A generalized staphylococcal scalded skin-like disease in lambs

An idiopathic disease involving skin and kidneys was seen in two Merino lambs from the same herd. A generalized skin exfoliation in association with acute renal failure were the most prominent clinical features. The condition resembled staphylococcal scalded-skin syndrome of man, and pure cultures of Staphylococcus aureus were isolated from the lesion. Acute renal failure was diagnosed by clinical, biochemical and histological criteria, and necropsy.     

Doxycycline toxicity in calves in two feedlots

Doxycycline toxicity caused by a large overdose (10 times the therapeutic dosage) in two feedlots is described. The clinical symptoms occurred after 2-3 days and mortality 5 days after the onset of the medication which was added to the milk replacement. Mortality reached 25% (five calves) and 27% (seven calves) in herds A and B, respectively. Pathological and histological findings revealed pulmonary oedema, myocardial degeneration and necrosis. These findings confirm the cardiovascular toxicity, caused apparently by doxycycline administration to the calves, and indicate the potential side-effects of this drug in cattle.     

Study of apparent hypersensitivity to Culicoides species in sheep in Israel

Between 1983 and 1997, a low incidence of seasonal allergic dermatitis was diagnosed in sheep in Israel aged eight months to eight years, in 10 flocks of a variety of breeds, but not the local Awassi breed. The 40 affected animals reacted with scratching, biting and vigorous stamping of the feet from April to November each year. The principal skin lesions were hyperkeratosis, spongiosis and infiltrations of eosinophils and mononuclear cells, typical of an allergic dermatitis which was probably a hypersensitivity reaction to biting insects. The epidemiological findings in relation to the area of Israel affected, the breeds of sheep and the distribution of the lesions suggested that the sheep's hypersensitivity was due to the bites of several species of Culicoides.     

Seasonal allergic dermatitis in sheep associated with Ctenocephalides and Culicoides bites

The clinical, epidemiological and histopathological findings of two pruritic dermatites in sheep in Israel are described. The first type of dermatitis affected mainly young animals with lesions predominantly on the legs. It occurred from March to November, with a peak in June. The second type affected animals of all ages and was mainly on the ventrum. It was sporadic but occurred throughout the year with a peak in October. The morbidity rate of this syndrome reached 4.3% in one flock. The histopathology of both conditions was consistent with an allergic dermatitis. Fleas and midges were collected and identified as Ctenocephalides felis felis and various species of Culicoides. The population density, seasonal activity, geographical distribution and feeding behaviour preferences of the insects and the incidence of the two types of dermatitis suggest that fleas and midges were the causal agents. Flea and midge bite pruritic dermatoses should be considered in the differential diagnosis of sarcoptic and psoroptic mange.     

The life cycle of Rhipicephalus bursa Canestrini and Fanzago, 1877 (Acarina: ixodidae) under laboratory conditions

The biology of Rhipicephalus bursa has not been thoroughly studied. In the present study R. bursa was bred in the laboratory and its biology worked out.Larvae, nymphs and adult Rhipicephalus bursa ticks were fed on sheep and were held at 28+/-1 degrees C and 89+/-1% relative humidity (RH) in a darkened incubator. The average weight of engorged females was 0.676g (range 0.353-1.128). The average weight of eggs laid by females was 0.344g (range 0.146-0. 554g). The average number of eggs laid was 7527 (range 6263-8860) and this was significantly correlated with the weight of the females. The index of Reproduction Efficiency (number of eggs per g weight of female) was 8469.6. The index of Conversion Efficiency (weight of eggs per weight of female) was 0.5037.Peak daily oviposition, at an average of 840 eggs per female, occurred on the 6th day of oviposition. After Day 6, the rate declined steadily. The average duration of the preoviposition period was 5.1 days (range 4-7 days). The oviposition period averaged 16.5 days (range 12-21 days), and was significantly related to both the weight of the female and the number of eggs laid. The average pre-hatching period was 31.2 days (range 24-45 days). The average feeding time of larvae and nymphs of this two host tick was 15.2 days (range 14-18 days). Female ticks fed for 5.9 days on the average.Heavier nymphs produced females and a shorter premoult period was noted for lighter male nymphs. The males/females ratio was 1.38:1. The time taken to complete the life cycle was on average 142.45 days (range 99-254 days).     

