Intradermal and serological testing for mites in healthy beagle dogs

Background – Intradermal testing (IDT) is widely used in veterinary medicine to select allergens for immunotherapy. The recommended concentration for mites is 250 protein nitrogen units (PNU)/mL. It is not known whether healthy dogs responding to this concentration have asymptomatic sensitization or irritation. Furthermore, interbatch and intersupplier variability of allergens has not been fully addressed. Hypothesis/Objectives – The incidence of positive IDTs in healthy beagles was recorded and the value of combining these results with serology to differentiate between asymptomatic sensitization and irritancy evaluated. Additionally, the interbatch and intersupplier variability of allergens was assessed. Animals – Seventeen healthy laboratory beagles with no history or clinical signs of canine atopic dermatitis were used. Methods – Intradermal tests were performed with four mite allergens from two suppliers (varying batches). An initial IDT at 250 PNU/mL was used to determine whether decreasing or increasing test concentrations were used in the subsequent titration IDTs. Additionally, two IgE ELISA tests from different manufacturers were performed. Results – Seven of 17 dogs showed IDT reactions at 250 PNU/mL. There were highly significant allergen interbatch and significant intersupplier correlations and agreement. The associations between the IDT reactions and the IgE serologies statistically identified two groups of dogs: one with positive serology and IDT reactions at 250 PNU/mL; and another with negative serology and IDT reactions. Conclusions and clinical importance – Our results suggest that dogs that have IDT reactions and positive serology are asymptomatically sensitized, while dogs that react at higher allergen concentrations, but have negative serology, do so as a result of irritant reactions.     

Clinical and endocrine responses to treatment with deslorelin acetate implants in ferrets with adrenocortical disease

OBJECTIVE: To evaluate the clinical and endocrine responses of ferrets with adrenocortical disease (ACD) to treatment with a slow-release implant of deslorelin acetate. ANIMALS: 15 ferrets with ACD. PROCEDURE: Ferrets were treated SC with a single slow-release, 3-mg implant of deslorelin acetate. Plasma estradiol, androstenedione, and 17-hydroxyprogesterone concentrations were measured before and after treatment and at relapse of clinical signs; at that time, the adrenal glands were grossly or ultrasonographically measured and affected glands that were surgically removed were examined histologically. RESULTS: Compared with findings before deslorelin treatment, vulvar swelling, pruritus, sexual behaviors, and aggression were significantly decreased or eliminated within 14 days of implantation; hair regrowth was evident 4 to 6 weeks after treatment. Within 1 month of treatment, plasma hormone concentrations significantly decreased and remained decreased until clinical relapse. Mean time to recurrence of clinical signs was 13.7 +/- 3.5 months (range, 8.5 to 20.5 months). In 5 ferrets, large palpable tumors developed within 2 months of clinical relapse; 3 of these ferrets were euthanatized because of adrenal gland tumor metastasis to the liver or tumor necrosis. CONCLUSIONS AND CLINICAL RELEVANCE: In ferrets with ACD, a slow-release deslorelin implant appears promising as a treatment to temporarily eliminate clinical signs and decrease plasma steroid hormone concentrations. Deslorelin may not decrease adrenal tumor growth in some treated ferrets. Deslorelin implants may be useful in the long-term management of hormone-induced sequelae in ferrets with ACD and in treatment of animals that are considered at surgical or anesthetic risk.     

Rapid in planta detection of Chalara fraxinea by a real-time PCR assay using a dual-labelled probe

Chalara fraxinea is a fungus currently threatening ash trees (Fraxinus excelsior) in several European countries. This emerging pathogen was assigned to the EPPO’s alert list and therefore accurate detection and identification tools are needed. Because of its slow growth rate on agar media and the frequent presence of fast-growing saprotrophic fungi within the host tissue, classical isolation techniques are time-consuming and sometimes inefficient. In this study, we used species-specific polymorphisms observed within the internal transcribed spacer region to design a primer pair and a dual-labelled probe to be used in a real-time PCR assay for the detection of C. fraxinea. The test proved to be specific, based on in silico and in vitro assessments, and could detect as little as 20 fg of C. fraxinea DNA. A protocol was developed in order to detect the pathogen directly in plant tissue and proved to be more efficient and rapid than isolation on agar plates. This new tool should be useful both for monitoring and to conduct epidemiology research on this emerging pathogen.     

Treatment of canine atopic dermatitis: 2010 clinical practice guidelines from the International Task Force on Canine Atopic Dermatitis

Atopic dermatitis (AD) is a common chronic relapsing pruritic skin disease of dogs for which treatment has varied over time and geographical location. Recent high quality randomized controlled trials and systematic reviews have established which drugs are likely to offer consistent benefit. The International Task Force for Canine AD currently recommends a multi‐faceted approach to treat dogs with AD. Acute flares should be treated with a combination of nonirritating baths and topical glucocorticoids, once an attempt has been made to identify and remove the suspected causes of the flare. Oral glucocorticoids and antimicrobial therapy must be added when needed. In dogs with chronic AD, a combination of interventions should be considered. Again, factors that trigger flares of AD must be identified and, if possible, avoided. Currently recognized flare factors include food, flea and environmental allergens, Staphylococcus bacteria and Malassezia yeast. Skin and coat hygiene and care must be improved by bathing with nonirritating shampoos and dietary supplementation with essential fatty acids. The severity of pruritus and skin lesions can be reduced with a combination of anti‐inflammatory drugs. Currently, medications with good evidence of high efficacy include topical and oral glucocorticoids, and calcineurin inhibitors such as oral ciclosporin and topical tacrolimus. The dose and frequency of administration of these drugs should be tailored to each patient considering each drug’s efficacy, adverse effects and cost. Allergen‐specific immunotherapy should be offered, whenever feasible, in an attempt to prevent recurrence of clinical signs upon further exposure to environmental allergens to which the patient is hypersensitive.     

