Detection of bacteraemia and host response in healthy neonatal foals.

REASONS FOR PERFORMING THE STUDY: Neonatal sepsis is a common problem in foals and is a primary cause of death in the post natal period. Transient bacteraemia and subsequent host responses have not been described in the equine neonate. OBJECTIVES: The primary objective of this study was to determine if transient bacteraemia occurs in foals within the first 72 h of life. Additional objectives included description of bacterial organisms associated with transient bacteraemia and concurrent cytokine gene expression in healthy foals. STUDY DESIGN: Prospective observational study in healthy foals. METHODS: Blood was aseptically collected for bacterial culture from observed spontaneously born foals at birth and 1, 2, 3, 4, 8, 12, 24, 48 and 72 h following birth. Samples taken at birth, 4, 12, 24, 48 and 72 h were analysed for interferon gamma (IFNγ), interleukin (IL)-1, IL-2, IL-6, IL-8, IL-10, IL-18 and monocyte chemotactic protein 1 (MCP1) cytokine gene expression quantified by RT-PCR. RESULTS: Bacteria were cultured from 9 of 70 samples submitted for blood culture. The positive samples were from 4 of the 7 foals, all of which remained healthy throughout and subsequent to the study. All positive blood cultures were from blood samples obtained at 12 h of age or earlier and IL-10 elevation coincided with positive blood cultures in healthy foals. Cytokine gene expression fluctuated with age. CONCLUSIONS: Positive blood cultures suggest transient bacteraemia may occur in healthy foals early in the post natal period. Age corrected normal values may be necessary to interpret cytokine concentration in diseased populations.

Parturition, dystocia and foal survival: a retrospective study of 1047 births.

REASON FOR PERFORMING STUDY: An understanding of the normal events of foaling, causes of dystocia and clinical outcomes is important for equine practitioners. OBJECTIVES: The goals of the present study were to: 1) evaluate factors that influence gestation length; 2) report duration of Stage II labour; 3) determine the frequency of dystocia and premature placental separation; and 4) determine the relationship between problems at foaling and foal survival. MATERIALS AND METHODS: Foaling records of 1047 mare births were evaluated. RESULTS: The average gestation length was 342.7 days [corrected] +/- 0.4 days, with no effect of mare age or breed observed. Mares carrying male fetuses had a longer gestation (P < or = 0.001) than mares carrying female fetuses. A majority (52.8%) of mares foaled at night between 2000 h and 0200 h when the facility was quiet. Dystocia occurred in 10.1% of all births and the incidence rate was higher in Thoroughbred mares than in Quarter Horse mares. The most common cause of dystocia was abnormalities of fetal posture. A delay in foal delivery beyond 40 min of Stage II of labour was associated with a significant increase in foal mortality. In addition, an increase in foal morbidity and mortality was noted when the interval from birth to standing or birth to nursing was prolonged. CONCLUSION: Early detection and rapid appropriate intervention are critical to foal survival in an equine dystocia. POTENTIAL RELEVANCE: Equine veterinarians should counsel horse owners that early recognition of a foaling problem and rapid, appropriate intervention are critical to the survival of a foal.

The effects of dexamethasone and prednisolone on pituitary and ovarian function in the mare.

REASONS FOR PERFORMING STUDY: Persistent mating induced endometritis is among the most common causes of infertility in the mare. Recently, improved pregnancy rates have been reported when corticosteroids were administered to 'problem mares' specifically, to modulate the post mating inflammatory response; however, the effect of treatment on pituitary and ovarian function requires further study. OBJECTIVES: To evaluate the effects of prolonged treatment with glucocorticoids on pituitary and ovarian function. METHODS: Eighteen cycling Quarter Horse mares in early oestrus were assigned randomly to one of 3 treatment groups: dexamethasone 0.05 mg/kg bwt i.v. twice a day, prednisolone 0.5 mg/kg per os twice a day, or placebo for 5 days. Mares were examined by ultrasound daily to evaluate reproductive function. Blood samples were collected daily to measure luteinising hormone (LH), progesterone and cortisol levels. RESULTS: Dexamethasone treatment caused greater (P<0.05) suppression of endogenous cortisol concentration (9.4 +/- 1.1 ng/ml) compared to prednisolone- (41.9 +/- 4.0 ng/ml) or placebo-treated mares (32.4 +/- 3.8 ng/ml). After 24 h, mares treated with dexamethasone exhibited lower uterine oedema scores than prednisolone- or placebo-treated mares. An ovulation rate of 40% was observed in dexamethasone-treated mares (2/5) compared to 83% for prednisolone (5/6) and 100% for placebo-treated (6/6) mares. An absence of a LH surge was noted in 3 of 5 dexamethasone-treated mares and one of 6 prednisolone-treated mares. CONCLUSIONS: Repeated administration of dexamethasone to mares in oestrus is associated with decreased uterine oedema, suppression of LH and a high rate of ovulation failure. It is recommended that dexamethasone treatment is limited to only 1 or 2 days and that a lower dose is considered in the management of persistent mating induced endometritis to avoid potential adverse affects on reproductive function.

