Efficacy of calfhood vaccination with Brucella abortus strain RB51 in protecting bison against brucellosis

In the studies reported here, protection induced by calfhood vaccination of bison with 1.2-6.1 x 10(10)CFU of Brucella abortus strain RB51 (SRB51) against a virulent strain of B. abortus was evaluated. Non-vaccinated and SRB51-vaccinated bison were intraconjunctivally challenged during midgestation with 3 x 10(7)CFU of virulent B. abortus strain 2308 (S2308). Maternal and fetal tissues were obtained within 24hour after abortion or parturition. Incidence of abortion was greater (P<0.05) in non-vaccinated as compared to SRB51-vaccinated bison (62% and 15%, respectively), with abortions occurring between 5 and 8 weeks after experimental challenge. Calves from bison vaccinated with SRB51 had a reduced (P<0.05) prevalence of fetal infection with S2308 as compared to calves from non-vaccinated bison (19% and 62%, respectively). Although the ability to recover the 2308 challenge strain from maternal tissues did not differ (P>0.05) between nonvaccinates and vaccinates (100% and 78%, respectively), calfhood vaccination with SRB51 reduced (P<0.05) recovery of S2308 from uterine or mammary gland tissues. In bison which did not abort, S2308 was routinely recovered in low numbers from maternal lymphatic tissues; particularly the parotid, bronchial, supramammary, and mandibular lymph nodes. The RB51 vaccine strain was not recovered at any time from maternal or fetal samples obtained at necropsy. Histological lesions associated with Brucella-induced abortions were suppurative placentitis, fetal broncho-interstitial pneumonia, and fetal histiocytic splenitis. The results of our studies suggest that calfhood vaccination of bison with SRB51 is efficacious in protecting against intramammary, intrauterine, and fetal infection following exposure to a virulent strain of B. abortus during pregnancy. As brucellosis is transmitted horizontally through fluids associated with the birth or abortion of an infected fetus, or vertically to the calf through the ingestion of milk containing B. abortus, our data suggest that calfhood vaccination with SRB51 will be beneficial in preventing transmission of brucellosis in bison.     

Early echocardiographic predictors of myxomatous mitral valve disease in dachshunds

Myxomatous mitral valve disease in dogs is heritable, and it is therefore important to detect the early signs of the disease. This study was conducted to assess the predictive value of early echocardiographic and auscultatory signs of mitral valve prolapse, measured in terms of the leaflet thickness, the area of the regurgitant jet, and the intensity of the murmur, on the increases in left ventricular end diastolic diameter (LVEDD) and left atrial diameter (LAD) in a population of 190 clinically healthy dachshunds followed up for three years. The most significant predictor of an increase in LVEDD was the interaction between the index of mitral valve prolapse and the area of the regurgitant jet (P < 0.0001). In dogs with a jet area greater than 50 per cent of the left atrium, the disease progressed more quickly in terms of increases in LVEDD in relation to the severity of the prolapse at the initial examination. In dogs with smaller jets, the initial prolapse index was not significantly associated with increases in LVEDD. The initial index of mitral valve prolapse, the area of the jet and the intensity of the heart murmur were all significant predictors of an increase in LAD.     

Parameters of production and partial characterization of feline interleukin 2

The conditions for the production of feline interleukin 2 (IL-2) from peripheral blood leukocytes (PBL) and splenocytes by concanavalin A (Con A) stimulation are described. Feline IL-2 was quantitated by measuring DNA synthesis in the murine IL-2-dependent cell line, CTLL-20. In addition, feline IL-2 was generated for the maintenance of long-term cultures of Con A-stimulated feline PBL and for biochemical characterization. Finally, IL-2 production was evaluated from the PBL of feline leukemia virus (FeLV)-infected cats. Con A at 9.6 micrograms/ml produced a plateau of peak IL-2 activity from 24 to 48 h following stimulation. The tumor promoter, phorbol myristic acetate, stimulated feline IL-2 production and enhanced Con A-stimulated feline IL-2 production. Fetal calf serum (FCS) was not required for IL-2 production; however, FCS at 5% (v/v) allowed for maximal Con A-stimulated IL-2 production. Feline IL-2 generated from Con A-stimulated splenocytes migrated with an apparent molecular size of 13.7 to 23 kD by gel filtration chromatography and supported the proliferation of Con A-activated feline PBL at a final concentration of 0.3 to 0.9 units/ml.     

Effect of flurbiprofen on facility of aqueous outflow in the eyes of dogs

Aqueous outflow from cannulated canine eyes was determined, using a constant-pressure perfusion technique. The effect of topically applied flurbiprofen, a cyclo-oxygenase inhibitor, on outflow in eyes with or without neodymium:yttrium aluminum garnet laser-induced inflammation was measured. Flurbiprofen caused decrease in aqueous outflow that was more marked in the inflamed eyes.     

