Risk factors associated with Coccidioides infection in dogs

OBJECTIVE: To evaluate potential risk factors for Coccidioides infection among dogs living in a region in which the organism is endemic (Pima and Maricopa counties, Arizona). DESIGN: Community-based longitudinal and cross-sectional studies. ANIMALS: 104 healthy 4- to 6-month-old puppies (longitudinal study) and 381 4- to 18-month-old dogs with unknown serostatus (cross-sectional study). PROCEDURE: Dogs in the longitudinal study were tested 3 times at 6-month intervals for anticoccidioidal antibodies; dogs in the cross-sectional study were tested only once. Owners of all dogs completed a questionnaire on potential environmental exposures. RESULTS: In the longitudinal study, the relative risk of infection for dogs that were outdoors during the day was 4.9 times the risk for dogs that were kept indoors. Seropositive dogs in the cross-sectional study were 6.2 times as likely to have access to > 1 acre to roam as were seronegative dogs. Logistic regression analysis indicated that the odds of infection increased with age (odds ratio [OR], 1.1), amount of roaming space (OR, 2.4), and walking in the desert (OR, 2.2). Walking on sidewalks had a protective effect (OR, 0.4). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in regions in which the organism is endemic, dogs that spend more time outdoors or have more land in which to roam are at greater risk of infection with Coccidioides spp.     

Endocrine pathogenesis of postweaning anestrus in swine: response of the persistently anestrous sow to hormonal stimuli

The endocrine function of the individual components of the hypothalamo-hypophyseal-ovarian axis of the postweaning anestrous sow was evaluated by monitoring the sow's response to exogenous estradiol, gonadotropin releasing hormone (GnRH), and gonadotropins. Sows (4 to 6/group) not returning to estrus by 42.8 +/- 3.1 days after weaning were assigned to 1 of the following treatments: 10 micrograms of estradiol benzoate (EB)/kg of body weight; 200 micrograms of GnRH, 1,000 IU of pregnant mare's serum gonadotropin (PMSG); 1,000 IU of human chorionic gonadotropin (HCG); or 4 ml of saline solution plus 2 ml of corn oil. A preovulatory-like surge of luteinizing hormone [(LH) greater than 12 hours in duration] was observed in all weaned sows treated with EB. All EB-treated sows exhibited estrus and ovulated but none conceived. Sows given GnRH had transiently increased (less than 3 hours) LH concentrations that were not associated with estrus or ovulation. Treatment with PMSG caused an increase in peripheral concentrations of 17 beta-estradiol that was followed by an LH surge, estrus, ovulation, and conception. Treatment with HCG caused an increase in circulating concentrations of 17 beta-estradiol that was accompanied by a surge of LH in some sows and ovulation in all sows. Not all sows treated with HCG exhibited estrous behavior, but conception occurred in 2 of 3 sows that were mated at estrus. None of the sows treated with saline plus corn oil had consistent changes in circulatory concentrations of 17 beta-estradiol or LH and none exhibited estrus or ovulated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interactions between the associations of parity, lactation length, and weaning-to-conception interval with subsequent litter size in swine herds using early weaning

Sixteen farms having an average lactation length between 14.9 and 18.9 days were selected based upon producers' willingness to keep records of production and lactation feed intake. Data contained 9162 subsequent litter-size records abstracted from computerized production information-system files and lactation feed-intake records. Two-way interactions between the associations of parity and lactation length, and parity and weaning-to-conception interval with subsequent litter size were found in the same statistical model. Subsequent litter size did not increase in parities 1 and 2 as lactation length increased – but subsequent litter size in sows of parities 3–6 increased. In only parity 1, sows with weaning-to-conception interval 6–12 days produced 0.5 fewer pigs at subsequent farrowing than those with weaning-to-conception interval 1–5 days. However, in multiparous sows, no difference in subsequent litter size was found between weaning-to-conception intervals 1–5 and 6–12 days.     

Nasal vascular hamartoma in a Domestic Shorthair cat

A nasal mass in a Domestic Shorthair cat was causing facial deformity, sneezing and intermittent epistaxis. Biopsy samples obtained previously had been non-diagnostic. Computed tomography images revealed an irregular, contrast-enhancing mass occupying a large portion of the righthand side of the nasal cavity. Previously described criteria for malignancy were not present. A ventral surgical approach combined with temporary, ipsilateral, common carotid arterial occlusion provided excellent access for debulking the lesion and collecting samples for histopathology. A nasal vascular hamartoma was diagnosed and clinical signs resolved postoperatively. This is the first documentation of this abnormality in the cat. Hamartomatous abnormalities should be included on the list of differential diagnoses for feline nasal mass lesions. The prognosis for hamartomatous lesions postoperatively is good, in keeping with their limited propensity for growth after maturity.     

