ABSTRACTS OF PAPERS PRESENTED AT THE 24TH ANNUAL

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ISRAEL JOURNAL OF

VETERINARY MEDICINE

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ABSTRACTS OF PAPERS PRESENTED AT THE 24TH ANNUAL

ISRAEL VETERINARY SYMPOSIUM, APRIL 17, 2000

Symposium chairperson: K. Perk

Koret School of Veterinary Medicine

MOLECULAR EPIDEMIOLOGY OF RABIES VIRUS ISOLATES FROM ISRAEL

AND OTHERS MIDDLE AND NEAR EASTERN COUNTRIES

D. David

1

, B. Yakobson

1

, J. Smith

2

and Y. Stram

3

1. Rabies Laboratory, Virology Division, Kimron Veterinary Institute 50250 Bet-Dagan.

2. Rabies Laboratory, Viral and Rickettsial Zoonoses Branch, Division of Viral and Rickettsial Diseases, National

Center for Infectious Diseases 1600 Clifton Road, N. E. Atlanta, GA 30333 USA.

Two hundred and twenty six isolates of rabies from different areas of Israel including three human isolated and one sample from South Lebanon were diagnosed between 1993 and

1998 by direct immunofluorescence using monoclonal antibodies to the viral nucleoprotein

(N). An epidemiological survey based on nucleotide sequence analysis of 328 bp from the Cterminus of the N protein coding region and the non-coding region between the nucleoproteinphosphoprotein (NS gene) was performed. Phylogenetic analysis of the Israeli isolates showed that they were related geographically but not according to host species. Five variant, geographically-related groups distributed in four national regions were indentified, In each region rabies virus was isolated from more than one animal species. A comparison of the sequence analysis of rabies samples from the rest of world revealed a two - nucleotide change that distinguished the Middle East variants from the rest.

THE EFFECT OF TWO VACCINATION PROTOCOLS ON THE DEVELOPMENT

OF HYPERTROPHIC OSTEODYSTROPHY AND IMMUNIZATION IN A LITTER OF

WEIMARANER DOGS

N. Safra

1

, H. Bark

1

, T. Waner

2

, I. Aizenberg

1

, A. Mosenco

1

, M. Radoshitsky

1

and S.

Harrus

1

1. School of Veterinary Medicine, Hebrew University of Jerusalem.,

2. Israel Institute for Biological Research, Ness Ziona.

The effect of two different vaccination protocols on the development of hypertrophic osteodystrophy (HOD) and immunization in a litter of 10 Weimaraner puppies was investigated. Five puppies (group 1) were vaccinated with a modified live canine parvovirus vaccine and two weeks later with a trivalent vaccine containing modified live canine distemper virus and advenovirus type 2 combined with a Leptospira bacterin. This vaccination cycle was repeated twice, at two week intervals. Group 2 was vaccinated with 3 consecutive multivalent vaccines containing modified live canine distemper virus, canine parvovirus, parainfluenza and adenovirus type 2 combined with a Leptospira bacterin at 4 week intervals. All puppies were first vaccinated at the age of 8 weeks. Three dogs in group 1 developed HOD, while all five dogs in group 2 developed HOD during the study period. Dogs in group 1 developed higher antibody titers to canine distemper virus and parvovirus compared to the dogs in group

2.

The results of this study futher strengthens the previously reported observation of a direct link between vaccination and clinical HOD in Weimaraners, and indicate that the 2 different vaccination protocols affected the pattern of appearance of HOD and immunization in the

Weimaraner puppies.

SEX DETERMINATION IN PSITTACINES

U. Bendheim

1

, Y. Plotsky

2

,A. Haberfeld

2

and E. Fire

2

1. Koret School of Veterinary Medicine, the Hebrew university of Jerusalem

2. Genepoint

In the past decade sales of pet bird have increased by 6% to 8% annually in Europe and the

USA, with parrots constituting most of the market. Along with the expansion of the trade in birds, international agreements were put into effect (CITES), making it more difficult to hunt and transport wild birds from one country to another, and forcing people to establish breeding farms. Such farming requires a precise matching of couples. Therefore, many bird species are sold in couples, since their behavior as a couple is special and preferable. Moreover, the age of sexual maturity is between 1 to 7 years and the breeding frequency in many species is once a year on average. Different species of birds (particularly most of the psittacines) do not have visible secondary sex characteristics. Hence, there is a need for sex diagnosis by surgical or hormonal methods in order to select breeding couples.

