Simulation of Potato Late Blight in the Andes. I: Modification and Parameterization of the LATEBLIGHT Model

ABSTRACT LATEBLIGHT, a mathematical model that simulates the effects of weather, host growth and resistance, and fungicide use on asexual development and growth of Phytophthora infestans on potato foliage, was modified so that it can be used in the Andes and, eventually, worldwide. The modifications included (i) the incorporation of improved equations for the effect of temperature on lesion growth rate (LGR) and sporulation rate (SR); (ii) the incorporation of temperature-dependent latent period (LP); and (iii) the use of experimentally measured parameters of LGR, SR, and LP for specific potato cultivars and pathogen lineages. The model was parameterized for three Peruvian potato cultivars (Tomasa, Yungay, and Amarilis) infected with isolates of a new clonal lineage of P. infestans that is currently predominant in Ecuador and Peru (EC-1).     

Molecular characterization of potentially zoonotic isolates of Giardia duodenalis in horses

Giardia isolates from eight horses from New York State (NY), USA and two horses from Western Australia (WA) were genetically characterized at the SSU-rDNA and triose-phosphate isomerase (TPI) genes. Phylogenetic analysis of the TPI gene provided strong support for the placement of both isolates of Giardia from horses in WA and a single isolate from a horse in NY within the assemblage AI genotype of G. duodenalis. Another two isolates from horses in NY placed within the assemblage AII genotype of G. duodenalis. Phylogenetic analysis of the TPI gene also provided strong bootstrap support for the placement of four G. duodenalis isolates from horses in NY into a potentially host-specific sub-assemblage of assemblage BIV. The results of this study are consistent with previous studies showing that assemblages AI and AII of G. duodenalis provide the greatest potential zoonotic risk to humans. Horses may therefore constitute a potential source for human infection of Giardia either directly or via watersheds.     

Light-microscopy evaluation of zonular fiber morphology in dogs with glaucoma: secondary to lens displacement

Lens displacement resulting in secondary glaucoma is common in terrier breeds. This study was carried out to evaluate whether light microscopy was useful in detecting abnormal patterns in zonular fiber protein. Eyes from 63 dogs with glaucoma secondary to lens displacement were evaluated for the presence of abnormal zonular fiber morphology using the following stains: hematoxylin and eosin, periodic acid Schiff (PAS), Masson's trichrome and Verhoeff's elastin stains. Two distinct forms of abnormal zonular fiber morphology were recognized and designated as zonular fiber dysplasia (ZFD) and zonular fiber collagenization (ZFC). ZFD protein morphology was characterized by being tightly adherent to the nonpigmented ciliary body epithelium, exhibiting a distinct lamellar and cross-hatched pattern and staining strongly positive with PAS and trichrome stains, and staining negative with elastin stains. ZFD was predominant in terrier breeds (18 of 29) and Shar-Pei dogs (4 of 29). ZFC abnormality was characterized by excessive zonular fiber that was not tightly adherent to the ciliary body epithelium and staining positive with PAS, trichrome (blue for collagen) and elastin stains. Only 7 of 19 dogs with ZFC changes were terrier breeds, and there was no pattern in the breeds affected. Fifteen of the 63 dogs used in the study had normal appearing zonular fibers. The staining pattern in these dogs matched normal controls by staining positive with PAS and Verhoeff's elastin stains and had only minimal positive staining with Masson's trichrome stain. Results suggest that light microscopy is useful in detecting breed-related changes in zonular fiber morphology in cases of glaucoma secondary to lens displacement. These changes may correlate with the presence of abnormal zonular fiber proteins and might be important in the pathogenesis of primary lens displacement in terrier and Shar-Pei dogs.     

Radiotherapy of Metastatic Seminoma in the Dog Case Reports

Four dogs with metastatic seminoma were treated with cesium 137 teleradiotherapy. Minimum total tumor dose ranged from 17 to 40 gray (Gy) and was usually given through bilateral opposing sublumbar ports in eight to ten fractions, with three fractions given weekly. The tumor regressed in all four dogs. The first dog (case 1) was free of tumor and died of non-tumor related causes at 57 months. The second dog (case 2) was free of tumor but was euthanatized at 37 months for a limb fracture. The third dog (case 3) was euthanatized for undertermined pulmonary disease 43 months after radiotherapy. The fourth dog (case 4) was euthanatized 6 months following radiotherapy because of transitional cell carcinoma and renal failure. No evidence of seminoma was found at necropsy. Radiotherapy was shown to be effective treatment for seminoma with regional metastasis.     

Assessment of the metabolic effects of hydrocortisone on llamas before and after feed restriction

OBJECTIVE: To evaluate the effects of administration of hydrocortisone on plasma concentration of insulin and serum concentrations of glucose, triglyceride, and nonesterified fatty acids (NEFAs) in llamas before and after feed restriction. ANIMALS: 9 adult female llamas. PROCEDURE: Feed was withheld from llamas for 8 hours. Blood samples were collected before (0 minutes) and 120, 180, 240, and 300 minutes after IV injection of hydrocortisone sodium succinate (1 mg/kg) for determination of plasma insulin concentration and serum concentrations of glucose, triglyceride, and NEFAs. The llamas were then fed a limited diet (grass hay, 0.25% of body weight daily) for 21 days, after which the experimental procedures were repeated. RESULTS: Compared with llamas that were not feed-restricted, llamas after feed restriction had significantly higher plasma insulin concentration and serum concentrations of triglycerides and NEFAs. Feed-restricted llamas after hydrocortisone injection had a significantly smaller increase in serum glucose concentration, a decrease (rather than an increase) in serum concentration of NEFAs, and no change in blood concentrations of insulin or triglycerides. CONCLUSIONS AND CLINICAL RELEVANCE: Short-acting glucocorticoid hormones did not appear to increase blood lipid concentrations in healthy llamas, regardless of ongoing fat mobilization. Thus, these hormones appear unlikely to be major direct contributors to diseases such as hepatic lipidosis or hyperlipemia. Although administration of hydrocortisone reduced serum concentration of fatty acids in feed-restricted llamas, its use has not been evaluated in sick camelids and cannot be considered therapeutically useful.     

