼠鼠肉后,可能通过干扰了睾丸轴的功能,对雄性幼犬的生殖发育能力产生影响。     

Effect of desmopressin on plasma factor VIII and von Willebrand factor concentrations in Greyhounds

Objective To determine the effect of 1-Deamino-8-D-argi-nine vasopressin on plasma concentrations of von Willebrand factor and factor VIII in Greyhound blood donors, and to compare the response of 1-Deamino-8-D-arginine vaso-pressin injection on plasma concentrations of von Willebrand factor between groups with different resting plasma concentrations of von Willebrand factor.
Animals Fifteen Greyhound blood donors were used. Dogs were grouped into three categories depending on their von Willebrand factor concentrations.
Procedure Desmopressin was administered subcuta-neously at 1 mg/kg to all dogs. Plasma von Willebrand factor and factor VIII concentrations were measured before and 10, 20, 30, 45, 60, 90 and 120 min after desmopressin injection.
Results The von Willebrand factor and factor VIII concentrations in all dogs increased significantly and remained higher than base-line throughout the 2 h period.
Conclusion Desmopressin is useful in increasing von Willebrand factor concentrations in Greyhound blood donors, including those with low resting concentrations.     

Effect of electroimmobilisation on ovine plasma concentrations of beta-endorphin/beta-lipotrophin, cortisol and prolactin

The effect of electroimmobilisation on the plasma concentrations of beta-endorphin/beta-lipotrophin (beta-EP/beta-LPH), cortisol and prolactin (PRL) has been assessed in sheep. Serial blood samples were collected from control and electroimmobilised animals during the first and fourth of a series of four repeated treatments over two days. After electroimmobilisation the mean (+/- SEM) plasma concentrations of beta-EP/beta-LPH increased significantly from 132 +/- 19 pg ml-1 to 545 +/- 111 pg ml-1; the plasma concentrations of cortisol also increased significantly from 22.3 +/- 3.5 ng ml-1 to 108.0 +/- 12.9 ng ml-1. There was no significant change in plasma PRL concentrations after electroimmobilisation and also no significant difference between the plasma concentrations of PRL in the control and electroimmobilised animals. There was no significant difference between the effects of the first and fourth exposure to electroimmobilisation on the plasma concentrations of beta-EP/beta-LPH, cortisol and PRL. These results suggest that the endocrine response to electroimmobilisation may be specific to the pituitary-adrenal axis.     

Time lag between peak concentrations of plasma and salivary cortisol following a stressful procedure in dairy cattle

Background

Measurement of salivary cortisol has been used extensively as a non-invasive alternative to blood sampling to assess adrenal activity in ruminants. However, there is evidence suggesting a considerable delay in the transfer of cortisol from plasma into saliva. Previous studies in cattle have used long sampling intervals making it difficult to characterise the relationship between plasma and salivary cortisol (PLCort and SACort, respectively) concentrations at different time points and determine whether or not such a time lag exist in large ruminants. Therefore, the objective of this study was to characterise the relationship between plasma and salivary cortisol and determine if there is a significant time lag between reaching peak cortisol concentrations in plasma and saliva across a 4.25 h time-period, using short sampling intervals of 10–15 min, following social separation in dairy cattle.Five cows were separated from their calves at 4 days after calving, and six calves were separated from a group of four peers at 8 weeks of age. Following separation, the animals were moved to an unfamiliar surrounding where they could not see their calves or pen mates. The animals were catheterised with indwelling jugular catheters 1 day before sampling. Blood and saliva samples were obtained simultaneously before and after separation.

Results

In response to the stressors, PLCort and SACort increased reaching peak concentrations 10 and 20 min after separation, respectively. This suggested a 10 min time lag between peak cortisol concentrations in plasma and saliva, which was further confirmed with a time-series analysis. Considering the 10 min time lag, SACort was strongly correlated with PLCort (P < 0.0001).

