Quantitative electroencephalography of medetomidine,medetomidine-midazolam and medetomidine-midazolam-butorphanol in dogs

The purpose of this study was to evaluate the effects of the administration of an alpha2-adrenoceptor agonist alone and in combination with other derivatives on brain wave activity. In addition, the diagnostic values of the electroencephalogram (EEG) for judging the depth of the balanced anaesthesia with an alpha2-adrenoceptor agonist was evaluated. The treatments comprised 20 microg/kg medetomidine (Me-20), 80 microg/kg medetomidine (Me-80), 20 microg/kg medetomidine and 0.5 mg/kg midazolam (Me-Mi) administered intramuscularly, and 20 microg/kg medetomidine with 0.5 mg/kg midazolam and 0.1 mg/kg butorphanol (Me-Mi-Bu). The EEG was recorded continuously at pre-administration, and at 7, 10, 20, 30, 45 and 60 min after administration. The recorded data were analysed by separating the power spectrum into 1-3, 4-7, 8-13 and 14-30 Hz bands. Spectral-edge analysis was used to calculate the spectral edge frequency 90 (SEF90) and the median edge frequency (MEF). Time-related changes in power spectrum analysis showed a significant increase in the Me-80 group in the 1-3 Hz band. The power for 1-3 Hz in the Me-80 group was significantly higher than in all the other groups. In the 14-30 Hz band, there was a significant reduction of power in all groups following administration of the agents. The SEF90 frequencies were significantly reduced in all groups except for the Me-20 group after administration of the agents. The SEF90 frequencies in the Me-20, Me-Mi and Me-Mi-Bu were all significantly higher than those in the Me-80 group. However, there was no significant difference between the Me-20, Me-Mi and Me-Mi-Bu groups in any analyses. Our results demonstrated that the changes in quantitative EEG made by the Me-Mi-Bu and Me-Mi groups were similar to those made by Me-20 groups. Present results suggest that the EEG should be interpreted with caution in assessing the anaesthetic level in balanced anaesthesia in dogs.     

Divergence of p33/34 gene of Theileria found in Cervus nippon in Japan

The 18S rRNA gene and the piroplasm major immunodominant protein gene (p33/34) of Theileria from various subspecies of sika deer in 8 different locations of Japan were analyzed. The similarity between 633 bp partial sequences of the 18S rRNA gene among various subspecies of sika deer was found to be between 99.7% and 100%. While the percent identities of the 412 bp partial p33/34 gene sequence and deduced amino acid sequences between Theileria of sika deer from Yamaguchi Prefecture and those found in deer from other Prefectures, were comparatively low, 68.7% to 70.1% and 64.1% to 70.0% respectively. These findings suggest that there are at least two genetically distinct strains of Theileria of sika deer in Japan.     

Effect of drug-eluting bead transarterial chemoembolization loaded with cisplatin on normal dogs

Transcatheter arterial embolization (TAE) and transcatheter arterial chemoembolization (TACE) are standard treatments for advanced hepatocellular carcinoma (HCC) and particularly for unresectable tumors or liver metastases in humans. However, reports on TACE used in veterinary medicine are few. This study aimed to evaluate the feasibility and safety of drug-eluting bead transarterial chemoembolization (DEB-TACE). We performed DEB-TACE in four clinically normal dogs and pharmacokinetically compared the results against hepatic arterial infusion (HAI) of cisplatin in two dogs. Drug-eluting beads (DEB) loaded with cisplatin were injected through a microcatheter for selective embolization of the left hepatic artery. After embolization, computed tomography (CT) images and histological examination findings were obtained during a 4-week observation period. Serum platinum concentrations were measured to evaluate cisplatin after each procedure. Biochemical analysis was performed during a 12-week observation period. Embolization was successful in all dogs, and there were no clinically apparent abnormalities. Embolization was confirmed up to 4 weeks after DEB-TACE in two of the four dogs and up to 1 week in the other two dogs using postoperative CT images. Cisplatin was not detected in peripheral veins in all dogs after DEB-TACE, but it was detected in trace amounts after HAI. DEB-TACE using cisplatin was safe and well tolerated by normal dogs. DEB-TACE may be useful in terms of determining systemic toxicity and drug concentration within tumors.     

Application of ventriculoperitoneal shunt as a treatment for hydrocephalus in a dog with syringomyelia and Chiari I malformation

A twenty-month-old Chihuahua male dog was presented to us suffering with ataxia. Based on the physical examination, X-ray and magnetic resonance imaging (MRI) examinations, we diagnosed the dog with hydrocephalus, Chiari I malformation and syringomyelia. Treatment consisted of internal medical treatment and the placement of a ventriculoperitoneal (VP) shunt. The ventricular dilatation was relieved and the dog improved neurologically; however, the Chiari I malformation and syringomyelia remained after surgically positioning the VP shunt.     

