Spatiotemporal interactions between wild boar and cattle: implications for cross-species disease transmission

Controlling infectious diseases at the wildlife/livestock interface is often difficult because the ecological processes driving transmission between wildlife reservoirs and sympatric livestock populations are poorly understood. Thus, assessing how animals use their environment and how this affects interspecific interactions is an important factor in determining the local risk for disease transmission and maintenance. We used data from concurrently monitored GPS-collared domestic cattle and wild boar (Sus scrofa) to assess spatiotemporal interactions and associated implications for bovine tuberculosis (TB) transmission in a complex ecological and epidemiological system, Doñana National Park (DNP, South Spain). We found that fine-scale spatial overlap of cattle and wild boar was seasonally high in some habitats. In general, spatial interactions between the two species were highest in the marsh-shrub ecotone and at permanent water sources, whereas shrub-woodlands and seasonal grass-marshlands were areas with lower predicted relative interactions. Wild boar and cattle generally used different resources during winter and spring in DNP. Conversely, limited differences in resource selection during summer and autumn, when food and water availability were limiting, resulted in negligible spatial segregation and thus probably high encounter rates. The spatial gradient in potential overlap between the two species across DNP corresponded well with the spatial variation in the observed incidence of TB in cattle and prevalence of TB in wild boar. We suggest that the marsh-shrub ecotone and permanent water sources act as important points of TB transmission in our system, particularly during summer and autumn. Targeted management actions are suggested to reduce potential interactions between cattle and wild boar in order to prevent disease transmission and design effective control strategies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0122-7) contains supplementary material, which is available to authorized users.     

Effects of triploidy on feed efficiency, morphometric indexes and chemical composition of shi drum, Umbrina cirrosa L.

Productive performances of triploid (3n) and diploid (2n) shi drum (Umbrina cirrosa L.) were evaluated over an experimental period of 76 days. Fish, selected according to body weight (196 specimens from each ploidy), were reared in tanks (two for each thesis) under the same environmental and dietary conditions. A practical extruded diet (crude protein: 43.4%; ether extract: 19.3%) was offered to fish according to a feeding rate that varied from 1% to 1.5% of live weight. Both at the beginning and at the end of the trials, samples of fish were submitted to morphometrics and chemical analysis. The final body weight and the specific growth rate of triploid fish were significantly lower than those of fish diploid. The feed efficiency of triploids showed a reduction in crude protein retention. Juvenile triploids evidenced a larger amount of coelomatic fat, and their gonads were atrophic. The whole‐body proximate composition of 3n fish was characterized by a higher ether extract and a lower crude protein content than 2n fish. Triploids had higher liver lipid content; there were no significant differences in viscera proximate composition. Sum, the results showed that chromosome set manipulation in this species can reduce productive performances at a juvenile stage, influencing some morphometric traits.     

A Preliminary Study of the Biological Control of Strongyles Affecting Equids in a Zoological Park

The main goal in this research was to determine the beneficial effect of incorporating biological procedures in parasite control programs for equids in zoological parks. Two trials were developed for Equus quagga, E asinus , and E africanus asinus. The first trial (September 2010 to August 2011) consisted of chemotherapy only (ivermectin plus praziquantel), and the second trial (September 2011 to September 2012) consisted of administration of chemotherapy and chlamydospores of the nematophagous fungus Arthrobotrys (Duddingtonia) flagrans. The effect of these measures was evaluated by the estimation of the reduction in the fecal egg counts (FECR). In the first trial, 100% FECR values were achieved 15 days after treatment in all the animals. The egg reappearance period (ERP) was 2-3 months for the equids, and all of them were passing strongyle eggs in the feces at 2-4 months after their deworming. In the second experiment, the FECR values were 100% in the three species. ERPs of 3 months in the European donkeys, 4 months in the Africans, and 6 months in the zebras were recorded. All the equids had positive results for the coprological flotation test 4-8 months after anthelmintic administration. This preliminary study demonstrates the incorporation of chlamydospores of nematophagous fungus, as A flagrans appears highly promising for reduction of the infective stages of the strongyles affecting captive animals, but the experimental design precludes true determination of whether the treatment is fully efficacious.     

