Stereoscopic Depth Sensitivity Differences between the Crossed and Uncrossed Directions

This study investigated the temporal sensitivity of crossed and uncrossed stereoscopic mechanisms of 48 observers using stimuli created from dynamic random-dot stereograms. The results showed thresholds were lower and depth was more veridical in the crossed than in the uncrossed direction.

Tolerability and pharmacokinetic profile of a novel benzene-poly-carboxylic acids complex with cis-diammineplatinum (II) dichloride in dogs with malignant mammary tumours

The pharmacokinetic profile, tolerability and efficacy of benzene-poly-carboxylic acids complex with cis-diammineplatinum (II) dichloride (BP-C1) were studied in dogs with mammary cancer. A three-level response surface pathway designed trial was performed on seven dogs. At each level BP-C1 was administered subcutaneously daily for 7 days followed by a 7-day rest period in a dose escalating manner. Adverse events according to VCOG-CTCAE, performance status and tumour progression were recorded. The pharmacokinetic profile followed a two-compartment model with rapid absorption, short distribution, and a slow elimination phase. The overall elimination half-life was 125 h. The maximum tolerated dose of BP-C1 was estimated to be above 0.46 mg kg^-1 . A significant reduction in VCOG-CTCAE toxicity which correlated negatively with increasing dose was found. The dogs' general performance status remained unchanged. No decrease in total tumour burden was found, although temporary tumour reduction was seen in some target tumours.

Inflammatory response to therapeutic gold bead implantation in canine hip joint osteoarthritis

Inflammatory changes associated with periarticular pure gold bead implants were studied in dogs involved in a clinical trial investigating motor dysfunction and chronic pain owing to hip joint dysplasia and osteoarthritis. Gold beads were percutaneously implanted via a needle into different locations surrounding the greater trochanter of the femur. Nine dogs with implants were necropsied. In all examined animals, characteristic histologic lesions were observed in the tissue surrounding the gold implants--namely, a fibrous capsule composed of concentric fibroblasts intermixed with a variable number of inflammatory cells and a paucicellular innermost layer of collagen with a few fibrocyte-like cells in empty lacunae. Lymphocytes dominated the inflammatory infiltrate, with rarely observed macrophages present in close proximity to the implant site. No giant cells were observed. Immunohistochemistry showed mixed populations of lymphocytes, both CD3 positive (T cells) and CD79a positive (B cells), which in some cases formed lymphoid follicles. Diffuse inflammatory changes were present to a minor extent in the perimysium and surrounding fascia. The inflammation observed in dogs is similar to that observed with gold implants in humans. It is possible that the clinically beneficial effect of gold beads for chronic osteoarthritis depends on sustained localized inflammation with localized release of soluble mediators. The encapsulation of the implant by a paucicellular and poorly vascularized fibrous capsule may help prevent an exaggerated inflammatory reaction by sequestering the gold bead from the surrounding tissue.

Breed differences in the proportional morbidity of testicular tumours and distribution of histopathologic types in a population-based canine cancer registry

Histologically verified tumours submitted to the Norwegian Canine Cancer Register from 1990 to 1998 were studied (n=14,401). The proportion of testicular tumours (n=345) was 2.4%, and the breakdown of histological tumour diagnoses is presented. The frequency of the most common histopathological types was 33% interstitial (Leydig), 26.4% Sertoli and 33.9% seminomas/germ cell tumours. The average age at diagnosis was 10 years, but was significantly lower for Sertoli cell tumours (8.6 years) than for the other tumour types. Following a histopathological re-evaluation, 22.5% of the original tumor diagnoses were modified. Proportional morbidity ratios were calculated and individuals from the breeds Shetland sheepdog and Collie were five times more likely to have testicular tumours than the overall average for the registry. Breed differences in the distribution of histopathologic types were observed. Shetland sheepdog and Collie were most commonly diagnosed with Sertoli cell tumours, while all tumours from Norwegian elkhound in this material were seminomas.

Risk factors affecting metaphyseal irregularities in the radius and ulna of growing Newfoundland dogs

The main objective of this study was to study risk factors affecting metaphyseal irregularities (MI) in the distal radius and ulna of growing Newfoundland dogs. Risk factors studied included the genetic effects, effects of litters, BW, circumferences of the distal radius and ulna (CDRU), and total serum alkaline phosphatase (ALP) concentrations. The study included 118 Newfoundland dogs (60 females, 58 males), derived from 32 litters. Body weight, separated on sex and MI, was fitted to the Gompertz function. Occurrence of MI differed significantly between sexes, with 55% of males and 35% of females affected (P = 0.03). Growth curves for the 2 groups of dogs, with and without MI, diverged after 60 to 70 d, and dogs with irregularities were heavier at maturity than dogs of the same sex without irregularities. In univariate analysis, the litter effect was a significant predictor of MI, explaining 32% of total variability of the MI incidence, but the genetic effects were not significant. However, the latter were significant in bivariate analysis of MI and BW. In the bivariate analysis, the effects of litter on MI and BW were significantly correlated at all observational points except at birth, 180 d, and 536 d. Total ALP concentrations decreased with increasing age, and differences between groups diminished with increasing age, indicating a negative effect of total ALP on MI. Correlation between MI and total ALP concentrations of litters was estimated in a bivariate analysis. This correlation was significant and ranged between -0.34 and -0.62. Similarly, the genetic relationship between total ALP and MI from 120 d of age onward varied between -0.31 to -0.60. However, correlations were only significant at 356 d of age (genetic correlation = 0.60; P = 0.01). The mean CDRU increased from 90 d of age toward a peak at 180 d. Thereafter, CDRU declined and stabilized at about 1 yr of age. The mean CDRU between the groups of dogs with and without MI diverged most at 90 d of age, then was nearly stable until 180 d and gradually declined until 356 d, when the CDRU began to equalize. Metaphyseal irregularities and CDRU levels of litter were significantly correlated. Litter effect was a significant predictor of MI. The effects of litters and the genetic effects on BW and MI were correlated at most phases of the growth of the dog. Similar, but lower, correlations were found for CDRU and MI, and total ALP and MI.

A longitudinal study on growth and growth variables in dogs of four large breeds raised in domestic environments

The main objective of this study was to describe the growth patterns of 4 large dog breeds [Newfoundland (NF), Labrador retriever (LR), Leonberger (LEO), and Irish wolfhound (IW)] raised in domestic environments and concomitant changes in 2 growth-related clinical variables: total serum alkaline phosphatase (ALP) and the circumference of the distal radius and ulna (CDRU). The second objective was to investigate whether these measurements were affected by a range of independent variables like age, sex, litter number, and birth weight. Seven hundred dogs were included in the study, and BW data, separated by breed and sex, were fitted to the Gompertz function. Birth weight, adjusted for litter number, differed significantly between sexes for 3 breeds (LEO, P = 0.004; NF, P = 0.02; LR, P = 0.009) and approached significance for IW (P = 0.07). Estimated mean BW increased rapidly during the first 100 d after birth in all 4 breeds, then plateaued, with maturity being reached between 351 (female LR) and 413 d (male NF). Estimated mature BW ranged from 30.8 kg for the female LR up to 65.7 kg for the male IW. Weight gain, as expressed by the derivative of the Gompertz function, reached its peak in the smallest breed (LR) at the youngest age, 89 d for the females and 95 d for males. Log-transformed BW was significantly related to age, breed, and sex, and the age x sex and age x breed interactions. Within breeds, age, birth weight, and litter number had a significant effect on log-transformed BW. The estimated average CDRU increased from 90 d of age toward a peak at 180 d. Thereafter, CDRU declined and stabilized at about 1 yr of age. The estimated total ALP concentrations decreased from 90 to 360 d of age, after which they stabilized, at mean concentrations varying among breeds from 98 to 131 IU/L. Maximum least squares mean total ALP concentrations were found at 3 mo of age in all breeds, with the greatest least squares mean concentration in the IW breed (713 IU/L). In a mixed model analysis of the complete data set, total ALP was affected (P < 0.001) by age, breed, and the interaction of age x breed. This study described the main factors influencing growth and provided reference data for other studies, including those related to nutrition and disorders of growth.

Double-blind, placebo-controlled trial of the pain-relieving effects of the implantation of gold beads into dogs with hip dysplasia

Seventy-eight dogs with pain due to hip dysplasia were studied in a controlled, double-blind clinical trial to evaluate gold bead implantation as a pain-relieving treatment. The dogs were randomly assigned to two groups, 36 in the gold implantation group and 42 in the placebo group. Both groups were treated equally regarding anaesthesia, hair clipping and penetration of the skin with the same type of needle. The gold implantation group had small pieces of 24 carat gold inserted through needles at five different acupuncture points and the placebo group had the skin penetrated at five non-acupuncture points so as to avoid any possible effect of stimulating the acupuncture points. A certified veterinary acupuncturist marked the points, and two surgeons performed the implantations according to a randomisation code made in advance. After 14 days, three months and six months, the owners assessed the overall effect of the treatments by answering a questionnaire, and the same veterinarian examined each dog and evaluated its degree of lameness by examining videotaped footage of it walking and trotting. The treatment was blinded for both the owners and the veterinarian. There were significantly greater improvements in mobility and greater reductions in the signs of pain in the dogs treated with gold implantation than in the placebo group. The veterinarian's and the owners' assessments corresponded well.

