A retrospective study of 40 dogs with polyarthritis

OBJECTIVE: To characterize the epidemiologic, clinical, laboratory, and radiographic findings from dogs with polyarthritis (PA). STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Forty dogs. METHODS: Medical records of 40 dogs with a diagnosis of PA were reviewed. Retrieved data included breed, age at admission, sex, weight, clinical signs, and the results of synovial fluid analysis, complete blood count, serum chemistry profile, urinalysis, serologic screening tests for infectious diseases, and radiographic examination of affected joints. RESULTS: The incidence of PA was 0.37%. Twenty-nine breeds were represented; 16 dogs were male, and 24 were female. Mean body weight was 20.1 +/- 15 kg. The mean age at admission was 5.6 +/- 4 years. Eighty percent of dogs with PA had difficulty or reluctance walking, 35% were lame, 33% had spontaneous vocalization without any obvious reason, 20% had exercise intolerance, 18% were febrile, and 7.5% had an inability to rise or move. Joint pain was identified in 40% of dogs. Synovial fluid color varied from colorless (36%) to yellow-tinged (36%) or hemorrhagic (28%). Synovial fluid mean cell count varied from 10 cells (400x) to 50 cells (1,000x). Leukocytosis occurred in 59% of the dogs and was more frequently identified in dogs with very severe synovial inflammation. Thirty-one percent of affected dogs were anemic. Serum biochemical profiles were considered abnormal in 13% of the dogs. Joint radiography did not identify erosive arthritis. CONCLUSIONS: PA is a common cause of locomotor abnormalities in dogs; however, true lameness and articular pain are not common clinical findings in dogs with PA. CLINICAL RELEVANCE: PA should be considered in the differential diagnosis for all dogs with difficulty walking.     

How to substantiate eradication of bovine brucellosis when aspecific serological reactions occur in the course of brucellosis testing

Collaborative work was financed by the EU to develop and assess new diagnostic tools that can differentiate between bovine brucellosis and bovine infections due to Yersinia enterocolitica O:9 either in conjunction with, or as an alternative to, the classical serological, bacteriological or allergic skin tests. Sixteen heifers were experimentally infected with Brucella abortus biovar 1 (five heifers), Brucella suis biovar 2 (two heifers), Y. enterocolitica O:9 (six heifers) and Y. enterocolitica O:3 (three heifers). Four heifers, naturally infected with Y. enterocolitica O:9 that presented aspecific brucellosis serological reactions were also included in the experiment. A self-limited infection was induced in cattle by B. suis biovar 2. All the brucellosis serological tests used, i.e. the slow agglutination test (SAW), the Rose Bengal test (RB), the complement fixation test (CFT), indirect and competitive ELISA’s, lacked specificity when used to analyze sera from Y. enterocolitica O:9 infected animals. A Yersinia outer membrane proteins (YOPs)-ELISA was also used and although the test is able to detect a Yersinia group infection, it provided no evidence of whether or not there is a possible brucellosis infection when dual infections are present. The brucellergen IFN-γ test showed a lack of specificity also. The only test that was proven to be specific is the brucellergen skin test. All brucellosis serological tests, except the indirect ELISA, were limited in their ability to detect B. abortus persistently infected animals.

Based on these experimental studies, a strategy was implemented as part of the year 2001 Belgian Brucellosis Eradication Program to substantiate the eradication of bovine brucellosis. Epidemiological inquiries have identified risk factors associated with aspecific serological reactions, possible transmission and infection of cattle by B. suis biovar 2 from infected wild boars; and both legal and administrative measures taken by the veterinary services. No cases of bovine brucellosis have been confirmed in Belgium since March 2000.     

Requirement for capsular antigen KX105 and fimbrial antigen CS1541 in the pathogenicity of porcine enterotoxigenic Escherichia coli O8:KX105 strains.

