Experimental transmission of intestinal coccidiosis to piglets: clinical, parasitological and pathological findings.

Twenty-eight piglets coming from a "specific pathogen free" herd were inoculated at three days of age with 50 000 or 100 000 sporulated oocysts of Isospora suis. Fecal samples were examined for oocyst shedding daily and several clinical parameters were recorded. Ten piglets were used as normal controls. Groups of piglets were euthanized from three days to 12 days postinoculation and routine necropsies were performed. Bacteriological, virological, parasitological and histopathological examinations were made on the intestinal tracts. The incubation period was four to five days. Clinical signs and microscopic intestinal lesions observed in the experimentally infected animals were similar to those reported in spontaneous cases of porcine neonatal coccidiosis. Lesions of villous atrophy in the small intestine seemed to result from the destruction of villous epithelial cells mainly during the peak of asexual reproduction which occurred around four to five days postinoculation. Intracellular coccidial organisms were difficult to find during the late atrophic and villous regrowth stages of the intestinal lesions. The prepatent period varied from four to seven days and the most common was five days. Eighty percent of the piglets kept alive more than four days postinoculation have shed oocysts. Piglets dosed with old sporulated oocysts (ten months old) shed many more oocysts than those infected with a fresh inoculum (less than two months old). The patent period was not determined precisely with the design of the experiment but some of the infected piglets shed oocysts for at least five days.     

Failure of dogs to shed oocysts after being fed bovine fetuses naturally infected by Neospora caninum

Neospora caninum is a protozoan that causes abortion in cattle. The dog has recently been identified as a definitive host for N. caninum. To verify if bovine fetuses can infect dogs, nine 2-4-month-old dogs were fed bovine fetuses naturally infected by N. caninum. None of the dogs excreted oocysts, seroconverted, had clinical signs or lesions compatible with N. caninum infection. Additional studies will be necessary to determine the natural mode of infection of dogs by N. caninum.     

Invasive multiple lymphangiomas in a young dog

An unusual case of multiple lymphangiomas with lymph node involvement is described. A seven-month-old, spayed female golden retriever was presented with a myriad of cystic masses in the inguinal and caudal mammary regions. She was diagnosed with congenital lymphangiomas (i.e., lymphatic hamartomas). As in human lymphangiomas, lymphatic endothelial cells expressing factor VIII-related antigen and smooth muscle were present in this case. A literature search did not identify similar characteristics in other reported canine lymphangiomas. The dog was treated surgically and had a recurrence. Following a second surgical intervention, she is now disease-free.     

Hog Cholera: IV. Detection of the Virus in Tissue Culture Preparations by the Fluorescent Antibody Technique

The fluorescent-antibody technique was employed for detection of hog cholera virus in tissue cultures inoculated with spleens of infected animals. As controls, cultures were also inoculated with material from normal swine and from those infected with other agents. In the first series 71 of 73 infected spleens, or 97 per cent, were detected. There were no false positive reactions among the controls. Results obtained with the second series of pigs showed that spleens collected during advanced stages of the disease were more satisfactory specimens than those collected earlier during the high temperature phase of infection. Findings with the third series of older swine indicated that their spleens were less satisfactory as a source of virus than those from young pigs. Tissues from freshly killed animals provided better specimen material than those from animals which had died.     

Early dexamethasone treatment after implantation of a sciatic-nerve cuff decreases the concentration of substance P in the lumbar spinal cord of rats with neuropathic pain

The main purpose of this study was to evaluate the effects of early dexamethasone treatment on pain-related peptides at an early stage in the development of neuropathic pain induced by implantation of a sciatic nerve cuff in Sprague Dawley rats (body weight 250 to 350 g). The rats were tested for touch sensitivity with the use of von Frey filaments before and 3 d after cuff implantation (n = 12) or sham surgery (n = 6). Half of the cuff-implanted rats received dexamethasone, 1 mg/kg intraperitoneally, 1 h after surgery. Spinal cords were collected on the 3rd day after surgery, and the lumbar enlargement was processed for the detection of selected peptides (neurotensin, substance P, cholecystokinin [CCK], vasoactive intestinal peptide, and calcitonin gene-related peptide) by means of liquid chromatography and tandem mass spectrometry. The right sciatic nerve of each rat was collected, fixed, and stained for histopathological evaluation. Except for neurotensin, all the peptides showed an increased concentration with neuropathic pain; however, the differences were significant (P < 0.05) only for substance P and CCK. In the animals treated with dexamethasone, mechanical allodynia was less pronounced (P < 0.01), and only the concentration of substance P was decreased significantly (P < 0.05). Sciatic nerve sections showed a decrease in C (P < 0.01) and Adelta (P < 0.03) fibres with neuropathic pain and a nearly normal percentage of C fibres after dexamethasone treatment. The dexamethasone-treated animals also had less inflammation detectable microscopically at the nerve constriction site compared with cuff-implanted animals that were not treated with dexamethasone. Our results suggest that in the early stages of neuropathic pain induced by an inflammatory process, dexamethasone may be a useful treatment and that substance P plays an important role in pain perception.     

Sperm Morphology in the Domestic Cat, and its Relation with Fertility: A Retrospective Study

Knowledge about normal ranges in semen quality and the association between sperm morphology and fertility in felids is limited. The aims of this retrospective study were to (1) define a normal spermiogram in cats; (2) evaluate possible effects of season, age and breed on sperm morphology; and (3) evaluate the relationship between sperm morphology and fertility. Semen samples collected by electroejaculation from 52 cats were evaluated for sperm morphology. The cats constituted two groups: a general population of cats (n = 48) and cats examined because of poor breeding records (n = 4). The general population was divided into household (n = 20), pedigree (n = 19) and colony cats (n = 9) and into three age classes, <12 months, 12-59 months and >or=60 months. The median percentage of normal spermatozoa in the general population was 44.0% (range 1.0-91.0%). Criteria were tentatively set for what was considered a normal spermiogram. The mean percentage of normal spermatozoa was higher during February to July than during August to January (p < 0.05). Pedigree cats had a lower mean percentage of normal spermatozoa than did household cats (p < 0.05). Age had no effect on the percentage of normal spermatozoa but was positively correlated with the percentage of proximal droplets. Of the cats with <40% normal spermatozoa (n = 19), all those with known breeding records (n = 11) had produced litters. The four cats examined because of poor breeding results had higher percentages of different sperm abnormalities than tentatively stipulated for the normal spermiogram. In two of these cats both sperm morphology and fertility changed over time.     

Management of inappetant sheep during export by sea

In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS)