Evaluation of short-term safety of ultrasound-guided foetal fluid sampling in the dog (Canis lupus familiaris)

BACKGROUND

In humans, analysis of amniotic fluid is widely used for diagnostic and prognostic purposes. Amniocentesis has scarcely been used in veterinary medicine to date, despite a tremendous potential for clinical and research applications in dogs. Our study aimed to establish a safe method for foetal fluid sampling in female dogs.

METHODS

Two transabdominal ultrasound-guided methods were assessed: the "free hand" and the needle-guided bracket sampling. In addition, through a subsequent routinely scheduled ovariohysterectomy, fluid was directly collected. Samples from 98 conceptuses were collected at day 46.7 ± 7.5 of pregnancy.

RESULTS

The amount of fluid retrieved varied between 0.5 and 5.0 ml per collection. Macroscopic examination of the uterus and conceptuses identified 53% of the puncture sites. Neither fluid leakage nor foetal injury was detected, and six hematomas (5.8%) were visible. Ultrasound-guided foetal fluid collection was found to be potentially safe, and it can be performed by using either transabdominal method.

CONCLUSION

Foetal fluid collection is possible with relative ease and low short-term risk, and may open paths for diagnostic, therapeutic and research purposes in dogs. The procedure can provide new insights into prenatal clinical medicine, including diagnostics of foetal deaths, early identification of heritable diseases and so on.

Reproducibility of the effects of homeopathically potentised Argentum nitricum on the growth of Lemna gibba L. in a randomised and blinded bioassay

BACKGROUND

A previous study reported a significant statistical interaction between experiment date and treatment effect of Argentum nitricum 14x-30x on the growth rate of duckweed (Lemna gibba L.). The aim of the present study was to investigate the stability of the test system and intra-laboratory reproducibility of the effects found.

METHODS

Duckweed was treated with A. nitricum potencies (14x-30x) as well as succussed and unsuccussed water controls. The outcome parameter area-related growth rate for day 0-7 was determined by a computerised image analysis system in two series of independent randomised and blinded experiments. Systematic negative control (SNC) experiments were carried out to investigate test system stability. Statistical analysis was performed with full two-way analysis of variance (ANOVA) and protected Fisher's Least Significant Difference (LSD) test.

RESULTS

In the first repetition series we found a significant treatment effect (p = 0.016), while in the second series no effect was observed. The negative control experiments showed that the experimental system was stable. An a posteriori subgroup analysis concerning gibbosity revealed the importance of this growth state of L. gibba for successful reproduction of the statistically significant interaction in the original study; flat: no interaction (p = 0.762); slight gibbosity: no interaction (p = 0.356); medium gibbosity: significant interaction (p = 0.031), high gibbosity: highly significant interaction (p = 0.005).

CONCLUSIONS

With the original study design (disregarding gibbosity status of L. gibba) results of the original study could not be reproduced sensu stricto. We conclude that the growth state gibbosity is crucial for successful reproduction of the original study. Different physiological states of the test organisms used for bioassays for homeopathic basic research must carefully be considered.

Short communication: Progressive motility of frozen-thawed canine semen is highest five minutes after thawing

Progressive motility is usually estimated by visual inspection using a light contrast microscope at X 100 immediately after semen collection or immediately after thawing frozen semen. Standard operating procedures have never been established for this test. The objective of this experiment was to examine time-dependent changes of motility after thawing cryopreserved canine semen. Semen of 35 dogs was collected, and volume, concentration, progressive motility, morphology, membrane integrity and HOS test were evaluated. For cryopreservation, CaniPRO^® Freeze A&B was used. Semen was thawed and diluted using CaniPRO^® culture medium. After thawing, semen was evaluated as before. In addition, every sample was evaluated for progressively motile sperm cells 0, 5, 20 and 60 min after thawing. Progressive semen motility was significantly highest five minutes after thawing.

The staircase of evidence – a new metaphor displaying the core principles of Evidence-based Veterinary Medicine

Background: Veterinary practitioners and clinicians should base their clinical decisions on the best evidence obtainable to provide best patient care. The evidence of information concerning diagnostic or therapeutic procedures and disease prevention can be ranked from weak to strong based on the methodology the information is generated by. Teaching the concepts and strategies of Evidence-based Veterinary Medicine, however, can be challenging. Students and practitioners should become competent in defining a clinical problem, retrieving of information from the literature and independent critical thinking. Several authors illustrated the levels of evidence ranked from strongest to weakest using a pyramid metaphor. The basis reflects information of the lowest evidence and towards the tip the evidence increases. The metaphorical concept of the pyramid, i.e. solid foundation and a narrow tip, however, does not adequately represent the hierarchy of evidence as the high evidence levels are represented by narrow fields and vice versa. Results: We propose an alternative schematic which may be used in order to display the respective evidence levels as a staircase. A reading pictogram character illustrates that the search for information should start at the highest step. To assess which metaphor can be more easily interpreted and is intuitively accessible a survey among 5th semester veterinary students was performed which was completed by 100 respondents. According to the results both metaphors adequately display the hierarchy of evidence. The staircase better represents the fact that high evidence information is more likely to be true and that one should start to look for high evidence when searching information. In contrast more students found that the pyramid represents distracting information i. e. that opinions and information from the internet provide a solid knowledge base. Conclusions: The staircase of evidence displays better the evidentiary value of information and how to perform a search for information of high evidence compared to the pyramid of evidence. It therefore can help to teach information search and interpretation strategies in order to answer specific clinical questions.

