G protein-coupled receptor (GPR) 120 is an unsaturated fatty acid receptor, which is associated with various physiological functions. It is reported that the genetic variant of GPR120, p.Arg270His, is detected more in obese people, and this genetic variation functionally relates to obesity in humans. Obesity is a common nutritional disorder also in dogs, but the genetic factors have not ever been identified in dogs. In this study, we investigated the molecular structure of canine GPR120 and searched for candidate genetic variants which may relate to obesity in dogs. Canine GPR120 was highly homologous to those of other species, and seven transmembrane domains and two N-glycosylation sites were conserved. GPR120 mRNA was expressed in lung, jejunum, ileum, colon, hypothalamus, hippocampus, spinal cord, bone marrow, dermis and white adipose tissues in dogs, as those in mice and humans. Genetic variants of GPR120 were explored in client-owned 141 dogs, resulting in that 5 synonymous and 4 non-synonymous variants were found. The variant c.595C>A (p.Pro199Thr) was found in 40 dogs, and the gene frequency was significantly higher in dogs with higher body condition scores, i.e. 0.320 in BCS4–5 dogs, 0.175 in BCS3 dogs and 0.000 in BCS2 dogs. We conclude that c.595C>A (p.Pro199Thr) is a candidate variant relating to obesity, which may be helpful for nutritional management of dogs.
Tick-borne diseases are often encountered in canine clinical practice. In the present study, a molecular epidemiological survey of dogs in Japan was conducted to understand the prevalence and geographical distribution of Babesia spp., Hepatozoon spp., Ehrlichia spp. and Anaplasma spp. Pathogen-derived DNA in blood samples obtained from 722 dogs with a history of exposure to ticks and/or fleas was examined by PCR. The prevalence of Babesia gibsoni, Babesia odocoilei-like species, Hepatozoon canis and Ehrlichia spp./Anaplasma spp. was 2.4% (16/722), 0.1% (1/722), 2.5% (18/722) and 1.5% (11/722), respectively. While B. gibsoni and Ehrlichia spp./Anaplasma spp. were detected in the western part of Japan, H. canis was detected in Tohoku area in addition to western and central parts of Japan.
The purpose of this study was to evaluate the dark adaptation time in canine electroretinography (ERG) using a contact lens electrode with a built-in LED. Twelve eyes of six normal laboratory beagle dogs were used and exposed to steady room light at 500 lux for 30 min for light adaption. ERG was recorded at different time points during dark adaptation in sedated and light-adapted beagles. The stimulus intensity was 0.0096 cd/m2/sec. The b-wave amplitude increased significantly until 25 min of dark adaptation, whereas no significant changes in amplitudes were observed after 30 min. Dark adaptation for more than 25 min would be necessary for accurate ERG in canine ERG using a contact lens electrode with a built-in LED.
Iron is involved in various physiological processes of the human body to maintain normal functions. Abnormal iron accumulation in brain has been reported as a pathogenesis of several neurodegenerative disorders and cognitive impairments. Hemojuvelin (HVJ) is a membrane-bound and soluble protein in mammals that is responsible for the iron overload condition known as juvenile hemochromatosis. Although iron accumulation in brain has been related to neurodegenerative diseases, it remains unknown the effect of mutation of HVJ gene on cognitive performance. In our studies, HJV(−/−) mice showed deficits in novel object recognition and Morris water maze tests. Furthermore, the expression ration of apoptotic marker Bax and anti-apoptotic marker Bcl-2 in the hippocampus and prefrontal cortex showed higher levels in HJV(−/−) mice. Our results suggested that deletion of HJV gene could increase apoptosis in brain which might contribute to learning and memory deficits in mutant mice. These results indicated that HJV(−/−) mice would be a useful model to study cognitive impairment induced by iron overload in brain.
