Review of studies assessing plaque accumulation and gingival inflammation in dogs

Periodontal disease is difficult to measure objectively. Many indices measuring plaque accumulation and gingivitis have been designed for humans, the Silness and L?e plaque index and Turesky modification of the Quigley and Hein plaque index being examples of well-accepted systems. It may, however, be beneficial to consider new or modified measurement systems for dogs, and such veterinary modifications need to be supported and clearly identified. This article reviews the origins of clinical periodontal indices now in common use in studies that examine the effectiveness of oral hygiene products.     

Trial introduction of the Willis dropped ovary technique for spaying cattle in northern Australia

OBJECTIVE: To compare the Willis dropped ovary technique with traditional spaying methods in extensive beef cattle herds in northern Australia. PROCEDURE: Three field trials were conducted simultaneously at different sites in northern Australia in 1996-97. Brahman and Brahman-Shorthorn cross heifers (n = 219, 2 years, 250 to 378 kg) and cows (n = 211, 3 to 16 years, 256 to 540 kg) were allocated by stratified randomisation to three treatments: spaying using the Willis dropped ovary technique (WDOT); spaying using traditional paralumbar and vaginal methods; and unspayed. Following these procedures, these nonpregnant, nonlactating cattle were then exposed to bulls (4 per 100 females) under extensive rangeland conditions for 12 months during which time weight, body condition, pregnancy and ovarian function were monitored and compared. RESULTS: Pregnancy rates varied from 60 to 90% for entire heifers and 80 to 100% for entire cows depending on site. The traditional spay methods were 100% successful in preventing pregnancy; the WDOT was 92 to 97% effective, depending on operator experience. The number of deaths was the same or higher in Willis spayed animals than other groups. Weight changes were similar in all groups at the three sites over the trial period. The time taken to spay using the WDOT was similar to or less than that required for the traditional methods. Uterine abnormalities were not observed in animals spayed with the WDOT, there were however 30 (12.4%) animals where excision of the ovary was incomplete; the still-attached ovarian remnant presumably accounting for the three pregnant animals in this group. CONCLUSION: The WDOT suffers from requiring a high degree of skill in transrectal ovarian manipulation. There were more deaths and more pregnancies than with traditional spay methods. More experienced operators can be expected to achieve lower mortalities, better contraception and higher processing rates. Pregnancy will occur as a consequence of ovarian remnants unless care is taken to ensure removal of the entire ovary.     

Radioimmunoassay of Plasma Insulin in Dogs and Monkeys: Application of the Dextran-coated Charcoal Separation Method

The coated-charcoal separation method of Herbert (10) for radioimmunological determination of insulin in plasma of dogs and monkeys was evaluated by recovery, dilution, and reproducibility experiments. When optimal conditions were maintained, the method was well suited for plasma insulin-assay in these animals. In normal dogs and monkeys, fasting concentrations of plasma insulin ranged from less than 0.078 to 1.0 ng/ml. Intravenous infusion of xylitol, glucose or tolbutamide increased levels of plasma insulin three to 18 times over fasting levels in normal animals but not in two spontaneously diabetic dogs.     

Feasibility of computed tomography in awake dogs with traumatic pelvic fracture

In veterinary medicine, general anesthesia or sedation is generally required to immobilize patients during computed tomography (CT) scanning. This may not be suitable in all patients because of risks of anesthesia. We evaluated the feasibility of pelvic CT examination in 14 awake animals with pelvic trauma. Physical restraint was applied by wrapping the patient in a towel and then taping to the CT table or by directly taping the patient to the CT table. The effect of patient positioning, cooperation on the CT table, preparation time for scanning, scanning time, frequency of repeat scans, image quality, and complications related to physical restraint were evaluated. Fractures were recorded and compared between radiography and CT. Ten of 14 dogs were scanned in lateral recumbency and four in sternal recumbency. All patients were cooperative with the exception of one that moved slightly during the scan. Both physical restraint methods were adequate for CT scanning. Patient preparation took less than 5 min while the scan time was typically less than 1 min. No repeat scans were required in any patient. The transverse CT image quality was good (10/14) or fair (4/14) for interpretation. When comparing the CT images to radiographs, more pelvic fractures were identified with CT than with radiography and a few patients were overdiagnosed based on radiographs. No complications or additional injuries associated with physical restraint were noticed.     