Comparison of serologic tests and bacteriologic culture for detection of brucellosis in swine from naturally infected herds.

OBJECTIVE: To compare results of 6 serologic tests with results of bacteriologic culture for Brucella suis in swine. DESIGN: Prospective study. ANIMALS: Two hundred twenty-one swine from 39 naturally infected herds. PROCEDURE: Blood samples and lymph nodes were collected at slaughter. Serologic tests conducted were the particle concentration fluorescence immunoassay, the automated complement fixation assay, the card test, the buffered acidified plate antigen assay, the standard tube test, and the rivanol test. Lymph nodes were plated on Farrell's medium and serum-enriched agar for bacteriologic culture. RESULTS: Sensitivities ranged from 57 (automated complement fixation assay) to 83% (standard tube test). Specificities ranged from 62 (standard tube test) to 95% (rivanol test). Brucella suis was isolated from 46 of the 221 (21%) pigs. For 8 of the 46 culture-positive pigs, results of all 6 tests were negative. CLINICAL IMPLICATIONS: Data illustrate the difficulty of eliminating brucellosis by means of a test-and-removal program and support the policy of slaughtering infected herds.

Diagnosis of hemochromatosis in young subjects: predictive accuracy of biochemical screening tests.

The reliability of serum iron, transferrin saturation, and serum ferritin in the detection of early iron overload in hemochromatosis was determined in 120 young (less than 35 yr old) relatives whose genetic susceptibility for the disease was determined by HLA typing of families. Serum ferritin and transferrin saturation demonstrated high levels of sensitivity and specificity, whereas serum iron concentration was an unreliable test in the detection of hemochromatosis. In hemochromatosis homozygotes there was an excellent correlation between serum ferritin and mobilized body iron (r = 0.92), 1 microgram/L of serum ferritin corresponding to approximately 7.5 mg of body iron stores. For a given age, serum ferritin values were higher in homozygotes compared with heterozygotes or homozygous-normal subjects and increased by approximately 65 micrograms/L X yr, reflecting the progressive accumulation of iron in hemochromatosis homozygotes. All hemochromatosis subjects with either hepatic fibrosis or cirrhosis had serum ferritin concentrations greater than 700 micrograms/L. We conclude that the combination of serum ferritin and transferrin saturation is a reliable screening regimen for the detection of hemochromatosis and for predicting the level of body iron stores in young hemochromatosis subjects.

Regulation of plasma ferritin by the isolated perfused rat liver.

The isolated perfused rat liver has been used to investigate the regulation of plasma ferritin in normal, iron-deficient and iron-overloaded states. Both 125I-labelled and non-labelled rat liver ferritins were rapidly cleared from the perfusion circuit with a half-life of approximately 30 min. Perfusion of livers from normal, iron-loaded or iron-deficient rats with blood obtained from normal, iron-loaded or iron-deficient rats showed that the liver takes up plasma ferritin, and releases ferritin into the perfusate to achieve a perfusate ferritin level appropriate to the iron stores of the animal from which the liver was taken. It is concluded that the liver is capable of both uptake and release of ferritin and that within the liver there resides a mechanism which maintains circulating ferritin concentrations at a level appropriate to body iron stores.

Computed tomography of a carotid body tumor.

A patient with a carotid body tumor was evaluated by computed tomography. The tumor demonstrated an enhanced rim and a central lower density. This corresponds to the "eggshell" appearance described angiographically in carotid body tumors.

Increased attenuation value in a hydropic gallbladder.

A case is presented in which the presence of sludge in a hydropic gallbladder altered both the usual sonographic and computed tomographic appearance of the gallbladder.

The round nipple shadow.

It is usually easy to distinguish the round nipple shadow from a lesion, especially by means of repeat radiographs with nipple markers. However, the radiologist must occasionally interpret a round density in the lower chest on the basis of a single radiograph or series of radiographs. Fortunately, a nipple shadow usually has a well-defined outer margin and a poorly defined inner margin. Differentiation of a nipple shadow from an extrapleural or pleural lesion is described. Attention to these findings may prevent needless additional study and patient apprehension.

Computed tomographic evaluation of aortic aneurysms.

Applications of computed tomography are being extended from the brain to other body parts. This report describes CT scanning of abdominal and thoracic aortic aneurysms in 30 patients. CT shows greatest promise in abdominal aortic scanning, where reliable identification of the aorta can be achieved even in the absence of enlargement or calcification. However, current limitations prevent visualization of internal detail such as intimal plaques or mural thrombi. Technical advances are described which should have an important bearing on this.

Osteoblastic bone metastasis in Zollinger-Ellison syndrome.

The authors describe a case of osteoblastic metastasis in a patient with Zollinger-Ellison syndrome resulting from the presence of a pancreatic tumor, which they believe is the first such case documented. Following a total gastectomy for hyperacidity in a 53-year-old woman, a gradually enlarging liver was treated with steptozotocin. Radiation therapy to the areas of bony metastases resulted in complete alleviation of pain.