Feeding under constant cold conditions resulted in a marginal shortening of feeding period and a major shortening of the subsequent developmental phase of all stages of Ixodes rubicundus Neumann 1904, the Karoo paralysis tick. Paralysis occurred in laboratory rabbits when nymphae were fed on them under constant warm, constant cold and fluctuating ambient winter conditions. This paralysis was found to be dependent on infestation rate and feeding conditions. Under constant cold conditions paralysis resulted from lower levels of infestation than under warm or under fluctuating winter conditions. Neurological parameters used in assessing the progression of the paresis are discussed.

Animals↗

PubMed1988

A field outbreak in Ile-de-France sheep of a cardiotoxicosis caused by the plant Pachystigma pygmaeum (Schltr) Robyns (Rubiaceae).

A field outbreak of Pachystigma pygmaeum intoxication in sheep is described. Noteworthy clinical signs were: respiratory distress, apathy and subcutaneous oedema of mainly the head. Gross changes included cardiomegaly, centrilobular hepatic necrosis and effusion of body cavities. Microscopically myocardial fibrosis, affecting predominantly the endocardium of the apex, left free ventricular wall and interventricular septum, was most striking in the majority of animals, whilst myofibre atrophy was present in 1 sheep.

Animals↗

PubMed1987

African swine fever. II. Functional disturbances of thrombocytes in pigs infected with virulent haemadsorbing and non-haemadsorbing virus isolates.

Increased bleeding time, impaired blood clot retraction and decreased thrombocyte aggregation were observed in pigs infected with virulent haemadsorbing and non-haemadsorbing African swine fever virus isolates. These changes appeared to be more frequent and more severe in pigs infected with the haemadsorbing virus isolates than in those infected with the non-haemadsorbing isolate. Moreover, the onset and severity of these changes followed the numerical decrease and morphological damage to these cells apparent in the last 2-3 days of the disease.

African Swine Fever↗

PubMed1986

African swine fever. I. Morphological changes and virus replication in blood platelets of pigs infected with virulent haemadsorbing and non-haemadsorbing isolates.

Replicating and mature viral particles were detected with the transmission electron microscope in blood platelets of pigs infected with virulent haemadsorbing and non-haemadsorbing African swine fever virus isolates. Although platelet numbers decreased terminally in infected pigs, the most noticeable morphological damage to these cells apparent in the last 2 days of the disease included cytoplasmic swelling, vacuolation, fragmentation and loss of dense granules.

African Swine Fever↗

PubMed1983

Suspected hybrid vetch (Vicia villosa crossed with Vicia dasycarpa) poisoning of cattle in the Republic of South Africa.

A description of the clinical signs and pathological changes is given of 2 outbreaks of suspected hybrid vetch poisoning in the Humansdorp district, Republic of South Africa. These were characterised by a severe dermatitis, high morbidity and mortality in older cows. Microscopically granulomatous lesions occurred in the kidneys, liver, myocardium, spleen and skin. Variable numbers of multinucleated giant cells and eosinophils were seen in these lesions. Acute multifocal hepatic necrosis was observed in 2 animals. Brief comparisons are made with outbreaks of vetch poisoning in other parts of the world.

Animals↗

PubMed1982

Leptospira interrogans serovar pomona associated with abortion in cattle: isolation methods and laboratory animal histopathology.

Leptospira interrogans serovar pomona was successfully isolated from cattle urine in the western Transvaal after an abortion storm had occurred. Direct inoculation of EMJH medium proved the most successful method. The selective agent, 5-fluorouracil, was most effective in controlling contamination when used at the 0,4 mg/ml level. The strain isolated was pathogenic in hamsters, but specific lesions and the leptospirae were seen only where overwhelming infection occurred.

Abortion, Veterinary↗

PubMed1982

Oak (Quercus rubor)poisoning in cattle.

Two outbreaks of oak poisoning in cattle in the Republic of South Africa are described. In the first outbreak 22 out of 80 head of cattle were severely affected while 40 out of a herd of 135 cattle were affected in the second outbreak. Of these 40, only one survived after 9 months despite vigorous treatment. Only young cattle under 2 years were affected during both outbreaks in spite of an average herd age of approximately 6 years in the second group of cattle. Clinical signs included severe weakness with a swaying gait, diarrhoea and dehydration. Some were pot bellied while others were emaciated and remained stunted. The most prominent macroscopic and microscopic lesion present in 3 animals autopsied, was a non-suppurative interstitial nephritis which was accompanied by oedema and ulceration of the caecum and colon. Histochemical studies were carried out on pigment granules observed in kidney sections.

Animals↗