IARS mutation causes prenatal death in Japanese Black cattle

Isoleucyl‐tRNA synthetase (IARS) c.235G > C (p.V79L) is a causative mutation for a recessive disease called IARS disorder in Japanese black cattle. The disease is involved in weak calf syndrome and is characterized by low birth weight, weakness and poor suckling. The gestation period is often slightly extended, implying that intrauterine growth is retarded. In a previous analysis of 2597 artificial insemination (AI) procedures, we suggested that the IARS mutation might contribute toward an increase in the incidence of prenatal death. In this study, we extended this analysis to better clarify the association between the IARS mutation and prenatal death. The IARS genotypes of 92 animals resulting from crosses between carrier (G/C) × G/C were 27 normal (G/G), 55 G/C and 10 affected animals (C/C) (expected numbers: 23, 46 and 23, respectively). Compared to the expected numbers, there were significantly fewer affected animals in this population (P < 0.05), suggesting that more than half of the affected embryos died prenatally. When the number of AI procedures examined was increased to 11 580, the frequency of re‐insemination after G/C × G/C insemination was significantly higher at 61‐140 days (P < 0.001). The findings suggested that the homozygous IARS mutation not only causes calf death, but also embryonic or fetal death.     

Brainstem Auditory Evoked Responses Elicited by Tone-Burst Stimuli in Clinically Normal Dogs

Brainstem auditory evoked responses (BAERs) to click and tone-burst stimuli (0.5, 1, 2, 4, and 8 kHz) were recorded from 32 ears in 16 adult Beagles. BAERs were used to establish a normative database and describe response thresholds and latencies (wave I-IV) for the different stimuli. The frequencies of sound used were 8, 4, 2, 1, and 0.5 kHz. Sound stimuli were delivered by a closed headphone and masking stimuli were not applied. The BAER waveforms obtained were similar to those reported previously, except for a frequency-following response evoked by 1-kHz tone-bursts. The threshold was lowest when clicks and 4-kHz tone-bursts were used. Significant differences were observed between the mean values of the peak latencies for clicks and 4-and 8-kHz tone-bursts. The tone-burst stimulation used in our experiment was shown to be an appropriate method for detecting the BAERs. Thus, for investigating the frequency-specificity of the auditory sense, BAER data obtained using tone-burst sound in dogs may be meaningful.     

Mechanisms responsible for reduced cardiotoxicity of mitoxantrone compared to doxorubicin examined in isolated guinea-pig heart preparations

We reported previously that doxorubicin, an anticancer agent that has an anthracycline structure, alters Ca2+ releasing and uptake mechanisms in the sarcoplasmic reticulum of myocardial cells. These effects of doxorubicin are apparently related to its cardiotoxicity. Mitoxantrone is a similar anticancer agent with an anthracenedion structure that has been shown to be significantly less cardiotoxic. In the present study, the effects of mitoxantrone on the functions of the sarcoplasmic reticulum were examined in isolated muscle preparations obtained from the guinea-pig heart. In electrically-stimulated left atrial muscle preparations, incubation in vitro for 4 hr with 30 or 100 microM mitoxantrone significantly prolonged the time to the peak of twitch tension, markedly increased the developed tension observed at lower stimulation frequencies, thereby attenuating the slope of positive force-frequency relationships, and increased the postrest contraction observed after a 60-sec quiescent period. In myocytes isolated from ventricular muscles, 30 microM mitoxantrone increased the peak and the size of intracellular Ca2+ concentrations ([Ca2+] i), and prolonged the time to peak [Ca2+]i. In skinned muscle fiber preparations obtained from the left ventricular muscle, 30 muM mitoxantrone significantly increased the caffeine-induced contraction without affecting the Ca2+ sensitivity of contractile proteins. These results suggest that mitoxantrone enhances Ca2+ release from the sarcoplasmic reticulum in isolated atrial muscle preparations obtained from the guinea-pig heart. Apparent enhancement of the sarcoplasmic reticulum functions, in contrast to anthracyclines that has been shown to suppress these functions, seems to explain the relative lack of marked cardiotoxicity of mitoxantrone.     

Cushing's disease complicated with thrombosis in a dog

Thrombosis is a potential complication of hyperadrenocorticism (HAC) in dogs. An 8-year-old male Beagle diagnosed with pituitary-dependent HAC had complicated with thrombosis in the caudal vena cava and abdominal aorta, which was treated by hypophysectomy and antithrombotic therapy. After hypophysectomy, hypercortisolemia disappeared and the general condition was also significantly improved. Ultrasonography after hypophysectomy revealed that the thrombus remained in the abdominal aorta, but the thrombus in the caudal vena cava had disappeared. However 692 days after the hypophysectomy, the dog had an acute onset of dyspnea and died. Postmortem examination revealed the presence of thrombi in the abdominal aorta and the pulmonary artery. Observations from this case show that HAC dogs must be attention to thrombosis.     

