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Biomedical subjects

B W Knol

Publications and source records attributed to B W Knol.

At least 19 recordsLinked to original sources
PubMed1998

Investigation of mortality and pathological changes in a 14-month birth cohort of boxer puppies.

This paper presents puppy mortality and postmortem findings for a birth cohort of boxer puppies born in the Netherlands between January 1994 and March 1995. In all, 457 litters were registered, of which 414 (90.6 per cent) were involved in the study. The 414 litters contained 2629 puppies, a mean litter size of 6.4 puppies. Of the 2629 puppies 571 (21.7 per cent) died or were euthanased before they were weaned at 50 days of age; there were 147 (25.7 per cent) stillbirths; 102 (17.9 per cent) were euthanased because they were white; 269 (47.1 per cent) of the puppies died during the first 21 days of life and 53 (9.3 per cent) puppies died between days 22 and 50. The cause of death or the reason for euthanasia was assessed by either the breeder or the veterinarian in 176 of these 269 puppies but was not determined in the other 93 puppies. Three hundred and two puppies were examined postmortem; the most important cause of death or reasons for euthanasia were inflammatory disorders (102; 33.8 per cent), non-inflammatory disorders such as asphyxia and malnutrition (66; 21.9 per cent), euthanasia because they were white (51; 16.9 per cent), and congenital abnormalities (45; 14.9 per cent). No cause of death or reason for euthanasia could be found for 38 puppies (12.6 percent)

Animal Welfare↗
PubMed1997

Influence of orchiectomy on canine behaviour.

One hundred and twenty-two dog owners were interviewed to obtain information about the effects of orchiectomy on the behaviour, unwanted side effects, and testosterone-dependent disease processes in their dogs. Behavioural problems were the main reason for orchiectomy, unwanted sexual behaviour being the most common, together with roaming, aggression, and abnormal urination behaviour. Objectionable sexual behaviour, inter-male aggression, roaming, and abnormalurination were reduced after orchiectomy in approximately 60 per cent of the dogs. The side effects of orchiectomy included increased bodyweight, increased appetite and decreased activity in less than 50 per cent of the dogs, and there was a significant relationship between increased appetite and bodyweight. The clinical signs of testosterone-dependent disease in most of the dogs either decreased or disappeared after orchiectomy.

Aggression↗
PubMed1994

Behavioural, household, and social problems associated with companion animals: opinions of owners and non-owners.

The goal of this investigation was to determine the extent to which owners of companion animals experienced problems with their animals, such as behaviour problems, and to discover their opinion about household problems such as the shedding of hairs and/or feathers. Furthermore, an attempt was made to discover the opinions of owners and non-owners about social problems such as 'companion animals make noise'. The findings are the result of a survey among 871 Dutch respondents. It was found that 43% of all companion animal owners had one or more problems with their animals. Dog and cat owners experienced many problems with the illness and the behaviour of their animals. The higher the income of the owner, the more likely he/she is to have problems with his/her animal's behaviour. Because animals with behaviour problems are a risk group, more should be done to prevent these problems. Owners of companion animals found shedding of hair or feathers the biggest disadvantage of keeping an animal. People in paid employment found cleaning the cage of the animal a bigger nuisance than did people not in paid employment. There were no differences in owner characteristics with regard to the household problems. The opinions of owners of certain species of animals, owners of other species, and non-owners about behavioural traits and the nuisance caused by that species of companion animal differed, which could lead to misunderstandings between these groups.

Animal Husbandry↗
PubMed1993

Hereditary necrotising myelopathy in Kooiker dogs.

A retrospective clinicopathological study of a neurological disorder in 22 Kooiker dogs (Dutch decoy dog) was made. The disease was found to occur equally in both sexes and clinical signs began at three to 12 months old. Physical examination revealed a progressive paresis of the hindlimbs. Post mortem examination showed symmetrical areas of malacia in the ventral, lateral and dorsal white matter of the spinal cord. In one dog dorsal white matter was spared. Cervical segments C4 to C8 were involved in all subjects. Rostral and caudal to these areas, Wallerian degeneration was prominent. The disease has much in common with similar myelopathies in the Afghan hound and the rottweiler. Indications of heritability were the similarity in clinical and pathological findings, the age of onset of the disease, and the significantly higher inbreeding coefficient in the patients than in the breed population (P = 0.001). All patients were descended from one pair. Segregation analysis suggested inheritance involving a simple autosomal recessive trait.

Animals↗
PubMed1993

GnRH in the male dog: dose-response relationships with LH and testosterone.