Common bird sexing methods in use today

Morphological difference (m.d.): There is great variability in the percentage of psittacine species with external sex differences according to geographical regions:

------------- 80% of psittacune species in South-East Asia and Oceania exhibit m. d.

------------- 42% of psittacune species in Austria exhibit m. d.

------------- 32% of psittacune species in Africa exhibit m. d.

------------- 13% of psittacune species in South America exhibit m. d. Furthermore, half of all psittacines in South America are Amazons, most of which exhibit minimal m. d.

There are interesting differences between similar and phylogenetically related species. Thus most Lory species do not exhibit m.d.. while among their smaller relatives, the Lorikeets, 13 out of 32 species (over 40%) do exhibit m. d.

However, even in psittacine species with m. d., veterinarians must resort to surgical or DNA sexing in species where the differences only appear when the bird is older. Thus, out of a total of 2935 sexing laparoscopies that were performed in Israel, 9.3% were on Ringneck

Parrakeets, 2.9% on Cockatoos, 2.3% on Plum-headed Parrakeets and 1.3% on Mounstache

Parrakeets, all of which have distinct m.d. in adulthood.

The main approaches to sex determination in psittacines without m. d., are as follows:

Surgical: By inserting an optical fiber into the abdominal cavity one can determine the type of gonads (testicles or ovaries). The procedure is performed under anesthesia. The disadvantages of this method are as follows: It cannot be perfomed on young chicks. The method not only requires special expertise by the veterinarian, but also relatively expensive equipment. It requires and intrustive surgical procedure under anesthesia. The main advantages are immediate results, and additional information about the gonads and possible pathological lesions in other organs.

Hormonal: Sex can be diagnosed by determing the ratio of estrogen to testosterone levels.

This method is not accurate in parrots and is not currentlt in use.

Sex chromosome differences with karyotype testing . This method requires live cells for diagnosis. Today only one laboratory in the USA can identify the sex of 300 different bird species using this method. The use of this method is limited primarily due to the difficulties that are involved in the transport of live cells, and it is time consuming and costly.

DNA differences: This method enables detection of differences of the DNA as detected by the polymerase chain reaction . The test is performed only in a few laboratories in Europe and the USA. Its usage is constantly on the rise. The disadvantage of this method is that it is time consuming since it requires sending blood samples to an overseas laboratory.

MEGABACTERIA IN BIRDS: CLINICAL AND PATHOLOGICAL ASPECTS

A. Lublin

1

, S. Mechani

1

, G. Eshkar

2

and Y. Weisman

1

1. Kimron Veterinary Institute, Bet Dagan

2. Vete rinary Clinic, Rishon Le’Zion

The disease caused by megabacteria is amongst the less familiar diseases to private practitioners in spite of its growing prevalence in Israel in the last years.

Megabacteria are very huge rod-shaped bacteria attacking the digestive system of birds, especially small pet birds such as canaries, finches and several psittacine species, and also poultry and ostriches. Their presence in the bird stomach, especially the proventriculus, and their feature to fill the proventricular glands that secret hydrochloric acid, causing elevated alkalinity in the stomach They therefore impair digestion and absorption of food, leading to progressive loss of body weight and emaciation. The clinical signs are: cahexia, swallowing difficulties with frequent regurgitation, greenish diarrhea, and accumulation of undigested food around the cloaca. Usually the appetite is not impaired. The bird dies within a few weeks to a few months from the clinical signs. The disease attacks birds of all ages,

In the department of Avian Diseases of the Kimron Veterinary Institute the disease was diagnosed in various avian species, usually small to intermediate-sized pet birds: canaries, finches, budgerigars, lovebirds, cockaties, and in chikens, turkeys and ostriches. Extreme high prevalence was found in canaries, lovebirds and budgerigars (in 45-60% out of the suspected birds that were tested). In large parrots only little prevelence of these bacteria could be found. During post-mortem examination it is pssible to run a fast microscopic diagnosis of the bacteria by direct scraping taken from the proventricular wall and especially from the lining of the proventriculus and the gizzard. The bacteria are seen also without stainig (X500 magnification is recommended) but it is possible to stain them with Giemsa or

Gram staining (Gram-positive). In heavy infection the bacteria can be diagnosed also by fecal or cloacal smears of live birds. In historical sections they are seen as red-coloured after PASstainig.