Stratification, blinding and placebo effect in a randomized, double blind placebo-controlled clinical trial of gold bead implantation in dogs with hip dysplasia

The purpose of this study was to investigate the need for and choice of stratification factors, and the effects of blinding and placebo in a clinical experiment. Eighty dogs with canine hip dysplasia (CHD) were included in a randomized, placebo-controlled and double blind clinical trial with stratified parallel group design, in which body weight and degree of CHD were used as stratification factors. Thirty-eight dogs were allocated to gold bead implantation and 42 to placebo. After six months, 33 of the 42 placebo-treated dogs received gold bead implantation in an open study lasting a further 18 months. The main outcome variable in the study was change in pain signs of CHD as assessed by the owner. No significant difference in the main outcome variable, regardless of the treatment given, could be detected in the two chosen stratification factors. The only factor to influence the main outcome variable significantly was age. The blinding procedure used in the study, in which 60% of the owners correctly guessed the treatment given, was found sufficient. Of those who guessed the treatment erroneously, 88% believed the treatment given was gold bead implantation. The treatment efficacy after six months in the blinded treatment group was found to be significantly larger compared to the efficacy obtained in the open study. A significant placebo effect was therefore detected.

CONCLUSION AND CLINICAL RELEVANCE

The age of the dogs influenced the outcome of the CHD treatment, and is recommended as a stratification factor. A significant placebo effect has to be expected and an optimal blinding procedure is necessary in similar clinical studies.

Population-based incidence of mammary tumours in some dog breeds

Data from two population-based studies in four Norwegian counties were used to calculate the crude incidence of mammary tumours, and the age- and breed-specific incidence of mammary tumours in female dogs of three different breeds. The largest study comprised 14401 histologically verified tumour cases from four counties covered by the Norwegian Canine Cancer Register. The registry covers about 25% of the total Norwegian dog population. The second study was a census in Norway that was sent to all owners of the following breeds: boxers, bichon frisé and Bernese mountain dogs, to estimate the age distribution of the female dog population at risk of developing mammary tumours. The crude incidence of malignant mammary tumours in female dogs of any breed was 53.3%. The highest relative risk ratio of mammary tumours was found in boxers, cocker spaniels, English springer spaniels and dachshunds. The mean age of histologically diagnosed mammary tumours was 7.9 years in boxers and 7.8 years in springer spaniels, compared with 8.8 years in all other breeds. In the four Norwegian counties from 1992 to 1997, the population-based incidence rates (for all ages) of malignant mammary tumours per 1000 female dogs per year were 35.47 in boxers, 3.87 in Bernese mountain dogs and 17.69 in bichon frisé. Mammary cancer is the most common tumour in female dogs in Norway, and represents a population of almost entirely reproductively intact females. The age-specific incidence rates for mammary cancer vary considerably among the three breeds that were studied in detail.

Calculation of urinary enzyme excretion, with renal structure and function in dogs with pyometra

The urinary enzyme markers of renal damage, alkaline phosphatase (AP), gamma-glutamyl transferase (GGT) and N-acetyl-beta-glucosaminidase (NAG), glomerular filtration rate (GFR) and renal biopsies were studied to evaluate renal status in dogs with pyometra. After ovariohysterectomy, urinary enzymes were measured daily for 12 days in 55 dogs, and again at a later follow-up visit. Thirteen dogs had high levels of at least one enzyme at initial presentation. Seventeen dogs had a transient increase in urinary enzyme values between one and five days after surgery. Enzyme values usually declined to low activities within 12 post-operative days. Renal biopsies demonstrated tubular abnormalities in many dogs. Mean GFR was 2.4 and 2.0 ml min(-1) kg(-1), respectively on day 1 post-operatively and at the follow-up visit 1-4 months later. High urinary enzyme values often reflected extensive lesions in renal proximal tubular cells and sometimes reduced GFR.

Adult-onset alcohol consumption induces osteopenia in female rats

BACKGROUND

Alcohol is a known risk factor for osteopenia and fracture in humans, and its effects on the skeleton have been studied extensively in animal models. Almost all studies of rats, however, have begun rats on alcohol diets while the animals were young and still growing. The purpose of the current study was to examine the effects of alcohol consumption on rats that began drinking alcohol as adults, so that the confounding effects of growth might be minimized.

METHODS

Nine-month-old female Sprague-Dawley rats were studied for two durations (8 and 14 weeks). The following diet groups were used for both durations: alcohol (n = 7), in which rats were fed a liquid diet containing ethanol (8.1% v/v; Lieber-DeCarli method); pair-fed (n = 7), in which rats were fed a caloric-equivalent liquid diet matched to the alcohol-fed animals; and pellet (n = 6), in which rats consumed standard rat chow and water. A cessation protocol was also used in which alcohol- and pair-fed groups were fed liquid diets for 8 weeks and then given pellet chow and water for 6 weeks, with pair feeding maintained during the cessation period.