Anaesthetic and cardiopulmonary effects of balanced anaesthesia with medetomidine-midazolam and butorphanol in dogs

The anaesthetic and cardiopulmonary effects of combinations of medetomidine (Me), midazolam (Mi) and butorphanol (Bu) were evaluated in dogs. The characterization of anaesthetic effects was assessed using a scoring system. The combinations tested were 20 or 40 micrograms/kg Me and 0.5 mg/kg Mi (20Me-Mi or 40Me-Mi) followed by either an intravenous injection of physiological saline solution (PSS) or Bu (0.1 or 0.3 mg/kg). The mixture of Me and Mi was injected intramuscularly, followed 15 min later by an intravenous injection of Bu or PSS in all six groups. The combined Me-Mi induced deep sedation but not profound anaesthesia. The effect of the subsequent Bu administration was observed in the scores related to its analgesic effect. There were no significant differences between the two doses of Bu, following either 20Me-Mi or 40Me-Mi in the duration of anaesthesia, heart and respiratory rates, rectal temperature, and anaesthetic and analgesic scores except for palpebral reflex, and interdigital web clamping scores. Therefore, we concluded that the addition of 0.1 mg/kg Bu to Me-Mi elicits adequate anaesthesia with adequate analgesic effect, and side-effects such as bradycardia, hypertension, and slight respiratory acidosis in some dogs.     

Verification of a phenotypic discrimination method for hybrid larch seedlings using DNA markers

The hybrid between Kuril larch (Larix gmelinii var. japonica) and Japanese larch (L. kaempferi) is an important afforestation tree species in Hokkaido, Japan, because of its rapid juvenile growth, straight stem, and resistance to bark gnawing by voles. To produce desirable hybrid seedlings, precise seedling discrimination is essential. However, continuous variations in morphological and phenological traits occur across L. gmelinii var. japonica × L. kaempferi and L. gmelinii var. japonica × L. gmelinii var. japonica seedlings. Therefore, we used DNA markers to verify and improve the morphological and phenological discrimination method. We collected seeds from an interspecific seed orchard and, using chloroplast DNA analysis, we showed that the hybridization rates of 1-year-old seedlings were different between years (2004, 23.2 %; 2005, 53.6 %) and between mother trees (2004, 5.8–39.4 %; 2005, 20.0–81.0 %). Discriminant analyses revealed that the root collar diameter of 2-year-old seedlings, number of sylleptic branches of 2-year-old seedlings, and day of terminal bud set in 1- and 2-year-old seedlings are traits that aid in discriminating hybrid seedlings. The proportions of correctly discriminated individuals were found to be 81.7–88.2 % when using improved phenotypic discrimination methods. These methods adopted traits with high discrimination abilities during discriminant analyses and determined the selection intensity according to the hybridization rate estimated from the DNA markers. In contrast, the proportions of correctly discriminated individuals obtained using the current method were lower, 72.7–78.5 %, because this method was based on seedling height and adopted a constant selection intensity.     

Clinical features and their course of pituitary carcinoma with distant metastasis in a dog

An 11-year-old male toy poodle with neurological symptoms was diagnosed with a macroscopic pituitary tumor, which produced adrenocorticotropic hormone. Radiation therapy with a linear accelerator was performed for the pituitary tumor, and resulted in good local tumor control. However, serum endogenous adrenocorticotropic hormone concentrations were uncontrollable even after the tumor disappeared. Abdominal computed tomography revealed splenic masses, and splenectomy was performed. Histopathological examination of the surgical specimen showed tumor cells with eosinophilic and finely granular cytoplasm suggestive of endocrine origin. Since these cells were positive for adrenocorticotropic hormone, the case was diagnosed as a pituitary carcinoma with distant metastasis. Necropsy revealed multiple metastases to the abdominal organs. This is the first case report describing canine pituitary carcinoma with distant metastasis.     

Genome‐wide association study and genomic evaluation of feed efficiency traits in Japanese Black cattle using single‐step genomic best linear unbiased prediction method

The objectives of this study were to better understand the genetic architecture and the possibility of genomic evaluation for feed efficiency traits by (i) performing genome‐wide association studies (GWAS), and (ii) assessing the accuracy of genomic evaluation for feed efficiency traits, using single‐step genomic best linear unbiased prediction (ssGBLUP)‐based methods. The analyses were performed in residual feed intake (RFI), residual body weight gain (RG), and residual intake and body weight gain (RIG) during three different fattening periods. The phenotypes from 4,578 Japanese Black steers, which were progenies of 362 progeny‐tested bulls and the genotypes from the bulls were used in this study. The results of GWAS showed that a total of 16, 8, and 12 gene ontology terms were related to RFI, RG, and RIG, respectively, and the candidate genes identified in RFI and RG were involved in olfactory transduction and the phosphatidylinositol signaling system, respectively. The realized reliabilities of genomic estimated breeding values were low to moderate in the feed efficiency traits. In conclusion, ssGBLUP‐based method can lead to understand some biological functions related to feed efficiency traits, even with small population with genotypes, however, an alternative strategy will be needed to enhance the reliability of genomic evaluation.     

Effect of chloropicrin fumigation on microbial communities evaluated by community-level physiological profile and the resistance against fusarium wilt

Different microbial communities characterized by the Biolog pattern were developed in the rhizosphere of radish grown on a rockwool hydroponic system treated with chloropicrinfumigated and non-fumigated soil suspensions although no differences were observed in their viable counts. Different microbial communities also were developed in the rhizosphere and non-rhizosphere. After the development of microbial communities in the rhizosphere, bud cells of Fusarium oxysporum that causes vascular wilt of radish plants were inoculated, and disease symptoms were examined. Treatment with the non-fumigated soil suspension was much more effective than that with the fumigated one in controlling the disease, indicating that the Biolog method might be applicable to characterize microbial communities that control the disease caused by F. oxysporum.