The pathological lesion appear especially in the digestive tract: dilatation of the proventriculus, thin proventricular wall and sometimes also the intestinal wall, bloody or black covering of the stomach wall, sometimes with gelatnious exudation, undigested food in the digestive tract even up to the cloacal opening.

Due to the unclear taxonomic position of megabacteria there is no consensus regarding treatment for this problem. There are those who claim that this agent is a fungus and not a bacterium while others claim that they are saprophytic bacteria belonging to the Lactobacilli group. Therefore, some clinicians recommend to treat with broad-spectrum antibiotics and others recommend anti-fungals. There is a recommendation to limit the ratio of concentrated food and to supplement vegetables, bread crumbs and egg yolk, and also to acidify the

drinking water (lemon juice, vinegar etc., as 6% of drinking water).

In a controlled experiment in a flock of budgerigars with recurrent outbreaks of megabacteriosis we found that administration of one dose of Lactobacilli suspension

( Luctobacillus spp.) directly into the crop dimished the infection rate from 90% to zero and also the infection score as determined by bacterial density on a microscopic slide. Due to the fact that Lactobacilli live and multiply also in the digestive tract their shedding lasted weeks after treatment but the status of the flock must be checked from time to time and treatment must be carried out again if necessary.

CARP ERYTHRODERMATITIS A NEW AND INCREASINGLY PREVALENT

DISEASE IN ISRAEL

S. Tinman

1

and S. Maurice

2

1. Central Fish Health Laboratory, 19150 Nir David, Israel

2. Institute of Biochemistry, Food Science and Nutrition, Faculty of Agriculture, Food and Environmental Quality

Sciences, The Hebrew University of Jerusalem, P.O.Box 12, 76100 Rechovot, Israel

The common carp ( Dor 70 x Yugoslavian) is intensively cultured in out-door earthen ponds thoughout the central and northern regions of Israel. Carp erythrodermatitis, a disease that has plagued European carp for several decades, was not observed in Israeli carp prior to

1997.

Subsequent to the initial observation at the Central Fish Health Laboratory (CFHL) in Nir

David, the incident of reported cases has consistently increased, with and increase of 96% from 1997 to 1998 and an additional 28% by summer 1999. An analysis of the temporal appearance of disease symptoms demonstrated a relativaly broad temperature range of 11-

23 0

C with a mean of 16.7±2.6

0 C. Disease symptoms were first observed in association with a decrease in ambient temperature during the fall and persisted during the colder winter days.

Once water temperature exceeded 23 0 C, ulcers rapidly healed and new cases were not observed. Clinical signs consist of deep ulcers accompanied by peripheral necrosis which is present in the epidermis and extends into the underlying musculature, hemorrhagic inflamation at the base of the finnage, and in expreme cases, slight to extreme exophthalmia.

The symptoms are limited to external involvement only, and no pathologic signs are apparent on gross examination of the internal organs. A comparative chemical analysis of serum from ulcerated and apparently healthy fish was performed and the findings were similar to those previously by recorded data. Achromogenic atypical Aeromonas salmonicida was consistently isolated on trypticase soy agar containing 0.01% Coomassie Brilliant Blue-R-250 from samples taken from the periphery of small ulcers. Identification of the bacterial isolates was performed by PCR for the presence of the virulent A-protein gene, SDS-PAGE of total bacterial proteins, biochemical enzymatic activity and DNA typing. These isolates were compared with cultures acquired from Japanese Koi carp ( Cyprinus carpio ) and goldfish

( Carassius auratus ) that are co-cultured with the common carp. It was determined that a single atypical strain is the causative agent of carp erythrodermatitis in Israeli carp and Koi while a different strain is responsible for goldfish ulcer disease.