RESULTS

Only minor effects developed in the rats in the 8-week group, but after 14 weeks, the cancellous bone of the proximal tibia was severely osteopenic in the alcohol-fed animals. The bone volume and trabecular number were both significantly lower in the alcohol-fed animals than in the pair-fed and pellet-fed control animals and also lower than in the alcohol-fed animals in the 8-week group. Mechanical properties of the cancellous bone in the distal femur also were significantly diminished in the 14-week alcohol-fed group. Composition and mechanical properties of the cortical bone in the femur diaphysis were largely unaffected, but the yield stress was significantly lower in the 14-week alcohol-fed group than in the 8-week alcohol-fed group. No significant effects were found in the cessation groups with regard to almost all parameters measured.

CONCLUSIONS

Our study results demonstrate that chronic adult-onset alcohol consumption leads to significantly diminished cancellous bone properties and that these effects depend on the duration of alcohol use.

Renal microcystic tubular lesions in two 1Year-old dogs - an early sign of hereditary renal cystadenocarcinoma?

As a part of a study of early renal changes in renal cystadenocarcinoma (RC), a 5-year-old German shepherd dog and two 1-year-old German shepherd mixed-breed dogs were examined. All three animals had bilateral, microscopic renal cysts, and the 5-year-old dog also had RC. Microscopical examination showed papillary hyperplastic tubular epithelial cells lining the inner wall of the renal cysts in all dogs. These cells showed strong reactivity with a monoclonal antibody against a broad-spectrum type of cytokeratin. The dam of the young dogs had suffered from autosomal dominant inherited RC and nodular dermatofibrosis (ND) syndrome. It is likely that the microscopic renal cystic lesions seen in the young dogs represented an early renal change in the RC/ND syndrome. This suggests that the diagnosis of RC can be made on suspected carriers by microscopical examination of renal biopsies as early as 1 year of age, i.e., before the dogs are used for breeding.

Genetic mapping of a naturally occurring hereditary renal cancer syndrome in dogs

Canine hereditary multifocal renal cystadenocarcinoma and nodular dermatofibrosis (RCND) is a rare, naturally occurring inherited cancer syndrome observed in dogs. Genetic linkage analysis of an RCND-informative pedigree has identified a linkage group flanking RCND (CHP14-C05.377-C05.414-FH2383-C05. 771-[RCND-CPH18]-C02608-GLUT4-TP53-ZuBe Ca6-AHT141-FH2140-FH2594) thus localizing the disease to a small region of canine chromosome 5. The closest marker, C02608, is linked to RCND with a recombination fraction (theta) of 0.016, supported by a logarithm of odds score of 16.7. C02608 and the adjacent linked markers map to a region of the canine genome corresponding to portions of human chromosomes 1p and 17p. A combination of linkage analysis and direct sequencing eliminate several likely candidate genes, including tuberous sclerosis 1 and 2 genes (TSC1 and TSC2) and the tumor suppressor gene TP53. These data suggest that RCND may be caused by a previously unidentified tumor suppressor gene and highlight the potential for canine genetics in the study of human disease predisposition.

Chromosomal assignment of canine TSC2, PKD1 and CLN3 genes by radiation hybrid- and linkage analyses

The canine tuberous sclerosis 2 (TSC2) gene has been mapped to canine chromosome 6 using a canine whole genome radiation hybrid panel. There is close linkage between canine TSC2 and the polycystic kidney disease 1 gene (PKD1), as has been observed in humans and other mammalian species. The gene responsible for the human juvenile form of neuronal ceroid lipofuscinosis (CLN3), maps close to TSC2 and PKD1 in humans, and is also syntenic in the dog. We further demonstrate linkage to a group of polymorphic markers assigned to canine chromosome 6 (CFA6).

The relationship between some plasma clearance methods for estimation of glomerular filtration rate in dogs with pyometra

The purpose of the present study was to compare different pharmacokinetic models for estimation of glomerular filtration rate (GFR) in 50 dogs with pyometra. GFR was estimated by plasma clearance (CLplasma) of iohexol by four 1-compartment methods (CL1c), a 2-compartment method (CL2c), and the trapezoidal method (CLtr). Regression analysis was performed to establish correction formulas for prediction of CLtr from the CL1c values and to find optimal times of sampling. Standardization of clearance values to body weight (kg), body surface area (m2) and extracellular fluid volume (ECFV) was compared by ranking of values. CLtr and CL2c values were similar, whereas CL1c overestimated CLtr. CLtr could be predicted from 2 samples at 2 and 3 hours after injection, using the formula CLtr = 4.52 + 0.84CL1c - 0.00080(CL1c)2 (R2 = .97). Similar relationships were found when sampling at 2 and 4 hours or at 2, 3 and 4 hours after injection, whereas predictions from the 3- and 4-hour estimates were not optimal (R2 = .79). The 2-sample methods for calculating GFR/ECFV generally produced unreliable predictions of the complete curve GFR/ECFV values. For some dogs, the choice of standardization procedure substantially changed the apparent level of renal function relative to other dogs in the study. We conclude that by applying an appropriate correction formula, GFR may be estimated using 2 blood samples at 2 and 3, or 2 and 4 hours after injection of iohexol when renal function is normal or moderately reduced. The method of standardizing the analysis with respect to body size may influence interpretation of the results substantially.