UTILIZATION OF INSTANTANEOUS EJECTION VOLUME IMAGES TO PRODUCE VENTRICULAR VOLUME CURVES FROM AN EQUILIBRIUM RADIONUCLIDE VENTRICULOGRAM

Equilibrium radionuclide ventriculograms were performed in 6 normal dogs during resting and isoproterenol challenged states. A new method of analysis of the equilibrium radionuclide ventriculograms using a simple digital subtraction technique was compared to traditional methods of analysis and echocardiography. There was no significant difference between ejection fraction values from the three methods tested. The equilibrium radionuclide ventriculograms ejection fraction was significantly increased following isoproterenol administration using both the new and traditional methods of analysis but the pre versus post-isoproterenol increase ejection fraction derived from echocardiographic measurements of ejection fractions was not significantly different. The new digital subtraction method consistently produced reproducible, high quality ventricular volume curves for the left and right ventricle. Left and right ventricular maximum and average emptying and filing rates were determined from the slopes of the volume curve and the results were similar to those previously published for man and dog. The emptying and filling rates of both ventricles were significantly increased following isoproterenol administration. The time to peak emptying significantly decreased following isoproterenol. Time to peak filing decreased following isoproterenol but the difference was not significant.     

Rapid detection of Chlamydia psittaci in vaginal swabs of aborted ewes and goats by enzyme linked immunosorbent assay (ELISA)

An enzyme linked immunosorbent assay (ELISA) for the detection of Chlamydia psittaci in vaginal swabs of aborted ewes and goats has been developed using microtiter plates coated with sheep anti-Chlamydia immunoglobulin G. This technique was compared to the direct isolation of the agent by plaque assay on McCoy cells. Among 89 specimens from animals in infected flocks, 58 were positive by both methods, seven were only positive by ELISA, and nine others were only positive by direct isolation (plaque assay). None of the 75 specimens from animals in healthy flocks gave a positive response in ELISA or the plaque assay. Unlike direct isolation in cell culture, the ELISA technique permitted the detection of Chlamydia even in the absence of special care in sampling and conservation of specimens.     

Technical Note: Software for Calculation of the Inverse Numerator Relationship Matrix

Software was developed to compute the non-zero elements of the inverse of the numerator relationship matrix used in estimation of (co)variances and breeding values. The program was written to be flexible with regard to format of the input pedigree file and integration with existing software packages for genetic evaluation. The program was further designed to be highly portable, with a minimum of compiler dependence, and to use dynamic rather than static memory allocation. Real time required to read and sort input pedigrees containing 5,000 to 100,000 animals with varying levels of inbreeding and to compute the non-zero elements of the matrix was < 9.5 min and increased as the numbers of animals in the pedigree file increased beyond 20,000 animals. Increased numbers of inbred animals in large (≥20,000 animals) pedigrees increased the time required to complete computations. Although a combination of alphanumeric animal identification codes were allowed, the time required to initially read pedigrees and, therefore, total run time was significantly decreased (P < 0.001) for large pedigrees when identification codes were strictly numeric for all animals.     

Serum pepsinogen levels to monitor gastrointestinal nematode infections in cattle revisited

The serum pepsinogen level is widely accepted as a useful parameter for monitoring gastrointestinal nematode infections in first-season grazing calves. However, several aspects, with possible implications for its practicality and the way to use the pepsinogen test, have received little attention to date. The objectives of this study were to evaluate (1) the reproducibility of a pepsinogen assay; (2) the required sample size for a reliable diagnosis and (3) the compliance to and effect of advice based on pepsinogen levels determined in year one on the nematode infection levels in the next generation of calves. Despite a high repeatability of the pepsinogen assay within the reference lab, the reproducibility between different labs was poor. There was more variation in pepsinogen levels between herds than between animals within a herd, suggesting that it is most useful to make a herd level diagnosis. Sample size calculation indicated that sampling seven animals sufficed to obtain a reliable indication of calf groups of up to 40 animals. Eighty-two herds were followed-up over two consecutive years and 39 (48%) had followed the advice that was formulated based on pepsinogen levels. Thirty-nine percent of the herds were advised to reduce the intensity of chemoprophylaxis. Samples from animals of those herds showed a higher pepsinogen level in the second year, but none of them had a mean pepsinogen level that is considered excessive. It is concluded that pepsinogen determination at housing from a limited number of animals can contribute to the design of the anthelmintic control strategy in the next year and a more targeted use of anthelmintics. However, more efforts are needed to harmonize the assay between veterinary diagnostic labs.     