The Spontaneously Diabetic Torii (SDT) fatty rat, a model for obese type 2 diabetes, shows bone quantitative abnormalities, namely low bone mineral density (BMD). The objective of this study was to evaluate bone morphological changes, in particular identifying the bone qualitative abnormalities, in the SDT fatty rat. Male SDT fatty rats showed increases in total trabecular area and trabecular number and decreases in trabecular thickness in cancellous bones of the proximal tibia, indicating trabecular miniaturization. The SDT fatty rat is useful for investigation of pathophysiological changes in bone quality in diabetic osteoporosis.
In June 2014, a male stray dog was recovered at Ente Nazionale di Protezione Animali (ENPA) kennel of Manfredonia, Apulia region, showing oral bleeding and physical prostration. The dog fell in a water canal and was trapped. During the clinical examination, a specimen of leech was revealed into its oral cavity. The parasite, probably entered by drinking unfiltered and contaminated water, has been identified as an adult of aquatic leech Limnatis nilotica. Leeches could overrun wide variety of animals, and few reports about blood sucking leech infestations in mammals are available in literature. This paper describes here the first oral hirudiniasis in a dog in Italy and highlights the possibility of human nasopharyngeal leech-related infection in Apulia region.
Avian amyloid A (AA) amyloidosis is commonly observed in adult birds with chronic inflammation, such as that caused by bacterial infection. We previously described vaccine-associated AA amyloidosis in juvenile chickens. In this study, the prevalence of amyloid deposition was measured in mature healthy chickens that survived a previous outbreak of avian AA amyloidosis while they were juveniles. Herein, we analyzed the amyloid deposition in mature chickens and compared the prevalence of amyloid deposition with juvenile chickens obtained in our previous study (Murakami et al., 2013). We found that: 1) amyloid deposition in the liver was absent in mature chickens, while juvenile chickens had a rate of 24%; 2) amyloid deposition in the spleen was observed in 36% of juvenile chickens and in 40% of mature chickens; 3) amyloid deposition in the pectoral muscle of mature chickens (43.75%) was approximately half that of juvenile chickens (88%). These results suggest that additional amyloid deposition in chickens previously exposed to AA amyloidosis may not worsen with age. Further, amyloid deposition in chickens may tend to regress when causative factors, such as vaccinations and/or chronic inflammation, are absent.
Bovine dilated cardiomyopathy (DCM) is an autosomal recessive genetic disorder causing congestive heart failure and subsequent death. Recently, a nonsense mutation c.343C>T in the bovine optic atrophy 3 (OPA3) gene had been reported to cause the DCM in Holstein cattle in Switzerland. However, the mutation has not been confirmed in bovine DCM outside Switzerland. Nine Holstein Friesian cows that were macroscopically and histologically diagnosed with or suspected of DCM and 12 control cows kept in Japan were tested for the mutation. The mutation surrounding OPA3 DNA fragment was amplified by PCR and subjected to direct sequences. The homogeneous c.343C>T mutation was proved to occur in all the affected cows and not in the control cows. The present study is the first report of the mutation in the DCM affected cows outside Switzerland.
A 10-year-old castrated male mixed-breed dog exhibited vomiting, lethargy and anorexia. An abdominal ultrasound examination revealed a focal dilation of the abdominal aorta. The dog died 2 days after examination, and necropsy revealed a ruptured aneurysm at the abdominal aorta between the kidneys. Histological examination revealed severe granulomatous and necrotizing pan-arteritis with fungal organisms. Graphium species was identified through DNA sequence analysis of the PCR product from formalin-fixed paraffin-embedded samples. To our knowledge, this is the first report of aortic aneurysm caused by Graphium species in a dog.
A 7-year-old female boxer dog died suddenly without any clinical signs. It was suspected that the dog had arrhythmogenic right ventricular cardiomyopathy (ARVC) due to ventricular premature complexes and ventricular tachycardia at 3 years of age. The final diagnosis of ARVC was confirmed by histological characteristics, such as loss of cardiocytes and fibrofatty replacement, occurring in the right and left ventricular walls. In the cardiocytes, non-lipid vacuoles were observed. Cardiac fibrosis and intimal thickening of the small arteries occurred without fatty replacement in the inner muscle layer including the papillary muscles of the left ventricular wall. This paper describes the pathomorphological details of an ARVC case with coincidental cardiac fibrosis in the inner muscle layer of the left ventricular wall.
