Retrospective comparison of azithromycin, clarithromycin, and erythromycin for the treatment of foals with Rhodococcus equi pneumonia

The objective of this retrospective study was to compare the efficacy of azithromycin-rifampin, clarithromycin-rifampin, and erythromycin-rifampin for the treatment of pneumonia caused by Rhodococcus equi in foals. Eighty-one foals with naturally acquired pneumonia caused by R. equi were included in the study. Information on age, sex, breed, physical examination findings, laboratory testing, and thoracic radiography was abstracted from each medical record. Foals were divided in 3 groups based on the antimicrobial agent selected for therapy. Short-term (discharge from the hospital) and long-term (apparently healthy as a yearling) success rates, days of hospitalization, days with fever, days with tachypnea, and percentage of radiographic improvement were compared among groups. Foals treated with clarithromycin-rifampin had significantly (P = .02) higher odds of overall short-term (odds ratio [OR] = 12.2) and long-term (OR = 20.6) treatment success and significantly fewer days with fever than foals treated with erythromycin-rifampin. Foals treated with clarithromycin-rifampin had a significantly (P = .03) higher percentage of radiographic improvement and a tendency (P = .06) toward higher odds of overall short-term (OR = 8.1) and long-term (OR = 11.8) treatment success compared to foals treated with azithromycin-rifampin. Among foals with severe radiographic lesions, the success rates of foals treated with clarithromycin-rifampin both short-term (88%) and long-term (83%) were significantly (P = .02) higher than that of foals treated with azithromycin-rifampin (0%). For each treatment group, the only reported adverse effect was diarrhea that was mild and self-limiting in most cases. The combination clarithromycin-rifampin is superior to azithromycin-rifampin or erythromycin-rifampin for the treatment of pneumonia caused by R. equi in foals in a referral population.     

Nitric oxide synthase expression in the endothelium of pulmonary arterioles in normal and pulmonary hypertensive chickens subjected to chronic hypobaric hypoxia

To determine whether or not exposure to chronic hypoxia and subsequent development of pulmonary hypertension syndrome (PHS) induce alterations in endothelial nitric oxide (NO) production in broiler's pulmonary vascular bed of broilers, we studied the expression of nitric oxide synthase enzyme in pulmonary endothelial cells by a nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemical staining reaction. For this purpose, 60 broilers of three different ages (17, 30, and 42 days) were used. The animals were distributed in two groups: a) 30 healthy (nonhypertensive) broilers and b) 30 chicks with PHS. All broilers in group b had fewer NADPH-diaphorase-positive endothelial cells in arterioles than did the nonhypertensive broilers. These differences were highly significant (P < 0.01). These results demonstrate for, the first time in broilers, that hypoxia-induced pulmonary hypertension is associated with a decrease of endothelial-derived NO expression in pulmonary vessels.     

Efficacy of oxytetracycline for treatment of papillomatous digital dermatitis lesions on various anatomic locations in dairy cows

OBJECTIVE: To evaluate efficacy of topical treatment with oxytetracycline solution among dairy cows with papillomatous digital dermatitis (PDD) lesions on the interdigital cleft, heels, or dewclaw. DESIGN: Clinical trial. ANIMALS: 70 dairy cows from a single herd. PROCEDURE: On the basis of anatomic location of PDD lesions, cows were allocated into 1 of 3 groups (interdigital cleft [n = 14], heels [30], or dewclaw [26]) and treated topically with oxytetracycline solution. Cows were examined 14 and 30 days after initial treatment. During each examination, pain and lesion size scores were recorded. RESULTS: On the basis of pain and lesion size scores, oxytetracycline appeared significantly less effective among cows with lesions on the interdigital cleft than for cows with lesions on the heels or the dewclaw. Number of cows with signs of pain or visible lesions after treatment was significantly higher for cows with lesions on the interdigital cleft than for cows with lesions on heels or the dewclaw. CONCLUSIONS AND CLINICAL RELEVANCE: Anatomic location of PDD lesions has an effect on the efficacy of topical treatment with oxytetracycline solution in dairy cows affected with PDD. Cows with lesions on the interdigital cleft were less likely to respond to treatment, compared with cows with lesions on the heels or the dewclaw.     

