2007 - 76 (3)

Modern pig breeding companies mostly have a high sanitary status. Nevertheless, acquiring new breeding stockeven from companies with a high sanitary status always implies certain hygienic risks. Purchased breeding stock maycarry infectious agents which are not monitored on the farm of origin, or may become contaminated during transport.SPF or minimal disease breeder pigs have no acquired immunity against the infectious agents which they are guaran -teed free of. Thus on arrival at the farm of destination, they come in contact with some of these agents and may developserious disease symptoms. There fore, newly acquired breeding stock should go into quarantine on arrival, and the pre -mises used for the quarantine should be thoroughly cleaned and disinfected before arival.

The present case study describes a 14-year-old female intact Staffordshire with large granular lymphocytic (LGL) leukemia with an aggressive clinical course. This is a rare lymphoproliferative disorder that is unique due to the morphology of the neoplastic lymphocytes, which are characterized by the presence of large round to irregularly shaped azurophilic cytoplasmic granules. The diagnosis was made on the basis of a combination of clinical signs (lethargy, anorexia, vomiting and diarrhea), routine hematology (anemia, thrombocytopenia, and circulatory neoplastic cells), cytology, histopathology (involvement of liver, spleen and bone marrow) and immunophenotyping. Neoplastic lymphocytes were characterized as T-cells likely expressing the gamma/delta receptor. This condition closely resembles hepatosplenic lymphoma in humans.

This paper describes the first outbreak of bovine babesiosis caused by Babesia divergens in Flanders, Northern Belgium. Since 2002, every year in spring and autumn fattening cows showed severe depression, anorexia, fever, anemia, jaundice and haemoglobinuria. Babesiosis was diagnosed based on the clinical signs and on the identification of B. divergens in blood smears and by IFAT and PCR. The management of this herd (continuous import of new susceptible animals) precluded the development of enzootic stability. Prevention of babesiosis in this herd was based on prophylactic or metaphylactic treatment with imidocarb and/or intensive tick control with flumethrin. However, these treatments did not prevent new outbreaks, despite a strong reduction of the number of ticks on the animals. A short review on B. divergens infections in cattle is included in this article.

The effect of the feeding history of dogs and of the addition of different fat sources (chicken lard (CL), rapid harvested salmon oil (RS) and non-rapid harvested salmon oil (NRS)) to their diet on the palatability of dog foods was investigated. Three diets were tested in twelve healthy adult Beagle dogs using a modified two-pan preference test: a basal diet with chicken lard (CL) and two diets with 1% salmon oil, one being with rapid-harvest salmon oil (RS) and the other with non-rapid-harvest salmon oil (NRS). Substitution of 1% chicken lard by 1% salmon oil decreased the (n-6):(n-3) fatty acid ratio from 9 to 5. The oxidative status in both oils and foods was rather low, but the difference between the two salmon oils was prominent. Absolute food intake did not differ significantly among the diets, most likely due to numeric differences in absolute food intake between test periods. Relative intake showed a significant difference between CL (38.5 % of total food intake) and NRS (28.1 %), whereas no difference was noted between RS (33.4 %) and NRS and between CL and RS. The preceding diet had no effect on diet preference.

In the present study, the practice of semen examination and semen processing in Belgian porcine artificialinsemination (AI) centers was evaluated by means of a written questionnaire. The questionnaire was sent to 50AI centers and 38 filled it in and returned it (response rate 76%). The size of the herds in the responding centers variedbetween 4 and 165 boars, with a mean of 45. In 80% of the AI centers, the semen doses contained at least 3billion spermatozoa. Sperm morphology and motility were considered the most important parameters forsperm quality evaluation. Semen morphology was systematically examined in 71% of AI centers. A lower limitof 80% normal spermatozoa was used in 66% of the AI centers. Motility was monitored systematically in everyejaculate in 94% of AI centers. A lower limit of 70% motility was used. Motility assessment was performed visuallyin all but one of the AI centers.Ninety-seven percent of Belgian AI centers used a short-term semen extender (storage for 3 days). Since sementransport times are short in Belgium, there is no necessity for long-term storage of diluted porcine semen.In 50% of the AI centers, long-term extenders (storage for 7 days) were used on a part of the collected semen,mainly for storage over the weekend. In some AI centers, extender solutions at room temperature are added tothe ejaculate, apparently without negative effects on fertility. Antibiotics are seldom supplemented to the extendedporcine semen. The semen doses contained in most cases 100 ml extended semen.The present study shows that the Belgian porcine AI centers generally incorporate semen quality examinationsin their daily routine, especially for motility assessment. In a minority of AI centers, especially the smaller ones,the semen morphology examination should be done more systematically. This focus on semen quality, togetherwith the consistent use of a sufficient number of spermatozoa per semen dose, reflects the concern of Belgian AIcenters to produce quality semen doses. In some AI centers, improvements in semen handling could be made,especially concerning the temperature of the extender and its preservation conditions.

Equine herpesvirus (EHV) 1 is an important pathogen of horses. Upon infection, the virus replicates in theupper respiratory tract. Then it spreads to internal organs via a cell-associated viremia. Local replication in in -ternal o gans may result in abortion and nervous system disorders. The currently designed vaccines are not ableto induce significant protection against EHV1-induced viremia. However, several vaccines are able to induce asignificant level of protection against either abortion or nervous system disorders. Which immune responsescorrelate with this protection is so far unknown. Besides vaccination, management will remain a crucial factor inthe prevention of EHV1-induced clinical signs. Management measures include the vaccination of all horses onthe premises to reduce infection pressure; the separate housing of young horses, adult horses and pregnant mares;strict hygiene measures and strict control of contact with horses from outside the premises. If, despite vaccination andthorough management, an outbreak of EHV1-induced disease occurs, treatment with antiviral agents may be useful.

Paper in Dutch

The use of improved diagnostic techniques has resulted in an increasing demand for effective treatment ofbrain tu mors. In this ar ti cle, the li te ra tu re on the use and re sults of dif fe rent ty pes of the ra pies such as sur ge ry,chemotherapy, radiation therapy, hormonal therapy, immunotherapy and gene therapy are being reviewed.The im por tant role of the blood-brain bar rier in all its as pects is con si de red. Espe ci al ly the ni tro sou re as, theirside ef fects and sur vi val ti mes are re vie wed in de tail. The most suc ces sful stra te gy in brain ne opla sia is mul -ti-modali ty treatment, whe re a combi nation of neurosurge ry, radi ation therapy and che mothe rapy is applied.Multi-modality therapy can be planned ide ally after obtaining a his tologic diagnosis.

Paper in Dutch