A serological study of exposure to arthropod-borne pathogens in dogs from northeastern Spain

There is limited information regarding the prevalence of many vector borne pathogens in Europe and especially in Spanish dogs. We investigated 206 sick and 260 clinically healthy dogs from three different regions in northeastern Spain for antibodies to Rickettsia conorii (Rc), Ehrlichia canis (Ec), Anaplasma phagocytophilum (Ap), Bartonella henselae (Bh), Bartonella vinsonii subsp. berkhoffii (Bvb), Leishmania infantum (Li) and Borrelia burgdorferi (Bb) and for antigen of Dirofilaria immitis (Di). Total prevalences were the following: Rc (56.4%), Li (30%), Ec (16.7%), Bh (16.8%), Ap (11.5%), Bvb (1.07%), Di (0.6%) and Bb (0.6%). Seroprevalences for Rc, Ec, Ap, Bh, and Bvb and Bb and Di antigens were similar among the three different study sites. The Ec seroprevalence, as determined by Snap 3DX, was statistically lower in dogs from Mallorca (0%) than Tarragona (16%) and Barcelona (5%) (P < 0.0001). Detection of Rc antibodies was associated with seroreactivity to Ec and Ap antigens (P = 0.018 and P = 0.002, respectively). IFA Ec antibodies were associated with Ap seroreactivity (P < 0.0001). There was no association between the clinical status, sex, time of the year when samples were collected, life-style or exposure to fleas or ticks and a positive test result for Ec, Bh, Bvb, or Bb antibodies or Di antigens. Li seroreactivity was associated with illness and living outdoors (P < 0.0001, P = 0.029; respectively), Rc seroreactivity with the male gender (P = 0.028) and Ap seroreactivity with living outdoors (P = 0.045). This study indicates that exposure to Rc, Li, Ec or related Ehrlichia spp., Bh and Ap or a related spp., is common whereas Di, Bb and Bvb is uncommon among dogs from the Mediterranean basin. We also provide serological data that suggests the existence of a novel Ehrlichia species on Mallorca island.     

Spatial distribution of seropositivity to the causative agent of granulocytic ehrlichiosis in dogs in California

OBJECTIVE: To assess spatial and temporal patterns of seroprevalence among dogs in California to the causative agent of granulocytic ehrlichiosis (GE). SAMPLE POPULATION: Sera of 1,082 clinically normal dogs from 54 of 59 counties in California in 1997 to 1998. PROCEDURES: Serum-specific IgG reactivity to Ehrlichia equi was assessed by use of an immunofluorescent antibody assay, using E. equi-infected horse neutrophils as substrate. Data were analyzed, using a geographic information system. Spatial analysis of seroprevalence included first order Bayesian analysis of seroprevalence and second order analysis of clustering by K-function and Cuzick-Edwards tests. Monthly seroprevalence among dogs was examined by use of regression on monthly densities of Ixodes pacificus adults and nymphs. RESULTS: Seroprevalence among dogs to E. equi was 8.68%. Data were seasonally bimodal with highest prevalence in winter (when adult ticks were abundant) and a secondary peak in late spring (corresponding to nymphal ticks). Humboldt County had the highest seroprevalence (47.3%), and other northern coast range counties had seroprevalence from 15 to 30%. CONCLUSIONS AND CLINICAL RELEVANCE: The patchy distribution of exposure to Ehrlichia organisms is a subset of the distribution of the tick vector. This may reflect enzootic cycles or climatic or historical factors that limited the range of the disease. Dogs, horses, and humans from north coast range counties in California are at increased risk of GE. These data provide a background for assessing risk of infection in horses and dogs, depending on geographic location. Dogs may be sentinels for assessing risk of GE in humans.     

霉菌毒素加剧病原微生物对动物的危害

动物饲料污染霉菌毒素的比例很高。一些研究发现高达70%的饲料样品被一种或多种霉菌毒素所污染(Pittet,1998;欧盟食品安全局,2004)。这些数据表明每种日粮中至少有一种原料可能含有霉菌毒素。在养殖场,很少观察到明显与霉菌毒素作用有关的病理症状。但当我们采样分析养殖场中所     