Idiopathic lymphoplasmacytic rhinitis in dogs: 37 cases (1997-2002)

OBJECTIVE: To determine clinical signs and rhinoscopic, computed tomographic, and histologic abnormalities in dogs with idiopathic lymphoplasmacytic rhinitis. DESIGN: Retrospective case series. ANIMALS: 37 dogs. PROCEDURE: Clinical information was obtained from medical records. Nasal computed tomographic images and histologic slides of biopsy specimens were reviewed. RESULTS: Dogs ranged from 1.5 to 14 years old (mean, 8 years); most (28) were large-breed dogs. Nasal discharge was unilateral in 11 of 26 (42%) dogs and bilateral in 15 of 26 (58%) dogs. In dogs with unilateral disease, duration of clinical signs ranged from 1.5 to 36 months (mean, 8.25 months; median, 2 months), and in dogs with bilateral disease, duration of signs ranged from 1.25 to 30 months (mean, 6.5 months; median, 4 months). Computed tomography (n = 33) most often revealed fluid accumulation (27/33 [82%]), turbinate destruction (23/33 [70%]), and frontal sinus opacification (14/33 [42%]). Rhinoscopy (n = 37) commonly demonstrated increased mucus and epithelial inflammation; turbinate destruction was detected in 8 of 37 (22%) dogs. Bilateral biopsy specimens from all 37 dogs were examined. Four dogs had only unilateral inflammatory changes. The remaining 33 dogs had bilateral lesions; in 20, lesions were more severe on 1 side than the other. CONCLUSIONS AND CLINICAL RELEVANCE: Findings suggest that idiopathic lymphoplasmacytic rhinitis is a key contributor to chronic nasal disease in dogs and may be more common than previously believed. In addition, findings suggest that idiopathic lymphoplasmacytic rhinitis is most often a bilateral disease, even among dogs with unilateral nasal discharge.     

Dietary antioxidants and behavioral enrichment enhance neutrophil phagocytosis in geriatric Beagles

The study objective was to determine the effects of feeding food enriched in antioxidants and a program of environmental/cognitive enrichment on selected ex vivo assays of inflammatory and immune cells in healthy geriatric Beagle dogs (n=21). Four groups of dogs were tested using a 2 x 2 factorial design. The 2-year longitudinal study included both nutritional (control food or antioxidant-fortified food) and behavioral (normal level or cognitive enrichment) interventions. Behavior enrichment included increased exercise, environmental enrichment, and a series of learning tasks. Phagocytosis of opsonized latex-coated beads by peripheral blood neutrophils was measured by flow cytometry and found to be significantly increased in dogs receiving both dietary antioxidants and cognitive enrichment. Simultaneous stimulation of cells with Con A and suppression with Dex resulted in decreased lymphocyte proliferation in dogs receiving both dietary antioxidants and cognitive enrichment, compared to dogs receiving dietary antioxidants or cognitive enrichment alone. There were no significant differences between the groups of dogs for percentages of CD4 and CD8 T-lymphocyte subpopulations before or after lymphocyte stimulation with Con A. These results support our hypothesis that both dietary antioxidants and behavioral enrichment enhance host defense mechanisms.     

Postanesthetic hyperthermia in cats: a retrospective comparison between hydromorphone and buprenorphine

OBJECTIVE: To determine the prevalence of postanesthetic hyperthermia [rectal temperature >40 degrees C (104 degrees F)] in a clinical population of cats. STUDY DESIGN: Retrospective study. ANIMAL POPULATION: One hundred and twenty-five cats with an age range of 2 months to 16.1 years, and weighing 3.9 +/- 1.5 kg. MATERIALS AND METHODS: Data were obtained from the medical records of 125 cats that underwent general anesthesia. Information on perioperative rectal temperatures, breed, sex, weight, surgical procedure, anesthetic time, surgery time, anesthetic and analgesic drugs were retrieved. STATISTICAL ANALYSES: Five groups of cats were compared; group 1 (n = 15) received acepromazine and no opioids; group 2 (n = 17) received acepromazine and buprenorphine; group 3 (n = 19) received acepromazine, buprenorphine and ketoprofen; group 4 (n = 45) received acepromazine and hydromorphone and group 5 (n = 29) received acepromazine, hydromorphone and ketoprofen. Data conformed to a split-plot repeated measures analysis of variance and was analyzed using SAS PROC MIXED. Post hoc tests were by means of Bonferroni t-test; < or = 0.05 was considered significant. RESULTS: Rectal temperature was significantly decreased in all groups at the end of anesthesia. Rectal temperature was significantly elevated at 1, 1.5, 2, 3, 4 and 5 hours after the end of anesthesia in group 4, and at 2, 3 and 4 hours in group 5. Sixty-four percent of cats in group 4 and 69% in group 5 had rectal temperatures >40 degrees C (104 degrees F) at one or more times in the postanesthetic period. The highest temperature recorded was 42.5 degrees C (108.5 degrees F) in one cat in group 4. Mean rectal temperature did not exceed the preoperative temperature at any time during the postanesthetic period in group 1, 2 and 3 animals. CONCLUSIONS: This study indicates an association between hyperthermia and perioperative administration of hydromorphone in cats. CLINICAL RELEVANCE: When hydromorphone is used in cats their body temperature should be closely monitored.