Ovarian and uterine changes during the oestrous cycle in female dogs.

CONTEXT: An accurate staging of sexual cycle is essential for the optimum timing of medical interventions. AIMS: Here, an updated insight into clinical, endocrinological and vagino-cytological parameters, and their correlation with histomorphology of ovarian and uterine tissue samples is presented. METHODS: Samples from 39 dogs were collected at various stages of the oestrous cycle: pro-oestrus (n =8), oestrus (n =12), dioestrus (n =9) (luteal phase) and anoestrus (n =10), according to clinical observations. Final allocation of samples was done after histomorphological evaluation of all tissues. Peripheral oestradiol-17ß (E2) and progesterone (P4) concentrations were measured, P4 by both chemiluminescent immunoassay (CLIA) and radioimmunoassay (RIA). KEY RESULTS: Differences were observed between determination of the stage of the oestrous cycle, either by clinical, endocrinological or histomorphological evaluation. Individuals considered to be in clinical and endocrinological oestrus, had entered the luteal phase according to histomorphology. P4 concentrations measured by two different assays differed, underlying the importance to understand that absolute P4 concentrations may deviate depending on the used assay. Comparison of E2 and P4 concentrations is suggested to be useful when defining the transition from early follicular phase to the time of ovulation. CONCLUSIONS AND IMPLICATIONS: Based on parallel histomorphological observations, combined with clinical and endocrinological findings on the same individuals, the present study emphasises that an accurate classification of the stage of the cycle in female dogs based solely on clinical and endocrinological assessments can be difficult. The histomorphological findings presented herein provide new insights into the transitional phases between the different stages of the oestrous cycle in the dog.

Progesterone and Luteinizing hormone secretion patterns in early pregnant gilts.

We studied luteinizing hormone (LH) pulsatility and episodic progesterone release of the corpus luteum (CL) on Day 11 and Day 21 in inseminated gilts and aimed to establish a relationship between these two hormones. Blood was collected at 15-min intervals for 12 hr on Days 11, 16 and 21 from a vena cava caudalis catheter. At euthanasia, eight gilts were pregnant and six gilts were not pregnant. Progesterone parameters (basal, mean, pulse frequency and pulse amplitude) did not differ between pregnant and non-pregnant gilts on Day 11, LH pulse frequency and amplitude tended to differ (p = .07 and p = .079). In pregnant gilts, basal and mean progesterone, progesterone pulse amplitude and frequency declined significantly from Day 11 to Day 21 (p < .05). A significant decline was also seen in the LH pulse amplitude from Day 11 to Day 21 (p < .05). None of the LH pulses was followed by a progesterone pulse within 1 hr on Day 21. On Day 11 and Day 21 appeared a synchronicity in the LH pulse pattern, as there were two or three LH pulses in 12 hr and these LH pulses appeared in the same time window. We conclude that on Day 11 and Day 21 of pregnancy in gilts, progesterone pulses do not follow an LH pulse within one hour. Further we demonstrated that the successful or not successful formation of a CL of pregnancy is independent of progesterone release on Day 11 after insemination. We confirmed the decline of progesterone from Day 11 to Day 21 in the vena cava caudalis and could demonstrate that this decline is partly due to lower progesterone pulse amplitude and frequency and that the decline occurs simultaneously with a decline in LH pulse amplitude.

GnRH-agonist deslorelin implant alters the progesterone release pattern during early pregnancy in gilts.

The aim of this study was to investigate the relationship of progesterone (P) and luteinizing hormone (LH) during recognition and establishment of pregnancy in the gilt. Therefore, the effects of eliminating episodic LH pulses on P patterns were determined during early pregnancy. To this end, a slow-release GnRH implant deslorelin was used for GnRH down-regulation. A group of gilts (GnRHa, n = 8) was implanted with the GnRH-agonist on Day 11 of pregnancy, while a control group (C, n = 5) was treated with a non-impregnated placebo implant. Blood was collected via a vena cava caudalis catheter at 10-min intervals for 8 hr on Day 16 and 21 of pregnancy. As expected, the GnRH implant reduced LH secretion (p < 0.01) and abolished LH pulses completely at Day 16 and Day 21 of pregnancy. On Day 16, there was no difference in P levels between the treatments. However, on Day 21, the GnRH-agonist treatment led to significantly increased P concentrations (p < 0.01) compared with the control gilts. Progesterone was secreted in a pulsatile manner in both treatment groups and no relationship between LH pulsatility and P pulsatility was observed. In conclusion, abolishment of LH pulsatility did not affect the pulsatile pattern of P secretion but led to an unexpected overall increase in P on Day 21 of pregnancy; this effect was delayed and occurred 10 days after commencing treatment with the GnRH depot agonist. The elevation of P on Day 21 of pregnancy in the GnRHa group suggests either a reduced negative feedback effect or an increased autocrine response by the corpora lutea.