Gastrointestinal pythiosis in 10 dogs from California

BACKGROUND: Pythium insidiosum is an aquatic oomycete that causes severe segmental thickening of the canine gastrointestinal (GI) tract, resulting in weight loss, vomiting, diarrhea, and death. Infection in dogs previously has been observed primarily in the southeastern United States. OBJECTIVE: To describe the clinicopathologic and epidemiologic findings associated with GI pythiosis in 10 dogs from California. METHODS: Dogs were initially identified on the basis of supportive clinical findings and routine histology. Pythiosis was confirmed in each dog with at least one of the following: immunoblot serology, enzyme-linked immunosorbent assay serology, immunohistochemistry, and culture followed by species-specific polymerase chain reaction, rRNA gene sequencing, or both. RESULTS: Between September 2003 and December 2006, GI pythiosis was confirmed in 1 dog from central California and 9 dogs that lived within a 30-mile radius of Davis, CA. Seven of 8 dogs for which environmental data were available had frequent access to flooded rice fields or other water sources. Esophageal lesions were present in 2 of 10 dogs. Common laboratory findings included eosinophilia (7/9), hypoalbuminemia (9/9), and hyperglobulinemia (8/9). Median survival time was 26.5 days (range, 0-122 days), and the disease was ultimately fatal in all 10 dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: The geographic distribution of pythiosis has widened in recent years to include the western United States. Factors that may have contributed to this change include altered rice-farming practices and landscape irrigation. Veterinarians in California should be familiar with the clinicopathologic features associated with GI pythiosis to aid in early diagnosis and effective treatment.     

Prevalence of enteric pathogens in dogs of north-central Colorado

To evaluate the prevalence of enteric pathogens in dogs of north-central Colorado, fecal samples were obtained from client-owned dogs presented to the Veterinary Teaching Hospital at Colorado State University for evaluation of acute small-bowel, large-bowel, or mixed-bowel diarrhea (n=71) and from age-matched, client-owned, healthy dogs (n=59). Infectious agents potentially associated with gastrointestinal disease were detected in 34 of 130 (26.1%) fecal samples. Agents with zoonotic potential were detected in feces from 21 (16.2%) of 130 dogs and included Giardia spp. (5.4%), Cryptosporidium parvum (3.8%), Toxocara canis (3.1%), Salmonella spp. (2.3%), Ancylostoma caninum (0.8%), and Campylobacter jejuni (0.8%). Positive test results occurred in dogs with or without gastrointestinal signs of disease. Dogs, particularly those in homes of immunocompromised humans, should be evaluated for enteric zoonotic agents.     

Survey of desert bighorn sheep in California for exposure to selected infectious diseases

From February 1983 to June 1985, 188 desert bighorn sheep (Ovis canadensis nelsoni, = 161 and Oc cremnobates, = 27) from 18 herds in 17 mountain ranges and one captive herd were caught, marked, and had blood, fecal, and nasal mucus samples collected. Nasal swab specimens were cultured bacteriologically and virologically specifically for parainfluenza-3 (PI-3) virus. Bacterial flora differed from herd to herd. Pathogenic pneumophilic bacteria (eg, Pasteurella sp) seldom were found. Parainfluenza-3 virus was isolated from 6 bighorn sheep in 3 herds. Fecal specimens were examined for parasite ova and low numbers of lungworm (Protostrongylus sp) larvae were found in feces from 2 herds. Sera were evaluated for antibodies against respiratory syncytial virus, ovine progressive pneumonia, infectious bovine rhinotracheitis, PI-3, bovine viral diarrhea, brucellosis, leptospirosis, contagious ecthyma, bluetongue, and epizootic hemorrhagic disease. Blood clots were cultured virologically for bluetongue and epizootic hemorrhagic disease. Serologic evidence of bluetongue and/or epizootic hemorrhagic disease was found in 9 herds, and bluetongue virus (serotypes 10,11,13 and 17) was isolated from 3 herds. Antibody titers against PI-3 and respiratory syncytial virus were found in 9 and 13 herds, respectively. Evidence of bovine viral diarrhea infection was found in 6 herds, whereas infectious bovine rhinotracheitis was found in only 1 herd. Antibody titers against contagious ecthyma were found in 9 of 18 herds in California, and active lesions were seen occasionally. Evidence of ovine progressive pneumonia, leptospirosis, or brucellosis was not found.     

Seroprevalence of antibodies to Neospora caninum in urban and rural dogs in north-west Italy

Sera were collected from 490 dogs from north-west Italy. One hundred and eighty-eight dogs were urban, while 302 dogs were rural. Among the latter, 190 were shepherd dogs and 112 were cattle farm dogs. Sera were tested for the presence of antibodies against Neospora caninum using the Neospora agglutination test. Seroprevalence at 1/40, 1/80, 1/160 dilution titres was significantly higher in rural (36.4%, 19.5%, 9.9% respectively) than in urban dogs (20.2%, 10.6%, 4.8% respectively). Seroprevalence did not differ significantly in males and females. In shepherd dogs, prevalence increased according to dogs' age, thus suggesting a post-natal exposure by horizontal transmission. The observed higher seroprevalence in rural dogs suggests the importance of lifestyle and alimentary habits (i.e. aborted foetuses, placentas and small mammals) in the acquisition of N. caninum infection. Our results confirm that dogs are exposed to N. caninum and play an important role in the epidemiology of N. caninum.     

