Veterinary Anatomy

Clinical and Haematological Studies in Dogs with Single and Mixed Experimental Trypanosoma Brucei and Ancyclostoma Caninum Infection

Mon, 05 Jun 2017 00:00:00 GMT

Clinical and Haematological Studies in Dogs with Single and Mixed Experimental Trypanosoma Brucei and Ancyclostoma Caninum Infection Ugwu, Christian Emetueobi Trypanosomosis is one of the most devastating diseases of animals caused by infection with a protozoan parasite trypanosome, which is transmitted by tse-tse fly. Besides anaemia, which is a cardinal symptom of the disease, infection also impairs the immune system of animals and renders them more susceptible to other. Under natural field condition, in areas where trypanosome and helminth parasites are endemic, mixed infection appears to be common. A study was conducted to determine the clinico-haematological manifestations in dogs experimentally infected with Trypanosoma brucei and Ancylostoma caninum singly and in combination. Twenty young local dogs were used in the study. They were randomly grouped into 4 with 5 dogs in each group; group A (uninfected control), group B (infected with A. caninum), group C (infected with T. brucei) and group D (mixed infection with A. caninum/T. brucei). For the mixed infection, dogs were initially infected with A. caninum and then T. brucei infection superimposed 23 days later by the time of patency of Ancylostoma eggs in the stool. Results of this study showed that the prepatent period (PP) of A. caninum infection in the dogs was 24.5±0.4 days. The PP of T. brucei infection alone was 5.0±0.0 days, but was 4.6±0.22 days in the mixed infection. Clinical signs of dullness, inappetence, anorexia, weakness, pale mucous membrane due to anaemia, rough hair coat were encountered in both infections. Additionally, specific signs of bloody diarrhea and sunken eyes were present in A. caninum infected dogs while fever, swollen face, bilateral ocular discharge and corneal opacity accompanied T. brucei infection. A combination of these signs in a more severe form characterized the mixed infection of both parasites. There was a significant decrease (P<0.05) in the packed cell volume (PCV) in all the infected groups (B, C and D) as from day 19 post infection (p.i.). Infection with Ancylostoma caninum caused significant increase (P<0.05) in the total leucocyte count of the dogs in group B from day 29 p.i., whereas significant decrease were recorded in trypanosome infected dogs group C and in mixed infection group (D) on days 38 and 34 p.i., respectively. The absolute neutrophil counts significantly increased (P<0.05) in group B by day 29 p.i. whereas significant decreases were recorded in groups C and D from day 34 p.i.. There was no variation in the absolute lymphocyte count except on day 20 p.i. when an increase was detected only in the mixed infection group (D). The absolute eosinophil counts significantly increased (P<0.05) in group B from day 14 p.i. in contrast to a significant decrease (P<0.05) in the mixed infection group (D) by day 34 p.i. There was no significant variation (P<0.05) in the absolute monocyte counts of the infected dogs. The results of the egg per gram (EPG) of faeces on days 28, 34 and 39 were 20300±12195, 81233±26410 and 67683±13971 for group B, and 34325±8044, 54425±24764 and 55800±12304 for group D, respectively, and showed no significant difference (P>0.05). It was concluded that concurrent infection of T. brucei and A. caninum resulted in enhanced pathogenicity manifested in remarkable clinico-haematological alterations in the infected dogs.

Occurrence of Rabies Virus among Apparently Healthy Dogs and Bats Slaughtered for Meat in Some Selected Local Governments of Enugu State

