Biomedical subjects
W Wouda
Publications and source records attributed to W Wouda.
[Increasing incidence of Salmonella dublin infections on dairy farms].
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[Pasteurella haemolytica serotyping].
Forty-nine strains of Pasteurella haemolytica were serotyped in a pilot study. The majority of strains were isolated from sheep which had died from fibrinous pneumonia and small numbers from cases of sepsis, polyserositis, mastitis and meningitis. Serotype A2 was found to be the most prevalent: 69.4 per cent. In addition, serotype A7 with 18.4 per cent and serotypes A1 and A6, both 6.1 per cent, were identified. Biotype T strains were not detected in this study. Further research is required into the seasonal prevalence of P. haemolytica serotypes in sheep and cattle. This knowledge may help to improve herd health schemes for sheep and cattle in the Netherlands.
[Endocarditis and meat inspection in slaughtering pigs. 1. Clinical, pathological and microbiological aspects].
The clinical, pathomorphological and microbiological findings during meat inspection in 599 pigs with endocarditis at slaughter were studied. Clinical signs were observed in 41 per cent of the pigs on ante-mortem inspection. Lameness was the most common sign. However, this symptom is not very specific of endocarditis. This is also true of various other symptoms. Only dyspnoea and drowsiness were indicative of endocarditis to some extent, but occurred only sporadically. Extracardial lesions were observed in 66 per cent of the pigs with endocarditis on post-mortem inspection. Metastatic processes (infarction or inflammatory foci) were most frequently detected in the kidneys. These were highly specific of endocarditis. In addition, the following changes were observed in decreasing incidence: signs of sepsis (hyperplastic splenitis, petechiae and degradation of organs), inflammatory lesions of the joints and legs, metastatic pneumonia and inflammation of the tail. Bacteriological examination was positive in 62 per cent of the cases. Streptococci were the organisms most frequently isolated (36 per cent), followed by Corynebacterium pyogenes (19 per cent) and Erysipelothrix rhusiopathiae (14 per cent). The discussion is concerned with the significance of these bacteria to meat-consumers.
[Endocarditis and meat inspection in slaughtering pigs. 2. Various aspects of meat inspection].
The results of meat inspection in 599 slaughtered pigs with endocarditis were studied. Of the pigs examined, 65 per cent were condemned. Condemnation was based on a positive bacteriological examination (Article 2 of the Meat Inspection Regulations) in almost every case. When bacteriological examination was negative, the animal was passed unqualified in nearly every case, regardless of the fact that symptoms were or were not detected in ante-mortem inspection and whether or not signs of sepsis were observed. Subsequently, efforts were made to determine the possible effects of omitting incisions into the hearts of pigs in which neither clinical nor morbid-anatomical examination suggested the presence of endocarditis. It was concluded that endocarditis would have passed unnoticed in 25 per cent of the pigs examined in this case. Of these pigs, fifty per cent were found to be positive on bacteriological examination. Finally, the financial consequences of condemning all pigs showing endocarditis were examined. Compared with current practice in meat inspection, this would result in an annual loss of Dfl. 60,000 in the situation prevailing in the Netherlands. However, if Articles 13, 17 and 18 of the Meat Inspection Regulations were strictly observed, the yield of the pigs passed would not offset the costs of examination.
[Fatal ovarian hemorrhage in 2 donor cows following embryo transplantation].
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Induction of demyelination by a temperature-sensitive mutant of the coronavirus MHV-A59 is associated with restriction of viral replication in the brain.