A model for predicting feed intake of growing animals during exposure to pathogens

A general model is proposed for predicting the effects of subclinical pathogen challenges of different doses and virulence on the relative feed intake (RFI) of animals. The RFI is defined as the feed intake (FI, kg/d) of the animal challenged by a pathogen divided by its FI in the same state had it not been challenged. Actual FI can be predicted from the RFI and the animal's state. The RFI was assumed to be affected only when animals were na?ve to a particular pathogen (i.e., had not previously experienced it) and when the challenge dose was above a predetermined threshold. The model is for the period from recognition of a pathogen through acquisition and subsequent expression of immunity. The way in which RFI changes with time is described by 5 main parameters and is based on data for RFI during different pathogen challenges of a range of hosts. Lag time (L, d) is the delay from a pathogen challenge until any effects on RFI are seen. Reduction time (R, d) describes the time it takes for the lowest value of RFI (lambda) to be achieved. The duration time (D, d) describes the time that lambda is maintained for, and rho (RFI/d) describes the rate of recovery of RFI until RFI = 1. There is no compensatory intake, and RFI is always < or = 1. The effects of host resistance on the values of the model parameters are proposed. Attempts were made to parameterize the model; when data were scarce, initial parameter values were derived on conceptual grounds. Predictions of the effects of pathogen dose, virulence, and host resistance are described and discussed. When comparing the responses in RFI for different genotypes, it is crucial to define the pathogen challenge (in terms of dose and virulence) and the degree of resistance of different hosts. Possible interactions between dose, virulence, and resistance were explored. Feed intake of healthy and challenged animals, at a time, may be different once the challenged animal has recovered (RFI = 1). The issue of reductions in FI during pathogen challenges is important for nutritionist and animal breeders. The large variation that has been observed for reductions in FI during pathogen challenges may be a viable point of selection. The points highlighted will aid selection strategies by quantifying the effects of pathogen dose and virulence, and time, on the FI of challenged animals. The proposed model may be integrated with other models of growth to predict animal performance during exposure to pathogens.     

Molecular evidence of vector-borne pathogens coinfecting dogs from Poland

Ticks of the genus Ixodes are vectors for many pathogens, including Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Rickettsia spp., and may also serve as vectors for Bartonella spp. However, the role of ticks in Bartonella transmission requires additional studies. The aim of this study was to investigate whether coinfection with two or more vector-borne pathogens can occur in the following three groups of dogs: I - dogs with suspected borreliosis (N = 92), II - dogs considered healthy (N = 100), and III - dogs with diagnosed babesiosis (N = 50). Polymerase chain reactions were performed to detect DNA of Anaplasma phagocytophilum, Rickettsia spp. and Bartonella spp. in the blood of dogs. In dogs of Group I, the DNA of both A. phagocytophilum and Bartonella sp. was detected (14% and 1%, respectively). In eight dogs, coinfection was indicated: A. phagocytophilum or Bartonella sp. with B. burgdorferi s.l. (the presence of antibodies against and/or DNA B. burgdorferi s.l.). In the case of five dogs positive for A. phagocytophilum DNA, no coinfection with B. burgdorferi s.l. was shown. In Group II, the DNA of A. phagocytophilum was detected in four dogs. In Group III, no pathogenic agents possibly transmitted by ticks were confirmed. No DNA of R. helvetica was detected in any of the groups studied.     

Aflatoxicosis in nine dogs after exposure to contaminated commercial dog food.

The purpose of this study was to characterize light and electron microscopic findings from 9 dogs that had consumed aflatoxin-contaminated commercial dog food from recalled batches. Four dogs died and 5 were euthanized after signs of liver failure. Analysis of feed and liver samples confirmed exposure to aflatoxin. Of the 9 dogs, 8 had classic signs of liver failure, and 1 had signs of liver failure. Enlarged, pale yellow livers were seen macroscopically at necropsy in the dogs with subacute hepatopathy, and cirrhosis was noted in the dog with chronic hepatopathy. Histopathologic findings included hepatic lipidosis, portal fibroplasia, and biliary hyperplasia, which supported a diagnosis of subacute toxic hepatopathy in the 8 symptomatic animals. Marked lobular atrophy, bridging portal fibrosis, and regenerative hepatocellular nodules characterized the dog with chronic hepatopathy. Electron microscopy revealed marked hepatocellular lipid vacuolation and early fibroplasia in the dogs with acute hepatopathy and marked fibrosis and regeneration in the dog with chronic hepatopathy. Analysis of feed for aflatoxin consistently revealed high levels of aflatoxin B1 (range of 223-579 ppb), and hepatic tissue contained elevated levels of aflatoxin B1 metabolite M1 (0.6-4.4 ppb). Although dogs are not commonly affected by aflatoxicosis, they are highly susceptible and can present with classic signs of acute or chronic hepatopathy. Characteristic gross, histologic, and electron microscopic changes help pathologists determine a presumptive toxic insult. Detecting aflatoxins or their metabolites in feed or liver specimens can help confirm the diagnosis of aflatoxicosis.     