Conclusions

Salivary cortisol correlates well with plasma cortisol and is a good indicator of the time-dependent variations in cortisol concentrations in plasma following acute stress. However, there is a time lag to reach peak cortisol concentrations in saliva compared to those in plasma, which should be considered when saliva samples are used as the only measure of hypothalamic-pituitary-adrenal axis response to stress in cattle.     

Genetic relatedness of methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolated from a dog and the dog owner

In the present study four methicillin-resistant Staphylococcus pseudintermedius (MRSP) strains isolated from a dog (n = 3) and the anterior nares of the dog owner (n = 1) were investigated by conventional and molecular methods. The species identity of the four S. pseudintermedius strains was confirmed by conventional methods, by PCR mediated amplification of S. intermedius/S. pseudintermedius specific segments of thermonuclease encoding gene nuc and by restriction fragment length polymorphism analysis of phosphoacetyltransferase encoding gene pta. Investigation of the four S. pseudintermedius for toxinogenic potential revealed that all four strains were positive for the exfoliative toxin encoding gene siet and the leukotoxin encoding genes lukS, lukF. The oxacillin and penicillin resistance of the four S. pseudintermedius strains could be determined by cultivation of the strains on oxacillin resistant screening agar base, ChromID MRSA Agar and Brilliance MRSA Agar and by multiplex PCR detecting the resistance genes mecA and blaZ. The genetic relatedness of the strains was studied by macrorestriction analysis of their chromosomal DNA using pulsed field gel electrophoresis (PFGE). According to PFGE all four S. pseudintermedius strains represent an identical bacterial clone indicating a cross transmission between the dog and the dog owner.     

Effects of breed, age of dam, birth year, birth season and sex on weaning weight of beef calves

Weaning weights of 442 beef calves (223 male and 219 female), born between 1997 and 2004 from cows of nine breeds (Hungarian Fleckvieh, Hereford, Aberdeen Angus, Red Angus, Lincoln Red, Charolais, Limousin, Blonde d' Aquitaine and Shaver) and maintained in the same conditions on peat-bog soil pasture at Keszthely, were evaluated. The effect of breed, age of dam, year/season of birth and sex of calf on the 205-day weaning weight was computed by analysis of variance (GLM). Overall mean of the 205-day weaning weight of all calves was 193 kg. The contribution to the total phenotypic variance of the 205-day weaning weight was: 18.60% by breed, 2.79% by age of dam, 43.23% by birth year, 3.95% by birth season and 31.43% by sex of calf. The evaluated factors had a significant (P < 0.05) effect on 205-day weight. Mean values by breeds were 198, 163, 206, 205, 182, 204, 181, 189 and 204 kg, respectively. According to the age of the dam, the weaning weight increased up to 5 years and after the maximum (205 kg) decreased. The minimum values were found in the group of 2- (178 kg) and 12-year-old (174 kg) cows. With respect to birth year, the highest weaning weight (238 kg) was observed in 2002 and the lowest (151 kg) in 1999. For birth season, winter, spring, summer and autumn, the 205-day weaning weight was 183, 196, 203 and 190 kg, respectively. Male calves reached 202 kg and female calves 185 kg mean value of the adjusted weaning weight.     

Clinical significance of plasma mannose concentrations in healthy and diabetic dogs

Circulating levels of monosaccharides can act as a reflection of systemic glucose/ energy metabolism. Characteristic changes observed in these levels can be seen in patients with diabetes and other metabolic disorders. There have been a few reports describing the significance of mannose metabolism as an energy source under physiological and pathological conditions. However, the relationship between circulating levels of mannose and the pathophysiology of diabetes mellitus are unknown in dogs. This study examined circulating levels of mannose between healthy control and diabetic dogs and evaluated the clinical significance of mannose levels in dogs. Diabetic dogs demonstrated a higher circulating level of mannose in comparison to normal healthy control dogs. Plasma mannose was positively correlated with plasma glucose and fructosamine, respectively. Interestingly, plasma mannose levels were affected by plasma insulin levels. In the context of feeding and glucose tolerance tests, plasma mannose levels responded to changes in circulating insulin levels. Circulating plasma mannose levels decreased after feeding in both control and diabetic animals in spite of observed insulin level differences. However, when glucose tolerance tests were given, a positive correlation between mannose levels and insulin levels was observed. Therefore, plasma mannose levels obtained via glucose tolerance testing may be used as a new diagnostic method for evaluating insulin resistance or deficiency in diabetic dogs.     

Development and validation of a sensitive enzyme immunoassay (EIA) for blood plasma cortisol in female cattle,buffaloes, and goats

A highly sensitive enzyme immunoassay (EIA) that used the second antibody coating technique and the cortisol-horseradish peroxidase conjugate as a label for determination of free and total cortisol in blood plasma of dairy animals (cows, buffaloes, and goats) was developed. For biological validation of the EIA, blood samples were collected from the animals at 48 and 24 h before and 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, and 132 h after dexamethasone administration. The EIA was performed directly with 20 μL of fresh plasma (for free cortisol) and also with 20 μL of heat-treated plasma (for total cortisol) after 1:5 dilutions with PBS. Cortisol standards ranging from 0.39 to 200 pg/well/20 μL were used, and the sensitivity of the EIA procedure was found to be 0.39 pg/well/20 μL, which corresponded to 0.02 ng/mL. In comparison with RIA the EIA was at least 4 times more sensitive and required 5 times less cortisol antiserum. In female cattle, buffaloes, and goats, the total, free, and bound plasma cortisol before dexamethasone administration was significantly (P < 0.05) higher than the total, free, and bound cortisol after dexamethasone administration. It can be concluded from these studies that the direct, sensitive EIA validated for estimating the free and total cortisol concentrations was sufficiently reliable and quick for studying the dynamics of cortisol distribution in blood plasma of dairy animals.     

Influence of age and sex on plasma lipid and lipoprotein concentrations and associated enzyme activities in cats

OBJECTIVE: To determine effects of age and sex on plasma lipid and lipoprotein metabolism in cats. ANIMALS: 33 kittens and 16 adolescent, 23 adult, and 10 senior cats. PROCEDURE: Plasma concentrations of cholesterol, triglyceride, and lipoprotein-cholesterol and activities of lipoprotein lipase, hepatic lipase, and lecithin:cholesterol acyl transferase (LCAT) were measured and compared within and among groups. RESULTS: Plasma cholesterol and triglyceride concentrations were significantly higher in 5- and 7-week-old kittens, compared with the same kittens after weaning and cats in the other age groups. Cholesterol concentration was significantly less in 20-week-old kittens, compared with adolescent and adult cats. Lipid and lipoprotein-cholesterol concentrations were not significantly different among the adolescent, adult, and senior groups, nor did sex influence lipid and lipoprotein-cholesterol concentrations in these groups. Activities of lipoprotein and hepatic lipases were significantly less in senior cats, compared with the other groups. Activity of LCAT was highest in 20-week-old kittens and was greater in sexually intact adult and adolescent females, compared with their male counterparts. After castration, activities of hepatic lipase and LCAT significantly decreased in adolescent male cats. CONCLUSIONS AND CLINICAL RELEVANCE: The upper limits of reference ranges for plasma cholesterol and triglyceride concentrations should be increased for kittens < 8 weeks of age. Low cholesterol concentrations in adolescent cats likely reflect high tissue demands for growth and steroidogenesis. Decrease in lipoprotein and hepatic lipase activity in senior cats could predispose this age group to hypertriglyceridemia, particularly in insulin-resistant cats or those fed a high fat diet.     

Unusual localization of Dirofilaria repens (Spirurida: Onchocercidae) infection in the testicle of a dog

This report describes an uncommon localization of Dirofilaria repens in the testicle of a nine-year-old dog from southern Italy. The dog underwent neutring and three adult nematodes were found in the tunica vaginalis. At gross anatomy, no pathological changes were observed on the tunica, in the testicle or epididymis. The parasites, one female and two males, were morphologically and molecularly identified as D. repens. This is the first report of D. repens in the canine testicle in Italy. This case report highlights the asymptomatic nature of D. repens infection, suggesting that dogs living in endemic areas may act as silent carriers. Careful screening and an effective chemoprophylaxis should be ensured for all animals potentially exposed to D. repens infection in order to reduce the risk of infection to humans in areas where the parasite is endemic.     

Effect of transportation on cortisol concentrations and on the circadian rhythm of cortisol in gilts

A study was conducted to determine whether the circadian rhythm of cortisol in gilts is disrupted or altered by transport. Sixteen ovariectomized gilts with indwelling jugular catheters were individually penned in an enclosed building (location 1). Blood samples were collected at 0700 and 1900 hours for 6 days. On day 7, gilts in groups of 4 were transported 5.6 km to environmentally controlled chambers (25 C) and were individually penned (location 2). On the day of transport, samples were collected at 0700 hours at location 1, immediately before and after transport in a trailer, after unloading at location 2, and at 1900 hours at location 2. For the first 6 days at location 2, blood samples were collected daily at 0700 and 1900 hours. For the 6 days at location 1, circadian rhythm was evidenced by higher cortisol concentrations in the AM hours than in the PM hours. During transport, serum cortisol concentrations increased (P less than 0.01). Highest concentrations developed at 0.5 hour after unloading; concentrations declined thereafter. During the first 6 days at location 2, circadian rhythm was evidenced by higher serum cortisol concentrations in the AM hours than in the PM hours. Therefore, the transportation of gilts 5.6 km to new pens was a transient stress causing a temporary increase in serum cortisol concentrations, but did not cause a disruption in the endogenous rhythm of cortisol.     

Effects of exogenous cortisol on the GH/IGF-I/IGFBP network in channel catfish

Glucocorticoids are known to hinder somatic growth in a number of vertebrate species. In order to better understand the mechanisms through which they may act in channel catfish, we examined the effects of feeding cortisol on the growth hormone (GH)/insulin-like growth factor-I (IGF-I)/IGF-binding protein (IGFBP) network. Fish (30.6 ± 3.0 g) were fed once daily for 4 weeks and treatments included: (1) High-cortisol (dietary cortisol provided at 400 mg/kg feed), (2) Low-cortisol (dietary cortisol provided at 200 mg/kg feed), and (3) Control (commercial catfish feed). Fish fed diets with cortisol weighed approximately 50% less than Controls. Feed intake was reduced by approximately 30% in both treatments of cortisol fed fish compared to Controls. A 20-kDa IGFBP was observed in plasma from High- and Low-treated fish while it was not detected in Control fish plasma. High-cortisol treatment increased pituitary GH mRNA expression approximately 10-fold while liver IGF-I mRNA expression was not different between cortisol-treated fish and Controls. Cortisol treatments decreased plasma levels of IGF-I. These data indicate that feeding cortisol for 4 weeks reduces weight gain, feed intake, and plasma levels of IGF-I and induces a 20-kDa IGFBP. One mechanism through which cortisol may impede growth of catfish is through an increase in a low molecular weight IGFBP which may lead to inhibitory effects on the action of IGF-I.     