Epidemiological and Bacteriological Aspects of Mastitis Associated with Yellow‐Jacket Wasps (Vespula germanica) in a Dairy Cattle Herd

The German wasp, Vespula germanica has been observed to injure teats of dairy cows, causing lesions that are associated with clinical and subclinical mastitis. The presence of skin lesions on the teats, caused by the wasps, was recorded in a dairy cattle herd located in the Samaria foothills during July–October 1999. Wasp‐inflicted injuries were found in 43.6% (58 of 133) of the adult cows and 1.4% (one of 71) of the first‐calving cows. They were located in 42.4% of cows (n = 25) on all quarters, 18 cows (30.5%) had lesions on the front quarters and 27.1% (n = 16) of cows on the hind quarters only. Clinical and subclinical mastitis were diagnosed in 61% (36 of 59) and 28.8% (17 of 59), respectively, of the injured adult and first‐calving cows. The most common bacterial isolates from the mastitic cows were Staphylococcus aureus 45.1% (n = 14), Streptococcus dysgalactiae 16.1% (n = 5), Streptococcus spp. 19.4% (n = 7) and others 13.9% (n = 5). The loss of milk production was estimated at 300 kg milk for each cow injured by wasps and exhibiting clinical mastitis. An increase in the bulk‐milk somatic cell count, from 186 × 10³ at 1 month prior to the outbreak to a peak of 1200 × 10³ in the post‐outbreak month, was noted. The culling rate reached 13.6% (eight of 59) of the affected cows. In summary, the considerable economic losses caused by the wasp infestation resulted from decreased milk production and a decline in milk quality, culling of affected cows, and increased demand for use of drugs and veterinary care.     

Epidemiological investigations of outbreaks of bovine ephemeral fever in Israel

In two epidemics of bovine ephemeral fever (BEF) in Israel, one in 1990 and one in 1999, the virus was probably carried by vectors transported by air currents across the Rift Valley and through the Red Sea trough. The disease broke out under optimal ecological conditions among vulnerable cattle populations and spread rapidly; it developed in the spring and summer and ended soon after the daily average ambient temperature fell below 16 degrees C in late autumn. The proportion of herds affected reached 78.4 and 97.7 per cent in 1990 and 1999, respectively. The highest rates of incidence, morbidity and mortality were recorded in dairy cattle herds in the Jordan Valley, the initial focus of the outbreaks, with a morbidity of 20 and 38.6 per cent in 1990 and 1999, respectively, and mortality among the affected animals of 2 and 8.6 per cent in 1990 and 1999, respectively. In 1991, the disease recurred sporadically in the central and southern regions of Israel in only three herds, but in 2000 the disease returned on an epidemic scale, and 85 per cent of herds were affected, with morbidity and mortality rates of 4-3 and 0-3 per cent, respectively. In the 1999 epidemic, the morbidity rate decreased from 38-6 per cent on average in the Jordan Valley to 12.8 per cent in the inner valleys and 5.3 per cent on the Mediterranean coastal plain, but the mortality rate increased from 8-6 per cent in the Jordan Valley to 14-3 per cent in the inner valleys, and to 28 per cent on the Mediterranean coastal plain, where the outbreak declined. An average of 2-7 per cent of the animals experienced a second attack of the disease two to six weeks later. The epidemic in 2000 was milder and shorter than that in 1999. All the cattle affected in both outbreaks were more than three months old. The vector(s) is not known for certain but the available evidence indicates that mosquitoes, and not Culicoides species, are the natural vectors of BEF virus in Israel.     

Case report: umbilical foreign-body granuloma in a lamb

An unusual case of umbilical foreign-body granuloma in a 3-week old lamb is described. The most prominent clinical finding was a large fibrous mass which bulged above the surface, adjacent to the umbilicus. Histologically, plant material surrounded by histiocytes, plasma cells, giant cells and fibroblasts were seen.