The neurovirulence of eight temperature-sensitive (ts) mutants of mouse hepatitis virus strain A59 in 4-week-old BALB/c mice was investigated. Whereas a dose of 100 p.f.u. of wild-type virus killed mice within a week, a 1000-fold higher dose of ts mutants did not. Three ts mutants induced demyelinating disease in the central nervous system (CNS). The pathology of the demyelinating disease caused by one mutant, designated ts-342, was studied in detail. Pathological changes, starting 3 days post-inoculation (p.i.), were characterized by inflammation and demyelination in the CNS. Antibody responses directed against all virus-specific structural proteins were present at 7 days p.i. No virus particles were observed by electron microscopy at 14 days p.i. However, macrophages and lymphocytes were abundant in the areas of demyelination. The growth kinetics in vivo of wild-type virus, ts-342 and a revertant of ts-342 were compared. Wild-type virus and the revertant replicated rapidly in the brain and spread to the liver causing a lethal hepatitis. Ts-342, however, replicated to a much lesser extent within the brain and could not be detected in the blood or liver. The ts lesion in the genome of ts-342 seems, therefore, to determine the outcome of the infection.
[A case of diprosopus in the cat].
A case of diprosopus in a spontaneously delivered live-born kitten is reported. All facial components were completely duplicated. Fusion of the skulls had occurred in the temporal region; a single ear was present at the site of fusion. Additional defects were a cleft lip in one face and cleft palates in both faces. The cerebral hemispheres and arterior portions of the brain stem were completely duplicated, whereas the cerebellum and caudal brain stem were partially duplicated. The pathogenesis and aetiology are discussed. It is believed that disprosopus originates during the (pre)gastrulation stage of embryonic development, either by coalescence of two embryonic fields following a double process of gastrulation or by bifurcation of the axial mesoderm during a single gastrulation.
Lobular capillary haemangiomas in young horses.
Seven cases of cutaneous haemangiomas in young horses are described, characterized by scattered, well demarcated but unencapsulated lobules, consisting of capillary sized vascular structures, separated by strands of fibrous tissue. In one case, a more cellular variant was distinguished with minor vasoformative capacity. The morphological features of these haemangiomas are compatible with bovine cutaneous angiomatosis and human granuloma pyogenicum. The lesions are considered to be vascular tumours rather than hamartomas or granulation tissue and "lobular capillary haemangioma" is suggested to designate this type of haemangioma. In one tumour, cavernous vascular structures were also present in addition to the capillary structures and so this tumour is considered to be a combined capillary and cavernous haemangioma.
Delayed swayback in goat kids, a study of 23 cases.
The results of a retrospective study of 23 goat kids with delayed swayback are reported. Principal clinical signs were ataxia, loss of postural control, spasticity of the hindlimbs, and muscular weakness, often progressing to permanent recumbency. Denervation of skeletal muscles was demonstrated by electromyography in 2 kids. Three kids slowly recovered during hospitalisation. Histopathological changes were characterized by degeneration of selected neuronal populations with their processes within the central and the peripheral nervous system. Affected systems included upper motor neuron, vestibular, general proprioceptive, and lower motor neuron pathways, with additional involvement of the cerebellar cortex in some animals. Our findings, including limited ultrastructural observations, support the notion that the neuraxon rather than the myelin sheath is the prime target of disease in delayed swayback. The available copper values of affected kids and their unaffected herd mates were significantly lower than those of random control goats, which provides further support for a role of copper deficiency in the aetiology of this disease in the goat.
Progressive ataxia due to central demyelination in Rottweiler dogs.
A clinicopathological study of a neurologic disease in Rottweiler dogs was conducted. Clinical data were available on 16 dogs, 11 of which were examined pathologically. All dogs had a history of progressive gait abnormalities, which had commenced insidiously at an age varying from 1.5 to 3.5 years. In most dogs the fore limbs were affected prior to the hind limbs. At neurologic examination ataxia of all 4 limbs was seen, in some instances accompanied by an apparent paresis. Proprioceptive positioning was delayed whereas spinal reflexes were often hyperactive. Plain and contrast radiographs of the spine did not reveal any compressive lesions in 5 dogs examined. Cerebrospinal fluid analysis in 4 dogs was normal. Electrodiagnostic testing in 3 dogs revealed no abnormalities. At pathologic examination demyelinating lesions were found in the central nervous system. These were largely confined to the cervical spinal cord and brain stem and had a rather characteristic more or less symmetric distribution. Pedigree data suggested that the disease is transmitted genetically.
