The hemodynamic effects of medetomidine continuous rate infusions in the dog

ObjectiveTo characterize the hemodynamic effects of continuous rate infusions (CRI) of medetomidine administered at doses ranging from 0 to 3 μg kg^?1 hour^?1.Study designProspective, blinded, randomized experimental trial.AnimalsSix adult purpose-bred mongrel dogs.MethodsAnesthesia was induced with sevoflurane for placement of arterial and venous catheters. Dogs recovered from anesthesia after which baseline hemodynamic measurements were obtained via lithium dilution cardiac output (CO) determination, with subsequent measurements via pulse power analysis to provide continuous CO determinations. Medetomidine, 1, 2, or 3 μg kg^?1 hour^?1 or a volume equivalent placebo, was administered via CRI for 60 minutes. Systolic, mean, and diastolic arterial pressure, heart rate (HR), CO and stroke volume were measured and stroke index (SI), cardiac index (CI), total peripheral resistance (TPR), and total peripheral resistance index (TPRI) were calculated at 3, 7, 10, 20, 30, 45, 60, 90, and 120 minutes from the start of the infusion.ResultsIncrease in dose decreased SI by 25%, 19%, and 30%, HR by 33%, 57%, and 60%, CI by 50%, 65%, 70% and increased TPRI by 109%, 235%, and 222% from baseline to the 60-minute measurement for the 1, 2, and 3 μg kg^?1 hour^?1 doses, respectively. HR, TPRI, and CI all showed significant differences over the duration of the study from the placebo treatment.ConclusionsMedetomidine CRI produces clinically relevant changes in CO, TPR, and HR. The demonstrated decrease in CO is largely because of bradycardia and the degree of cardiovascular depression appears to be dose-dependent. These findings are consistent with previously described hemodynamic changes with single bolus administration of medetomidine.Clinical relevanceLow-dose medetomidine CRIs produce clinically relevant hemodynamic depression at doses as low as 1 μg kg^?1 hour^?1 and should be used cautiously in dogs.     

Report on the 43rd Annual Meeting of the DPG-Working Group Nematology

Journal of Plant Diseases and Protection -     

Orthodromic Reciprocating Tachycardia and Heart Failure in a Dog With a Concealed Posteroseptal Accessory Pathway

A 4-month-old male Labrador Retriever was presented for recurrent bouts of pulmonary edema associated with tachycardia. Initial physical examination and echocardiography were unremarkable, and the electrocardiogram revealed only an intraventricular conduction disturbance. Subsequent recordings showed paroxysmal supraventricular tachycardia (SVT) (340 beats/min), which consistently produced pulmonary edema. The supraventricular tachycardia was unresponsive to adenosine, esmolol, and propranolol; was variably and transiently responsive to various vagal maneuvers and precordial thumps; and was always responsive to IV diltiazem. Multiple life-threatening episodes of SVT occurred, however, despite the chronic administration of oral diltiazem, propranolol, and procainamide. Diastolic cardiac dysfunction was documented by Doppler echocardiography and was thought to contribute to the development of pulmonary edema. A subsequent electrophysiologic study confirmed the presence of an atrioventricular posteroseptal accessory pathway that participated in orthodromic reciprocating tachycardia. This pathway was determined to conduct only in the retrograde direction ("concealed accessory pathway"). Intraoperative IV procainamide titration terminated the arrhythmia, which could not be reinduced when procainamide blood concentration approximated 20 μg/dL. Increasing the oral procainamide dose to achieve such plasma concentrations was successful in eliminating orthodromic reciprocating tachycardia, preventing heart failure, and returning Doppler indices of diastolic function to normal.     

Long-term catch trends and risk assessment of the Critically Endangered white-spotted wedgefish (Rhynchobatus djiddensis) from South Africa

1. The white-spotted wedgefish (Rhynchobatus djiddensis) is a Critically Endangered shark-like ray in the family Rhinidae. Throughout its Western Indian Ocean distribution, it is targeted for its valuable meat and fins and is reported to have undergone major population declines. However, there remains a need for species specific time-series data to accurately assess localized population declines.
2. This study used two independent long-term (37 and 40 years) time-series catch data from competitive shore angling and shark nets to investigate the size composition and catch per unit effort (CPUE) and conduct a risk assessment for the population on the east coast of South Africa.
3. From 1977 to 2017 the competitive shore fishery captured 7,703 individual R. djiddensis, whilst shark nets in the same region captured 2,856 individuals from 1981 to 2017. Individuals captured in the nets had a sex ratio of 1.8:1 females to males, and were larger than those caught by the anglers. Although the mean annual sizes of net-caught individuals were above the size of reported sexual maturity, there was little evidence to suggest that any individuals captured were reproductively active.
4. Both the competitive shore fishery and shark net catches exhibited strong seasonal trends with the majority of R. djiddensis catches occurring from October to May peaking in austral summer. Standardized CPUE from the competitive shore fishery declined substantially between 1977 and 2017 and shark net catches exhibited a significant (p < 0.05) fourfold decline in annual nominal CPUE from 1981 to 2017.
5. Ultimately, a risk assessment showed a 65.1% decline in abundance over a period of three generation lengths, which indicates that the sampled population of R. djiddensis in South Africa should be classified as Endangered according to the IUCN Red List using criterion A2b. The conservation implications of this are discussed.