Fri, 02 Jun 2017 00:00:00 GMT

Occurrence of Rabies Virus among Apparently Healthy Dogs and Bats Slaughtered for Meat in Some Selected Local Governments of Enugu State Eze, Ukamaka Uchenna This work was undertaken to investigate whether or not rabies virus is present in the brains and saliva of apparently healthy dogs and bats slaughtered for human consumption in Enugu State, Southeastern Nigeria; attempt to establish possible exposure potential of humans to rabies virus through handling, processing, selling, buying, and consumption of dog meat and to establish the genotype of the viral isolates if any. A total of 100 questionnaires were distributed to those that sell dog or dog meat. One hundred and fifty two dog heads and fifty nine bat heads were collected from markets, restaurants and bars where these animals are slaughtered and consumed as delicacy in the study area and processed accordingly. The points of collection were georefrenced using global positioning system (GPS). Sex and age of dogs were noted at points of collection. Eighty seven percent of the dog meats sold were sourced from dogs bought from homes and markets while the rest (13%) were sourced from stray dogs. Eighty one percent of the respondents reported eating dog meat because it cures some diseases including reducing high blood pressure while the rest (19%) perceive it just as any other meat. Specifically, 50% was of the opinion that the meat of rabid dog enhances male libido. Twelve percent of respondents had been bitten by suspected rabid dog in the course of the business yet only one person (2%) indicated that he received full course of anti-rabies vaccination in a hospital. Seventy one percent of the respondents had slaughtered and eaten suspected rabid dogs. Out of the 152 dog brain samples examined, 18 (12%) were positive for rabies virus antigen using FAT while 17 (11%) were positive using MIT. Nine (17.6%) out of 51 male and nine (8.9%) out of the 101 female dog heads examined were positive for rabies virus antigen. seventeen (13%) of the 131 adult dog brains tested positive for rabies virus antigen, while 1(5%) of the puppy brains tested positive. There was no significant association (p > 0.05) between gender or age and the occurrence of rabies virus antigen in the brain of dogs. There was no significant association (p > 0.05) between occurrence of rabies virus antigen and senatorial zones. Out of a total of 10 salivary glands from positive brains that were analyzed by FAT, all (100%) tested positive for rabies virus antigen. All the 59 (100%) bat brain samples tested were negative for rabies virus antigen using FAT. All the rabies virus isolates from dog brain samples belonged to genotype 1 rabies virus (true rabies virus). The geographic information system (GIS) revealed that the positive dog brain samples were collected from 5 out of the 6 local government areas (LGAs) sampled and from 7 locations within the 5 LGAs; Udenu (1 location), Enugu North (1), Nsukka (2), Igbo-Etiti (2), and Udi (1). This study has shown that some of the apparently healthy dogs slaughtered for meat in Enugu state carry rabies virus and secrete the virus in their saliva without showing clinical signs. All the isolates belonged to genotype 1 rabies virus. No rabies virus antigen was found among apparently healthy bats slaughtered for meat in Enugu state. Furthermore, this work has revealed that those involved in dog trade or butchering have high exposure potential to rabies virus antigen

Evaluation of the Developmental Morphology of the Eyeball of the Red Sokoto Goat (Capra Hircus)

Fri, 02 Jun 2017 00:00:00 GMT

Evaluation of the Developmental Morphology of the Eyeball of the Red Sokoto Goat (Capra Hircus) Nlebedum, U.C. This study traced the developmental histology of the eyeball of the Red Sokoto goat during the prenatal and postnatal stages. Thirty Red Sokoto goat fetuses, 10 neonatal and 10 adult goat heads obtained from the abattoir were used for this study. The fetuses were aged using the standard formula while those of the adult goats were estimated by dentition. The eyes were dissected from the head and assigned to five groups (A-E). Eye samples were routinely processed for histological studies. Sections were examined with a light microscope and photographed with a Moticam digital camera attached to a microscope. Corneal thickness was measured in all groups and data obtained were analysed using analysis of variance. Variant means were separated using the least significant method (LSD) and significant difference was accepted at probability level (p < 0.05). The corneal primordium was present in the eyes of fetuses in group A. The anterior and posterior epithelia were of the simple cuboidal type. The corneal epithelium became bilayered while the primordium of the limbus and the sclera appeared. In group B, the Descemet’s membrane was visible. All the layers of the sclera except the lamina fusca were fully differentiated. The differentiating lamina cribrosa appeared at this stage. In group C, the Bowman’s layer was observed. The limbus, lamina cribrosa and sclera were well differentiated with the entire scleral layers present. In group D, the corneal epithelium had more cellular layers and pigments were observed in limbus. In group E, the corneal epithelium was of the non keratinized stratified squamous type. The Descemet’s membrane was thick. Apart from the cornea, all other regions of the fibrous coat had more melanocytes and pigments in group E. The central and peripheral corneal thicknesses of the adults (242.29 ± 23.95; 179.34 ± 8.37) were significantly higher (p < 0.05) than those of the fetuses of 2nd (68.50 ± 7.14; 71.20 ± 6.93), 3rd (90.47 ± 8.85; 68.35 ± 4.73) and 4th (81.71 ± 14.11; 88.87 ± 15.26) months of gestation and also that of the neonate (91.61 ± 15.81; 90.99 ± 9.08). In the eyes of group A, the iris was present as well as the iridopupilary membrane. The annular sinusoid was also present, choroidal differentiation was also initiated. Also pigment cells appeared in the stroma of the iris along with the dilator pupilary muscle myocytes. The ciliary body appeared as ciliary folds covered by a bilayered epithelium. The formation of the trabecular meshwork had been initiated while the iridocorneal angle was still closed. The angular aqueous plexus was seen at this stage. The choroid also started differentiating. In group B, the constrictor pupillary muscle had appeared while the iridopupillary membrane had started regressing. The granula iridica also had started forming and the pectinate ligament appeared. The formation of the tapetum fibrosum was initiated at this stage. In group C, the ciliary folds formed the ciliary processes. The iridocorneal angle opened at this stage with the dorsal angle opening before the ventral one. In group D, the iridopupilary membrane had broken down and the anterior iridal surface was thrown into folds. The ciliary cleft was also formed at this stage. In group E, the crypts of Fuschs were seen on the anterior iridal surface. Few radially and circularly oriented muscle fibers were also seen in the ciliary body and the suprachoroidal space also appeared. The retinal primordium was present in the eyes of group A as well as the commencement of differentiation into retinal layers and cell types. The retinal cell types and layers appeared in the eyes of group B. The physiologic cup appeared in the eyes of group C at the optic nerve head. In group E, the rows of cells in the outer nuclear layer and inner nuclear layer of the retina were fewer than those in group D. Glial cells were seen at the optic nerve head at this stage. In group A, the lens capsule was present. The lens epithelium was of the pseudostratified and simple columnar types centrally and equatorially respectively. This changed to simple cuboidal and simple columnar centrally and equatorially in groups C and D. In group E, the lens epithelium was made up of simple cuboidal type centrally and simple columnar type at the equator. Hyaloid vessels were present in group A, became smaller and sparse in group C, few were seen on the posterior surface of the lens and equator in group D and they were absent in group E. The development of the nervous and vascular layers progressed posterior-anteriorly while that of the fibrous layer progressed anterior-posteriorly. Also the pigmentation of the different parts of the eye increased with fetal growth and was highest in the adult. This study has shown that by late 3rd trimester, the RSG eyeball has acquired a full complement of the nervous, vascular and fibrous layers along with other structures necessary for vision. Therefore it essentially had the same morphology as in the adult and appeared capable of carrying out the function ascribed to the eyeball in the adult.