Evidence-based Medicine in Animal Reproduction

With new knowledge being generated and published daily, the importance of evidence-based approaches in veterinary medicine is obvious. Clinicians must stay current or risk making poor decisions that clients may challenge. Especially in animal reproduction, several new substances and procedures to diagnose or treat reproductive disorders have been introduced in the last years. On the other hand, a closer look at the quality of published literature on animal reproduction reveals major deficits in methodology and reporting of many clinical trials. We strongly recommend systematically assessing the quality of scientific information when reading journal papers before using the given information in practice. The aim of evidence-based medicine (EBM) is to base the decisions in the practice of medicine on valid, clinically relevant research data. Therefore, we suggest that students should become familiar with the concepts of evidence-based veterinary medicine (EBVM) at the beginning of their veterinary education. Concepts and supporting tools such as checklists for literature assessment have been developed and validated. The purpose of this article is to review and discuss the importance of incorporating EBVM in animal reproduction. The need for further research that produces strong evidence in different fields of animal reproduction and better reporting of relevant study information is obvious.

Reproducibility of effects of homeopathically potentised gibberellic acid on the growth of Lemna gibba L. in a randomised and blinded bioassay

BACKGROUND

Reproducibility of basic research investigations in homeopathy is challenging. This study investigated if formerly observed effects of homeopathically potentised gibberellic acid (GA3) on growth of duckweed (Lemna gibba L.) were reproducible.

METHODS

Duckweed was grown in potencies (14x-30x) of GA3 and one time succussed and unsuccussed water controls. Outcome parameter area-related growth rate was determined by a computerised image analysis system. Three series including five independent blinded and randomised potency experiments (PE) each were carried out. System stability was controlled by three series of five systematic negative control (SNC) experiments. Gibbosity (a specific growth state of L. gibba) was investigated as possibly essential factor for reactivity of L. gibba towards potentised GA3 in one series of potency and SNC experiments, respectively.

RESULTS

Only in the third series with gibbous L. gibba L. we observed a significant effect (p = 0.009, F-test) of the homeopathic treatment. However, growth rate increased in contrast to the former study, and most biologically active potency levels differed. Variability in PE was lower than in SNC experiments. The stability of the experimental system was verified by the SNC experiments.

CONCLUSIONS

Gibbosity seems to be a necessary condition for reactivity of L. gibba to potentised GA3. Further still unknown conditions seem to govern effect direction and the pattern of active and inactive potency levels. When designing new reproducibility studies, the physiological state of the test organism must be considered. Variability might be an interesting parameter to investigate effects of homeopathic remedies in basic research.

Does oral administration of the amino acid tyrosine affect oestradiol-17β concentration and sexual behaviour in the bitch?

The oral administration of the amino acid, tyrosine, has been for years recommended in order to improve fertility, especially to improve copulation behaviour in female dogs. However, evidence is comparatively poor. The objective of our study was to determine whether oral administration of tyrosine has an effect on oestradiol-17β concentrations and the oestrous behaviour in the bitch. Fifty bitches were randomly allocated to one of two treatment groups in which each dog received 100mg/kg/day of either tyrosine or milk sugar orally between Day 3 and Day 9 of heat. Every two to three days, a gynaecological examination was performed and blood samples were taken to determine oestradiol-17β and progesterone concentrations. The day of ovulation was estimated by clinical findings, and according to the specifications of the laboratory, once progesterone values exceeded 12.7nmol/l. The observed copulation behaviour was not different between the groups. No differences in volume and visual nature of vaginal discharge were observed. At the day of ovulation, mean oestradiol-17β concentration in the treated group was 163.4pmol/l and 162.2pmol/l in the placebo group, respectively. In conclusion, feeding tyrosine to female dogs between Day 3 and Day 9 of heat did not alter visual signs of heat or copulation behaviour, and did not alter oestradiol-17β concentration.

Endoscopic resection of a vaginal septum in a bitch and observation of septa in two related bitches

CASE HISTORY

In 2008, a 3-year-old female Labrador Retriever was presented for routine breeding soundness evaluation.

CLINICAL FINDINGS

Vaginal endoscopy revealed an 8-cm long and 1-cm thick vaginal septum. Surgical resection of the septum was performed under general anaesthesia using a bipolar high-frequency resectoscope. Three months later the bitch was naturally mated and subsequently delivered five male and two female puppies without complications. Both female puppies were examined at the age of 12 and 15 months and showed a vaginal septum with a diameter of 0.3 and 0.5 cm, respectively.

DIAGNOSIS

Vaginal septa in three related bitches.

CLINICAL RELEVANCE

This is the first report describing the use of a bipolar high-frequency resectoscope for vaginal surgery in dogs. The septum could be resected quickly, with preservation of surrounding structures. Furthermore, it is the first report collecting information about familial presentation of vaginal septa in female dogs. Based on this case, we suggest that consideration should be given to the possible risk of inheritance of vaginal septa before considering surgical resection and breeding of female dogs.