     

Predicting behavioral changes associated with age-related cognitive impairment in dogs

OBJECTIVE: To monitor the progression of age-related behavioral changes in dogs during a period of 6 to 18 months and to determine whether signs of dysfunction in any of 4 behavioral categories can be used to predict further impairment. DESIGN: Age-stratified cohort study. ANIMALS: 63 spayed female and 47 castrated male dogs 11 to 14 years of age. PROCEDURE: Data were collected from randomly selected dog owners who were interviewed by telephone twice at a 12- to 18-month interval; data were included if the dog had lived > or = 6 months between interviews. The interview focused on signs of impairment in the following behavioral categories: orientation in the home and yard, social interactions with human family members, house training, and the sleep-wake cycle. Dogs were determined to have impairment in 0 behavioral categories (on the basis of < or = 1 sign for each category), impairment in 1 category (> or = 2 signs of dysfunction in that category), or impairment in > or = 2 categories. RESULTS: Between interviews, 22% (16/73) of dogs that did not have impairment in a category at the time of the first interview developed impairment in that category by the time of the second interview. Forty-eight percent (13/27) of dogs that had impairment in 1 category at the time of the first interview developed impairment in > or = 2 categories by the time of the second interview and were significantly more likely to develop impairment in > or = 2 categories, compared with dogs that initially had impairment in 0 categories. Dogs with 1 sign of dysfunction in orientation were significantly more likely to develop impairment in that category, compared with dogs that had 0 signs of dysfunction in orientation. CONCLUSIONS AND CLINICAL RELEVANCE: Age-related behavioral changes in dogs are progressive. Clinicians should consider trying to predict which dogs are most likely to become progressively impaired during the subsequent 6 to 18 months.     

专家试图解开PCV2和PMWS之迷

研究人员正伤透了脑筋,因为与猪圆环病毒(PCV2)有关的疾病(下称"PCV2有关疾病")一直困扰着全美国的商品肉猪生产者.     

Evaluation of urine marking by cats as a model for understanding veterinary diagnostic and treatment approaches and client attitudes

OBJECTIVE: To obtain information regarding diagnostic and treatment approaches of veterinarians and attitudes and beliefs of clients about a common clinical problem, urine marking in cats. DESIGN: Cohort study. STUDY POPULATION: 70 veterinarians providing care for urine-marking cats and 500 owners of urine-marking cats. PROCEDURE: Veterinarians were interviewed via telephone regarding criteria for diagnosis of urine marking and recommended treatments. Cat owners who responded to recruitment efforts for a clinical trial for urine-marking cats were interviewed via telephone regarding whether and from what sources they sought help to resolve the marking problem. RESULTS: Almost a third of veterinarians did not seem to correctly distinguish between urine marking (spraying) and inappropriate urination. Those that did make this diagnostic distinction reported recommending environmental management and prescribing medication significantly more often that those that did not make this distinction. Seventy-four percent of cat owners sought help from their veterinarians for urine marking; other common sources of information were the Internet and friends. Among those who did not consult a veterinarian, the most frequently cited reason was that they did not think their veterinarian could help. Among cat owners who consulted their veterinarians, 8% reported receiving advice on environmental hygiene and 4% on environmental management (limiting intercat interactions), although veterinarians who correctly diagnosed urine marking reported giving such advice 100 and 83% of the time, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results may serve as a model for obtaining information critical to developing veterinary continuing education and public outreach programs for animal owners for various diseases.     

Dealkylation and loss of capacity for reactivation of cholinesterase inhibited by sarin

Inhibition of rat brain acetylcholinesterase by (32)P-sarin in vivo results initially in (32)P-isopropylmethylphosphonylated enzyme. The percentage of inhibited enzyme that could not be reactivated by pyridinium aldoxime methochloride (aged enzyme) approximated the amount of radioactivity identified as (32)P-methylphosphonate. The (32)P-isopropyl methylphosphonate not released fromthe inhibited enzyme by the oxime accounted for 51 +/- 10 percent ( standard deviation) of the radioactivity fixed to brain tissue. It showed no correlation with aging and was probably bound to sites other than acetylcholinesterase.     

The liver lipid fatty acid profiles of seven Indian Ocean shark species

We have assessed the fatty acid profiles of the livers from seven shark species (Carcharias taurus (raggedtooth/grey nurse), Carcharhinus limbatus (blacktip), Carcharhinus obscurus (dusky), Carcharhinus leucas (Zambezi/bull), Sphyrna lewini (scalloped hammerhead), Carcharhinus brevipinna (spinner), and Galeocerdo cuvieri (tiger)) found off the east coast of South Africa. While there was generally little variation between the species, Carcharias taurus showed fatty acid profiles that would be most favourable in human nutrition, in that it showed both low saturated (SFA) (37.1%) and high polyunsaturated fatty acid (PUFA) (26.6%) levels. However, all species showed profiles rich in PUFA, thus utilising the liver oil from sharks caught as part of the bycatch when fishing for teleost species would avoid unnecessary wastage of a potentially valuable resource. This revised version was published online in July 2006 with corrections to the Cover Date.