FIELD OBSERVATIONS OF A HERPES VIRAL DISEASE OF KOI CARP

(CYPRINUS CARPIO) IN ISRAEL

S. Tinman and I. Bejerano

Central Fish Health Laboratory, 19150 Nir David, Israel

During the first week of May 1998 and following uncontrolled introduction of Koi carp from

Europe, massive mortality of Cyprinus carpio species was observed along the Coastal plain.

This outbreak, first reported during the early spring months, was followed by 2 further outbreaks during the fall of 1998, and the early spring of 1999. Economic losses included more than 600 metric tons of common carp and 4 million dollars of high quality Koi intended for export.

Although this disease process was observed as being highly contagious and extremely virulent, morbidity and mortality were restricted to Koi and common carp populations. Several other species (including other cyprinids such as Goldfish) within the same ponds remained completely asymptomatic to the disease. During the three-week period of the outbreak, every

Cyprinus carpio population within the region was affected. Mortality rates were consistently

80% in every pond.

The disease process was triggered by specific temperatures, as indicated by its reappearance during the transien range of spring and fall (18-27 0 C). Temperature seems to be the most dominant environmental factor affecting the clinical presence of disease. Gross external clinical signs included severe necrosis of gill tissue, superficial hemorrhages, and increased mucus production. Internally fish showed petechial hemorrhages on the liver, and other inconsistent pathological changes. Behavioral symptomology included fatigue and exhibition of gasping movements in areas of shallow water. Affected C. carpi o populations were characterized as highly susceptible to various non-specific secondary infection of parasitic, bacterial, and fungal origin. Biochemical asays of C. carpio blood samples revealed severe osmoregulatory dysfuction, a general hypoproteinemia, and hepatic dysfunction.

Additional studies exhibited a general state of immunosupression in infected fish, compared to normal populations. All tests yielded negative results for all known viral diseases of carp.

Histological sections of hematopoeitic kidney tissue and gill epithelium of infected fish revealed the presence of intranuclear inclusion bodies. These particles, viewed with electron microscopy, were found to be characteristic of herpesvirus-like forms. Lately, the agent was cultured and identified by Hedrick et al. (USA) as Koi herpesvirus (KHV). Recently similar results were found in Israeli laboratories. In the attempt to characterize the epidemiological character of the virus several cohabitation trials were conducted early in the diagnostic process. The majority of Koi and common carp, which were regarded as survivors of clinical outbreaks, were found to be resistant to consecutive disease outbreaks and/or challenge. Our studies show that this resistance could not be transferred congenitally to the next generation.

Current studies are focused on development of rapid diagnostic methods (molecular, cell lines and blood analysis). In addition, much effort is focused on development of resistant carp populations (resistant strains of carp and artificial immune resistance).

PROBABLE TOXICOSIS IN COWS CAUSED BY CISTUS SPP.

I. Yeruham

1

, U. Orgad

2

, S. Perl

2

, Y. Avidar

2

, M. Bellaiche

2

, M. Liberboim

1

and A.

Sholsberg

2

1. Kimron Veterinary Institute, 50250 Bet Dagan

2. Hachaklait

A probable toxicosis caused by ingestion of Cistus creticus (incanus ) and C. salviifolius bushes in a herd of beef cows grazing in the Carmel foothills is described.

This rare toxicosis probably occured due to predominance of these spp. in poor pasture undergoing regrowth after severe fire damage, and a relative scarcity of annual and perennial fodder plants.

The animals had received a supplement of polyethylene glycol at a dosage of 40 g/cow/day during June to November in their drinking water.

A progressive syndrome developed comprising cachexia, depression, difficulty in urinating, anorexia, subcutaneous edema under the jaw, dry rough coats, crusted muzzles. The eyes showed marked chemosis with hyperemic sclera. A high mortality rate of 59% (20/34 animals) in first and second calving cows, which were newly introduced to this pasture, and 5.4%

(4/74) in adult cows, was noted during two study years. Increases in blood urea, creatinine, aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), inorganic phosphorus and triglyceride (TG) were noted. The main pathological findings were cystitis and in some cases pyelonephritis, with greatly increased bladder wall thickness.