Postnatal exposure to a progestin does not prevent uterine adenogenesis in domestic dogs

To assess the effects of a single supraphysiological postnatal administration of a progestogen on uterine glands in dogs, 10 females were randomly assigned to a medroxyprogesterone acetate 35 mg (MPA; n = 6) or placebo (n = 4) group within the first 24 h of birth. The safety of the treatment was also evaluated. A transient mild clitoris enlargement appeared in MPA-treated females. Microscopic postpubertal uterine assessment revealed the presence of uterine glands in all cases without significant differences in the area occupied by the glands per µm² of endometrium nor in the height of the uterine epithelium.     

Perinuclear antineutrophil cytoplasmic autoantibodies in dogs infected with various vector-borne pathogens and in dogs with immune-mediated hemolytic anemia

Objective-To determine the prevalence of perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) in dogs with confirmed or suspected immune-mediated hemolytic anemia (IMHA) or dogs infected with various vector-borne pathogens, including Rickettsia rickettsii, Bartonella henselae, Bartonella vinsonii subsp berkhoffii, Ehrlichia canis, Borrelia burgdorferi, and Leishmania infantum. Animals-55 dogs with confirmed or suspected IMHA, 140 dogs seroreactive for vector-borne pathogens, and 62 healthy dogs and dogs seronegative for vector-borne pathogens. Procedures-Samples were allocated to subgroups on the basis of the health status of the dogs and the degree of seroreactivity against various vector-borne pathogens. Serum samples were tested retrospectively via indirect immunofluorescence assay to determine pANCA status. Results-26 of 55 (47%) dogs with confirmed or suspected IMHA and 67 of 140 (48%) dogs seroreactive for vector-borne pathogens had positive results when tested for pANCA. Serum samples with the highest antibody concentrations against L infantum antigen had the highest proportion (28/43 [65%]) that were positive for pANCA. One of 20 (5%) dogs seronegative for tick-borne pathogens and 8 of 22 (36%) dogs seronegative for L infantum had positive results for pANCA. One of 20 (5%) healthy dogs had serum antibodies against pANCA. Conclusions and Clinical Relevance-pANCA were detected in a high percentage of dogs with IMHA and vector-borne infectious diseases. Therefore, pANCA may be a relatively nonspecific marker for dogs with inflammatory bowel disease, although they could represent a biomarker for immune-mediated diseases and infections.     

Electrophoretic examination of changes in the protein spectrum of dogs after exposure to beta, beta'-dichlorodiethylsulfide]

In serum proteins, the alpha 3 + 4-globulin subfraction increases with a corresponding decrease of albumins. A statistically significant rise was observed from the 24th-48th hour from application with a progressive tendency reaching its maximum in the terminal stage of intoxication. This elevation reaches the values of 100% of the initial control values in the terminal stage. The drop in albumins is less significant and almost reciprocal with the rise of alpha-globulin content. In the values of beta-globulins, a change was observed in the quotient of beta 1/beta 2 globulins. No changes were ascertained in the values of gamma-globulins. Our results correspond to the data published by Gjessing and Chanutin, who observed a drop in albumins and rise in alpha-globulins after percutaneous implantation of the substance. The results suggest that the latent time between implantation and a statistically significant rise of the alpha-globulin fraction in the serum is 24-48 hours.     

The correlation between California mastitis test results and the presence of mastitis pathogens in composite milk samples

Extract

In this, the Ira Cunningham Memorial Lecture, I will not detail all the Professor's achievements. He did so much so well, that I would be hard put to do justice to his record in the time available. What I will do is reflect on his professionalism and on the way he took that professionalism out to work in society.     

Perceptions,practices, and consequences associated with foodborne pathogens and the feeding of raw meat to dogs

This study explored the impact of feeding raw meat to dogs on the fecal prevalence of several enteric bacterial zoonotic pathogens. Campylobacter jejuni was isolated from 1/42 (2.6%) raw meat-fed dogs. Salmonella enterica was isolated from 2/40 (5%) of the raw meat feeds, 6/42 (14%) raw meat-fed dog feces, none of the dogs that did not receive raw meat (P = 0.001), 4/38 (10.5%) of the vacuum cleaner waste samples from households where raw meat was fed, and 2/44 (4.5%) of vacuum cleaner waste samples from households where raw meat was not fed to dogs (P = 0.41). Responses to a questionnaire probing practices and beliefs regarding raw meat feeding that was administered to dog owners demonstrated that dog owners may either not be aware or refuse to acknowledge the risks associated with raw meat-feeding; thus, they may neglect to conduct adequate intervention strategies to prevent zoonoses among themselves and their families.