VALIDATION OF NEW BITE BLOCK‐TYPE HEAD‐IMMOBILIZATION DEVICES FOR RADIOTHERAPY IN DOGS

An ideal head‐immobilization method provides a high level of accuracy and reproducibility in the immobilization. Various head‐immobilization methods for radiotherapy have been published and are excellent in terms of accuracy; however, these methods are complicated to use, and labor intensive. The present study describes two new bite block‐type head‐immobilization devices designed for higher stability and lower vertical variation. The device designed in our previous study (the bite block‐type head‐immobilization device; Device A) was modified by making a groove on the top the horizontal plate (Device B) for a stable ventral‐dorsal position, or beneath the horizontal plate (Device C) for a stable dorsal‐ventral position. The three devices were objectively compared with respect to setup time, and accuracy of the computed tomography scan images by two authors independently. Five male healthy beagles were used in this study. For each device, the setup time and the variation in the coordinates were measured five times for each dog. The mean setup times for Devices A, B, and C were 3.3, 1.5, and 2.4 min, respectively, showing the groove modifications were able to reduce the setup time (in device B, by at least 50%). Moreover, three‐dimensional analysis of the computed tomography images revealed that the measurement variability of Device A (1.6 ± 1.0 mm) was significantly higher than that of Device C (0.7 ± 0.4 mm; P < 0.001). Collectively, our results show that use of a bite block‐type head‐immobilization device with a groove improves the setup time and head‐immobilization accuracy.     

非结核性分支杆菌的致病性及其鉴定方法

非结核性分支杆菌属于放线菌目,分支杆菌科,分支杆菌属,其分布广泛,可传染家畜及人类。近年来随着越来越多的非结核性分支杆菌疾病被发现并报道出来,已经引起人们的广泛关注和学者的研究兴趣。由于非结核性分支杆菌其临床表现与结核性分支杆菌极为相似,诊断起来有一定的困难。根据国内外近几年的报道,对非结核性分支杆菌从易感人群、感染部位及长期慢性生长等角度综述其致病性,举例说明其临床症状,再总结比较了传统分析鉴定法、噬菌体分析法、聚合酶链式反应技术和核酸探针等几种非结核性分支杆菌的鉴定方法,建议在临床表征相似时,不仅仅采用传统方法进行分离鉴定,应该采用多种分离方法相结合来进行细菌的分离鉴定,减少时间,节约成本,同时继续研发新的分类方法。     

Enrichment of low-abundance proteins from bovine and porcine serum samples for proteomic studies

One of the main applications of serum proteomics is the identification of new biomarkers for animal disease or animal production. However, potential obstacles to these studies are the poor performance of affinity serum depletion methods based on human antigens when using animal samples, and loss of minor serum components bound to albumin and other proteins. In the present study, we have analyzed the efficiency and reproducibility of the ProteoMiner® beads with bovine and porcine serum samples, and compared to a traditional immunoaffinity-based albumin and IgG depletion system specific for human samples. The ProteoMiner kit is based on the use of a combinatorial peptide binding library and intends to enrich low-abundance proteins.     

Enrichment of low-abundance proteins from bovine and porcine serum samples for proteomic studies

One of the main applications of serum proteomics is the identification of new biomarkers for animal disease or animal production. However, potential obstacles to these studies are the poor performance of affinity serum depletion methods based on human antigens when using animal samples, and loss of minor serum components bound to albumin and other proteins. In the present study, we have analyzed the efficiency and reproducibility of the ProteoMiner® beads with bovine and porcine serum samples, and compared to a traditional immunoaffinity-based albumin and IgG depletion system specific for human samples. The ProteoMiner kit is based on the use of a combinatorial peptide binding library and intends to enrich low-abundance proteins.     