Guidelines for resident training in veterinary clinical pathology. III: cytopathology and surgical pathology

The Education Committee of the American Society for Veterinary Clinical Pathology has identified a need for improved structure and guidance of training residents in clinical pathology. This article is the third in a series of articles that address this need. The goals of this article are to describe learning objectives and competencies in knowledge, abilities, and skills in cytopathology and surgical pathology (CSP); provide options and ideas for training activities; and identify resources in veterinary CSP for faculty, training program coordinators, and residents. Guidelines were developed in consultation with Education Committee members and peer experts and with evaluation of the literature. The primary objectives of training in CSP are: (1) to develop a thorough, extensive, and relevant knowledge base of biomedical and clinical sciences applicable to the practice of CSP in domestic animals, laboratory animals, and other nondomestic animal species; (2) to be able to reason, think critically, investigate, use scientific evidence, and communicate effectively when making diagnoses and consulting and to improve and advance the practice of pathology; and (3) to acquire selected technical skills used in CSP and pathology laboratory management. These guidelines define expected competencies that will help ensure proficiency, leadership, and the advancement of knowledge in veterinary CSP and will provide a useful framework for didactic and clinical activities in resident‐training programs.     

Influence of glucose infusions on luteinizing hormone secretion in the energy-restricted, primiparous, lactating sow.

The objective of this experiment was to evaluate the influence of glucose infusion during lactation on LH secretion in the energy-restricted sow. Ten primiparous Landrace x Yorkshire sows (152 kg postfarrowing) were fed a low-energy (6.5 Mcal of ME/d), high-lysine (45 g/d), corn-soybean meal diet throughout lactation. On d 18 of lactation, sows received a continuous infusion (1 L/12 h) of glucose (50% dextrose solution) or .9% saline from 1200 to 2400. Blood samples were drawn every 15 min for an 18-h period on d 18 to evaluate concentrations of plasma glucose, serum insulin, and serum LH before (600 to 1200) and during (1215 to 2400) the infusions. The glucose infusion immediately increased (P less than .001) plasma glucose and serum insulin relative to preinfusion levels. Glucose and insulin concentrations in sows receiving the glucose infusion were higher (P less than .001) throughout the infusion period relative to concentrations in sows receiving a saline infusion. Glucose infusions had no influence on LH pulsatility during the 12-h infusion period. In contrast to the response observed in the nutrient-restricted gilt, these results indicate that glucose infusions do not result in an immediate increase in pulsatile LH secretion in the energy-restricted, lactating sow.     

Effects of season and estradiol-17 beta on luteinizing hormone release in ovariectomized sows.

This study examined the ability of estradiol-17 beta (E2) to suppress LH release in the sow during different months of the year. Six chronically ovariectomized sows were fitted with vena caval cannulas (d 0) and blood samples were collected at 6-h intervals for 6 d. Sows were treated s.c. with E2 capsules (24 mg of E2/275 kg of BW) at d 3. Additional blood samples were collected at 15-min intervals for 8 h on d 2 and 5. After each 8-h frequent sampling period, sows were treated i.v. with GnRH at .5 microgram/kg of BW, and blood samples were collected at 10-min intervals for 3 h. The protocol was repeated at monthly intervals for 13 mo. Luteinizing hormone concentrations were determined for all serum samples, and E2 concentrations were quantified in samples collected at 6-h intervals. Data were analyzed by split-block analyses of variance. Serum E2 concentrations increased (P less than .001) from 5.0 +/- .3 pg/ml before E2 treatment to 26.0 +/- .2 pg/ml after E2 treatment. The interval from GnRH administration to peak LH concentration was shorter (P less than .001) before E2 treatment than after E2 treatment (28.7 +/- 2.2 vs 71.0 +/- 2.2 min). It was evident that baseline LH, mean LH, pulse frequency, and pulse amplitude and LH release after GnRH administration failed to demonstrate seasonal changes. In summary, LH release was suppressed after treatment with E2 and was affected minimally by month of the year. In addition, E2 inhibitory effects of LH release included hypothalamic and anterior pituitary sites of action.