Biomedical subjects

P F Woodall

Publications and source records attributed to P F Woodall.

9 recordsLinked to original sources

PubMed2005

Elephant shrews as hosts of immature ixodid ticks.

Two hundred and seventy-three elephant shrews, consisting of 193 Elephantulus myurus, 67 Elephantulus edwardii and 13 animals belonging to other species, were examined for ixodid ticks at 18 localities in South Africa and Namibia. The immature stages of Ixodes rubicundus, Rhipicentor nuttalli, Rhipicephalus warburtoni and a Rhipicephalus pravus-like tick were the most numerous of the 18 tick species recovered. Substantial numbers of immature Rhipicephalus arnoldi, Rhipicephalus distinctus and Rhipicephalus exophthalmos were also collected from elephant shrews at particular localities. Larvae of I. rubicundus were most numerous on E. myurus in Free State Province from April to July and nymphs from June to October. Larvae of R. nuttalli were most numerous on these animals during April, May, August and September, and nymphs in February and from April to August. The immature stages of R. warburtoni were collected from E. myurus only in Free State Province, and larvae were generally most numerous from December to August and nymphs from April to October.

Animals↗

PubMed1994

Morphology of intestinal villi in African antelope (Artiodactyla: Bovidae).

Villous morphology in 16 species of African antelope varied from finger-like and leaf-like to ridge-like forms. Some species showed uniform villi whereas it was variable in others. There was a slight indication that leaf-like and finger-like forms become more frequent in the distal regions of the small intestine. The variation in morphology was not associated with body size or phylogeny, but did show a significant correlation with diet: species with high moisture content and/or high fibre levels (equivalent to low bulk values) in the digesta were more likely to have ridges, which were the lowest of the villi.

Animals↗

PubMed1989

The effects of increased dietary cellulose on the anatomy, physiology and behaviour of captive water voles, Arvicola terrestris (L.) (Rodentia: Microtinae).

1. Wild water voles and captives on high fibre diets had significantly longer and heavier digestive tracts (especially the caecum) than captives fed a low fibre diet. 2. Increasing dietary cellulose increased food intake, faecal output and metabolic rate, and decreased digestibility. Some but not all added cellulose was digested. 3. The passage of food through the digestive tract was significantly faster on the diet with added cellulose. 4. Coprophagy included eating directly from the anus and eating faecal pellets from the floor of the cage. The frequency of the latter type increased significantly for animals on a high fibre diet.

Animals↗

PubMed1989

Periodontal disease in southern African bushpigs (Potamochoerus porcus) and warthogs (Phacochoerus aethiopicus).

Periodontal lesions were found in 14 of 100 bushpig (Potamochoerus porcus) skulls and nine of 103 warthog (Phacochoerus aethiopicus) skulls from southern Africa. The prevalence of periodontal disease showed a significant increase with age in the bushpig but not in the warthog skulls. All the lesions affected the cheek teeth, particularly the molars. The lower prevalence of lesions in older warthogs may be associated with their specialised molars and abrasive diet.

Africa, Southern↗

PubMed1988

Dimensions and allometry of testes, epididymides and spermatozoa in the domestic dog (Canis familiaris).

Dimensions of the testes, epididymides and spermatozoa were measured from a sample of 104, mainly cross-bred, domestic dogs ranging in body mass from 5 to 48 kg. Allometric analyses in relation to body mass indicated isometric changes in testicular mass but epididymal mass and the mass of the cauda epididymidis and sperm numbers in the cauda showed significant positive allometry. Total sperm length, seminiferous tubule diameter and the relative proportion of tissues in the testis showed no significant correlation with body mass, but sperm principal piece length showed a low correlation with body mass. We suggest that the positive allometry of epididymal mass and sperm numbers is related to promiscuous mating and sperm competition in stray dogs.

Animals↗

PubMed1988

Periodontal disease in feral pigs (Sus scrofa) from Queensland, Australia.

Periodontal lesions were present in 26 of 107 feral pigs (Sus scrofa) that were shot in southern Queensland. The severity of the lesions varied from gingivitis to extensive destruction of the alveolus and its contents. Examination of slaughtered domestic pigs revealed a similar prevalence of lesions (12 of 52). Only cheek teeth were affected, and molars were affected more frequently than premolars. In both feral and domestic pigs, prevalence of periodontal disease affecting bone increased with age. Although periodontal disease is recognized as a common and often serious problem in many mammalian species, both domestic and wild, it has rarely been recorded in the pig. It is considered that the most severe lesions would have interfered with mastication but that the contribution of the disease to mortality of feral pigs in Australia is probably not great.

Animals↗

PubMed1988

The rostral nasal anatomy of two elephant shrews.

The nasal anatomy of Elephantulus brachyrhynchus and E. myurus shows adaptations needed for a long, mobile snout with no special chemosensory features. Olfactory and vomeronasal neuroepithelia do not extend rostral to the nasal opening of the incisive ducts. Their fine structure presents no unusual features. Separate dorsal, lateral and ventral cartilages and fenestrations in the septal cartilage permit snout flexibility. Dorsal and ventral tubular glands extend the whole length of the snout under the dermis but only release their secretions at the tip, together with the products of the nasolacrimal and lateral nasal gland ducts. These secretions may protect the bare rostral epithelium from the chemical defences of termites and ants, which are major food items. A ventral groove in the snout communicates directly with the sulcus of the incisive papilla on the rostral palate. The oral openings of the incisive ducts also lie within the sulcus. Variability in the relation of the vomeronasal duct to the incisive duct and in the presence of taste buds on the incisive papilla in the two species of Elephantulus studied here limit their value as evidence of relationships between elephant shrews and other insectivores and prosimians.

Animals↗

PubMed1987

Caecal size and function in the rock elephant shrew Elephantulus myurus (Insectivora, Macroscelididae) and the Namaqua rock mouse Aethomys namaquensis (Rodentia, Muridae).

1. The relative size of the digestive organs and the function of the caeca of an insectivorous elephant shrew Elephantulus myurus (Macroscelididae) and of a herbivorous rodent Aethomys namaquensis (Muridae) were compared. 2. Both species had similar body mass but A. namaquensis had a significantly heavier total digestive tract, full stomach, and caecum and a longer large intestine and caecum than E. myurus. 3. Both species had similar total volatile fatty acid (VFA) concentration and VFA % composition although A. namaquensis had a significantly higher % of n-butyric acid. Both had a similar caecal NH3-N concentration. 4. The presence of a functional caecum in E. myurus supports the view that Macroscelididae have evolved from ancestral herbivores and not from insectivores.

Animals↗

PubMed1985

On mammalian sperm dimensions.

Data on linear sperm dimensions in mammals are presented. There is information on a total of 284 species, representing 6.2% of all species; 17.2% of all genera and 49.2% of all families have some representation, with quantitative information missing only from the orders Dermoptera, Pholidota, Sirenia and Tubulidentata. In general, sperm size is inverse to body mass (except for the Chiroptera), so that the smallest known spermatozoa are amongst those of artiodactyls and the largest are amongst those of marsupials. Most variations are due to differences in the lengths of midpiece and principal piece, with head lengths relatively uniform throughout the mammals.

Animals↗