Evaluation of the Morphology of the Female Reproductive System of the Grasscutter (Thryonomys Swinderianus, Temminck 1827)

Wed, 15 Mar 2017 00:00:00 GMT

Evaluation of the Morphology of the Female Reproductive System of the Grasscutter (Thryonomys Swinderianus, Temminck 1827) Onoja, Benedict Onu Fifteen female grasscutters, obtained from David Mark Farms, Otukpo, Benue State, Nigeria, were used for the study. They were randomly assigned to 3 groups of 5 each according to their ages; 1-3 months, 4-6 months and 7-9 months. They were acclimatized for 14 days. The live weights of the grasscutters were obtained. They were then euthanized with gaseous chloroform in an air-tight container. The female reproductive system (ovaries, uterine tubes, uterine horns, uterus duplex, cervix and vagina) were carefully dissected out and observed for gross features. The morphometry was also obtained. Each segment was then fixed in 10% Bouin’s solution and 10% neutral-buffered formalin of equal volume for 24 hours and processed routinely for light microscopy. Photomicrographs of the sections were taken using Moticam MC 2001 digital camera. The data were subjected to one way analysis of variance. Variant means were separated using Duncan’s multiple range test. Significance was accepted at p < 0.05. Grossly, the ovaries were spindle-shaped at 1-3 months, oval at 4-6 months and round at 7-9 months. In all the age groups studied, the uterine horns had a firm consistency on palpation, the uterus presented the appearance of a double uterus, the cervix had a rubber-stopper consistency on palpation, and the vagina had a soft consistency on palpation. The weight and length of each segment of the female reproductive system of the grasscutter increased as the animal attained puberty. Thus, the organ sizes and lengths may not be pre-determined pre-natally, but increased proportionately as the animal attained puberty. There were significant (p < 0.05) variations between the means of the relative weight and length of the ovaries, uterine tubes, uterine horns, uterus duplex, cervix and vagina of all the age groups. Histomorphologically, the oocyte was peripherally located in the Graafian follicle as well as corpora haemorrhagica and lutea in the cortex at 7-9 months. An intensely eosinophilic vaginal plug that was absent in the lumen of the vagina at 1-3 and 4-6 months, was very conspicuous at 7-9 months. The female grasscutter could thus be said to attain puberty at 7 months of age.