The present study describes the clinical, serological and bacteriolological findingsin calves from two beef herds experiencing outbreaks of pneumonia. The clinical signs were nasal discharge, cough, pyrexia and increased respiratory rates. The morbidity and mortality rates over a month period were 40.72% and 15.63% respectively. Laboratory investigations revealed that bovine viral diarrhea virus (BVDV) was involved in and probably initiated both outbreaks as indicated by a significant increase in antibody titers against BVDV in sera of convalescent calves (paired serum samples). No antibodies bovine herpesvirus-1 (BHV-1), bovine respiratory syncytial virus (BRSV) and parainfluenza-3 (BPIV-3) viruses were detected in both acute and convalescent sera. Mycoplasma bovis was concurrently demonstrated in lungs of affected calves as it was isolated from 13 (81.25%) of examined lungs suggesting that there may be a synergism between bovine viral diarrhea virus and Mycoplasma bovis in the pathogenesis of pneumonia. A total of 15 (68.18%) isolates of Mannheimia haemolytica, 5 (22.73%) Pasteurella multocida, 1 (4.54%) Pseudomonase aerugenosa, 3 (13.64%) Staphylococcus aureus, 3 (13.64%) Actinomycis pyogenes, 1 (4.54%) Klebsiella pneumonae, 1 (4.54%) Streptococcus pneumonae, 2 (9.09%) E. coli and 2 (9.09%) Aspergellus fumigatus were recovered from lungs of calves suffering from pneumonia.

The present study was designed to investigate trypanosomiasis among one of native freshwater fish breed in Egypt namely catfish (Clarias gariepenus). Fifty fish were collected during summer season from the river Nile at Giza markets. The fish were examined for the presence of trypanosoma in the blood. Trypanosoma were detected in 10 (20%) of the collected fish. The main clinical signs of infected fish with trypanosoma were emaciation, dullness, respiratory distress, loss of escape reflex, mild ascitis and paleness of the gills. Post-mortem examination of infected fish revealed paleness of the internal organs (liver and kidneys) and slight congestion of spleen. Haematological examination of infected fish revealed significant decrease in erythrocytic count, haemoglobin and packed cell volume but significant increase in total leucocytic count accompanied with neutrophilia and eosinophilia. Serum biochemical analysis demonstrated a significant decrease in urea, total protein and albumin while a significant increase in AST, ALT, ALP, creatinine, glucose and 1- globulin were recorded. Microscopic examination of organ histopathological sections revealed cloudy swelling of hepatocytes with activation of kupffer cells, depletion of lymphocytes with thickening of tile trabeculae in spleen. While in kidney, necrobiotic changes of epithelial lining of renal tubules with vacuolation of glomeruli as well as hemorrhages were recorded.

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.

Fifteen outbreaks with clinical picture and post- mortem lesions similar to that of rabbit haemorrhagic viral disease (RHVD) were investigated in vaccinated flocks during the period between February and July 2005 at Kafr El-Sheikh Governorate. Twelve representative liver homogenate were positive in haemagglutination test (HA) using human type (O) washed RBCs, with titer more than 1/160. Detection of virus particles by electron microscopy, histopathological findings as well as pathogenicity test , confirmed that the outbreaks were RHVD. The possible role of field rats for the transmission and spread of RHVD among rabbitaries was studied. Cross reactivity and cross protection tests were conducted. These tests proved that the newly emerged RHVD isolates were not closely related to classical local vaccinal strain of RHVD and may be a variant strain.

A total of 980 camels were employed in this study for evaluation of somediagnostic procedures used for diagnosis of camel trypanosomiasis. Clinicalexamination revealed that 180 (18.37%) camels showed sings of illness including, loss of body weight, anemia, abortion, decrease of animal production and edema in some parts of the body. Parasitological examination of camel’s blood smears revealed the presence of Trypanosoma evansi in 57 (5.82%) camels. ELISA detected 99 (63.06%) positive cases while suratex test identified 80 (50.96%) positive cases. Results of mice inoculation test for detection of Trypanosoma evansi among camels showed that 69 (43.95%) camels were positive. The present study clarified that suratex test was 100% sensitive for diagnosis of trypanosomiasis followed by ELISA (98.55%).

Psittacine beak and feather disease (PBFD) is a common viral disease of wild and captive psittacine birds characterized by symmetric feather loss and beak deformities. The causative agent, beak and feather disease virus (BFDV), is a small, circular single-stranded DNA virus that belongs to the genus Circovirus. BFDV can be detected by PCR or the use of haemagglutination (HA) and haemagglutination inhibition (HI) assays that detect antigen and antibodies respectively. Erythrocytes from a limited number of psittacine species of Australian origin can be used in these tests. In South Africa, the high cost of these birds makes them difficult to obtain for experimental purposes. Investigation into the use of erythrocytes from African Grey parrots and Brown-headed parrots yielded positive results showing the haemagglutinating activity of their erythrocytes with purified BFDV obtained from confirmed clinical cases of the disease. The HA activity was further confirmed by the demonstration of HI using BFDV antiserum from three different African Grey parrots previously exposed to the virus and not showing clinical signs of the disease.