Dose-response relationships between GnRH and LH, and between GnRH and testosterone, were investigated in six male dogs by intravenous administration of a GnRH analogue at different doses. Each dose of GnRH analogue induced an immediate rise in the plasma concentration of LH and then a rise in plasma testosterone concentration. Irrespective of the dose used, the rise in testosterone began 10 min after the GnRH injection. Administration of GnRH at doses of 0.01, 0.1, 1, 10 and 100 micrograms kg-1 resulted in maximum LH concentrations in plasma (mean +/- SEM; n = 6) of 22 +/- 7, 27 +/- 6, 40 +/- 7, 57 +/- 13 and 56 +/- 10 micrograms l-1, respectively. These doses induced maximum concentrations of testosterone in plasma (mean +/- SEM; n = 6) of 16 +/- 4, 20 +/- 4, 22 +/- 3, 22 +/- 4 and 24 +/- 7 nmol l-1, respectively. The lag time between peak concentrations of LH and testosterone varied from 35 to 55 min. The calculated maximum response of testosterone to LH, secreted by the anterior pituitary after GnRH injection, was 1.8 times higher than to GnRH. It was concluded that intravenous administration of GnRH induced marked and dose-dependent increases in plasma concentrations of LH and testosterone, and that there does not appear to be a direct effect of GnRH on Leydig cells in male dogs.

Animals↗
PubMed1992

[Owner and dog: like seeks like?].

The aim of this investigation was to find out whether there are similarities or differences between the personality of the dog owner and the character of his of her dog. Ten owners of four different breeds of dog (40 owners in total) participated in this investigation. Some of the findings indicate resemblances in the character of the owners of certain breeds of dog. However to test the significance of these results more respondents are needed and a uniform character test for the dogs must be used.

Animals↗
PubMed1992

Effects of methods used for blood collection on plasma concentrations of luteinising hormone, testosterone, and cortisol in male dogs.

The effects of two putative stressors relative to the collection of blood, namely the environment of the treatment room and the pain associated with venepuncture, on plasma levels of luteinising hormone (LH), testosterone and cortisol were examined in six trained male experimental dogs. Blood samples were collected from the dogs in a treatment room as well as in the kennels (control), and by venepuncture as well as via an indwelling intravenous catheter (control). No significant influence of either stressor on plasma levels of LH, testosterone or cortisol was found. Plasma concentrations of these hormones varied considerably both between and within dogs. Mean (+/- SEM; n = 6) plasma concentrations were 4.3 +/- 1.0 micrograms/l for LH, 4.6 +/- 1.9 nmol/l for testosterone and 68 +/- 10 nmol/l for cortisol. It was concluded that the putative stressors, the environment of the treatment room and the pain associated with venepuncture, did not significantly influence plasma levels of LH, testosterone or cortisol in trained male experimental dogs. This conclusion implies that under the experimental conditions described, the validity of results will not be affected by the method of blood collection used.

Animals↗
PubMed1992

The relationship between homozygosity and the occurrence of specific diseases in Bouvier Belge des Flandres dogs in The Netherlands.

Since purebred dog populations represent closed gene pools, a relatively high level of consanguinity between individuals, and hence of inbreeding, is common. This case control study was conducted to establish the possible connection between the actual level of homozygosity due to inbreeding and specific diseases (flea allergy, osteochondrosis, laryngeal paralysis, neoplasm, autoimmune disease, hypoplastic trachea, and food allergy) occurring in the Bouvier Belge des Flandres breed. One hundred and sixty-eight animals referred to the Utrecht University Clinic formed the patient group. Each of the seven diseases was chosen because of the demonstrability of the diagnosis. Each animal was chosen because one of the selected diseases was established in that individual, and because its pedigree was complete. All dogs of the patient group were born between 1 January 1980 and 31 December 1985. A control group (n = 123) was randomly chosen from the total population of registered Bouviers born in the Netherlands in the same period. pedigree data were obtained from the Dutch Kennel Club. The extent of inbreeding was determined for all animals using Wright's inbreeding coefficient. The distribution of inbreeding coefficients in each patient group was compared with the distribution in controls. Inbreeding coefficients in the control group ranged from 0.0 to 0.406. Animals in which osteochondrosis, food allergy, autoimmune disease, neoplasm, or hypoplastic trachea was diagnosed had higher inbreeding coefficients than controls. It was concluded that in the Bouvier Belge des Flandres dog population examined, the level of homozygosity was positively correlated with occurrence of these diseases.

Animals↗
PubMed1992

Pituitary-dependent hyperadrenocorticism in a family of Dandie Dinmont terriers.

Adrenocortical function studies were performed in seven Dandie Dinmont terriers with pituitary-dependent hyperadrenocorticism. The ability of dexamethasone at a dose rate of 0.1 mg/kg body weight to suppress cortisol secretion was only moderate in four out of the six dogs tested. Concentrations of alpha-melanocyte-stimulating hormone in plasma were highly increased. Responses to stimulation with corticotrophin-releasing hormone and the dopamine-antagonist haloperidol, examined in three animals, were moderate or absent. These results indicate that adrenocortical stimulation, i.e. hyperadrenocorticotrophism, was caused by pituitary lesions which were functioning autonomously. In six of the seven animals there was a very close familial relationship and the coefficients of relationship and the coefficients of inbreeding were significantly higher than in a representative control population. It was concluded that these seven related terriers with hyperadrenocorticotrophism had the biochemical characteristics of de-novo neoplasms of proopiomelanocortin-producing cells, and there was evidence for a genetic involvement in tumorigenesis.

Adenocarcinoma↗