The requirement for capsular antigen KX105 and fimbrial antigen CS1541 in the pathogenicity of porcine enterotoxigenic Escherichia coli O8:KX105 strains lacking the colonization factor antigens K88, K99, 987P and F41 was investigated using two encapsulated strains and their acapsular variants, one of which produced the fimbrial antigen CS1541 in vitro. None of the strains adhered in vitro to enterocytes isolated from newborn colostrum-deprived piglets. All of the strains caused diarrhea in orally infected, hysterotomy-derived, colostrum-deprived piglets although a great variability in the clinical response of the piglets was observed. Colonization of the small intestine of infected piglets by these strains was only moderate and no differences in the ability to colonize the small intestine was noted between the strains. All of the strains reacted in the indirect fluorescent antibody test with both CS1541 and 987P antisera when applied to organisms in the intestines of infected piglets. A control strain expressing the 987P fimbrial adhesin also reacted with the CS1541 antiserum applied to organisms in the intestines of an infected piglet. It was concluded that capsular antigen KX105 was not essential for intestinal colonization and production of diarrhea in hysterotomy-derived colostrum-deprived pigs, and that fimbrial antigen CS1541 does not promote in vitro adherence to enterocyte brush borders but could be important in bacterial colonization in vivo.     

Establishment of woody plants in Mediterranean old fields: opportunity in space and time

The establishment of woody plants following agricultural abandonment in the Mediterranean region is a very widespread process which underlines the extent of the rural exodus. The installation windows in space and time were studied in the French Mediterranean region for two common woody plants, Buxus sempervirens and Fraxinus angustifolia and for a group of common woody fleshy-fruited species. These plants differ in their principal modes of dispersal which are respectively, barochory, anemochory and ornithochory. Their installation was analyzed in relation to the seed shadows, the spatial patterns and the age structures of the seedlings. The majority of the seeds were dispersed over short distances, although some animal vectors may promote a limited amount of long distance dispersal. Hence, whatever the mode of dispersal, a few seeds are often dispersed far from the maternal plant. The combination of several dispersal types in one plant species is a frequently observed feature, one being dominant at a small scale, and related to successional processes, the other being dominant at a larger scale and related to invasive processes. In the old fields the spatial pattern of seedlings closely follow the observed seed shadows. However, competition with the maternal plants may lead to, in some cases, a recruitment deficit close to the seed-bearers. Age structures show that woody plants often install very early after the abandonment of cultivation and that the installation window in time is shortened by the development of a dense herbaceous cover. It is concluded that the installation of woody plants in Mediterranean old fields cannot be reduced to a general rule. The rate and extent of installation depends mainly on the spatial distribution of the seed-bearers, therefore of the spatial patterns of the landscape.     

Determination of affinity of Pasteurella multocida isolates for porcine respiratory tract mucus, and partial characterization of the receptors

The ability of 25 Pasteurella multocida isolates to adhere in vitro to porcine respiratory tract mucus was examined. Microplate wells were coated with crude mucus preparation, then bacteria were added. After incubation, unbound bacteria were removed by washing, and the number of mucus-bound bacteria was estimated by quantitation of the adherent colony-forming units and by use of an ELISA. Pasteurella multocida had affinity to respiratory tract mucus, although significant differences were not observed in affinity of capsular type-A and type-D isolates. Preliminary characterization, using ultrafiltration, gel filtration chromatography, electrophoresis, and enzymatic treatments, indicated that the receptors may be a class of protein molecules of low molecular weight (less than 25,000). The origin of these receptors, however, is not known at this time.     

Metabolism of the fungicide triforine in barley plants

The metabolic fate of [³H]-triforine in barley plants has been studied. 15 and 30 days after treatment, unchanged triforine amounted to 57.5 and 43.2% respectively, and of three soluble metabolites detected, piperazine (0.3 and 4.0%) and N-[2, 2,2-trichloro-1-(piperazin-1-yl)ethyl] formamide (12.9 and 8.4%), the latter for the first time as a metabolite in plants, were identified using t.1.c. with four solvent systems. The solid residue contained 23.1 and 38.2% of bound label after 15 and 30 days respectively.     