On the basis of epidemiology, clinical signs, clinico-pathological and pathological findings and renal histology, a tentative diagnosis of Cistus toxicosis was made.

EPHEMERAL FEVER (THREE-DAY SICKNESS) IN CATTLE IN ISRAEL

I. Yeruham

1

, D. Tyomkin

1

and M. Van-Ham

2

1. Hahaklait

2. Veterinary Services

Ephemeral fever is an infection of cattle and buffalo. The causal virus is classified as a rhabdovirus and the vector is culicodes spp. and mosquitoes (Culex spp., Aedes spp.). Most probably they are the source for the virus in the winter.

Ephemeral fever was decribed earlier in Israel. From 1930 to 1990, 6 outbreaks were recorded. All outbreaks occured in the summer and outumn. The appearance of the disease depends on seasonal activity of the arthropods which spread the virus. Wind activity plays a part in the spreading the virus from one geographic area to another.

In 1990 the disease was diagnosed on September 9 and lasted for almost two months. In

1999 the disease was diagnosed on May 26 and lasted almost 7 months. The geographic area where the disease appeared first and the mode of spread were identical in both outbreaks.

The disease rate was high especially among dairy cattle in community settlements located in the Syrian African Rift Valley. In 1990 the average morbidity rate was 20% and in 1999 it was

40%. The morality rate in 1990 was 3% and in 1999 it was almost 4% per herd. The average abortion rate was 2.5%.

The lowest morbidity rate was notice among calves younger than 4 months old. Older calves till the partition reached 15.6%, heifers 34.4%, and cows 38.4%, and dry cows - 9.8% morbidity. The mortality or slaughter rate have a similar trend with 0.4% in calves till a year old and 4.4% for the number of cows in the herd.

The morbidity rate in general was lower as the distance increased from the original focus of infection while the mortality and slaughter rate on the contrary increased.

Milk production losses were estimated as 380 per milking cow. Also an increase in somatic cell count was registered in the sick milking cows. This increase reached a 3-fold count compared to the healthy cows in the same herd. There was also an increased prescription of drugs and in medical care.

In clinical follow-up in 14 family dairy cattle farms in 8 villages much higher mortality and morbidity rates were recorded.

EPIDEMIOLOGICAL, BACTERIOLOGICAL AND ECONOMICAL ASPECTS OF

MASTITIS ASSOCIATED WITH YELLOW JACKET WASPS (VESPULA

GERMANICA) IN A DAIRY CATTLE HERD

I. Yeruham

1

, A. Schwimmer and Y. Braverman

2

1. Hahaklait

2. Kimron Veterinary Institute, Bet Dagan

The German wasp, Vespula germanica (Fabr.) (Hymenoptera: Vespidac) has been observed to injure dairy cows teats, causing lesions that lead to clincal or subclinical mastitis. The presence of skin lesions on the teats caused by wasps was recorded in a dairy cattle herd located in the Samaria foothills during July through October.

43.6% (58/133) of the adult cows and 1.4% (1/17) of the first-calving cows respectively were injured by the wasps. 43% (n=25) of all quarters, 27.6% (n=16) of the front quarters and

29.3% (n=17) of the hind quarters were injured. In 62% (36/58) of the adult cows and one first calving cow, and in 29.3% (17/58) of the cows clinical mastitis and subclinical mastitis respectively were diagnosed. The most common bacteria isolated from the cows were

Staphylococcus aureus 45.1% (n=14), Streptococcus dysgalactiae 16.1% (n=5), and

Streptococcus spp. 22.6% (n=7).

The loss in milk production was estimated to be 300 kg milk per cow injured by wasps with clinical mastitis. An increase in the bulk-milk somatic cell count from 186x10 3 in the month prior to the outbreak to 435x10 3 in the post outbreak month was noted. The culling rate reach

12% (7/58) of the affected adult cows and the one affected first-calving cow was also culled.

