Cytologie bij zangvogels : een nuttige diagnostische tool

Disease outbreaks in Passeriformes housed in group are often of infectious origin. Clinical signs observed are often similar and non-specific. In these cases, cytology is an invaluable tool for developing a presumptive or definitive diagnosis that can guide disease management decisions within a flock. In the first part of this review, the basic principles of cytological sampling techniques and the evaluation of the cytological findings are described. In the second part, an overview of important infectious diseases in Passeriformes is given, in which cytology may lead to a definitive or presumptive diagnosis

An atypical case of proventricular dilatation in a Red-and-green Macaw (Ara Chloropterus)

A Red-and-green Macaw (Ara chloropterus) was presented with regurgitation and passage of undigested seeds in the feces. Radiographic examination revealed dilatation of the proventriculus. Contrast radiography was performed and revealed that the proventricular dilatation and associated clinical signs resulted from circumferential thickening of the proventricular wall leading to severe narrowing of the lumen of the proventriculus. Testing for parrot bornavirus (PaBV) was negative. After the initiation of antimicrobial treatment because of suspected bacterial overgrowth, all clinical signs resolved two weeks after the start of the treatment, and radiographs taken four months after initial presentation revealed a normal appearance and size of the proventriculus. In the present case, bacterial proventriculitis associated with hyperplasia of the proventricular wall was put forward as a final but presumptive diagnosis highlighting the need to differentiate bacterial proventriculitis from other causes of proventricular dilatation in macaws

An atypical case of proventricular dilatation disease in a red-and-green macaw (Ara chloropterus)

A Red-and-green Macaw (Ara chloropterus) was presented with regurgitation and passage of undigested seeds in the feces. Radiographic examination revealed dilatation of the proventriculus. Contrast radiography was performed and revealed that the proventricular dilatation and associated clinical signs resulted from circumferential thickening of the proventricular wall leading to severe narrowing of the lumen of the proventriculus. Testing for parrot bornavirus (PaBV) was negative. After the initiation of antimicrobial treatment because of suspected bacterial overgrowth, all clinical signs resolved two weeks after the start of the treatment, and radiographs taken four months after initial presentation revealed a normal appearance and size of the proventriculus. In the present case, bacterial proventriculitis associated with hyperplasia of the proventricular wall was put forward as a final but presumptive diagnosis highlighting the need to differentiate bacterial proventriculitis from other causes of proventricular dilatation in macaws

Research note : lyophilization of hyperimmune egg yolk : effect on antibody titer and protection of broilers against Campylobacter colonization

Oral administration of antibodies is a promising strategy against various infectious diseases. Previously, it was demonstrated that passive immunization by providing hyperimmune egg yolk through the feed reduces Campylobacter jejuni colonization in broilers. Campylobacteriosis is the most commonly reported bacterial foodborne zoonosis worldwide, and poultry products are the number one origin of these bacteria for human infection. To date, no effective control measures exist to limit Campylobacter colonization in the chicken's intestinal tract. Here, the effect of lyophilization of hyperimmune egg yolk on protection of broilers against C. jejuni was investigated. During an in vivo trial, broiler chickens were prophylactically given feed with lyophilized hyperimmune or non-immunized egg yolk powder starting from day 1 after hatch. At day 11, broilers were inoculated with C. jejuni according to a seeder model. Five days later, all broilers were euthanized and cecal content was examined for C. jejuni colonization. No decrease in C. jejuni colonization was found. The freeze-drying resulted in a 16-fold decrease of the antibody titer in the yolk powder compared to the fresh yolks, presumably caused by structural changes in the antibodies. In conclusion, applying freeze-dried hyperimmune egg yolk failed to protect broilers against C. jejuni colonization, possibly because lyophilization affected the antibodies' functionality

België ontsnapt niet aan het 'rabbit hemorrhagic disease virus-2'

Since 2016, an extensive spread of RHDV2, a virus variant of the classical rabbit hemorrhagic disease virus (RHDV) is ongoing in the Belgian rabbit population. Both variants of the virus usually cause acute death without prior symptoms. Vaccination against both variants of the virus is possible. In Belgium, only a vaccine protecting against the classical RHDV has been registered. On their own responsibility, veterinarians are allowed to import a vaccine protecting against RHDV2 that is registered in another EU member state, in accordance with the so-called legislative waterfall-system. The current epidemiological situation warrants preventive vaccination of rabbits against RHD. It should be noted that myxomatosis is currently rather neglected in view of the increased attention for the RHDV2 spread. Myxomatosis also still causes a high mortality in both wild and domesticated rabbits. Veterinarians should correctly inform the public about the two important viral diseases in rabbits and the possibilities for prevention

Improved Linear Crosstalk Precompensation for DSL

Crosstalk is the major source of performance degradation in next generation DSL systems such as VDSL. In downstream communications transmitting modems are co- located at the central office. This allows crosstalk precompensation to be employed. In crosstalk precompensation the transmitted signal is pre-distorted such that the pre-distortion destructively interferes with the crosstalk introduced by the channel. Existing crosstalk precompensation techniques either give poor performance or require modification of customer premises equipment (CPE). This is impractical since there are millions of legacy CPE modems already in use. We present a novel crosstalk precompensation technique based on a diagonalization of the crosstalk channel matrix. This technique does not require modification of CPE. Furthermore, certain properties of the DSL channel ensure that this diagonalizing precompensator achieves near-optimal performance