An automated spectrophotometric method for measuring canine ceruloplasmin in serum

An automated method for the determination of ceruloplasmin activity was developed and validated in canine serum. The method is based on the in vitro oxidase activity that this protein shows with substances such as p-phenylenediamine. In order to determine optimum assay conditions, the effects of the substrate concentration, buffer pH, reaction time and EDTA on the reaction were evaluated. The precision of the assay was good with within-run and between-run coefficients of variation lower than 10%. The method measured the ceruloplasmin values in a proportional and linear manner (r = 0.99) with a limit of detection of 0.0007 +/- 0.0001 Delta Abs/min. A temperature of -20 degrees C kept the reagent stable for 30 days. The method is cheap and easy to adapt to any automated biochemical analyser, considerably decreasing the processing time required with the manual method. Additionally it allows to differentiate dogs with pyometra and trauma from clinically healthy dogs.     

Epidemiological study on porcine circovirus type 2 (PCV2) infection in the European wild boar (Sus scrofa)

Porcine circovirus type 2 (PCV2) is considered as the causative agent of postweaning multisystemic wasting syndrome (PMWS) in domestic pigs, where the virus is ubiquitous as evidenced by serological surveys. We present the results of the first nationwide sero-survey on the presence of PCV2 antibodies in European wild boars, and report the first PMWS case in a wild boar from Spain. Sera from 656 hunter harvested wild boars from 45 different geographical sites and 22 additional imported animals were analysed by means of an immunoperoxidase monolayer assay (IPMA). We also examined the tissues from 55 healthy and one diseased wild boars for the presence of PCV2 nucleic acid and PMWS lesions by in situ hybridisation and histopathology, respectively. Additionally, abundance estimates of wild boars and field interviews were carried out on 30 sampling sites. The prevalence of medium to high PCV2 serological titres among the examined wild boars was 47.89 +/- 1.9%. Seropositive wild boars appeared in all but one of the geographical regions analysed. Seroprevalence and titre of PCV2 antibodies were closely related to the management of the wild boar populations. Wild boars from intensively managed, farm-like populations had higher prevalence than wild boars living in more natural situations. The effect of wild boar abundance and management on PCV2 antibody prevalence was further evidenced by the high correlation existing between the relative abundance estimates of animals and the percentage of wild boars with medium to high levels of PCV2 antibodies. PCV2 nucleic acid was detected in the tissues of three wild boars. One of these was diagnosed as PMWS. The results, in addition to information on piglet mortalities, suggest a potential role of PMWS in piglet mortality in intensively managed wild boar populations.     

A Field Investigation into Delivery Systems for Agents to Control Moniliophthora roreri

This paper describes a factorial trial designed to investigate the delivery systems of fungal biological agents (Clonostachys rosea), applied as single strain or as strain mixture, in comparison with copper hydroxide as a chemical standard against Moniliophthora roreri in cocoa. Application techniques compared were motorised mistblowers fitted with rotary atomisers and hydraulic sprayers fitted with cone nozzles giving a narrow angle of spray. The third factor was the presence or absence of an emulsifiable rape-seed adjuvant oil in the tank mixture. Copper fungicide was the best agent for moniliasis control and resulted in the highest yield. Both the mycofungicides reduced sporulation of the pathogen. Net reduction of inoculum was best for the hydraulic sprayer-applied copper fungicide and the motorised mistblower-applied single-strain biocontrol agent. Overall, directional hydraulic sprays were found to be somewhat superior to the motorised mistblower technique, with its dissipated cone of spray. Addition of the adjuvant oil was the least important of the factors, but efficacy depended on the agent used, with a significant enhancement in the efficacy of copper with oil but a detrimental effect on C. rosea.     