TREATMENT THREE CLINICAL CASES OF TETANUS IN HORSES BY

INTRATHECAL INJECTION OF TETANUS ANTITOXIN

A. Steinman

1

, R. Haik

1

, D. Elad

2

and G.A. Sutton

1

1. Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Large Animal

Department, Veterinary Teaching Hospital, P.O.B. 12, 76100 Rehovot, Israel

2. Kimron Veterinary Institute, P.O.B. 12, 50250 Bet Dagan, Israel

Tetanus is a highly fatal disease for which routine treatment is well described in the literature. Intrathecal administration of tetanus antitoxin as an adjunct to routine treatment has been mentioned, but clinical reports are scarce. The lack of reports leaves us with many unsolved questions.

We describe intrathecal administration of tetanus antitoxin in three cases of tetanus in horses.

Diagnosis of tetanus was based on a biological assay in the case of the foal, and was based on the history of a subsolar abscess 1 to 2 weeks earlier and the clinical signs on presentation in the two yearlings. Tetanus antitoxin was administered in the foal into the atlanto-occipital space and in the two yearlings into the lumbo-sacral space. The latter method, although mentioned as an alternative, has never to the best of our knowledge, been described in a case report. No adverse effects were noted in any of the three cases. One yearling died of respiratory failure, the second yearling improved initially but was euthanized due to secondary complications, and the foal completely recovered.

We believe that intrathecal administration of tetanus antitoxin is important as an adjunct to the routine treatment of tetanus in horses, but further data should be collected reagarding the dose, the site of administration, the additional administration of steroids and adverse effects.

THE INTERACTION BETWEEN CLIMATIC FACRORS AND BLUETONGUE

OUTBREAKS IN ISRAEL AND THE EASTERN MEDITERRANEAN, AND THE

FEASIBILITY OF ESTABLISHING BLUETONGUE-FREE ZONES

Y. Braverman

1

, F. Chechik

2

and B. Mullens

3

1. The Kimron Veterinary Institute, Bet Dagan, Israel

2. The Meteorological Services, Bet Dagan, Israel

3. Department of Entomology, University of California, Riverside, CA, USA

Israel has accumulated extensive information on bluetongue (BT) occurrence in sheep flocks and sentinel cattle in various region of the country for more than 30 years.

Meteorological parameters had not been independently correlated with the occurrence of BT over the entire period. Meteorological parameters preceding years with high prevalence of bluetongue (1975, 1987, 1988 and 1994) (average of 43 sheep flocks affected) were compared with those for years with little or no BT transmission (1980, 1981, 1983 and 1992).

Winter preceding high-BT seasons were significantly warmer; the average maximum temperature of the coldest month was 2 to 3 0 C higher, and the average maximum and minimum temperatures were 1 to 2 0 C higher. After extermely dry and warm winters over the eastern Mediterranean, such as those of 1998 and 1999, single cases of BT occured in 1998 and none in 1999. Rainfall in BT outbreak years was approximately normal, whereas winters preceding low-BT seasons were wetter (40% more rainfall than average in the coldest month and 17% more winter rainfall overall). BT outbreak years had significantly more winter days with maximum temperatures higher than 13 or 18 0 C,and more nights with minimum temperatures > 5 0 C. Average maximum temperature below 16.5

0 C for the coldest winter month were associated with low-BT seasons, while winters with more than 18 days warmer than 18 0 C were followed by high BT outbreaks. In most parts of Israel except mountains >700 m above sea level, the average maximum temperture of the coldest winter month is >12.5

0 C, which is thought to enable the survival of BT viruses. Mountain areas also have fewer animals/km 2 than lowland areas, and more of these are BT-resistant ruminants such as goats.

Two “safe zones” with regard to export of ruminants and their products are proposed: in the

Arava Desert Valley and on mountains above 700 m. Bluetongue outbreaks are not known in these regions. The Arava is regarded as a particulary low-risk region because there are smaller numbers and presumed lower survival of the principal vector, Culicoides imicola . The

Arava Desert Valley is also outside the persian Trough air stream, which seems to be connected with the introduction of BT into Israel. These safe zones might be exploited for export of animals and germplasm.

