Detection and distribution of anti-leptospiral antibody among dogs and their handlers.

The incidence of leptospirosis seems to be on the rise and could be an alarming indirect indication of a global re-emergence. It is a potential public health threat when dogs are speculated to be involved in the transmission of leptospirosis through possible subclinical harbouring of Leptospira spp. and subsequent shedding into the environment. This study aimed to detect anti-leptospiral antibodies among dogs and their handlers using the microscopic agglutination test (MAT). Blood samples from 266 apparently healthy dogs and 194 dog handlers were collected at four working dog organisations and four dog shelters. Serum samples were tested using MAT against 20 leptospiral serovars with a cut-off titre >=1:100 (dog) and >=1:50 (dog handlers). Seventy dogs (70/266; 26.3%) were seropositive mainly against serovars Icterohaemorrhagiae, Ballum, Bataviae and Javanica (titres ranged: 1:100-1:800). Sixty-seven dog handlers (67/194; 34.5%) were seropositive mainly against serovars Grippotyphosa, Icterohaemorrhagiae and Malaysia (titres ranged: 1:50-1:200). Dogs were seropositive due to exposure, vaccination or active infection. Seropositive dog handlers could indicate exposure or active infection. This shows the potential of dogs in maintaining and spreading the infection in Malaysia. Due to the occupational risk as a result of frequent contact with dogs and exposure to contaminated environments, dog handlers should be made aware of the presence of this zoonotic disease.

Detection and distribution of anti-leptospiral antibody among dogs and their handlers

@# The incidence of leptospirosis seems to be on the rise and could be an alarming indirect indication of a global re-emergence. It is a potential public health threat when dogs are speculated to be involved in the transmission of leptospirosis through possible subclinical harbouring of Leptospira spp. and subsequent shedding into the environment. This study aimed to detect anti-leptospiral antibodies among dogs and their handlers using the microscopic agglutination test (MAT). Blood samples from 266 apparently healthy dogs and 194 dog handlers were collected at four working dog organisations and four dog shelters. Serum samples were tested using MAT against 20 leptospiral serovars with a cut-off titre >1:100 (dog) and >1:50 (dog handlers). Seventy dogs (70/266; 26.3%) were seropositive mainly against serovars Icterohaemorrhagiae, Ballum, Bataviae and Javanica (titres ranged: 1:100–1:800). Sixty-seven dog handlers (67/194; 34.5%) were seropositive mainly against serovars Grippotyphosa, Icterohaemorrhagiae and Malaysia (titres ranged: 1:50–1:200). Dogs were seropositive due to exposure, vaccination or active infection. Seropositive dog handlers could indicate exposure or active infection. This shows the potential of dogs in maintaining and spreading the infection in Malaysia. Due to the occupational risk as a result of frequent contact with dogs and exposure to contaminated environments, dog handlers should be made aware of the presence of this zoonotic disease.

Seroprevalence of Leptospirosis in Working Dogs.

Working dogs are canine animals that have been trained to assist human beings in carrying out various tasks. They help in guarding property, performing rescues, assisting the visually impaired or physically handicapped, searching for drugs, explosives, and others. Leptospirosis is one of the most widespread zoonotic diseases in the world and a commonly occurring disease of the tropics and subtropics. In Malaysia, all working dogs are normally vaccinated with serovars, Pomona, Icterohaemorrhagiae, Canicola, and Grippotyphosa based on protocols recommended from other countries. The duration of immunity in vaccinated dogs for Leptospira can last up to 13 months; however, there is no full crossprotection between the different serovars. Five representative canine units from different government agencies in Malaysia (n = 96 dogs) were recruited in this study. For detection, the microscopic agglutination test was performed by incubating the serum from dogs with various serovars of leptospires, namely, Icterohaemorrhagiae, Canicola, Pomona, Grippotyphosa, Australis, Bataviae, Javanica, Tarassovi, Hebdomadis, Lai, and Pyrogenes. The plasma obtained was used for polymerase chain reaction (PCR) analysis, for the detection of 16S rRNA, and lipL 32 genes of Leptospira. Out of the 96 dogs sampled, only 3 dogs were positive toward serovars, Australis, Bataviae, and Javanica, based on the cutoff point at 1:80. The seroprevalence of canine leptospirosis in this population was 3.1% (n = 3/96). However, all 96 blood samples of working dogs tested negative for both pathogenic and nonpathogenic Leptospira genes. The results revealed that, by vaccination alone, working dogs were not fully protected against leptospirosis and could pose a risk to dog handlers. A preventative and control protocol for leptospirosis is warranted, and its implementation should be monitored and improved accordingly from time to time, in order to maintain a healthy condition in both working dogs and their handlers.