Internal radionuclide therapy of primary osteosarcoma in dogs, using 153Sm-ethylene-diamino-tetramethylene-phosphonate (EDTMP)

Fifteen dogs were referred because of a spontaneous bone tumor, lameness, and local pain. The osteosarcoma diagnosis was established by clinical examination, X-ray, bone scintigraphy, and histological examination of biopsy material. The tumors were located in the extremities (n = 12), scapula (n = 1), maxilla (n = 1), and the frontal bone (n = 1). The dogs were given one to four i.v. injections of 153Sm-labeled ethylene-diamino-tetramethylene-phosphonate (153Sm-EDTMP; 36-57 MBq/kg body weight). Three dogs had surgery in addition to the radionuclide treatment. Platelet and WBC counts showed a moderate and transient decrease. No other toxicity was observed. Average tumor doses after a single injection were approximately 20 Gy, considerably higher in some areas because of inhomogeneous uptake. Macroscopically distant metastases were detected in seven dogs at autopsy. One dog died from an intercurrent disease, free of cancer, 5 months after the radionuclide treatment. None of the dogs was cured. The median and mean survival times from the first treatment to death or euthanasia were 150 and 252 days, respectively. Nine of the dogs had obvious pain relief, and five of them seemed pain-free: one for 20 months and one for 48 months. It is concluded that high tumor doses may be deposited in dog osteosarcomas by 153Sm-EDTMP, and the ratio between tumor dose and the dose to surrounding tissues is favorable. The treatment gives pain relief and in some cases tumor growth delay. In combination with surgery, 153Sm-EDTMP may prolong life significantly and possibly cure the disease because the development of metastases are seemingly postponed. No serious side effects were observed.

Pharmacokinetic aspects of measurement of glomerular filtration rate in the dog: a review

Glomerular filtration rate (GFR) is estimated by means of clearance, defined as the volume of plasma that has been cleared of a particular substance per unit time. Glomerular filtration rate may be estimated by measuring the renal clearance of a filtration marker using data from both urine and plasma or by plasma clearance using only plasma data. Several alternative pharmacokinetic models are used for the calculation of clearance using various filtration markers with slightly different pharmacokinetic properties. The purpose of this article is to discuss how the choice of marker and pharmacokinetic model may influence estimated GFR values and to elucidate commonly used methods and reported GFR values in the dog.

Genetic markers linked to neuronal ceroid lipofuscinosis in English setter dogs

The neuronal ceroid lipofuscinoses (NCL) are a group of fatal autosomal recessive neurodegenerative diseases occurring in human and some domesticated animal species. A canine form of the disease (CNCL) has been extensively studied in a Norwegian colony of inbred English setters since 1960. A resource family developed for genetic mapping and comprising 170 individuals was typed for 103 genetic markers. Linkage analysis showed three genetic markers to be linked to the disease locus with the closest marker at a distance of about 3 CM. Two other loci were linked with these markers making a linkage group of five genetic markers. The linkage group spanned a distance of 54 CM. Two genes for human forms of the disease, CLN2 and CLN3, have been identified and mapped to human chromosome 11p15 and 16p12, respectively. The present study did not indicate any linkage between CNCL and the canine CLN3 homologue or to homologues of markers for genes that map close to human CLN2.

Hereditary multifocal renal cystadenocarcinomas and nodular dermatofibrosis in 51 German shepherd dogs

The clinical findings in German shepherd dogs with hereditary multifocal renal cystadenocarcinomas and nodular dermatofibrosis are presented. Between 1978 and 1996, 51 cases were examined. Eight cases were detected after being offered a clinical examination because the disease was present in a parent. The remaining 43 dogs were diagnosed after an unsolicited visit to a clinic because of a specific problem. Skin lesions were the main reason (37 per cent) the owners presented their dog for examination. The mean age at diagnosis of renal cystadenocarcinomas and nodular dermatofibrosis was 8.2 years. The male-to-female ratio was 1.1, while the corresponding figure for a reference population was 1.25. Enlarged and abnormally shaped kidneys were palpated in 60 per cent of the dogs and were detected by radiography in 86 per cent of cases. The renal lesions, including metastases, were the main reason for euthanasia and death. The mean age at death was 9.3 years, and the mean age at the first detection of nodular dermatofibrosis was 6.4 years.

