Images of Diseases

The chapter contains annotated color images of emerging diseases and exotic diseases in wild and domesticated animals

The Effects of Ascorbic Acid on In Vitro Heterophil Function

As a feed additive, ascorbic acid has been shown to have a protective effect against bacterial and viral diseases and to reduce the impact of detrimental stress in chickens. This study examined the effect of ascorbic acid treatment on in vitro heterophil function by examining random migration and phagocytosisa nd bacterialk illing of Staphylococcuasu reus. Heterophils were evaluated in broiler chickens ranging from 5 to 16 wk of age, and age differences were seen. Significant increases in bacterial killing were found in heterophils treated with ascorbic acid, and this difference tended to be greater in chickens from 5 to 10.5 wk of age. No significant differences were found in phagocytosis or random migration, but ascorbic acid tended to decrease random migration. The most significant effect on in vitro heterophil function was an increase in bacterial killing

Images of Emerging and Exotic Diseases of Animals

The chapter contains annotated color images of emerging diseases and exotic diseases in wild and domesticated animals

Gastrointestinal Endoscopic Exfoliative Cytology: Techniques and Clinical Application

Cytologic examination of exfoliative specimens obtained during endoscopy is a useful and reliable adjunct to mucosal biopsy for the diagnosis of gastrointestinal (GI) tract diseases in dogs and cats. Clinical advantages of endoscopic cytology include simplicity, rapidity of diagnosis and minimal invasiveness. Cytologic smears are graded on the basis of objective criteria, including the presence and number of inflammatory, atypical, and epithelial cells as well as the presence of bacteria, hemorrhage, debris/ingesta, and mucus. There is high correlation between results obtained from endoscopic cytology and histologic examination, and discordant results are infrequent. Brush cytology is useful in detecting mucosal inflammation, whereas touch cytology is more likely to detect acute purulent and erosive mucosal lesions. Alimentary lymphoma my be readily diagnosed using either technique. This article provides an overview of how cytologic smears are prepared and evaluates their diagnostic accuracy

Comparison of Heterophil Phagocytosis for Heterophil- Adapted Salmonella enteritidis (HASE) and Wild-Type Salmonella enteritidis (SE)

Serial passage of Salmonella enteritidis (SE) yields heterophil-adapted SE (HASE) strains that have resulted in decreased shedding of SE in feces and reduced egg contamination. Additionally, increasing the number of heterophil passages further reduced the number and frequency of fecal shedding. To evaluate SE and heterophil interaction, nine SE strainsw ere fluoresceini sothiocyanate-labeledw hen viable. There were six wild-types:S E TK 474, SE TK 584, SE TK 599, SE TK 600, SE TK 655, and SE TK 657; and three HASE strains: TK 499 heterophil adapted five times, TK 598 heterophil adapted six times, and TK 605 heterophil adapted 11 times. Trials were repeated seven times in duplicate with heterophils isolated from seven healthy chickens. Heterophils were incubated with the bacterial strains at 41 C for 15 min, and 10,000 heterophils were analyzed by flow cytometry. Percentage of phagocytosis and mean channel number of fluorescence were compared. Both parameters were significantly increased for all HASE-type strains compared with wild-type, nonadapted SE strains. Increased phagocytosis of HASE bacterial strains may be significant in processing and elimination of the HASE strains and may be related to the protective effect of HASE by decreased shedding of wild-type SE challenge strains

Use of Rapid Cytochemical Staining to Characterize fish blood granulocytes in Species of Special Concern and Determine Potential for Function Testing

Studies of innate immunity in fish species of special concern are essential for better understanding of their health status during hatchery rearing conditions. The cytochemical and morphological characterizations of blood granulocytes have been used to provide information about phylogenetic differences and determine the potential use of neutrophil function assays. Rapid, simple, cytochemical staining kits used routinely for staining mammalian granulocytes have been used to characterize granulocytes from blood of four fish species: Arctic grayling, cutthroat trout, June sucker, and shovelnose sturgeon. Blood smears were stained with Peroxidase 391 (myeloperoxidase, MPO), alkaline phosphatase (AP), Periodic Acid Schiff (PAS) and Diff-quick stain; examined using bright field and differential interference contrast microscopy. Granulocytes on blood smears were evaluated based on the cell morphology, and presence or absence of the specific chromogen. Presence of lymphocytes, monocytes, platelets/thrombocytes and granulocytes was determined in all fish species. Arctic grayling, June sucker, and cutthroat trout had MPO positive granulocytes, while shovelnose sturgeon heterophils had positive reaction for leukocyte AP, but not MPO. Presence of MPO indicated potential to measure oxidative burst and degranulation of neutrophil primary granules in Arctic grayling, cutthroat trout and June sucker. Absence of MPO in shovelnose sturgeon suggested use of different enzyme marker (AP) in degranulation assay for this species. Standardization of cytochemical techniques allowed forrapid screening of leukocyte types, reducing the number of fish, time and effort to select adequate neutrophil function assays to be used in studies of health status in species of special concern

Experimental Canine Leptospirosis Caused by Leptospira Interrogans Servars Pomona and Bratislava