Seroprevalence and molecular detection of leptospirosis from a dog shelter.

A study on seroprevalence and molecular detection of canine leptospirosis was carried out in a dog population (randomly selected n=80 dogs) from an animal shelter X. All the dogs in Shelter X appeared clinically healthy. Eighty blood samples were obtained and their serum were serologically examined using Microscopic Agglutination Test (MAT) against 10 Leptospira serovars. Plasma samples obtained were subjected to Polymerase Chain Reaction (PCR) assay. Three out of 80 dogs (3.8%) tested positive for L. bataviae based on MAT at a titer of 1:80. The seroprevalence of 9 other Leptospira serovars was not evident in this study. All the dogs tested negative against leptospirosis with PCR assay. In conclusion, canine leptospirosis was detected in dogs in this animal shelter. L. bataviae was identified as the infecting serovar. To our knowledge, this is the second report of serovar Bataviae infection in dogs in Malaysia. The 3 dogs in our study could possibly be a source of leptospiral infection to other dogs and may shed the bacteria into the environment. This serovar is not available in canine vaccination programs, therefore the dogs are not protected from this disease. Further investigation is warranted to determine whether the infected dogs are carriers of this serovar.

Prevalence of leptospirosis in healthy dogs and dogs with kidney disease in Klang Valley, Malaysia.

Leptospirosis is under-reported and remarkably neglected in Malaysia, especially in companion animals. In recent years, dogs have become popular pets and potentially act as one of the risk factors for human leptospiral infection. The purpose of this study was to determine the serological and molecular status of leptospirosis in healthy and dogs with kidney disease in Klang Valley, Malaysia and to gain insight of the possible serovars involved in the dog population in Klang Valley, Malaysia. Blood samples were obtained from 57 dogs (19 kidney disease patient; 38 healthy dogs, respectively). Serum samples obtained from these animals were screened for leptospiral antibodies by the microscopic agglutination test (MAT). Polymerase chain reaction (PCR) assay was performed on plasma samples to detect leptospiral DNA. By MAT, three out of 19 (15.8%) dogs with kidney disease were positive for L. canicola. One out of 38 (2.6%) healthy dogs was positive for L. icterohemorrhagiae. The overall seroprevalence for leptospirosis in dogs in Klang Valley, Malaysia was 7.0% (n=4/57). Only one out of the 19 dogs (5.3%) with kidney disease was tested positive to pathogenic Leptospira by PCR assay. All the 38 healthy dogs were negative. Positive results in healthy dogs and dogs with kidney disease for leptospirosis warrant further investigation of leptospirosis in dog population in Malaysia. The prevalence and incidence of this disease in the dog population in this country need further investigation.

Prevalence of leptospirosis in healthy dogs and dogs with kidney disease in Klang Valley, Malaysia

Leptospirosis is under-reported and remarkably neglected in Malaysia, especially in companion animals. In recent years, dogs have become popular pets and potentially act as one of the risk factors for human leptospiral infection. The purpose of this study was to determine the serological and molecular status of leptospirosis in healthy and dogs with kidney disease in Klang Valley, Malaysia and to gain insight of the possible serovars involved in the dog population in Klang Valley, Malaysia. Blood samples were obtained from 57 dogs (19 kidney disease patient; 38 healthy dogs, respectively). Serum samples obtained from these animals were screened for leptospiral antibodies by the microscopic agglutination test (MAT). Polymerase chain reaction (PCR) assay was performed on plasma samples to detect leptospiral DNA. By MAT, three out of 19 (15.8%) dogs with kidney disease were positive for L. canicola. One out of 38 (2.6%) healthy dogs was positive for L. icterohemorrhagiae. The overall seroprevalence for leptospirosis in dogs in Klang Valley, Malaysia was 7.0% (n=4/57). Only one out of the 19 dogs (5.3%) with kidney disease was tested positive to pathogenic Leptospira by PCR assay. All the 38 healthy dogs were negative. Positive results in healthy dogs and dogs with kidney disease for leptospirosis warrant further investigation of leptospirosis in dog population in Malaysia. The prevalence and incidence of this disease in the dog population in this country need further investigation.