Computed tomography of hereditary multifocal renal cystadenocarcinomas in German shepherd dogs

The purpose of the study was to characterize the renal lesions of hereditary renal cystadenocarcinomas in the German shepherd dog using computed tomography (CT). Fourteen dogs with renal cystadenocarcinomas and nodular dermatofibrosis, and two unaffected dogs were studied. There were nine dogs with spontaneous disease and seven dogs from a test mating. The characteristic renal CT findings of renal cystadenocarcinomas were bilateral multiple cysts and tumor masses of various sizes. The earliest changes were detected between 4 and 5 years of age and the smallest cysts measured 2-3 mm in diameter. Abdominal CT examination gives a wide field view and excellent anatomic images of the kidneys. It is easy to differentiate between cysts and solid tumors. CT examination is useful for the early detection of renal cystadenocarcinomas and for screening suspected carrier dogs before breeding.

A population-based case-control study of canine mammary tumours and clinical use of medroxyprogesterone acetate

We investigated whether or not an association could be found between mammary tumours and prior clinical use of medroxyprogesterone acetate (MPA) in bitches. A population-based retrospective age-matched case-control study was designed based on interviews with the owners of the bitches. The proportion of bitches with diagnosed mammary tumours (group MT+, n = 98) that had received progestin injections was compared with the proportion in a control group without mammary tumours (group MT-, n = 98). In the case group 39%, and in the control group 21% of the bitches had been treated with MPA. A significantly higher number of bitches with mammary tumours had been exposed to progestins, compared with the control group without mammary tumours (odds ratio = 2.32, Chi-square = 7.01, p = 0.008). Bitches treated clinically with low doses of MPA to avoid oestrus were at a greater risk of developing mammary tumours, the majority of which were histologically malignant (91%).

Comparison of two surgical treatments of gastric dilatation-volvulus in dogs

The purpose of this randomized clinical study was to compare the effect of 2 surgical methods in the treatment of gastric dilatation-volvulus (GDV) in dogs. One group of dogs (group A) was treated with and one group (group B) without fixation of the stomach. Group A consisted of 21 cases (including 2 dropouts) and group B of 10 cases. The dogs in group A received decompression, anatomical repositioning of the stomach and a circumcostal gastropexy and the dogs in group B (the control group) received the same treatment without gastropexy. Supportive treatment was the same for both groups. The randomization of the dogs in groups A and B was successful with only small differences between the 2 groups in the breed, age, sex and initial decompression methods. At the end of the study (censoring time), the median survival times were significantly different between group A and group B, respectively 549 and 107 days. There were no recurrences in group A while in group B 3 dogs (50%) experienced a recurrence within 6 months. The overall death rates within the first year were 32% in group A and 80% in group B. The death rates caused by GDV and GDV related causes only, after one year of follow-up, were 19% and 71% for groups A and B, respectively. This study shows that treatment that included circumcostal gastropexy significantly reduced the recurrence of GDV and prolonged the postoperative survival time compared with treatment that did not include fixation of the stomach.

Estimation of glomerular filtration rate in normal sheep by the disappearance of iohexol from serum

The aim of the study was to establish reference values for glomerular filtration rate (GFR) in healthy sheep from the clearance of iohexol in serum. Fifteen healthy sheep were tested twice with 14 to 21 days between tests. No side-effects were observed after iohexol injections and all the sheep were clinically normal during and after the study. The mean clearance of iohexol estimated by the two-compartment method was 1.8 ml/min per kg (95% CI = 1.6-2.0) in the first trial and 1.7 ml/min per kg (1.5-1.9) in the second trial. The mean GFRiohexol estimated by a one-compartment method was 1.9 ml/min per kg (1.7-2.2) in the first trial and 1.8 ml/min per kg (1.6-2.0) in the second. The GFR values were similar to those reported for the inulin method. The results indicate that the iohexol method is valid for estimating GFR in sheep, and it is easier to perform than the inulin method.

Maxillectomy and targeted radionuclide therapy with 153Sm-EDTMP in a recurrent canine osteosarcoma

An eight-year-old dog with a local relapse of an osteosarcoma was treated with partial maxillectomy and systemic radionuclide therapy that involved two injections, 43 and 45 megabecquerels per kg bodyweight of the bone-seeking agent samarium-153-ethylenediaminetetramethylene phosphonic acid (153Sm-EDTMP), 15 weeks apart. A transient drop in white blood cell count and platelet count was observed following each 153Sm-EDTMP treatment. Follow-up 21 months after surgery revealed no evidence of local recurrence or metastases. The dog was in excellent condition, suffering only minor sequelae from the surgical procedure. Compared with historical controls treated with surgery alone, the combination of surgery and systemic radionuclide therapy seems a promising strategy for the treatment of canine osteosarcoma.