Lymphocytes from one side of the bovine mammary gland migrate to the contra lateral gland and lymph node tissue

The four quarters of bovine mammary glands are completely separated and two quarters on each side (right or left) are connected to ipsi lateral supra mammary lymph nodes. It is not clear whether cells infused into the cistern of the mammary gland are capable of migrating to lymph nodes or the general circulation. To examine cell migration, a prescapular lymph node was removed from each of two lactating and three non-lactating dairy cows, and isolated lymphocytes were stained with Hoechst 33342. Autologous stained cells were infused into the mammary gland and then activated by intramammary infusion of zymosan-stimulated serum (source of C5a). After 17 h, Escherichia coli J5 bacterin was infused into the contra lateral mammary gland to mimic infection. After 43 h cows were euthanized and tissue samples (mammary quarters, right and left supra mammary, mesenteric, ileocecal and prescapular lymph nodes, liver and spleen) were collected for microscopic examination as well as flow cytometric analysis. Hoechst stained cells were detected not only in infused quarters, but also in contra lateral quarters as well as in both supra mammary lymph nodes. This indicates that cells infused into the mammary gland migrate to contra lateral tissues and supra mammary lymph nodes.     

Determinants of weak femoral artery pulse in dogs with mitral valve prolapse

In three substudies encompassing 247 dogs from two breeds predisposed to myxomatous mitral valve disease (MMVD), femoral artery pulse strength was palpated and related to potential explanatory factors, including quantitative echocardiographic measures of MMVD, aortic and femoral artery diameter and wall thickness and blood pressure. In addition, in 109 Cavalier King Charles Spaniels (of which 61 were included in the three substudies mentioned above), the relation between femoral artery pulse strength and presence of thrombocytopenia was investigated. In 26% of the dogs, a pulse 相似文献   

Nutrient status of crop contents of rural scavenging local chickens in Tanzania

1. A total of 144 chickens purchased from peasants in Morogoro, Tanzania were slaughtered, their crops dissected and the contents analysed. The birds consisted of 48 chickens from each of three climatic zones (warm and wet, warm and dry, cool and wet). Seventy-two chickens were slaughtered in each season, that is short rainy and long rainy season. 2. Cereal grains, bran, green forages, insects/worms and kitchen food wastes were the main crop contents and their composition varied significantly with season and climate. 3. The overall mean chemical compositions (g/kg) of the crop contents were: 430.8 +/- 107.78 dry matter (DM), 104.4 +/- 43.47 crude protein (CP), 61.2 +/- 36.48 ether extract (EE), 58.2 +/- 26.29 crude fibre (CF), 125.4 +/- 58-27 ash, 6.3 +/- 5.19 calcium (Ca) and 3.6 +/- 2.41 phosphorus (P). 4. CP, EE, ash and P contents varied significantly (P<0.05) with season but contents of DM, CF and Ca were not significantly different. 5. CP content was significantly higher (P<0.05) in growers than in adults while the reverse was true for Ca content. Other variables did not differ significantly. 6. Significant differences (P<0.05) in chemical composition were observed among the zones in all parameters except for CP content. 7. The study showed that the chemical composition of feeds eaten by rural scavenging chickens was below the nutritional requirements and varied with season, climate and age of birds.     

Evaluation of the bone injection gun as a method for intraosseous cannula placement for fluid therapy in adult dogs

OBJECTIVE: To evaluate the Bone Injection Gun (BIG) for placement of intraosseous cannulas through impact penetration and compare it with a standard Jamshidi bone marrow needle (JBMN) and to compare fluid delivery dynamics through each device. STUDY DESIGN: Randomized in vivo study. ANIMALS: Forty-eight mature dogs. METHODS: During surgical laboratories, dogs were randomly assigned to 2 groups (n = 24), and intraosseous access in the proximal tibial metaphysis was obtained using a BIG or JBMN. Variables measured during placement included insertion success, time required for placement, and alterations in respiratory rate (RR), heart rate (HR), and systolic blood pressure. After placement, maintenance fluids were administered to 6 dogs from each group, and fluids were administered under pressure to 6 dogs from each group to compare rates of delivery through each device. After euthanasia, the tibiae were harvested to evaluate and compare the morphologic consequences of needle and cannula placement. RESULTS: Successful placement occurred in 20 (83%) dogs for the BIG and 23 (96%) dogs for the JBMN, which was not significantly different (P =.3475). Time required for placement was significantly less (P =.0024) for the BIG (mean, 22.4 +/- 8.2 seconds) compared with the JBMN (mean, 42.0 +/- 28.1 seconds). Significant increases in RR occurred in both groups and in the HR for the BIG group, but significant differences were not noted between groups. Mean rate of pressurized fluid administration was similar for both groups. Two distinct patterns of cortical bone damage occurred, but the clinical significance of this observation is uncertain. CONCLUSIONS: The BIG provides more rapid access to the intraosseous space for fluid administration than the JBMN. CLINICAL RELEVANCE: The BIG is an effective alternative for obtaining rapid access to the intraosseous space for emergency fluid and drug administration.     

Hyperadrenocorticism treated with metyrapone followed by bilateral adrenalectomy in a cat

A 6-year-old spayed female cat was evaluated for uncontrolled diabetes mellitus and poor hair coat. Clinicopathologic abnormalities included high serum activity of liver enzymes, hyperglycemia, hypercholesterolemia, glucosuria, and an exaggerated response to ACTH stimulation. Abdominal ultrasonography revealed large adrenal glands. Hyperadrenocorticism was diagnosed. Treatment for a facial abscess was instituted along with administration of metyrapone for hyperadrenocorticism. After stabilization, bilateral adrenalectomy was performed. The cat recovered without complications and has remained clinically normal for 5 months with treatment of desoxycorticosterone pivalate and prednisone. Treatment with metyrapone appeared to stabilize the cat metabolically and clinically prior to surgery.