TRANSPLACENTAL EFFECTS OF HIGH-FAT DIETS ON CHEMICALLY INDUCED

TUMORIGENESIS IN OFFSPRING

I. Zusman, G. Kossoy, B. Sandler, G. Yarden, H. Benhur, A. Stark and Z. Madar

Koret School of Veterinary Medicine and Institute of Biochemistry, Food Science and Nutrition, Faculty of Agricultural, Food and Environmental Quality Sciences, Hebrew University of Jerusalem, and Kaplan Medical Center, Rechovot, Israel

We evaluated whether feeding pregnant females a diet high in olive-oil content that demonstrated a tumor-preventive effect in adults has a similar preventive effect on chemically-induced mammary gland cancer in rat offspring. The control group was fed the same 7% corn-oil diet as their mothers. Experimantal group I was fed the 7% corn-oil diet while their mothers received the 15% olive-oil diet. Experimental group II was fed the same

15% olive-oil diet as their mothers. Offspring were twice administered 7,12dimethylbenz(a)antracene (DMBA) in a dose of 10 mg/rat. Maternal feeding of rats with the

15% olive-oil died did not show distinct tumor preventive effect: the number of tumor-bearing rats reached 52.0% in control offspring, increased to 60/6% among offspring of experimantal group II and to 67.7% in offspring of experimantal group I. In spite of this fact, the mean tumor size was significantly smaller in offspring born to mothers fed the 15% olive-oil diet compared

to those born from mothers fed a control diet (2.9 and 2.4 vs. 5.9 cm 2 , respectively). Diffrent types of lymphocytes (B and T cells) and the synthesis of apoptosis-related proteins (Fas ligand (FasL), p53, bcl-2) were studied in order to evaluate activity of the splenic immune system and of a tumor. On a cellular level, maternal feeding a diet rich in olive oil before pregnancy results in different manners in their offspring, and results dependent on the type of feeding of progeny. In the spleen, the feeding of mothers with the 15% olive-oil diet activated the reaction of B and T systems to the carcinogenic effect already in offspring fed a control diet. In offspring fed the same rich fat diet, the activation of the lymphoid system was manifested in higher degree. In a tumor, activity of Tcell killers/suppressors, macrophages and of the synthesis of bcl-2 protein was found to manifest on the border of tumors in both groups of offspring born to mothers fed the 15% olive-oil diet. Although, activity of all parameters was significantly higher in offspring fed th same rich-fat diet. A high correlation was found between different parameters studied. The findings indicate that feeding mothers on a diet high in fat concentrations retains its cancer-inhibiting role in offspring, but such a role is manifested in different ways, mostly on the cellular level.

CONTROL OF TICKS WITH ENTOMOPATHOGENIC NEMATODES AND FUNGI

M. Samish

1

, G. Gindin

2

, E. Alekseev

1

and I. Glazer

2

1. Kimron Veterinary Inst., P.O.Box 12, 50250, Bet Dagan, Israel

2. A.R.O., The Volcani Center, P.O.Box 6, 50250, Bet Dagan, Israel

The biocontrol of plant pests is already very well established. Many examples of commercial fruit and vegetable protection by biocontrol agents without the involvement of chemical pesticides can be cited.

The development of tick biocontrol is however far behind that of plant pests. As yet there exist no commercial anti tick biocontrol agents. The increasing resistance of ticks to acaricides, the reduction in permitted residues, the awarenes for the need of a “clean” environment and the demand of the market for “organic” foods necessitate the introduction of alternatives to chemical pesticides.

Ticks spend about 20% of their life on their host and most of their time they are hidden in humid niches on or in the upper layer of the ground. Such humid places may be well suited for the activity of entomopathogenic nematodes as well as fungi.

We found that the cattle tick Boophilus annulatus is highly susceptible to various entomopathogenic nematode strains under laboratory conditions as well as in buckets filled with soil. The susceptibility of the ticks was similar to that of insects, which are commercially controlled by such nematodes.

Dipping Boophilus annulatus ticks in a suspension of 1x10 7 conidia/ml of entomopathogenic fungi Metarhizium anisopliae resulted in over 90% mortality.

The success in killing ticks by these two types of agents under laboratory conditions does not guarantee success under field conditions. However if we extrapolate from the success obtained in this research of biocontrol of plant pests it appears to be highly desirable to invest increasing efforts in microbial control of ticks.