Respiratory bronchoscopy of subadult American alligators (Alligator mississippiensis) and tracheal wash evaluation.

Twelve healthy approximately 3-yr-old captive-born 4.5-9 kg American alligators (Alligator mississipiensis) each had bronchoscopy and tracheal washes performed four times during a 10-mo period to evaluate seasonal respiratory microbiology and cytology. Cytologic evaluation of most samples showed a small amount of mucus and low numbers of ciliated columnar epithelium, cubodial epithelium, and keratinized squamous cells. No bacteria or parasites were observed, and there was no seasonal variation in the cytology. No significant bacterial or fungal growth was identified in any season. Hematology performed in the spring and fall evaluations showed seasonal variation in the red blood cell count, hemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin concentration, eosinophil count, and thrombocyte count. The lower respiratory tract (at the tracheal level) of healthy subadult alligators appears to be sterile, and cytology is similar to that described in domestic mammals.     

Race-start characteristics and risk of catastrophic musculoskeletal injury in Thoroughbred racehorses

OBJECTIVE: To identify race-start characteristics associated with catastrophic musculoskeletal (MS) injury in Thoroughbred racehorses at 2 racetracks in Florida during 1995 through 1998. DESIGN: Matched case-control study. ANIMALS: 97 Thoroughbreds (case horses) that incurred a catastrophic MS injury during racing and 388 Thoroughbreds (control horses) randomly selected from noninjured participants and matched on the basis of racetrack and year. PROCEDURE: Incidence of MS injury was calculated for all race meets at 2 racetracks in Florida from 1995 through 1998. Race-start characteristics were compared among case and control horses, using conditional logistic regression. RESULTS: Overall incidence of MS injury was 1.2/1,000 race starts (97/79,416 starts). Incidence of injury was significantly higher for turf races (2.3/1,000 starts) than for dirt races (0.9/1,000 starts). Sex, number of days since last race, and racing surface were associated with risk of injury; geldings, > or = 33 days since the last race, and turf racing surface were associated with a higher risk of injury. CONCLUSIONS AND CLINICAL RELEVANCE: Incidence of injury among Thoroughbreds in Florida was associated with sex, number of days since last race, and racing surface. Days since last race may have been an indicator of previous health and lameness problems. Racing surface may have been a risk factor for MS injury because turf races tended to be more competitive than dirt races. Horses running in turf races were more likely to participate in races with a large field, handicap races, long races, and races with high purses.     

Comparing Small‐Scale Testing Methods for Predicting Wheat Gluten Strength Across Environments

Gluten strength is the main factor determining the rheological and processing properties of wheat. Rapid, small‐scale tests that can indirectly predict gluten strength are extremely important for wheat‐breeding selection, particularly when using pedigree methodology. The efficiency and reliability of three small‐scale tests (SDS sedimentation volume [SDSS], swelling index of glutenin [SIG], and lactic acid retention capacity [LARC]) across three environments (E1, no stress; E2, drought stress; and E3, heat stress) were evaluated by using 15 common wheat and nine durum wheat cultivars. In the case of common wheat, SIG highlighted its advantage for predicting gluten strength, even under stress environments, compared with LARC and SDSS, whereas SDSS showed the best relationship with bread loaf volume. For durum wheat, SIG showed the best predicting value in E1 and E3; however, under drought stress, SDSS, SIG, and LARC all lost their good ability for predicting gluten strength in durum wheat, which needs further investigation. Also, the comparison between two mixograph parameters (mixograph peak time and mixograph peak integral) for predicting gluten strength and the suitability of testing SIG and LARC with whole meal (or semolina) instead of refined flour were also investigated.     