Comparison of two surgical treatments of gastric dilatation-volvulus in dogs

The purpose of this randomized clinical study was to compare the effect of 2 surgical methods in the treatment of gastric dilatation-volvulus (GDV) in dogs. One group of dogs (group A) was treated with and one group (group B) without fixation of the stomach. Group A consisted of 21 cases (including 2 dropouts) and group B of 10 cases. The dogs in group A received decompression, anatomical repositioning of the stomach and a circumcostal gastropexy and the dogs in group B (the control group) received the same treatment without gastropexy. Supportive treatment was the same for both groups. The randomization of the dogs in groups A and B was successful with only small differences between the 2 groups in the breed, age, sex and initial decompression methods. At the end of the study (censoring time), the median survival times were significantly different between group A and group B, respectively 549 and 107 days. There were no recurrences in group A while in group B 3 dogs (50%) experienced a recurrence within 6 months. The overall death rates within the first year were 32% in group A and 80% in group B. The death rates caused by GDV and GDV related causes only, after one year of follow-up, were 19% and 71% for groups A and B, respectively. This study shows that treatment that included circumcostal gastropexy significantly reduced the recurrence of GDV and prolonged the postoperative survival time compared with treatment that did not include fixation of the stomach.

A retrospective study of conservative treatment of gastric dilatation-volvulus in the dog

A retrospective study of 103 dogs with gastric dilatation-volvulus (GDV) treated conservatively during the period 1985-1989 was performed. The date and number of recurrences, and the date and cause of death along with breed, age and sex were collected from clinic records and from a questionnaire sent to the owners (77% response). The treatment consisted of emptying the stomach with a stomach tube, gastrocentesis if necessary and treating shock. All of the affected dogs were from moderate to large sized breeds and the study showed that particular breeds appear to be predisposed to GDV. The average age was 7.2 years and there was no gender predisposition. Sixty-six per cent of the dogs survived the initial treatment and 50% of the dogs were still alive 1 month after treatment. Thirty-nine dogs (71%) received recurrence between 5-760 days after initial treatment. Fifty-six per cent had recurrence within 3 months and all except 2 dogs, within 1 year. Data for the time of death, regardless of cause, was available for 68 dogs. Of these 59 (81%) died within a year after initial treatment. Conservative treatment was found to be an adequate life-saving procedure in the acute stage of GDV, but could not alone prevent recurrence of the disease.

Temporal integration differences between crossed and uncrossed stereoscopic mechanisms

In this study, we investigated temporal integration of disparity information for crossed and uncrossed stereopsis. Across three experiments, exposure duration thresholds were measured for stereoscopic stimuli created from dynamic random-dot stereograms. In Experiment 1, an investigation of disparity detection showed that detection thresholds were equal for the crossed and uncrossed directions. In Experiment 2, an examination of duration limits for depth perception showed that critical durations were lower, and depth more veridical, for crossed depth than for uncrossed depth. In Experiment 3, an investigation of depth discrimination revealed that discrimination thresholds were lower for crossed depth than for uncrossed depth. These results suggest that crossed and uncrossed mechanisms differ in terms of their temporal integration properties at processing levels involving the computation and discrimination of depth.

Estimation of glomerular filtration rate in dogs with 99M-Tc-DTPA and iohexol

The glomerular filtration rates (GFR) of 18 dogs of different breeds were estimated by simultaneously comparing the plasma decay curves of 99M-Tc-diethylenetriaminepentaacetic acid (Tc-DTPA) and the contrast medium iohexol. Nine of the dogs were clinically healthy, and nine had renal disease. After the intravenous injection of the two substances, nine to 12 blood samples were taken during the first six hours and in some cases up to 24 hours. The total clearance of the substances was determined by one- and two-compartment models. Individual GFRiohexol values, estimated by using a two-compartment model in 16 of the dogs, ranged from 39.0 ml min-1 m-2 to 84.3 ml min-1 m-2 and for GFRTc-DTPA from 41.1 ml min-1 m-2 to 106.6 ml min-1 m-2. The GFRiohexol values estimated by using a one-compartment model in the 18 dogs ranged from 4.52 ml min-1 m-2 to 105 ml min-1 m-2 and for GFRTc-DTPA from 5.4 ml min-1 m-2 to 118.9 ml min-1 m-2. The agreement between the two methods was good, as shown by a limits of agreement plot. The ratio of GFRTc-DTPA/GFRiohexol was 1.15 throughout the range of measurement (SD = 0.085). The study indicates that the iohexol method is a valid measure of GFR in the dog. The practical aspects make it a useful tool in small animal practice.