Experimental modification of reciprocal recurrent selection in oil palm breeding in Cameroon

Reciprocal recurrent selection (RRS) exploits the genetic complementarity of dura populations of palms with a small number of large bunches and tenera/pisifera group of palms with large number of small bunches. An extra phase was introduced to RRS just after the second cycle of selection where outstanding dura derived from (DA3D × DA5D) combinations of the second cycle were self-pollinated for seed production. Best palms based on the phenotype were selected and crossed with pisifera of second cycle offspring of LM2T. [(DA3D × DA5D) self-pollinated × LM2T self-pollinated] progenies were field tested at La Dibamba (Cameroun) from 1987 to 1997. They were precocious with regard to the three-first years’ bunch yields (13.16–15.77 t/ha). Homogeneity for all bunch yield components and homogeneity for vertical growth were illustrated by low values of the variation coefficient (5.75–7.75%). The oil yield was 107% of the control against 115% from [(DA3D × DA5D) × LM2T self-pollinated] progenies of the second cycle of RRS, mostly due to poor mesocarp to fruit and poor oil to mesocarp ratios which led to a low oil extraction rate. The extra selection phase led mainly to homogenisation of progenies but also reduced the fruit quality. However, three progenies whose average oil yield represented 115% of the control (4.87 t/ha) in addition to their precocity can be released to oil palm growers. The extension of RRS did not fully meet expectations and poses the problem of its reliability.     

Electrocardiography‐guided and retrospective analysis of central venous catheter placement in the dog

Objective To compare the success rates of central venous catheter placement (CVCP) in dogs using electrocardiograph (ECG)‐guided and external landmark (‘blind’) techniques. To report success rates determined retrospectively of CVCPs in dogs using external landmarks at a tertiary referral institution. Study design Prospective blinded comparison of techniques. Retrospective analysis of case records. Animals Adult Beagles weighing 11.9 ± 2.6 kg were used in the experimental group (n = 38). Various breeds of dogs were in the retrospective clinical group (n = 33). Methods Laboratory dogs were anesthetized and CVCPs were placed using a modified Seldinger technique. Catheter tip position was first based on external landmarks and then the catheter was repositioned using an ECG‐guided placement. The ECG‐guided technique used the V‐lead with the positive electrode attached to the guide wire. Catheter placement was determined by moving the catheter cephalad and caudad to the point of maximum p‐wave amplitude and then withdrawing the catheter 1–2 cm from this point. Catheter position with each technique was determined using a lateral thoracic radiograph. Retrospective data were collected from the medical records of dogs that had CVCPs using anatomical landmarks and corresponding thoracic radiographs. Results The number of successful CVCP attempts was the same for both prospective groups (21/38). There was no statistically significant difference in success between the ECG‐guided technique and the blind technique. From the retrospective investigation 10/33 of the cases that fit the criteria had correct CVCPs. Conclusions and clinical relevance The odds of correctly placing a central venous catheter by ECG‐guidance were the same as the external landmark technique. The ECG‐guided technique may be useful in situations where external landmarks are not readily available.     

Forest liming durably impact the communities of ectomycorrhizas and fungal epigeous fruiting bodies

? Liming is a forestry practice used to counteract forest decline in acidic soils. It consists of direct Ca and Mg input to forest soil, which restores tree mineral nutrition, but also modifies microbial communities in soil. The aim of this study was to assess the effects of liming on both belowground (ectomycorrhizal root tips) and aboveground (epigeous sporocarps) fungal communities.

? Results showed that the modification of soil chemical properties (pH, and Ca-Mg contents versus total free Al and Fe concentrations) was a stronger factor of ECM community structuring than tree host. The species appearing in limed plots were ubiquist or known as good competitors and replaced acidophilic and stress species.

? At the sporocarp level, tree host was a stronger factor of community structuring than soil chemical properties associated with liming. On the whole, there was a shift in the community composition from a typical acidophilic forest fungal community of medium altitude in the untreated plots to a less typical one, with the reduced dominance of acidophilic fungi while many late-stage forest species appeared.

? We finally suggest a marker species (Russula ochroleuca) to assess both above and belowground effects of liming on ectomycorrhizal communities.

     

The timing of inorganic fertilization of sunfish ponds

Fertilization with diammonium phosphate (20 kg/ha per application) was initiated at different dates in each of four treatments replicated three times in 0.04-ha ponds. Although there were some differences in averages of total and filtrable orthophosphate concentrations and phytoplankton abundance among treatments (P < 0.05), sunfish production was not influenced by the timing of fertilization (P > 0.05). Phytoplankton blooms did not develop in any of the treatments until late spring or early summer. The failure of phytoplankton to respond to fertilization in late winter and early spring was apparently related to low water temperature and competition by macrophytes. In larger, deeper ponds (> 0.5 ha), inorganic fertilization will cause phytoplankton blooms in early spring even when water temperatures are low.     

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.