An 8-year-old, spayed, female Shiba dog was presented to a referring veterinarian with a complaint of chronic diarrhea and anorexia. Ultrasound and radiographs revealed an irregular mass in the pelvic cavity. The mass and the affected section of colon were surgically removed. Histopathological examination revealed multifocal coalescing granulomas and effaced intestinal structures. Central necrotic debris surrounded by multinucleated giant cells, lymphocytes, plasma cells and neutrophils was observed. Numerous, irregularly branched hyphae with pale basophilic, thin walls and occasional bulbous enlargements at the tips were present. Polymerase chain reaction identified Basidiobolus ranarum, successfully confirming a definitive diagnosis of basidiobolomycosis. To the best of our knowledge, this is the first report of intestinal basidiobolomycosis in a dog.
Somatostatin receptor 2 (SSTR2) is a negative regulator of cell proliferation in human breast cancer. Since there is little information about SSTR2 in canine mammary gland tumor (MGT), we clarified its distribution and expression level in normal mammary gland, benign MGT and malignant MGT. SSTR2 expression determined by immunohistochemical staining was observed in the cytoplasm of luminal epithelial cells. The intensity was negatively correlated with malignancy: normal tissues and some of the benign tumors had the highest levels, while the malignant tumors had little or no SSTR2 expression. As for the Western blotting, SSTR2 protein level in benign tumors was significantly lower than the normal mammary gland. On the other hand, SSTR2 protein levels in two of three malignant tumors were higher than the other groups. These results suggest that SSTR2 expression alters according to the malignancy of canine MGT.
Maropitant is a neurokinin 1 receptor (NK1R) antagonist that is clinically used as a new anti-emetic drug for dogs. Substance P (SP) and its receptor NK1R are considered to modulate gastrointestinal peristalsis. In addition, SP works as an inflammatory mediator in gastrointestinal diseases. Aim of this study is to clarify the effects of maropitant on intestinal motility and inflammation in mice. Ex vivo examination of luminal pressure-induced intestinal motility of whole intestine revealed that maropitant (0.1–10 µM) increased frequency of contraction, decreased amplitude of contraction and totally inhibited motility index in a concentration-dependent manner. We measured intestinal transit in vivo by measuring transportation of orally administered luminal content labeled with phenol red. Our results demonstrated that maropitant (10 mg/kg, SC) delayed intestinal transit. Geometric center value was significantly decreased in maropitant-treated mice. Anti-inflammatory effects of maropitant against leukocytes infiltration into the intestinal smooth muscle layer in post-operative ileus (POI) model mice were measured by immunohistochemistry. In POI model mice, a great number of CD68-positive macrophages or MPO-stained neutrophils infiltrated into the inflamed muscle region of the intestine. However, in the maropitant treated mice, the infiltration of leukocytes was not inhibited. The results indicated that maropitant has ability to induce disorder of intestinal motility in mice, but has no anti-inflammatory action in the mouse of a POI model. In conclusion, in mice, maropitant induces disorder of intestinal motility in vivo.
The effects of papaverine on carbachol (CCh) -and high K+- induced contraction in the bovine abomasum were investigated. Papaverine inhibited CCh (1 µM) -and KCl (65 mM) -induced contractions in a concentration-dependent manner. Forskolin or sodium nitroprusside inhibited CCh-induced contractions in a concentration-dependent manner in association with increases in the cAMP or cGMP contents, whereas papaverine increased cGMP contents only at 30 µM. Changes in the extracellular Ca2+ from 1.5 mM to 7.5 mM reduced verapamil-induced relaxation in high K+-depolarized muscles, but papaverine-induced relaxation did not change. Futhermore, papaverine (30 µM) and NaCN (300 µM) decreased the creatine phosphate contents. These results suggest that the relaxing effects of papaverine on the bovine abomasum are mainly due to the inhibition of aerobic energy metabolism.