[Registration of canine cancer]

A Norwegian Canine Cancer Registry, covering four of 19 counties, has been operative since March 1990. Until the end of April 1994 about 6,000 tumours have been registered, more than 50% of these being manifestly or potentially malignant. Among 14 selected breeds the relative risk ratio for all tumours varies with factor 35 from boxer to dunker, the boxer having the highest tumour risk. The percentage distribution of specified tumour types also varies greatly between breeds, mammary cancer constituting 59% of all neoplasms in the dachshund, but only 4% in the Bernese mountain dog. Because of the genetic diversity between breeds the dog is a suitable species for differentiation between genetically determined predisposition and environmental influences in the etiology of cancer. Epidemiological surveillance of cancer morbidity in dogs may be a useful instrument for tracing carcinogens, even in the surroundings of man.

A retrospective study of conservative treatment of gastric dilatation-volvulus in the dog

A retrospective study of 103 dogs with gastric dilatation-volvulus (GDV) treated conservatively during the period 1985-1989 was performed. The date and number of recurrences, and the date and cause of death along with breed, age and sex were collected from clinic records and from a questionnaire sent to the owners (77% response). The treatment consisted of emptying the stomach with a stomach tube, gastrocentesis if necessary and treating shock. All of the affected dogs were from moderate to large sized breeds and the study showed that particular breeds appear to be predisposed to GDV. The average age was 7.2 years and there was no gender predisposition. Sixty-six per cent of the dogs survived the initial treatment and 50% of the dogs were still alive 1 month after treatment. Thirty-nine dogs (71%) received recurrence between 5-760 days after initial treatment. Fifty-six per cent had recurrence within 3 months and all except 2 dogs, within 1 year. Data for the time of death, regardless of cause, was available for 68 dogs. Of these 59 (81%) died within a year after initial treatment. Conservative treatment was found to be an adequate life-saving procedure in the acute stage of GDV, but could not alone prevent recurrence of the disease.

The Psychosis Project: outcome and cost-effectiveness of a psychoeducational treatment programme for schizophrenic adolescents

The outcome of a psychoeducational treatment programme for very early-onset schizophrenics was compared with a standard reference treatment. The study sample consisted of 12 patients in each group. Clinical outcome was assessed by relapses during the 2-year treatment period and changes in psychosocial functioning as measured by the Global Assessment Scale. A cost-effectiveness analysis was also carried out. The results indicated that the most effective programme measured by relapse was also the cheapest: the psychoeducational programme. Patients with poor premorbid psychosocial functioning benefit most from this treatment. Decisive with respect to how effective the programme can be is the cooperativeness of patients' parents and their ability to change their emotional attitudes toward the patient.

Hereditary multifocal renal cystadenocarcinomas and nodular dermatofibrosis in the German shepherd dog: macroscopic and histopathologic changes

A syndrome characterized by bilateral, multifocal renal cystadenocarcinomas and nodular dermatofibrosis was found in 43 German shepherd dogs. Affected kidneys varied in weight from normal to 2950 g. The cut surface revealed multiple solid and cystic tumors that varied in size from barely visible to 27 cm in diameter. Metastases were found in ten of the 23 dogs examined since 1979. All 23 dogs had numerous firm nodules in the skin and subcutis, and ten of 11 bitches had multiple uterine leiomyomas. Histological examination of the renal cortex showed multifocal hyperplastic to highly malignant epithelial proliferations. Skin lesions consisted of dense collagen fibers, and the uterine tumors consisted of interlacing bundles of smooth muscle cells. Pedigree analysis strongly indicates that the syndrome is hereditary, probably in an autosomal dominant pattern. This seems to be the first description of such a syndrome in domestic animals. Comparable syndromes in man are discussed.

Kinetics of intravenously administered lactose in cows

Four adult Norwegian Red cows were employed in an experiment designed to study the kinetics of lactose. The cows were given 50 g or 60 g of lactose by rapid intravenous injection of a 10 % lactose solution. Blood samples were taken at different intervals after injection, and lactose concentrations in the samples determined by an enzymatic/spectrophotometric method.

The mean half-time for lactose elimination was 85.7 min, and for distribution 8.4 min. The mean apparent volume of distribution was calculated to be 0.189 1/kg, and total body clearance 1.55 ml min−1 kg−1.

There was evidence to suggest that lactose mainly is eliminated renally from its distribution volume by glomerular filtration in the cow.

[Obliteration of all teat cisterns in a cow]

A rare case of agalactia in a 7 year old cow is described. At the start of the 5th lactation all the teat cisterns were obliterated. Post mortem x-ray examination, with bariumsulfate contrast deposition in the glandular--and the teat cisterns, showed horizontal membranes in the proximal half of the teat cisterns. The membranes were 13--20 mm thick and consisted of fibrous tissue. Glandular tissue, distal parts of teat cisterns and teat canals were normal, and there was no sign of mastitis Obliteration of the teat cisterns, which had developed during the dry period, between the 4th and 5th lactation periods, were assumed to be a result of improper machine milking. The importance of overmilking is discussed.