A semiquantitative cytological evaluation of normal and pathological samples from the external ear canal of dogs and cats

Abstract  Numbers of desquamated epithelial cells, yeast cells and bacterial organisms were counted in samples collected from the external ear canal of 37 normal dogs and 16 normal cats, and from 24 dogs and 22 cats with otitis externa. The aims of the study were to establish quantitative reference ranges and to correlate these data with the clinical status of the dogs and cats. Numbers of yeast cells and bacterial organisms were significantly increased in dogs ( P  = 0.05; P  = 0.0001) and cats ( P  = 0.0001; P  = 0.0001) with otitis externa, and in most cases high counts were correlated with clinical signs. Mean Malassezia counts per high-power dry field of ≥ 5 in the dog and ≥ 12 in the cat were considered abnormal. Mean bacterial counts per high-power dry field of ≥ 25 in the dog and ≥ 15 in the cat were considered abnormal. When used to differentiate normal from inflamed external ear canals, these figures provided a low sensitivity but a specificity of ≥ 95%.     

Broncholithiasis in a cat: clinical findings, long-term evolution and histopathological features

A 14-year-old neutered male Persian cat was evaluated because of an acute exacerbation of a chronic cough of 2-3 years of duration. Physical examination was normal except for the auscultation of accentuated breath sounds and wheezes cranially on both sides of the chest. Complete blood count, biochemical parameters and urinalysis were normal. Thoracic radiographs showed a generalised nodular pattern with multiple mineral opacities. Oral prednisone and doxycycline were prescribed. Two weeks later, the frequency of the cough was significantly reduced. Terbutaline was recommended for relief of acute exacerbations. Three years later the cat was evaluated again due to a non-related disease that led to the euthanasia of the cat. Concerning its respiratory disease, the cat had experienced nearly asymptomatic periods of 3-6 weeks of duration punctuated by acute exacerbation periods of 7-10 days, during which terbutaline was useful to relieve the cough. Thoracic radiographs showed a mild increase in the size and extent of the pulmonary mineralisation. Histopathologically, mild bronchitis and bronchiectasis were evident, accompanied by calcified bronchial plugs and marked hyperplasia and hypertrophy of the seromucinous glands. Based on clinical and pathoanatomical findings, a final diagnosis of miliary broncholithiasis and bronchiectasis was made. Broncholithiasis should be considered in differential diagnosis of pulmonary mineralisation in cats. When no concomitant diseases are present, this rare disease appears to have a slowly progressive evolution that does not appear to carry a bad prognosis and may be satisfactorily managed with combinations of bronchodilators and corticosteroids.     

Effects of the butyric acid‐producing strain Clostridium butyricum MIYAIRI 588 on broiler and piglet zootechnical performance and prevention of necrotic enteritis

The objective of this study was to assess the effects of a probiotic strain Clostridium butyricumMIYAIRI 588 (CBM588) on broiler and weaned piglet health and zootechnical performance. Five field studies were carried out in broilers and five in weaned piglets under European feed additive guidelines. Each study followed a randomized blocked design with two treatments: Control (basal diet) and CBM588 supplemented groups. The zootechnical performance parameters selected were body weight, daily gain, feed intake and feed efficiency (feed:gain). Broilers fed diets with CBM588 gained significantly more weight (+2%, p < .001) and exhibited significantly better feed efficiency (?1.6%, p < .001) in comparison with Controls. Similarly, analysis of pooled data of weaned piglet trials showed that CBM588‐fed piglets were significantly heavier than Controls (+2.6%, p = .014), exhibited significantly higher mean daily gain (+4.7%; p = .004), and significantly improved feed efficiency (?4.2%, p = .001). In addition to the zootechnical efficacy studies, the preventive effect of CBM588 on necrotic enteritis (NE) was assessed in a natural challenge model in broilers where CBM588 reduced the incidence and severity of NE lesions. These data indicate the potential of CBM588 to improve broiler and weaned piglet zootechnical performance, and to make a positive contribution to animal health.