Frequency, body distribution, and population size of Malassezia species in healthy dogs and in dogs with localized cutaneous lesions.

Malassezia species are commensal organisms of human and animal skin that occasionally act as opportunistic pathogens. The lipid-dependent species are associated with human skin disorders, whereas the non-lipid-dependent species (Malassezia pachydermatis) is considered as an opportunistic secondary pathogen affecting the canine skin surface and ear canal. This study evaluated the relationship between Malassezia yeasts, their population size, and the occurrence of skin lesions from healthy and skin-diseased dogs. The efficiency of cytological examination and fungal culture for Malassezia detection was also evaluated. From March 2002 to July 2003, 33 healthy dogs and 54 dogs with pruritic localized skin diseases were examined; skin swabs (1218) were collected from 7 anatomical sites for culture and cytological examination. Malassezia prevalence according to anatomical site and the agreement between cytological results and fungal cultures were statistically analyzed. Differences in mean colony forming unit counts between positive healthy and diseased dogs were evaluated using the Bonferroni test for post hoc pair-wise comparisons. In healthy dogs, Malassezia yeasts were most frequently isolated in the perianal and perioral areas. The frequency of isolation and population size of Malassezia species were higher in dogs with localized dermatitis, especially in affected areas, indicating a role for Malassezia in the occurrence of skin lesions. Malassezia pachydermatis was the species most commonly cultured from the skin and external ear canal of healthy and diseased dogs; isolation of lipid-dependent yeasts from healthy dogs was less frequent. Using fungal culture as the gold standard, cytological examination showed good relative specificity (95%) but very low relative sensitivity (30%).     

Serological evidence of Brucella species infection in odontocetes from the south Pacific and the Mediterranean

Sera from 58 odontocetes taken in fisheries off Peru in 1993 to 1995 and from 24 cetaceans stranded along the Spanish coast of the Mediterranean in 1997 to 1999 were tested for the presence of Brucella species antibodies in competitive and indirect ELISAS (cELISA and iELISA). Among the animals from Peru, 21 of 27 (77.8 per cent) Lagenorhynchus obscurus, three of six Delphinus capensis, one of two inshore and two of three offshore Tursiops truncatus and five of 20 (25 per cent) Phocoena spinipinnis were positive in the cELISA. Brucella species antibodies were also observed in two of 16 (12.5 per cent) Stenella coeruleoalba and in one of two Ttruncatus from the Mediterranean. These data provide the first evidence for the presence of cetacean brucellae in the south Pacific Ocean and the Mediterranean Sea.     

Progress and limits of TSE diagnostic tools

Following the two "mad cow" crises of 1996 and 2000, there was an urgent need for rapid and sensitive diagnostic methods to identify animals infected with the bovine spongiform encephalopathy (BSE) agent. This stimulated research in the field of prion diagnosis and led to the establishment of numerous so-called "rapid tests" which have been in use in Europe since 2001 for monitoring at-risk populations (rendering plants) and animals slaughtered for human consumption (slaughterhouse). These rapid tests have played a critical role in the management of the mad cow crisis by allowing the removal of prion infected carcasses from the human food chain, and by allowing a precise epidemiological monitoring of the BSE epizootic. They are all based on the detection of the abnormal form of the prion protein (PrP(Sc) or PrP(res)) in brain tissues and consequently are only suitable for post-mortem diagnosis. Since it is now very clear that variant Creutzfeldt-Jakob disease (vCJD) can be transmitted by blood transfusion, the development of a blood test for the diagnosis of vCJD is a top priority. Although significant progress has been made in this direction, including the development of the protein misfolding cyclic amplification (PMCA) technology, at the time this paper was written, this objective had not yet been achieved. This is the most important challenge for the years to come in this field of prion research.