Investigation on the association between atopic dermatitis and the development of mycosis fungoides in dogs: a retrospective case-control study

In human medicine, the relationship between the immunodysregulation observed in atopic dermatitis (AD) and the development of mycosis fungoides (MF) has triggered considerable interest due to the increasing number of patients with MF who have a previous history of AD. The purpose of this retrospective case-control study was to investigate whether dogs diagnosed with MF were more likely to have AD. The records of 96 000 canine patients at the University of Florida were searched. Inclusion criteria were a clinical and histological diagnosis of MF. Dogs admitted to the University of Florida, Veterinary Medical Center during the same time period (1991-2004) without a diagnosis of MF were included as controls. Four controls for each study dog were randomly selected (matched by year of admission). Frequency of AD and other exposure variables were compared among case and control dogs by using conditional logistic regression. Records of 19 dogs with a diagnosis of MF were identified. Five of them (5/19, 26.3%) had previous diagnosis of AD. The odds of having MF was 12 times (OR = 12.54; 95% CI = 1.95-80.39; P < 0.01) higher in dogs with AD than in dogs without AD. In conclusion, this study suggests an association between AD and MF in dogs. Future studies are necessary to confirm this finding and to investigate the pathogenic mechanisms involved in this association.     

Anthelmintic effects of Salix babylonica L. and Leucaena leucocephala Lam. extracts in growing lambs

Twenty Katahdin?×?Pelibuey crossbreed male lambs, 3 to 4 months of age and 24?±?0.3 kg of body weight, were used to study the anthelmintic effects of administering extracts of Salix babylonica L. (SB) and Leucaena leucocephala Lam. (LL). Lambs had not been treated with anthelmintics previously and were randomly allocated into four groups of five lambs each in a completely randomized design. Treatments were as follows: control (lambs fed on total mixed ration without extracts), SB (as control plus S. babylonica L. extract at 30 ml/day), LL (as control plus L. leucocephala Lam. extract at 30 ml/day), and SBLL (as control plus 30 ml/day of S. babylonica L. and L. leucocephala Lam. extracts in a 1:1 (v/v) mixture) for 63 days. Extracts were orally administered before the 8:00 a.m. feeding to each lamb. Rectal fecal samples were collected from each lamb at day 22 (P1), day 43 (P2), and day 63 (P3) of the experiment. Adult worm and egg counts were determined in each fecal sample immediately after collection. Plant secondary metabolites of total phenolics, saponins, and the aqueous fraction were 50 % lower in the SB versus LL extracts. Overall, the oral administration of extracts has improved the egg and worm count reductions in lamb feces by 54, 47, and 40 % for LL, SB, and SBLL, respectively, versus the control lambs. Reductions of worm egg counts in lamb feces were higher (P?<?0.05) in P2 and P3 versus P1. Extracts of SB and LL or possibly isolated bioactive compounds could be a promising alternative to conventional anthelmintics to treat gastrointestinal parasites of small ruminants. Such treatments could be used in control strategies against gastrointestinal nematodes in organic and conventional production systems.     

Mitigation of salt stress in wheat seedlings by a <Emphasis Type="Italic">gfp</Emphasis>-tagged <Emphasis Type="Italic">Azospirillum lipoferum</Emphasis>

Root colonization and mitigation of NaCl stress on wheat seedlings were studied by inoculating seeds with Azospirillum lipoferum JA4ngfp15 tagged with the green fluorescent protein gene (gfp). Colonization of wheat roots under 80 and 160 mM NaCl stress was similar to root colonization with this bacterial species under non-saline conditions, that is, single cells and small aggregates were mainly located in the root hair zone. These salt concentrations had significant inhibitory effects on development of seedlings, but not on growth in culture of gfp-A. lipoferum JA4ngfp15. Reduced plant growth (height and dry weight of leaves and roots) under continuous irrigation with 160 mM NaCl was ameliorated by bacterial inoculation with gfp-A. lipoferum JA4ngfp15. Inoculation of plants subjected to continuous irrigation with 80 mM NaCl or to a single application of either NaCl concentration (80 or 160 mM NaCl) did not mitigate salt stress. This study indicates that, under high NaCl concentration, inoculation with modified A. lipoferum reduced the deleterious effects of NaCl; colonization patterns on roots were unaffected and the genetic marker did not induce undesirable effects on the interaction between the bacterium and the plants.