Canine protothecosis: review of the literature and report of an additional case

A review of protothecosis in dogs revealed that this malady usually begins in the gastrointestinal tract and progresses to systemic involvement. Clinical signs generally include bloody diarrhea or blood-stained feces as well as blindness, ataxia, and polyuria. Histologically, myriads of protothecal organisms in different stages of development are found in the granulomatous lesions. Two main species have been culturally identified: Prototheca zopfii and P wickerhamii. In the absence of cultural studies, species identification can be accomplished readily by immunofluorescence. The present case involved P zopfii infection in a 5-year-old female Cocker Spaniel that had bloody diarrhea, with a history of bloody diarrhea 6 months earlier.     

Accelerated chilling of carcasses to improve pork quality

Our objectives were to determine the optimal accelerated chill time immediately postmortem necessary to improve the quality of pork muscle and to decrease the incidence of pale, soft, and exudative pork. Carcasses from 81 market hogs were cooled either by conventional chill (CC) at 2 degrees C or by accelerated chill (AC) at -32 degrees C for 60, 90, 120, or 150 min, and then placed into a 2 degrees C cooler for the remainder of the 24-h chill period. Loin muscle pH was higher (P < 0.05) for the carcasses that were accelerated chilled longer than 60 min. Although loin visual color, texture, and firmness scores increased (P < 0.05) with AC time, no improvements were noted beyond 60 min. Color, pH, texture, firmness, and CIE L*a*b* values of fresh ham muscles were not (P > 0.05) affected by AC. In addition, AC did not (P > 0.05) affect purge, drip, or thaw loss of fresh products, sensory scores of loins or processed hams (except initial juiciness; P < 0.05), water-holding capacity of processed hams, or processing characteristics of hams. Cooking loss and Warner-Bratzler shear values for hams and loins were not (P > 0.05) affected by AC. Accelerated chilling caused loins to be darker (lower L* value; P < 0.05) and to have lower (P < 0.05) b* values (less yellow) than CC loins. Accelerated chilling increased water-holding capacity in fresh hams, bound water being the greatest (P < 0.05) in the 120- and 150-min AC groups. These results demonstrate that improvements in pork loin quality can be made using freezer-accelerated chilling for carcasses.     

Effect of boar exposure at time of insemination on factors influencing fertility in gilts

The effect of boar exposure during artificial insemination (AI) on semen backflow, fertilization, and embryo quality was evaluated. Gilts (approximately 170 d) were induced into estrus with PG600, and ovulation was synchronized using hCG 72 h later. Estrus detection was initiated after PG600 and continued at 12-h intervals. At estrus, gilts were allotted to receive boar exposure (BE, n = 20) or no boar exposure (NBE, n = 20) during AI. Gilts receiving NBE were identified to be in estrus prior to AI and the boar was then removed for 1 h, whereas gilts in the BE group received 15 min of exposure during AI. Insemination occurred in crates at 12 and 24 h after onset of estrus with 3 x 10(9) sperm/80 mL. Backflow was collected continuously with samples taken at time 0, (during AI), and at 0.25, 0.5, 0.75, 1, 2, 4, and 8 h after first and second AI. The effect of treatment was evaluated for time of insemination (min), backflow (mL), and sperm in backflow samples. Oviducts were flushed 2 d after first AI to evaluate the effect oftreatment on fertilization rate, accessory sperm numbers on embryos (scored 1 to 5), and embryo quality. There was no effect of first or second AI; therefore, data were pooled. Average duration of AI was 3.7 +/- 0.2 min and was not influenced by BE (P < 0.10). However, during the initial stage of AI, BE reduced the volume of semen (18.6 vs 32.4 +/- 3 mL) and the number of sperm lost (0.8 vs 1.3 +/- 0.15 x 10(9) sperm) compared to NBE (P < 0.05). There was a treatment x time effect (P < 0.05) for volume of backflow. By 45 min, the BE gilts lost more volume (9.0 vs 3.6 mL) compared to the NBE group, but sperm loss did not differ. Between 1 and 8 h after AI, neither volume nor sperm loss was influenced by treatment. By 8 h, total leakage (65 vs 63 mL) and total sperm loss (1.6 x 10(9) vs 1.8 x 10(9) sperm) were not influenced by BE (P > 0.10). However, more accessory sperm (P < 0.01) were found on embryos for the NBE (> or = 11 sperm/embryo) compared to BE embryos (< or = 10 sperm/embryo). Despite this observation, percentages of fertilized embryos (99.5 +/- 0.5 %) and number of embryos (11.5 +/- 0.1) were not different (P > 0.10). In conclusion, AI in the presence of a mature boar did not affect total semen leakage, sperm loss, fertilized embryos, or embryo quality. The importance of boar exposure during insemination was evident from less leakage during insemination, but had no effect on fertility; this suggests that the elimination of boar exposure during AI may not be deleterious to reproductive performance.     

Cutaneous hypersensitivity reactions to Psoroptes ovis and Der p 1 in sheep previously infested with P. ovis--the sheep scab mite

We have previously shown that infestation with Psoroptes ovis induces an IgE response and intense tissue eosinophilia, typical of a Type I hypersensitivity response [Parasite Immunol. 22 (2000) 407]. Intradermal tests (IDSTs) suggest that there are also delayed and Arthus-type responses to this parasite. In order to study the nature of ovine cutaneous reactions to P. ovis, na?ve controls and experimentally infested sheep (n = 5) were challenged intradermally with mite antigen. Challenge elicited immediate (P < 0.001) and delayed (P < 0.005) wheal reactions in sensitised sheep. At 6 (P < 0.02) and 30 h (P < 0.001) the predominant infiltrating cells were eosinophils. To explore the role of circulating antibodies, na?ve sheep (n = 5) were subjected to Prausnitz-Kustner (PK) tests. These elicited immediate (P < 0.02) but not delayed wheal reactions. At 6 h eosinophils (P < 0.001) dominated the infiltrate. These results suggest that P. ovis allergens provoke an IgE-dependent immediate and late phase response and a cell-mediated eosinophil-rich delayed-type hypersensitivity response (ER-DTH).     

3-methylindole induces transient olfactory mucosal injury in ponies

Response to 3-methylindole (3MI) varies among species. Mice recover from 3MI-induced bronchiolar epithelial injury but sustain persistent olfactory mucosal injury with scarring and epithelial metaplasia. In contrast, 3MI induces obliterative bronchiolitis in horses and ponies, but olfactory mucosal injury has not been reported. To evaluate the effect of 3MI on equine olfactory mucosa, ponies were dosed orally with 100 mg 3MI/kg (n = 9) or corn oil vehicle (n = 6). All ponies treated with 3MI developed obliterative bronchiolitis with mild olfactory injury. By 3 days after 3MI dosing, olfactory epithelium appeared disorganized with decreased and uneven surface height and scalloping of the basement membrane zone. Epithelial cells of Bowman's glands were hypertrophic. Proliferation of olfactory epithelium and Bowman's glands was supported by an increased mitotic index and positive immunohistochemical staining for proliferating cell nuclear antigen as compared with controls. The activity of 11beta-hydroxysteroid dehydrogenase, an olfactory mucosal cytosolic enzyme localized to sustentacular and Bowman's glandular epithelial cells, was concurrently decreased. By 9 days postdosing, olfactory mucosal lesions had lessened. Results indicate that 3MI transiently injures equine olfactory mucosa without the extensive necrosis, scarring, or metaplasia seen in murine olfactory mucosa or in equine bronchiolar epithelium.