Comparison of azaperone-detomidine-butorphanol-ketamine and azaperone-tiletamine-zolazepam for anaesthesia in piglets.

OBJECTIVE: To investigate a combination of azaperone, detomidine, butorphanol and ketamine (DBK) in pigs and to compare it with the combination of azaperone, tiletamine and zolazepam (TZ). STUDY DESIGN: Prospective, randomized, blinded, cross-over study. ANIMALS: Twelve clinically healthy crossbred pigs aged about 2 months and weighing 16-25 kg. METHODS: Pigs were pre-medicated with azaperone (4 mg kg(-1)). Ten minutes later anaesthesia was induced with intramuscular DBK (detomidine 0.08 mg kg(-1), butorphanol 0.2 mg kg(-1), ketamine 10 mg kg(-1)) or TZ (tiletamine and zolazepam 5 mg kg(-1)). The pigs were positioned in dorsal recumbency. Heart and respiratory rates, posture, anaesthesia score, PaO(2), PaCO(2), pH and bicarbonate concentration were measured. t-test was used to compare the areas under time-anaesthesia index curve (AUC(anindex)) between treatments. Data concerning heart and respiratory rates, PaO(2), PaCO(2) and anaesthesia score were analysed with anova for repeated measurements. Wilcoxon signed rank test was used for the data concerning the duration of sedation and anaesthesia. RESULTS: The sedation, analgesia and anaesthesia lasted longer after DBK than TZ. The AUC(anscore) were 863 +/- 423 and 452 +/- 274 for DBK and TZ, respectively (p = 0.002). The duration of surgical anaesthesia lasted a median of 35 minutes (0-105 minutes) after DBK and a median of 15 minutes (0-35 minutes) after TZ (p = 0.05). Four pigs after DBK and six after TZ did not achieve the plane of surgical anaesthesia. The heart rate was lower after DBK than after TZ. Both treatments had similar effects on the other parameters measured. CONCLUSIONS: At the doses used DBK was more effective than TZ for anaesthesia in pigs under field conditions. CLINICAL RELEVANCE: The combinations can be used for sedation and minor field surgery in pigs. The doses and drugs chosen were insufficient to produce a reliable surgical plane of anaesthesia in these young pigs.

Evaluation of bioequivalence after oral, intramuscular, and intravenous administration of racemic ketoprofen in pigs.

OBJECTIVE: To assess bioequivalence after oral, IM, and IV administration of racemic ketoprofen in pigs and to investigate the bioavailability after oral and IM administration. ANIMALS: 8 crossbred pigs. PROCEDURES: Each pig received 4 treatments in a randomized crossover design, with a 6-day washout period. Ketoprofen was administered at 3 and 6 mg/kg, PO; 3 mg/kg, IM; and 3 mg/kg, IV. Plasma ketoprofen concentrations were measured by use of high-performance liquid chromatography for up to 48 hours. To assess bioequivalence, a 90% confidence interval was calculated for the area under the time-concentration curve (AUC) and maximum plasma concentration (C(max)). RESULTS: Equivalence was not detected in the AUCs among the various routes of administration nor in C(max) between oral and IM administration of 3 mg/kg. The bioavailability of ketoprofen was almost complete after each oral or IM administration. Mean +/- SD C(max) was 5.09 +/- 1.41 microg/mL and 7.62 +/- 1.22 microg/mL after oral and IM doses of 3 mg/kg, respectively. Mean elimination half-life varied from 3.52 +/- 0.90 hours after oral administration of 3 mg/kg to 2.66 +/- 0.50 hours after IV administration. Time to peak C(max) after administration of all treatments was approximately 1 hour. Increases in AUC and C(max) were proportional when the orally administered dose was increased from 3 to 6 mg/kg. CONCLUSIONS AND CLINICAL RELEVANCE: Orally administered ketoprofen was absorbed well in pigs, although bioequivalence with IM administration of ketoprofen was not detected. Orally administered ketoprofen may have potential for use in treating pigs.

Plasma progesterone concentration depends on sampling site in pigs.

The objective of this study was to examine a possible difference in progesterone concentrations between the systemic venous blood and the caudal vena cava in early pregnant gilts. Nineteen crossbred pregnant gilts were offered three different regimens of feeding to examine influence of feeding on the secretion pattern of progesterone. The groups were high (H-H), low (L-L) and low-high (L-H) receiving 3.6, 1.8 and 1.8/3.6 kg/day, respectively. Catheters were placed in a jugular vein and the caudal vena cava (to sample ovarian secretion) on day 19 of pregnancy. Two consecutive samples taken at 30-min intervals were collected four times a day for 5 days (days 20-24). In addition, three gilts were simultaneously sampled from both catheters at 30-min intervals for 12 h on day 22. Progesterone concentration was significantly lower in the jugular vein compared with the caudal vena cava in all three feeding groups (P<0.001). An indication of episodic pattern of progesterone production occurred in plasma collected from the caudal vena cava, but not from the jugular vein. Dietary intake did not cause a profound effect on plasma progesterone concentrations during days 20-24 of gestation. It seemed that ovarian progesterone was released into the vena cava in an episodic pattern and there were implications that these episodes were temporally associated with LH pulses.

Quantification of Mycobacterium avium subspecies in pig tissues by real-time quantitative PCR.

BACKGROUND: Mycobacterioses in animals cause economical losses and certain Mycobacterium avium subspecies are regarded as potential zoonotic agents. The evaluation of the zoonotic risk caused by M. avium subspecies requires information about the quantities of Mycobacterium strains in infected animals. Because M. avium subspecies in pig tissues are difficult or even impossible to quantify by culturing, we tested the suitability of a culture-independent real-time quantitative PCR (qPCR) assay for this purpose. METHODS: Mycobacterial DNA was extracted from porcine tissues by a novel method and quantified by Mycobacterium genus specific qPCR assay targeting the 16S rRNA gene. RESULTS: The response of the qPCR assay to the amount of M. avium subspecies avium mixed with porcine liver was linear in the range of approximately log105 to log107 Mycobacterium cells per 1 g of liver. The assay was validated with three other M. avium subspecies strains. When the assay was applied to porcine lymph nodes with or without visible lesions related to Mycobacterium avium subspecies infections, around 104-107 mycobacterial genomes per gram of lymph nodes were detected. CONCLUSIONS: The qPCR assay was found to be suitable for the quantification of Mycobacterium avium subspecies in porcine lymph nodes and liver.

Physiological indicators of stress and meat and carcass characteristics in tail bitten slaughter pigs.

BACKGROUND: Tail biting is a common welfare problem in pig production and in addition to being a sign of underlying welfare problems, tail biting reduces welfare in itself. The aim of this study was to evaluate the effects of tail biting on different pre and post mortem indicators of stress in slaughter pigs and on carcass and meat characteristics. A total of 12 tail bitten (TB) and 13 control (C) pigs from a farm with a long-term tail biting problem were selected for salivary cortisol analyses before and after transport to the slaughterhouse. After stunning, samples were taken for the analysis of serum cortisol, blood lactate, intestinal heat shock protein 70 (HSP70), and meat quality characteristics. In addition, body temperature immediately after and muscle temperature 35 min after stunning were measured, as well as lean meat percentage and carcass weight. RESULTS: TB pigs showed a lower cortisol response to the transport-induced stress than C pigs and also had a lower serum cortisol concentration after stunning. HSP70 content in the small intestine was higher in the TB pigs than in C pigs. TB pigs had a considerably lower carcass weight therefore produced a lower total amount of lean meat per carcass than C pigs. CONCLUSIONS: This study suggests that prolonged or repeated stress in the form of tail biting causes a blunted stress response, possibly a sign of hypocortisolism. In addition, it underlines the importance of reducing tail biting, both from an animal welfare and an economic point-of-view.

Prevalence of and risk factors associated with viral and bacterial pathogens in farmed European wild boar.

The aim of this study was to estimate in farmed European wild boars the prevalence of and risk factors associated with a range of common porcine viral and bacterial infections, namely, porcine parvovirus (PPV), porcine circovirus type 2 (PCV2), swine influenza virus (SIV), Aujeszky's disease virus (ADV), classical swine fever virus (CSFV), swine vesicular disease virus (SVDV), coronavirus causing transmissible gastroenteritis (TGEV), porcine reproductive and respiratory syndrome virus (PRRSV), Mycoplasma hyopneumoniae, Lawsonia intracellularis, Brucella spp., and Leptospira spp. A sampling frame was compiled based on a national record of wild boar farmers, and 32 farms were surveyed. Serological screening was carried out on 303 samples from animals slaughtered between 2005 and 2008, and random-effect logistic regression models were developed for pathogens with a 'non-zero' prevalence. The apparent animal prevalence for PPV, PCV2, and L. intracellularis was 46.5% (95% confidence interval [CI] 41-52%), 51.1% (95% CI 45-57%) and 59.2% (95% CI 54-65%), respectively. Apparent farm seroprevalence rates for PPV, PCV2 and Lawsonia intracellularis were 56.3% (95% CI, 39-73%), 21.9% (95% CI, 8-36%) and 78.1% (95% CI, 64-92%), respectively. No antibodies were detected against SIV, ADV, CSFV, SVDV, TGEV, PRSSV, Leptospira spp., Brucella spp., or M. hyopneumoniae. Increasing herd size, proximity to dense populations of domestic swine and later sampling times within the survey period were found to be risk factors. Overall, the seroprevalence of these pathogens in farmed wild boar was similar to that in the farmed domestic pig population in Finland. However, it is possible that the rearing of wild boars in fenced estates may predispose them to particular infections, as reflected in higher antibody titres.