Endostatin, a fragment of collagen XVIII, is known as an endogenous angiogenesis inhibitor, and its serum concentration increases in various cardiovascular diseases. T-type Ca2+ channel, low voltage-activated Ca2+ channel, is not expressed in adult ventricular myocytes. Re-expression of T-type Ca2+ channels in cardiac myocytes is thought to be involved in the development of cardiac hypertrophy. We examined the effects of endostatin on T-type Ca2+ channel current by whole-cell patch clamp technique in freshly isolated adult guinea pig ventricular myocytes, which exceptionally express T-type Ca2+ channels. Although endostatin 300 ng/ml had no effect on L-type Ca2+ current, it significantly inhibited T-type Ca2+ current. These data indicate that endostatin can be an endogenous inhibitor of T-type Ca2+ channels in the cardiac myocytes.
The pharmacokinetics of acetaminophen was investigated following oral dosing to Shiba goats in order to evaluate the properties of gastric emptying. Acetaminophen was intravenously and orally administered at 30 mg/kg body weight to goats using a crossover design with a 3-week washout period. The stability of acetaminophen in rumen juice was also assessed. Acetaminophen concentrations were measured by HPLC. Since acetaminophen was stable in rumen juice for 24 hr, the extremely low bioavailability (16%) was attributed to its hepatic extensive first-pass effect. The mean absorption time and absorption half-life were unexpectedly short (4.93 and 3.35 hr, respectively), indicating its marked absorption from the forestomach, which may have been due to its smaller molecular weight. Therefore, acetaminophen was considered to be unsuitable for evaluating gastric emptying in Shiba goats.
We investigated the influence of pneumoperitoneum#(PP) and postural change under inhalation anesthesia with isoflurane, which is routinely used in dogs, on the cardiovascular and respiratory systems. As test animals, 6 adult beagles were used. To induce anesthesia, atropine, butorphanol and propofol were intravenously injected. Anesthesia was maintained with 1.3 MAC (1.7%) isoflurane. The following were the experiment conditions: I:E ratio, 1:1.9; tidal air exchange, 20 ml/kg; and ventilation frequency, 14 times/min. Respiration was regulated so that the PaCO2 was approximately 35 to 40 mmHg before the start of the experiment. PP with CO2 (intraperitoneal pressure 15 mmHg) and a postural change (15°C) was performed during the experiment. As parameters of circulatory kinetics, heart rate (HR), mean aortic pressure (MAP), mean pulmonary arterial pressure (MPAP), central venous pressure (CVP), femoral venous pressure (FVP) and cardiac output (CO) were measured. As parameters of respiratory kinetics, airway pressure (PAW) and blood gas (BG) were measured. There were significant increases in HR, MAP, MPAP, CVP, FVP, CO, PAW and PaCO2 after PP in the horizontal position. There were significant increases in CVP, FVP, PAW and PaCO2 after PP in the Trendelenburg position. There were significant increases in the MPAP, CVP, FVP, PAW and PaCO2 after PP in the inverse Trendelenburg position. There was a significant difference in FVP after PP between the Trendelenburg position and inverse Trendelenburg position. The results of this experiment suggest that appropriate anesthesia control, such as changing the ventilation conditions after PP, is required for laparoscopic surgery under inhalation anesthesia with isoflurane.
Most anesthetics have an immuno-suppressive effect on cellular and neurohumoral immunity, and research shows that total intravenous anesthesia (TIVA) with propofol has a greater immuno-protective effect than inhalational anesthesia in human medicine. However, in veterinary clinics, these effects remain ambiguous. To clarify the details, we focused on propofol and isoflurane, investigating clinical blood hematology and immunological profiles drawn from healthy dogs under and after two anesthesia techniques. Twelve healthy adult beagles were included in this study, randomly assigned to the propofol anesthesia group (group P: n=6) or the isoflurane anesthesia group (group I: n=6). In both groups, the number of lymphocytes in peripheral blood decreased after 2 hr of anesthesia (2 hr), but group P showed significantly less decrease than group I. For T-lymphocyte subsets examined by flowcytometry, the ratio of CD3+, CD4+ and CD8+ lymphocytes in the peripheral blood mononuclear cell (PBMC) of group P at 2 hr also exhibited a high level compared to group I. Moreover, for mRNA expression of cytokines measured by real-time PCR, the IL2 (pro-inflammatory cytokine) of group P showed no decrease like group I. The IL10 (anti-inflammatory cytokine) of group P also showed no increase like group I, while both cytokines maintained nearly the same level until 2 hr. These results suggest that, compared to propofol, isoflurane had more strongly immuno-suppression caused by anesthesia, and propofol itself might have some immuno-protective effects. Thus, TIVA with propofol might benefit immunological support in the perioperative period of dogs.