OVINE LENTIVIRUS AS ANALOGS TO AIDS

K. Perk

Koret School of Veterinary Medicine, Hebrew University of Jerusalem A majority of ovine lentivirus (OvLv) infections seen on farms develop after long incubation and a slow progression of disease to death but in nature they may also have short latency and cause acute leukoencephalitis and/or acute arthritis and pneumonia in young kids or lambs with exceptionally high mortality. Histopathologically, OvLv diseases may be characterized by lymphoid infiltration, lymphoid hyperplasie with germinal centers and plasmocytosis in the lungs and/or in the CNS, joints and udder. Lymphoid hyperplasis in lymph nodes and spleen, as well as lymphoid infiltration in the kidneys, are almost always seen in advanced cases. In some cases, it shows similarities to lymphoproliferative diseasses that are considered malignant. Alveolar epithelial hyperplasia in the lungs is generally also seen, especially in older goats with caprine arthritis, encephalitis virus (CAEV), and proliferation of these epithelial cells may form acine and papillary structures and in some cases are histopathologically indistinguishable from tumor nodules seen in sheep pulmonary adenomatosis. Because of complexities in the host-lentivirus interaction, cell-associated transmission and extensive antigenic and genomic variation among infacting isolates, control of infection or prevention of spread are problematic by traditional methods and exploration of alternative control strategies employing selection and expansion of animals genetically resistant to OvLv or transgenic for certain viral genes, merits consideration. Interestingly, the pure Awassi sheep breed are susceptible to infection but do not develop the disease, as do

European breeds or crose-breeds in Israel, i.e. they are infected but not diseased. It seems that the local Beduin black gost breed is resistant to infection of CAEV under natural conditions. Their imported counter-parts are highly susceptible to both viruses. If verified, disease control could be accomplished either by expansion of resistant breeds or by identification, cloning and selecting for or introducing genes responsible for OvLv resistance.

PROPHYLACTIC EFFECT OF DORAMECTIN ON CANINE SPIROCERCOSIS

E. Lavy, I. Aroch, A. Markovics, H. Bark, A. Hagag and S. Harrus

School of Veterinary Medicine, Hebrew University of Jerusalem and The Veterinary Institute

Bet DaganThe prophylactic effects of doramectin on canine spirocercosis infection was investigated in 12 groups of beagle dogs artificially infected with Spirocerca lupi larvae. Group

1 (5 dogs) received three subcutaneous injections of doramectin (200µg/kg), at one month internvals. Group 2 (5 dogs) served as untreated controls. One month after the last injection, all 10 dogs were orally challenged with 40 infectious larvae (L3) of S. lupi . Two dogs from the control group (group 2) died suddenly on days 34 and 55 post infection from hemothorax due to aortic rupture. On necropsy aortic aneurysms were found in both dogs.

S. lupi worms were found in one dog. The 3 remaining dogs in group 2 developed esophageal granulomas which were initially detected by endoscopy four months post infection. S. lupi eggs were also detected in the feces of these 3 dogs at 5 months post infection. No esophageal abnormalities were detected in the 5 dogs in group 1. and all fecal examinations were negative for S. lupi eggs, up to 5 months post infection. We conclude that doramectin administered monthly is an efficient prophylactic regimen for S. lupi challenge.

"YUNNAN PAI YAO-A CHINESE HERBAL MEDICINE FOR PREVENTION

& TREATMENT: OF HAEMORRHAGE IN ANIMALS"

Ch. Ben-Yakir and S. Ben-Yakir

"Hod-Hasharon Veterinary Clinic"

Bleeding in animals bother veterinarians all over the world, since we are dealing with a great variety of animal species, and not as in humane medicine we do not carry different types of blood to all the different animals, nor do we carry diagnostic kits that we have to treat for bleeding.

In the lecture we will discuss a traditional Chinese medicine that is assisting us in prevention and treatment of bleeding in animals.

The remedy is getting popular in the last few years in differnt parts of the global veterinary community.

We will give indications for use, contra-indications, dosages for different species of animals, drug composition, pharmacology and pharmaco-kinetics and our own experience with this drug.

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