品种,性别和日龄对肉兔饲料转化率的影响

试验选用大耳白，加里福尼亚兔和比利时兔，通过对试验兔７５－１５０日龄生长阶段饲料转化率的测定，结果表明：日龄是影响试兔饲料转化率的主要限制性因素（Ｐ＜０．０１）。由此得出：要提高商品兔的生产效率，必须注重兔的早期饲养管理，使之在较短的时间同进入生长高峰，加快周转，而饲养“长寿兔”将使商品兔生产的经济效益显著降低。     

冷热刺激对犬血清皮质醇、促肾上腺皮质激素及血液生理指标的影响

对体重为4 5±0 5kg的雄性京巴、沙皮和杂种宠物犬,随机分成2组,每组9只,由桡静脉采取自身对照血液后,冷应激组置于0℃的冰水混合物中30min,分别于刺激结束后0h、1h、2h采血;热应激组置于41～42℃的环境中1h,分别于刺激30min和60min时,刺激结束后1h和2h采血。测定血样中的红细胞数、白细胞数、血红蛋白含量、红细胞比容、血沉、红细胞脆性等血液指标,并用放射免疫法测定血清中的皮质醇、促肾上腺皮质激素(ACTH)的浓度。结果表明:在热刺激条件下,各试验期皮质醇和ACTH的浓度均高于各自对照期,但热刺激30min和60min时,与各自对照期相比,皮质醇浓度和ACTH浓度差异均极显著(P<0 01);刺激结束后1h,皮质醇浓度与对照期相比差异仍极显著(P<0 01),ACTH浓度差异显著(P<0 05);刺激结束后2h二者虽都高于对照期,但差异不显著(P>0 05)。冷刺激条件下,各试验期皮质醇和ACTH的浓度均高于各自对照期,其中冷刺激结束时均差异极显著(P<0 01),结束后1h差异显著(P<0 05),结束后2h差异不显著(P>0 05)。冷热刺激对各项血液生理指标也都有或多或少的影响。以上结果显示:上述神经内分泌和血液生理指标的改变与急性冷热应激反应有关,提高了机体对环境变化的适应能力,从而保证生命活动的正常进行。     

First isolation of Neospora caninum from the faeces of a dog from Portugal

We report the in vitro isolation of Neospora caninum from the faeces of a naturally infected 8-year-old male stray boxer from Portugal. Vero cell cultures were infected using parasite stages obtained after oral inoculation of γ-interferon knockout mice with 10² sporulated oocysts. The isolate was identified by microscopical examination, as well as histological, immunological and molecular methods including a DNA-microsatellite-based typing technique, and was subsequently named NC-P1. The DNA-microsatellite pattern observed in the NC-P1 isolate was not previously reported for any N. caninum isolate. To our knowledge, this is the first isolation of N. caninum from the faeces of a naturally infected dog from Portugal.     

Effect of exogenous ACTH on serum corticosterone and cortisol concentrations in the Moluccan cockatoo (Cacatua moluccensis)

The effects of exogenous adrenocorticortrophic hormone (ACTH) on the serum corticosterone and cortisol concentrations were determined in 28 mature Moluccan cockatoos (Cacatua moluccensis), a representative of the psittacine species. Birds were randomly assigned to 4 groups (2 ACTH-treated groups and 2 saline-treated controls). Group I (10 cockatoos [5 males and 5 females] ) was given 15 IU of ACTH after blood samples (base line) were taken at 10:00 AM. Blood samples were taken again at 30 minutes and 2.5 hours after ACTH administration. Group II (10 cockatoos) was given similar treatment, but blood samples were taken at 1 and 4 hours after ACTH was administered. Groups III and IV (each of 4 birds) were given saline solution injections as controls. Blood samples were taken at 30 minutes and 2.5 hours after injection (group III) and at 1 and 4 hours after injection (group IV). All serum samples were analyzed for cortisol and corticosterone. Serum corticosterone concentration increased significantly (P less than 0.01) from base-line levels (26 ng/ml) to 108 ng/ml within 30 minutes after ACTH was administered. The high values were maintained for 3 hours and then decreased to 40 ng/ml at the end of 4 hours. Male birds seemed to respond to the ACTH treatment quickly and maintained increased concentration for a shorter period when compared with the responses seen in female birds. Serum cortisol values remained low throughout the experimental period. These results indicate that serum corticosterone was responsive to ACTH administration, but cortisol was not. In addition, there may be a difference in the responses between male and female members of the species.