In this study, scaling, polishing and daily tooth brushing were performed in 20 beagle dogs, and the number of oral bacteria was determined using a bacterial counter. The dogs were randomized into the scaling (S), scaling + polishing (SP), scaling + tooth daily brushing (SB) and scaling + polishing + tooth daily brushing (SPB) groups. Samples were collected from the buccal surface of the maxillary fourth premolars of the dogs immediately after scaling and every week thereafter from weeks 1 to 8. Throughout the study, the number of bacteria was significantly lower in the SB and SPB groups compared with the S group. The findings suggest that daily tooth brushing inhibited oral bacterial growth in the dogs.
Neonicotinoids, some of the most widely used pesticides in the world, act as agonists to the nicotinic acetylcholine receptors (nAChRs) of insects, resulting in death from abnormal excitability. Neonicotinoids unexpectedly became a major topic as a compelling cause of honeybee colony collapse disorder, which is damaging crop production that requires pollination worldwide. Mammal nAChRs appear to have a certain affinity for neonicotinoids with lower levels than those of insects; there is thus rising concern about unpredictable adverse effects of neonicotinoids on vertebrates. We hypothesized that the effects of neonicotinoids would be enhanced under a chronic stressed condition, which is known to alter the expression of targets of neonicotinoids, i.e., neuronal nAChRs. We performed immunohistochemical and behavioral analyses in male mice actively administered a neonicotinoid, clothianidin (CTD; 0, 10, 50 and 250 mg/kg/day), for 4 weeks under an unpredictable chronic stress procedure. Vacuolated seminiferous epithelia and a decrease in the immunoreactivity of the antioxidant enzyme glutathione peroxidase 4 were observed in the testes of the CTD+stress mice. In an open field test, although the locomotor activities were not affected, the anxiety-like behaviors of the mice were elevated by both CTD and stress. The present study demonstrates that the behavioral and reproductive effects of CTD become more serious in combination with environmental stress, which may reflect our actual situation of multiple exposure.
Pyrene (PY) is a polycyclic aromatic hydrocarbon (PAH) that is often used as a biomarker for human and wildlife exposure to PAHs. As the metabolites of PAHs, similar to their parent compounds, pose public health risks, it is necessary to study their characteristics and tissue-specific distribution. The present study was performed to experimentally characterize PY metabolites and analyze the tissue-specific distribution of the conjugated metabolites after oral administration of PY to rats. PY metabolites, such as pyrenediol-disulfate (PYdiol-diS), pyrenediol-sulfate (PYdiol-S), pyrene-1-sufate (PYOS), pyrene-1-glucuronide (PYOG) and 1-hydroxypyrene (PYOH), were detected in rat urine. Although glucuronide conjugate was the predominant metabolite, the metabolite composition varied among tissues. Interestingly, the proportion of PYOH was high in the large intestine. Furthermore, PYOH was the only PY metabolite detected in feces.
In Japan in 2013, two cattle in the northwestern part of Kagoshima Prefecture developed fever and swallowing difficulty and were suspected of having Ibaraki disease. The epizootic hemorrhagic virus (EHDV) genome was detected from diseased and asymptomatic cattle by reverse transcription-polymerase chain reaction (RT-PCR). High neutralization antibody titers to Ibaraki virus (IBAV) ranging from 1:128 to 1:1,024 were observed in the RT-PCR-positive cattle, and the virus was isolated in one of the IBAV-positive farms. A pairwise alignment and phylogenetic analysis based on the major outer coat protein VP2 encoded in segment 2 revealed a close relationship between the isolated viruses and previous IBAV isolates. The phylogeny of VP2 also suggested that an IBAV variant isolated in 1997 was distinct from IBAV and sorted into a heterogeneous serotype, EHDV serotype 7. The findings revealed the reemergence of Ibaraki disease in Japan after a 26-year absence. Interestingly, the co-circulation of EHDV serotype 1 with IBAV was observed in the affected region, suggesting the potential reassortment between two heterogeneous serotypes in the field. Sentinel surveillance in Kagoshima Prefecture indicated that the incursion of IBAV occurred in October 2013 and that its spread was limited within the small area. Inadequate environmental temperatures for vector transmission in late autumn might have limited the virus spread to a wider region. The reemergence of Ibaraki disease showed us the importance of continuous vaccination to prevent economic losses.
VP22 is a major tegument protein of Equine herpesvirus type 1 (EHV-1) that is a conserved protein among alphaherpesviruses. However, the roles of VP22 differ among each virus, and the roles of EHV-1 VP22 are still unclear. Here, we constructed an EHV-1 VP22 deletion mutant and a revertant virus to clarify the role of VP22. We found that EHV-1 VP22 was required for efficient viral growth in cultured cells, but not for virulence in a hamster model.
Fifty-five samples (15.62%) collected from dogs and cats were identified as canine parvovirus (CPV) infection in Beijing during 2010–2013. The nucleotide identities and aa similarities were 98.2–100% and 97.7–100%, respectively, when compared with the reference isolates. Also, several synonymous and non-synonymous mutations were also recorded for the first time. New CPV-2a was dominant, accounting for 90.90% of the samples. Two of the 16 samples collected from cats were identified as new CPV-2a (12.5%), showing nucleotide identities of 100% with those from dogs. Twelve samples (15.78%) collected from completely immunized dogs were found to be new CPV-2a, which means CPV-2 vaccines may not provide sufficient protection for the epidemic strains.
The present report describes Syphacia (Syphacia) maxomyos sp. n. (Nematoda: Oxyuridae) from two species of spiny rats, Maxomys musschenbroekii from Sulawesi and M. whiteheadi from Sumatra. It is characterized by a cephalic plate extending laterally with dorsoventral constriction and stumpy eggs with an operculum rim reaching pole. It is readily distinguishable by the former feature from all of hitherto known representatives of this genus in Indonesia, but it resembles parasites in Murini and Hydromyni rodents in continental Asia and Sahul. This is the first Syphacia species distributed in both the Sunda Shelf and Sulawesi with the exception of Syphacia muris, a cosmopolitan pinworm found in rodents of the of genus Rattus. It is surmised that S. maxomyos is specific to Maxomys and that it was introduced to Sulawesi by dispersal of some Maxomys from the Sunda Shelf.
African rainforest harbors herbivores at high density. However, because plants and soils typically lack in some essential minerals, rainforest is not always a suitable habitat for herbivores. How they fulfill the mineral requirements is therefore an important question to animal ecology and conservation. Although large marshes, called ‘bais’, are often mentioned as efficient mineral-resource, little information on other sodium resources has still been available. Our laboratory works and field surveys found that a peculiar item, decaying wood stumps of Anthostema aubryanum, played as a major sodium resource for herbivores in Moukalaba-Doudou National Park, Gabon. When A. aubryanum is alive, the sodium content of its bark is low and its latex is toxic. Sodium is accumulated in decaying stumps (mean=1,343 mg/kg dry matter). Eight herbivores visited stumps to ingest the dead wood. Fecal sample analysis revealed that western lowland gorillas, a species most-frequently using the stumps, consumed large amount of the dead wood as regular food. Our findings suggest that decaying A. aubryanum is critical sodium-resources and is a key species for herbivores in our study area. Importance of the A. aubryanum may be particularly large there, because it is a limited sodium-rich material that is available year round. Our study site is known as the site where the densities of several herbivores are among the highest at Central Africa. The relatively high herbivores density in our study site may partly depend on decaying A. aubryanum as sodium resources.