Lymph nodes (Ln) are the preferred samples for virus isolation and detection. In the present study, carcass and visceral Ln of apparently healthy cattle were screened for the presence of bovine herpes virus type 1 (BHV-1) and bovine ephemeral fever virus (BEFV) antigens. A total of 198 Ln (114 carcasses Ln and 84 visceral Ln) were collected. Lymph node homogenates were assayed by agar gel precipitation test (AGPT), rapid Staphyloccocal protein A (SPA) agglutination test and Dot-ELISA. The overall results revealed that BHV-1 antigens were detected in 43.9%, 56.1% and in 68.4% of carcass Ln, and in 29.8%, 47.6% and 57.1% of visceral Ln collected from slaughtered cattle by AGPT, SPA agglutination test and Dot-ELISA respectively. On the other hand, BEFV antigens were detected in 5.3%, 38.6% and 52.6% of carcass Ln, and in 6%, 41.7% and 54.8 % of visceral Ln collected from slaughtered animals by AGPT, rapid SPA agglutination test and Dot-ELISA respectively. The results showed high percentage of positive samples with SPA agglutination test and Dot- ELISA in comparison to AGPT for both BHV-1 and BEF.

Dairy cattle reared in western Kenya are exposed to medium to high levels of trypanosomosis risk. The social background, farm characteristics and dairy cattle productivity of 90 and 30 randomly selected farmers from medium- and high-risk trypanosomosis areas, respectively, were compared. All the 120 farmers were visited between July and August 2002. Data analysis was performed using descriptive statistics and analysis of variance. The results showed that increased trypanosomosis risk represented by an increase in disease prevalence in cattle of 1% to 20 % decreased the density of dairy cattle by 53 % and increased the calving interval from 14 to 25 months. The increased risk was also associated with a significant increase in cattle mortalities and in a lactation period of 257 to 300 days. It was concluded that removal of the trypanosomosis constraint on dairy production would lead to expansion of dairying since the domestic demand for dairy products is expected to increase.

Seroprevalence rates of Toxoplasma gondii anti-antibodies in adult goats and sheep from different parts of Zimbabwe were determined. A total of 225 (67.9 %) of the 335 serum samples tested were positive for anti-T. gondii IgG antibodies with the indirect fluorescent antibody test. There were differences in antibody seroprevalences among communal land goats from the different agro-ecological zones (Natural regions IIb and III: 80 and 96.7 %, respectively; Natural region IV: 65.9 %; Natural region V: 45 %; and Natural region III had a significantly higher seroprevalence than IV and V. The highest seroprevalences found in Natural regions II b and III are likely to be linked to the existence of more households and hence the possibility of a higher concentration of domestic cats that increases the chances of environmental contamination with their faeces harbouring T. gondii oocysts. The seroprevalence rate in sheep from a large commercial farm (10 %) was significantly lower than that of sheep reared under the communal grazing system (80 %). Overall, significantly higher proportions of seropositive animals had antibody titres of 1:50 (34.2 % of 225) and 1:100 (44 % of 225) as compared to the 9.8 % and 12 % with antibody titres of 1:200 and > 1:400, respectively.

In the present study, 3 pooled proventricular homogenates were collected from 3 broiler flocks, of chicken 15 to 30 days old, from Monofia Governorate. The 3 flocks were suffered from low growth rate, poor feed conversion rate, uneven growth and increased mortalities. Necropsy of dead chickens revealed proventriculitis with increased proventriculus size. IBD viral antigen was detected in the pooled proventricular homogenate of each flock by AGPT using reference antibodies against IBDV and RT-PCR technique. No other viruses were detected; such as Reo virus, CAV, NDV, IBV and ALV-J. Further characterization of the IBDV isolates were conducted by RFLP assay on PCR products using MboI and BstOI restriction enzymes. Results demonstrate that the 3 IBDV isolates are identical in their RFLP pattern and related to the Del/E variant strain of IBDV.

Evaluation of amitraz against ticks and mites infestation in cattle and sheep in comparison with diazinon and deltamethrin was performed. Amitraz showed over 95 % inhibition of oviposition and hatching of laid eggs at dilution of 1:500 while diazinon and deltamethrin produced around 90 % inhibition of oviposition at the same dilution. Fed ticks were more susceptible for all tested acaricides than the unfed ticks, where amitraz reached its full effectiveness (100 % kill of fed and unfed) 2 weeks after application while diazinon and deltamethrin produced over 90 % at the same dilution. Spraying application of amitraz 12.5 % resulted in 100 % tick control by day 5 and the effect was maintained for further 28 days whereas diazinon and deltamethrin were fully effective by days 9 and 13, respectively and their efficacy were maintained for 16 and 20 days, respectively. Spraying application of amitraz 12.5 % produced 100 % efficacy as no live mites were found on day 17 and maintained in full effectiveness till day 33 where respraying was needed. In conclusion, amitraz produced rapid detachment of ticks from animals; its residual effect was long and protected animals from re-infestation for 29 days and was able to eradicate psoroptes mite infestation in sheep.