Objective—To evaluate gross, histopathologic, and serum biochemical findings caused by Leptospira interrogans serovars pomona and bratislava inoculated in dogs. Animals—Twenty-seven 8-week-old female Beagles. Procedure—Dogs were randomly assigned to challenge or control groups. Challenge groups were conjunctivally inoculated on 3 successive days with 5 X 107 L interrogans serovar pomona (n = 12) or serovar bratislava (11). Clinical signs were recorded throughout the experiment, and clinical pathology assays, bacteriologic culture, and necropsies (6 or 7 dogs necropsied at each time point) were done on postinoculation day (PID) 7, 10, 14, and 20. Results—Infection could not be confirmed in any serovar bratislava–inoculated dog, and control dogs remained healthy throughout the experiment. Positive culture and fluorescent antibody test results were confirmed in 11 of 12 serovar pomona–inoculated dogs. Fever and lethargy starting at PID 7 were the most common clinical signs in serovar pomona–infected dogs. On day 10, gross lesions included multifocal renal and pulmonary hemorrhage and perirenal edema. Serovar pomona–inoculated dogs had histopathologic lesions including hepatitis, interstitial nephritis, and pneumonia at PID 7, 10, 14, and 20. Increases in BUN, anion gap, and bilirubin concentration occurred on PID 10, 14, and 20. Platelet counts in dogs with positive results of bacteriologic culture were decreased from baseline values on PID 10, 12, and 14. Conclusions and Clinical Relevance— Conjunctival inoculation with L interrogans serovar pomona resulted in a high rate of infection with concomitant hemorrhagic and inflammatory lesions of the kidneys, liver, and lungs

Clinical and Pathologic Comparison of Acute Leptospirosis in Dogs Caused by Two Strains of Leptospirosis Kirschneri Serovar Grippotyphosa

Objective—To develop a method for inducing acute leptospirosis in dogs. Animals—31 nine-week-old female Beagles. Procedure—Beagles were randomly assigned to 2 inoculation groups or a control group. Dogs were inoculated on 3 successive days by conjunctival instillation of 5 X 107 cells of Leptospira kirschneri serovar grippotyphosa strain 82 (12 dogs) or strain RM 52 (14 dogs). Control dogs (n = 5) were similarly inoculated with sterile leptospiral culture media. Clinical signs, clinicopathologic variables, anti-leptospiral antibody titers, and evidence of leptospires in tissues and body fluids were evaluated. Dogs were euthanatized and necropsied on days 7, 14, 22, or 28 after inoculation or as required because of severe illness. Results—Clinical signs in infected dogs included conjunctivitis, lethargy, diarrhea, dehydration, vomiting, and icterus. Consistent clinicopathologic alterations included azotemia, hyperphosphatemia, increased anion gap, hyperbilirubinemia, and an increase in alkaline phosphatase activity. Leptospires were cultured from the kidneys (11/12), urine (6/9), aqueous humor (9/12), blood (12/12), and liver (12/12) of dogs inoculated with strain 82. Only 3 of 14 dogs became infected after inoculation with strain RM 52. Histopathologic lesions in infected dogs included interstitial nephritis, renal tubular degeneration and necrosis, pulmonary hemorrhage, and hepatic edema and perivasculitis. Conclusions and Clinical Relevance—Conjunctival exposure to L kirschneri serovar grippotyphosa strain 82 resulted in acute leptospirosis in all inoculated dogs, but only 3 of 14 dogs inoculated with strain RM 52 became infected. This method of infection by serovar grippotyphosa can be used to study the pathogenesis and prevention of leptospirosis in dogs

Anesthetic Efficacy of Tricaine Methanesulfonate, Metomidate and Eugenol: Effects on Plasma Cortisol Concentration and Neutrophil Function in Fathead Minnows (Pimephales promelas Rafinesque, 1820)

Anesthetic efficacy, plasma cortisol concentration, and two parameters of neutrophil function (oxidative burst and degranulation of primary granules) were compared among three anesthetics in the fathead minnow: tricaine methanesulfonate (MS 222), metomidate hydrochloride (MTMD), and eugenol (EUG). The optimum anesthetic concentration was determined as: MS 222 75 mg L− 1, EUG 30 mg L− 1 and MTMD 4 mg L− 1. Handling and crowding stress was induced in fish with (SA) and without (S) anesthetic. Plasma cortisol concentration was measured at 0, 30, 90, and 240 min after stress and found to increase at 30 min post-stress in S and SA MS 222 groups, but not in SA MTMD and SA EUG groups. To test the effects of different anesthetics on neutrophil function, fish were divided into a baseline control group, a group exposed to handling and crowding stress (S) and a stressed anesthetized group (SA). Fish were assayed for neutrophil function before and after stress (24 h, 72 h and 7 days). The degranulation of neutrophil primary granules was measured as exocytosis of myeloperoxidase (MPO) using 3, 3′, 5, 5′-tetramethylbenzidine as a substrate. Degranulation of primary granules was decreased to 60–75% of non-stressed control in stressed and fish treated with MS 222, and was not affected when MTMD and EUG were used. The degranulation of primary granules proved to be a useful assay for measuring the effects of stress on neutrophil function in fish. Eugenol and metomidate prevented stress-induced decrease of neutrophil function while MS 222 did not

Immunomodulatory Effects of beta-Glucan on Neutrophil Function in Fathead Minnows (Pimephales Promelas Rafinesque, 1820)

Stimulatory effects of yeast b-1,3–1,6-glucans on neutrophils have long been recognized, but effects of glucans on degranulation of primary granules in fish neutrophils have not been previously reported. Neutrophil function was monitored during in vitro and in vivo application of glucans to non- (NS), acute- (AS) and chronically stressed (CS) fish. b-Glucan proved to be a strong and quick (80%, 2 min) stimulant of degranulation. Dietary glucan increased degranulation in NS fish, and prevented a decrease in AS fish. Degranulation in CS fish returned to NS levels 3 days after the glucan diet was fed. Fathead minnows appear to be a useful model to investigate neutrophil degranulation in fish exposed to different environmental conditions and immunomodulators. Use of b-glucans in fish diets prior to AS and during chronic stress can enhance neutrophil function, potentially increasing disease resistance and survival rates after transportation or exposure to poor water quality