A retrospective study of intervertebral disc herniation in dogs in Japan: 297 cases

We investigated the epidemiological characteristics of intervertebral disc herniation (IVDH) in Japan in a large population using a retrospective study. The sample population was dogs (n=297) with IVDH in Japan. Medical records were reviewed for breed, sex, age, affected interspace and neurological severity. The dogs were comprised of 132 cases of cervical IVDH (C-IVDH) and 165 cases of thoracolumbar IVDH (TL-IVDH). In Japan, the Dachshund, Beagle and Shih Tzu tended to suffer from both C-IVDH and TL-IVDH. The Shiba Inu, a characteristic Japanese dog breed, suffered from both C-IVDH and TL-IVDH, although there was little data relating to the whole breed. Male dogs tended to suffer from C-IVDH and TL-IVDH at a rate almost twice that of females in Japan. Among the three predominant dog breeds, the Dachshund, Beagle and Shih Tzu, the Dachshund tended to suffer from both C-IVDH and TL-IVDH at an earlier age than the Beagle, and the Beagle tended to suffer from both C-IVDH and TL-IVDH earlier than the Shih Tzu. Among the three predominant breeds, the Shih Tzu, in particular, tended to suffer from both C-IVDH and TL-IVDH at multiple sites. Our data from Japan were in partial agreement with previous data from the U.S.A., and epidemiological characteristics of IVDH peculiar to Japan were also identified.     

Effects of pimobendan for mitral valve regurgitation in dogs

Pimobendan has a dual mechanism of action: it increases myocardial contractility by increasing calcium sensitization to troponin C and it promotes vasodilation by inhibiting PDEIII. This study examined the effects of pimobendan on cardiac function, hemodynamics, and neurohormonal factors in dogs with mild mitral regurgitation (MR). The dogs were given 0.25 mg/kg of pimobendan orally every 12 hr for 4 weeks. With pimobendan, the heart rate and stroke volume did not change, but the systolic blood pressure gradually decreased and the degree of mitral valve regurgitation tended to decrease. Renal blood flow was significantly increased and the glomerular filtration rate was slightly increased at 2 and 4 weeks. Furthermore, over the 4-week period, the plasma norepinephrine concentration decreased significantly, the systolic index increased slightly, the left atrial diameter and the left ventricular diameters decreased significantly, and the heart size improved. Given these results, pimobendan appears to be useful for treating MR in dogs. However, further long-term studies of pimobendan involving a larger number of dogs with mild and moderate MR are needed to establish the safety of pimobendan and document improvements in quality of life.     

Clinical evaluation of left ventricular moderator band in 12 dogs

We retrospectively examined clinical data for 12 dogs in which echocardiography revealed the presence of left ventricular moderator bands (LMB). Physical examinations, electrocardiography and echocardiography revealed slight cardiac murmurs, increasing QRS complex and left ventricular turbulent flow (6 of the dogs), respectively. No differences were observed with respect to gender, and no specific clinical symptoms or types of dog that frequently develop this disorder were found.     

Total cystectomy and subsequent urinary diversion to the prepuce or vagina in dogs with transitional cell carcinoma of the trigone area: A report of 10 cases (2005–2011)

The cases of 10 dogs with transitional cell carcinoma of the urinary bladder that underwent total cystectomy were retrospectively reviewed to evaluate the feasibility and outcome of total cystectomy and ureteral transplantation to the prepuce or vagina. Dehiscence of ureterostomy (n = 2), pyelonephritis (n = 3), oliguria (n = 2), azotemia (n = 1), and ureteral obstruction (n = 1) were observed complications. The estimated median survival time was 385 days. This study demonstrates the feasibility of total cystectomy and subsequent urinary diversion to the prepuce or vagina in dogs. Compared to previous ureterocolonic anastomosis, this technique is associated with fewer gastrointestinal and neurologic complications.     

Post-traumatic stress disorder in participants of foot-and-mouth disease epidemic control in Miyazaki,Japan, in 2010

Foot-and-mouth disease (FMD) occurred in Miyazaki, Japan, in 2010, and 290,000 animals were culled. This paper describes the mental distress of the volunteers who had been dispatched to Miyazaki for disease control two years after the epidemic. It also assesses risk factors for post-traumatic stress disorder (PTSD). A participatory appraisal and self-administered questionnaire survey were conducted in 2012 for those who were dispatched to Miyazaki in 2010. The Impact of Event Scale-Revised (IES-R) was used as an indicator of PTSD, and univariate and multivariable analyses were performed. Of the 875 respondents, 1.3% had higher IES-R scores than the cut-off point (25), which is suggestive of PTSD. Mental stresses during and soon after FMD control and after two years were described. Four risk factors associated with high IES-R scores were found: transporting culled animals (P<0.01), stress during FMD control (P<0.01) and at the time of the survey (P<0.01), and lack of someone to talk to about FMD-associated stress at the time of the survey (P<0.01). Veterinarians, livestock technicians and clerical officers involved in FMD control still suffer from mental stress two years later. Public services should provide an opportunity for them to consult with mental health specialists. These findings should be used to better prepare workers who deal with infectious diseases of animals, especially when they must be culled. The establishment of a collaborative framework between veterinary and mental health services is recommended.