The virulence of four South African field isolates of NAD-dependent Haemophilus paragallinarum and two field isolates of NAD-independent H. paragallinarum has previously been tested in unvaccinated chickens. In this study, the disease profiles caused by the NAD-dependent isolates of H. paragallinarum in vaccinated chickens were studied. It was shown that the clinical signs induced in the vaccinated chickens were substantially less severe than were those in unvaccinated chickens, as was expected. However, due to the high virulence of the serovar C-3 isolates, clinical signs in the vaccinated chickens challenged with this isolate were still detected. These were as severe as those occurring in unvaccinated chickens challenged with serovar B-1 isolates. Although the clinical signs induced in unvaccinated birds challenged with serovar A-1 were more severe than those occurring when vaccinated birds were challenged with serovar C-3, the overall disease profiles were similar. Substantial clinical signs were recorded in vaccinated birds challenged with serovar C-3. This could be interpreted as vaccination failure if the disease profile obtained in unvaccinated birds is not considered. It was found that a high level of protection was provided by this vaccine against challenge by serovar C-3. The high virulence of this serovar resulted in the development of clinical signs in vaccinated birds. These findings could possibly explain the large number of so-called vaccination failures that are reported in South Africa.

The concentration of organochlorines (OCs) such as organochlorine pesticides and polychlorinated biphenyls were measured in adipose tissue collected from 14 male hippopotami at Mfuwe in the southern part of the Luangwa National Park, Zambia. The samples contained low levels of OCs, and the concentrations of OCs were comparable to or lower than reported for wild herbivores studied in other parts of the world.

The taxonomic status of some nippostrongyline nematodes deposited in the National Collection ofAnimal Helminths, Onderstepoort, is revised. Heligmonina boomkeri n. sp. is described from Aethomys chrysophilus from South Africa. The most closely related species by the body measurementsand the pattern of the caudal bursa is Heligmonina bignonensis Diouf, Bâ & Durette-Desset, 1997, a parasite of Mastomys erythroleucus from Senegal. It differs from the new species mainly in thenumber of ventral cuticular ridges at mid-body (four versus five) and the left ala in the male is shorterthan the body diameter. The systematic position of Heligmonina spira (Ortlepp, 1939) and Neoheligmonella capensis (Ortlepp, 1939) is confirmed here through their synlophe, which was not previously studied.

During the period between January 1999 and December 2000, the distribution and seasonal patterns of amphistome infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Cattle faecal samples were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of intermediate host-snail populations and the climatic factors influencing the distribution were also determined by sampling at monthly intervals for a period of 24 months (November 1998 to October 2000) in six dams and six streams in the highveld and in nine dams in the lowveld communal grazing areas. Each site was sampled for relative snail density and the vegetation cover and type, physical and chemical properties of water, and mean monthly rainfall and temperature were recorded. Aquatic vegetation and grass samples 0-1 m from the edges of the snail habitats were collected monthly to determine the presence or absence of amphistome metacercariae. Snails collected at the same time were individually checked for the emergence of larval stages of amphistomes. A total of 16 264 (calves 5 418, weaners 5 461 and adults 5 385) faecal samples were collected during the entire period of the study and 4 790 (29.5 %) of the samples were positive for amphistome eggs. For both regions the number of animals positive for amphistome eggs differed significantly between the 2 years, with the second year having a significantly higher prevalence (P < 0.01) than the first year. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), for adult cattle than calves (P < 0.01), and in the wet over the dry season (P < 0.01). Faecal egg output peaked from October to March in both years of the study. Bulinus tropicus, Bulinus forskalii and Biomphalaria pfeifferi were recorded from the study sites. The main intermediate host for amphistomes was B. tropicus with a prevalence of infection of 8.5 %. However, amphistome cercariae were also recorded in Biom. Pfeifferi and B. forskalii. Amphistome cercariae were recorded from both the highveld and lowveld areas with peak prevalence during the post-rainy season (March to May). Metacercariae were found on herbage from the fringes of the snail habitats between February and August, with most of the metacercariae concentrated on herbage 0-1 m from the edges of the habitats. Based on the epidemiological findings a control programme was devised. From this study, large burdens of immature flukes could be expected in cattle during the dry months. Since adult cattle would be resistant to the pathogenic effects of the migrating immature amphistomes the target for control would be young animals being exposed to the infection for the first time. Therefore, the first anthelmintic treatment can be administered in calves in mid June when maximum migration of immature amphistomes starting 3-4 weeks after infection in the early dry season would be expected. A second treatment could be given in late July or early August to remove potentially dangerous burdens of immature flukes acquired later in the dry season. Where resources permit, another strategy would be to treat against the mature flukes in March or April in order to reduce the number of eggs deposited on pastures and the opportunity for infection of the intermediate host snails. To reduce cercarial shedding by the intermediate host snails molluscicides can also be applied during the peak transmission periods (April/May and August/September).