The development of thyroid glands of New-Zeland rabbits was studied in 28 fetuses (10-30 days) and 28 rabbits (3 days-5 years). The thyroid premordia appeared at the 12th day of gestation as 2 masses of cords and clumps of cells. The gland assumed the bilobed form with a narrow isthmus in between at the 18th day. Small primitive follicles with narrow empty lumina appeared in 14-day-old fetuses. True follicles were recorded in 20-22 days old fetuses while colloid was seen in the lumina of the central follicles at the 24th day. Light (C- or Parafollicular) cells were seen for the first time at the 12th day. With development of the follicles, C-cells appeared between the follicular cells and some of them come in contact with colloid. The ultimobranchial body (UBB) was observed in 20 days old fetuses close to the thyroid anlage and entered into its tissue at the 22nd day. Later on, it gave thyroid-like follicles or ultimobranchial cysts. With the electron microscope (EM) follicular cells of earlydeveloping fetuses were not yet differentiated. They contained few ill-developed rough endoplasmic reticulum (rER) and mitochondria. The organelles became well developed and the cells started to secrete colloid in full term fetuses. The maximum rate of secretory activity was achieved in the glands of adult rabbits. Changes in the thyroid glands during the postnatal life up to 5 years of age (age of senility) were followed up and described.

Elevated rectal temperature, mucopurulent nasal discharge, mortalities and abortion of pregnant ewes were the main clinical abnormalities recorded in sheep flocks at Seedy Salem Village, Kafr Al-Sheikh Governorate, Egypt following their vaccination by the attenuated Rift Valley vaccine. Meanwhile, 45 of the farmers in the village showed variable findings suggestive for a RVF epidemic and 17 farmers died of haemorrhagic fever as reported by the World Health Organization, WHO (2003). Blood serum samples were collected from 78 humans and 86 sheep and tested for RVF antibodies. We found that, where 11 (12.94%) and 10 (19.30%) of sheep and human sera respectively were positive. The recent history of vaccination of such flocks using the attenuated RVF vaccine lead us to suggest that the used vaccine might be the source of such epidemic.

The objective of this study was to determine whether Bos taurus cattle differ form Bos indicus in their susceptibility to infection with the Muguga stabilate of Theileria parva and in their resistance to the resultant disease. Ten Friesians (B. taurus), ten improved Borans (B. indicus), ten unimproved Borans (B. indicus) and ten Zebus (B. indicus) born to dams from an East Coast fever (ECF) endemic area were inoculated with an infective dose50 dilution of T. parva Muguga stabilate 147. All the animals except one Friesian and one Zebu developed schizont parasitosis. All the improved Borans, nine of the Friesians, eight of the unimproved Borans and six of the Zebus developed a febrile response. Four of the improved Borans, four of the Friesians and three of the unimproved Borans died of theileriosis. No significant difference (P > 0.05) in the prepatent period occurred between the groups, but the Zebus had a significantly shorter duration of schizont parasitosis (P > 0.05) and took a significantly shorter time to recover (P > 0.05) than the other three groups. There was no significant difference in the two parameters between the other three groups. The study showed that three B. indicus breds and a B. taurus breed are equally susceptible to T. parva infection. However, Zebus born to dams from an ECF endemic area showed a better ability to control the course of disease than cattle from ECF free areas.

This paper focuses on the geographical distribution and habitats of Bulinus forskalii, the snail intermediate host of the conical fluke of equids, Gastrodiscus aegyptiacus as reflected by the 1 209 samples in the database of the National Freshwater Snail Collection of South Africa. The 362 different loci on record represent an extensive distribution in KwaZulu-Natal Province, the Limpopo Province, the coastal areas of the Eastern Cape Province and the south-eastern part of the North West Province. Although it was recorded from all types of water-body represented in the database, the highest percentages of samples were recovered from dams (30.4 %) and brooks (28.2 %). The majority of samples came from perennial habitats (59.1%), 60.7% from habitats with standing water, 54.0 % from habitats with clear water and 71.8 % from habitats of which the water was described as fresh. The majority of samples (39.5 %) were collected in habitats of which the substratum was recorded as muddy. The highest percentage of samples, by far (81.5 %), was collected in habitats that fell within the mean yearly temperature interval ranging from 15-20 °C. An integrated decision tree constructed from the data in the database indicated that temperature and type of water-body played a decisive role in determining the presence of B. forskalii in a given area. The results of experimental exposure to miracidia of a local strain of both Schistosoma haematobium and Schistosoma mattheei in the laboratory indicated that a local strain of B. forskalii was incompatible with both these strains of parasite. Research to clarify the role of B. forskalii in the transmission of both Calicophoron microbothrium and G. aegyptiacus in South Africa, is recommended.

The pharmacokinetic profile of difloxacin was investigated in camels after single intravenous and intramuscular administration of 5 mg kg-1 b.wt. After i. v. injection, serum concentration time curve was best described as two compartment open model. The distribution and elimination half lives (t0.5 (') and t0.5())) were 0.513± 0.01 h and 6.3±0.15 h. respectively. Difloxacin was distributed extravascularly with a volume of distribution (Vdss) 1.10 ± 0.035 l kg-1., and total body clearance (CLB) of 0.141+ 0.031 l kg-1 h-1. following intramusclar injection, peak serum concentration (Cmax) 2.59 ± 0.19 ug ml-1 attained after Tmax 3.05 ± 0.035 h. The absorption and elimination half lives (t0.5 (ab) and t0.5 (el)) were 0.95 ± 0.003 and 5.86 ± 0.33 h., respectively. The systemic bioavailablility (F) and the plasma protein binding were 87.95 and 23 %, respectively.