Myocardial collagen deposition and inflammatory cell infiltration in cats with pre-clinical hypertrophic cardiomyopathy.

The histological features of feline hypertrophic cardiomyopathy (HCM) have been well documented, but there are no reports describing the histological features in mild pre-clinical disease, since cats are rarely screened for the disease in the early stages before clinical signs are apparent. Histological changes at the early stage of the disease in pre-clinical cats could contribute to an improved understanding of disease aetiology or progression. The aim of this study was to evaluate the histological features of HCM in the left ventricular (LV) myocardium of cats diagnosed with pre-clinical HCM. Clinically healthy cats with normal (n = 11) and pre-clinical HCM (n = 6) were identified on the basis of echocardiography; LV free wall dimensions (LVFWd) and/or interventricular septal wall (IVSd) dimensions during diastole of 6-7 mm were defined as HCM, while equivalent dimensions <5.5 mm were defined as normal. LV myocardial sections were assessed and collagen content and inflammatory cell infiltrates were quantified objectively. Multifocal areas of inflammatory cell infiltration, predominantly lymphocytes, were observed frequently in the left myocardium of cats with pre-clinical HCM. Tissue from cats with pre-clinical HCM also had a higher number of neutrophils and a greater collagen content than the myocardium of normal cats. The myocardium variably demonstrated other features characteristic of HCM, including arteriolar mural hypertrophy and interstitial fibrosis and, to a lesser extent, myocardial fibre disarray and cardiomyocyte hypertrophy. These results suggest that an inflammatory process could contribute to increased collagen content and the myocardial fibrosis known to be associated with HCM.

Comparative pharmacokinetics and pharmacodynamics of tablet, suspension and paste formulations of atenolol in cats.

This study compared the pharmacokinetic and pharmacodynamic profiles of an extemporaneously prepared (compounded) atenolol paste and suspension for oral administration, against the commercially available divided tablet in healthy cats. Eleven healthy cats (mean: age 4 ± 0.4 year, weight 5.0 ± 0.7 kg) were dosed twice-daily with 12.5 mg atenolol (tablet, paste or suspension) for 7 days in a randomized cross-over design with a 7-day wash-out period. On day 7, an electrocardiogram was performed before and immediately after stress provocation (jugular venipuncture) at prestudy screening, and at 2, 6 and 12 h after morning dosing. Systolic arterial blood pressure (BP) was assessed following the second electrocardiogram. Plasma was collected at prestudy screening, and at 1, 2, 6 and 12 h to measure atenolol plasma concentrations. Mean atenolol dose was 2.5 mg/kg (range: 2.1-3.3 mg/kg). Stress-induced rise in heart rate was attenuated (P < 0.05) at every time point compared to baseline for all formulations. Although the paste significantly attenuated stress-induced elevation in heart rate at all time points, the effect was not consistently equivalent to the tablet. The BP was not altered (P > 0.05) at any time point by any formulation. In conclusion, there were no significant differences (P > 0.05) in any of the pharmacokinetic parameters or pharmacodynamic profiles of the paste and suspension compared to the commercially available tablet.

X-ray colour imaging.

A prototype X-ray colour imaging system has been assembled using the principle of tomographic energy-dispersive diffraction imaging (TEDDI). The new system has been tested using samples of nylon-6, aluminium powder and deer antler bone. Non-destructive three-dimensional images of the test objects have been reconstructed on a 300 microm scale with an associated diffraction pattern at each voxel. In addition, the lattice parameters of the polycrystalline material present in the sampled voxels have been determined using full pattern refinement methods. The use of multiple diffracted parallel colour X-ray beams has allowed simultaneous spatially resolved data collection across a plane of the sample. This has simplified the sample scan motion and has improved data collection times by a factor scaling with the number of detector pixels. The TEDDI method is currently limited to thin samples (approx. 1-2mm) with light atoms owing to the very low detection efficiency of the silicon detector at X-ray energies above 25 keV. We describe how these difficulties can be removed by using semiconductor detectors made from heavier atomic material.