Comparison of two automated multi-channel blood cell counting systems for analysis of blood of common domestic animals

An automated, multi-channel blood cell counting system (S-Plus) was compared to a reference counting system using blood samples from 187 animals of four species. The standard red cell bath aperture current of 150 volts (V) was used during analysis of 75% of the samples. At this setting, all samples with a Mean Corpuscular Volume (MCV) greater than 50 fl had accurate erythrocyte counts. As the MCV decreased below 50 fl, the severity of false low erythrocyte counts and false high MCV values increased. The remaining 25% of samples were analyzed with the red cell bath aperture current increased to 200 V. At this setting, only 5% or less of erythrocytes from animals with normal MCV values(>36 fl)were below the erythrocyte threshold. The red cell distribution width values provided by the S-Plus indicated that equine and bovine erythrocytes have greater anisocytosis than canine and feline erythrocytes. Leukocyte counts were significantly lower on the S-Plus (p<0.01). Canine and equine samples most frequently had platelet size distribution within the S-Plus platelet counting threshold window. Electronic whole blood platelet counting appeared unsatisfactory in cats due to large platelet size and erythrocyte-platelet size overlap. Small platelet size in cattle indicated that further modifications of the red cell bath aperture current would be required to count and size platelets in this species. Following electronic modifications, this state-of-the-art system appears adaptable to hematologic profiling in most species.     

Genotyping of Ureaplasma diversum isolates using pulsed-field electrophoresis

Ureaplasma diversum has been associated with reproductive disorders in cattle and in the present study genotypic variations among U. diversum isolates obtained from the vaginal mucus of healthy cattle and sick animals were analyzed by enzymatic digestion and pulsed-field gel electrophoresis (PFGE). The influence of time and broth volume was important in obtaining sufficient cell sediment and DNA for PFGE. The method presented a high discriminatory power and satisfactory reproducibility for the analysis of detected variations among U. diversum isolates and strains. Different band profiles and wide genotypic heterogeneity were detected but no association between DNA polymorphism and sick or healthy animals could be established.     

Annual meeting keynote address: Animal agriculture and emerging social ethics for animals

Businesses and professions must stay in accord with social ethics, or risk losing their autonomy. A major social ethical issue that has emerged in the past three decades is the treatment of animals in various areas of human use. This point can be illustrated with numerous examples across all areas of animal use. These examples reflect society's moral concern having outgrown the traditional ethic of animal cruelty that began in biblical times and is encoded in the laws of all civilized societies. There are five major reasons for this new social concern, most importantly, the replacement of husbandry-based agriculture with industrial agriculture. This loss of husbandry to industry has threatened the traditional fair contract between humans and animals, and resulted in significant amounts of animal suffering arising on four different fronts. Because such suffering is not occasioned by cruelty, a new ethic for animals was required to express social concerns. Since ethics proceed from preexisting ethics rather than ex nihilo, society has looked to its ethic for humans, appropriately modified, to find moral categories applicable to animals. This concept of legally encoded rights for animals has emerged as a plausible vehicle for reform. The meaning of this ethical movement for animal agriculture is examined. Animal agriculture should explore ways to replace the animal husbandry lost to industrialization.     

The effects of different methods of accounting for observations from euthanized animals in survival analysis

The issue of euthanasia is unique to veterinary clinical studies evaluating survival time. The decision to euthanize an animal is based on several factors including the health of the animal but also age and cost of treatment. The literature shows inconsistent methods used to account for observations from euthanized animals. Also, over 50% and up to 100% of animals in many studies have been euthanized.Our study illustrates the effects of different methods of accounting for observations from euthanized animals in survival analysis. Three data sets with different proportions of outcomes (alive, lost-to-follow-up, dead due to disease of interest, dead due to other disease, euthanized due to disease of interest, euthanized due to other disease) were used. Each data set was stratified according to treatment or a group characteristic (e.g. tumor type). Our methods for accounting for observations from euthanized animals were established from methods used in the literature and included right-censoring. Kaplan-Meier product-limit survival-function estimation was performed on each data set.Different methods resulted in inconsistent conclusions of significant differences between strata. At times, the ranking of the estimates of median survival time for strata was reversed. Right-censoring and use of Kaplan-Meier methods is inappropriate to evaluate observations from euthanized animals because censoring of such observations is informative. The current methods used by clinical investigators are inadequate to measure survival time reliably.     