[Frontal sinusitis in a horse with a neurological complication].
The case of a horse affected with frontal sinusitis, in which neurological complications occurred following trepanation, is reported. The previous history of the animal as well as the clinical, radiological and pathological findings are discussed.
Spinal nematodosis in a donkey with posterior paresis.
Spinal nematodosis in a four-year-old donkey is described. The animal showed progressive hindlimb paresis of sudden onset. Necropsy revealed extensive degeneration and inflammation in the lumbosacral part of the spinal cord, caused by a nematode larva of the suborder Strongylina, probably L4 or L5 of Strongylus vulgaris.
Sensory neuronopathy in dogs: a study of four cases.
A neurological disease which selectively affects the primary sensory pathways was observed in 4 dogs. Clinical signs were dominated by ataxia due to impaired position sense. Deficient or abnormal pain sensation was also observed. Difficulty in eating probably arose from oral and lingual sensory deficit. The lesions were characterized by degeneration and loss of central and peripheral primary sensory axons, with a predilection for large myelinated fibres. The concept of a sensory neuronopathy was supported by the finding of neuronal degeneration and loss in dorsal root ganglia seen in 2 dogs. The cause of the disease is not known. The presence of mononuclear inflammatory cells in acute lesions suggests an infectious or autoimmune disease. Toxic and genetic factors are also to be considered.
Neurological disorders, virus persistence and hypomyelination in calves due to intra-uterine infections with bovine virus diarrhoea virus. I. Clinical symptoms and morphological lesions.
The clinical and pathological findings after a natural intra-uterine infection with BVD-virus in a Friesian dairy herd are described. The virological and serological aspects will be discussed in a separate paper (30). In a period of 4 years, 11 calves were born with the following nervous symptoms: more or less serious incoordination, tremor, oscillating nystagmus, and a negative blinking reflex. The pupillary and sucking reflexes were normal. No ocular defects, such as lenticular opacity or retinal atrophy were observed. The first calf was born in 1979. Within 6 months the symptoms disappeared. After a normal conception and pregnancy this animal gave birth to 2 clinically normal calves in 1981 and 1982. The second calf died at the age of 2 months, due to an ulcerating enteritis. In 1980, again 8 calves with the same nervous symptoms were born within a period of 3 months. Two calves died at the age of 3 days and 5 weeks respectively; 2 calves were sold when 10 days and 3 weeks old; one calf did not improve and was necropsied at the age of 17 days. The remaining 3 calves showed only a slight hypermetria when examined after 6 months. At that time nystagmus was only visible with ophthalmoscopy. Two calves were slaughtered when 10 months old. The last one, a bull, proved to be sterile and was necropsied at the age of 1 1/2 year. A calf, born in 1981, recovered within a week and was necropsied at the age of 15 days. The last calf, born in 1982, did not improve at all and was necropsied at the age of 14 days. During these 4 years none of the other animals in the herd showed any symptoms due to an acute or chronic BVD-virus infection. At post mortem examination of 6 animals no macroscopically visible malformations were found. Hypomyelination and abnormal glial cells were evident in 5 cases, especially in the two youngest calves which did not show any improvement. One of them had had an obvious thymic hypoplasia. The calf which recovered within a week showed only very slight changes. In one of the calves slaughtered at 10 months, inflammatory lesions were found in the brain. The diagnosis was confirmed by virological investigations. Clinically as well as pathologically there was a close resemblance to Border disease in lambs and congenital tremor in piglets after prenatal exposure to Hog cholera virus.
Biliary atresia in a texelaar lamb. A case report.
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Internal hydrocephalus of suspected infectious origin in young dogs.
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Squamous metaplasia of renal tubular epithelium in a dog with a granulosa cell tumour.
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