The veterinarian and animal welfare

At no important point does the Animals Protection Statute mention the competence of Veterinarians, but the "competent Authority". Also, the Animal Epidemics Statute and the Federal Hunting Statute provide for the cooperation of the veterinarian, but not for his competence to make decisions. This situation is even being overlooked by the investigating authorities, when in the case of using animals for "sport" or other problematic events, questions of the animals psychology and ethology have to be dealt with. In the courts the remarks of non-specialist qualified persons can lead to wrong decisions as can either unsuitable or wrong evidence.     

Diagnosis of heartwater in the live animal: experiences with goats in Guadeloupe

A presumptive diagnosis of heartwater in the living animal can be based on clinical and epidemiologic observations. In Guadeloupe, heartwater can be confused with haemonchosis in goats or cerebral babesiosis in cattle. Confirmation of the clinical diagnosis by brain biopsy is useful in experimental infections but is hardly applicable in the field. Positive results were obtained from 92% of animals 16 to 18 days after experimental infection. In febrile animals the best results were obtained between the 3rd and 6th days of the thermal response. Diagnosis can also be supported by serological tests. These are useful for monitoring experimental infections and for checking recovered animals in the field. Nineteen goats out of 27 were negative on Day 1 of the febrile reaction but positive a week later. The remaining 8 goats were positive on Day 1 and had greatly increased antibody titres a week later. Confirmation of a diagnosis can also be achieved by subinoculating into susceptible animals either blood or suspensions of ticks collected from suspect animals and then homogenized. Ticks that have engorged on a suspect animal can be allowed to moult and then fed on a susceptible animal to test their infectivity. These methods are time consuming but useful for heartwater surveys.     

Managing America's wild horses and burros

Fifteen years after passage of the Wild Free-Roaming Horse and Burro Act, die Bureau of Land Management and the Forest Service had made significant progress in the management of this resource, but many aspects of the program remained controversial. Program emphasis centered on control of herd size as prescribed in locally developed resource management plansand disposition of excess animals that were captured and removed. Population trends from 1971 to 1986 indicated a steady increase in numbers through 1984 and a gradual decline since that time,but numbers were still about twice the estimated appropriate management level. Budget trends reflected an increased concern in the Congress about management levels and a rapidly escalating cost of maintaining unadopted excess animals. Proposed solutions to these problems included destruction of unadopted animals or their sale, the latter of which would require legislation. Research conducted on wild horses and burros through 1982 centered on range relationships, census techniques, and foaling rates. A new research effort called for in the 1985 appropriation focused on fertility control methods and strategies for population management. A wild horse and burroadvisory board was established in 1986 to advise the Secretaries of the Interior and Agriculture on matters pertaining to management, protection, and control of wild horses and burros on the Nation's public lands.     

Sensitive, semi-nested RT-PCR amplification of fusion gene sequences for the rapid detection and differentiation of Newcastle disease virus

A rapid, sensitive and specific semi-nested RT-PCR was developed to detect and differentiate virulent and avirulent strains of Newcastle disease virus (NDV). For a total of 67 NDV strains, the results obtained from the semi-nested RT-PCR were consistent with those from nucleotide sequence analysis, plaque forming assays, mean death time (MDT) measurements and intracerebral pathogenicity index (ICPI). Furthermore, 13 class I NDV strains can be characterized by the semi-nested RT-PCR approach, which was feasible by the conventional methods. The detection limit for the semi-nested RT-PCR was two plaque forming units (PFU) both for NDV strain F48E9 in allantoic fluid and for isolate APMV1/ch/ChinaND4031 in oral or cloacal swabs. In conclusion, this semi-nested RT-PCR method offers a new assay for the rapid detection and differentiation of NDVs.