Epidemiological study on clinical bovine dermatophilosis in northern Ethiopia

A total of 5586 indigenous and cross breed cattle were examined for clinical dermatophilosis, and 292 (5.22%) were positive. In indigenous cattle, statistically discernible (p < 0.05) difference was recorded between the prevalence in wet (5.5%) and dry (4.0%) seasons. During both seasons, infestation with A. Variegatum significantly (p < 0.05, chi 2 = 59.9) influenced clinical dermatophilosis. A. variegatum-infested cattle were at 7x higher risk (OR, Odds Ratio = 6.8) of acquiring the disease than non-infested ones. Logistic regression analysis of the overall prevalence showed a significant difference (p < 0.05) between prevalence in indigenous and cross breeds; the crossbreeds being at about 3x higher risk (OR = 2.68). Improved management reduced the prevalence in cross breeds from 15.1% in dry to 8.6% in wet season suggesting the significance of management in the epidemiology of dermatophilosis. The disease occurrence was also significantly (p < 0.05, chi 2 = 133.05) affected by agro-climatic (altitude) variation suggesting the impact of rainfall, humidity, vegetation and vector population that varied with altitude. Age and gender had no influence (p > 0.05) on the disease. Our result showed that season of the year, breed, management, infestation with A. variegatum and agro climatic difference are important risk factors influencing the disease pattern in the region. A tick control strategy and a better and adequate management particularly when keeping cross breeds are recommended.     

Histopathologic patterns of nephropathy in naturally acquired canine visceral leishmaniasis

Although the nephropathy of visceral leishmaniasis (VL) is known both in humans and dogs, histopathologic alterations have not been thoroughly studied. We examined renal alterations in 55 dogs with naturally acquired VL compared with five noninfected dogs from an endemic area in northeastern Brazil. Glomerulonephritis was found in 55 dogs, interstitial alterations in 53 dogs, and tubular changes in 43 dogs with VL. The glomerular alterations found were minor glomerular abnormalities (n = 8, 14.5%), focal segmental glomerulosclerosis (n = 10, 18.2%), mesangial proliferative glomerulonephritis (n = 17, 32.7%), membranoproliferative glomerulonephritis, (n = 18, 30.9%), crescentic glomerulonephritis (n = 1, 1.8%), and chronic glomerulonephritis (n = 1, 1.8%). Morphometric and ultrastructural studies complemented the analysis. The five control animals exhibited no glomerular alterations. The glomerular lesions were related to functional alterations. Considering that the alterations of canine and human nephropathy in VL are very similar, the data obtained in this study constitute an important contribution to the understanding of canine and human VL nephropathy.     

Effects of Short-Term High Carbohydrate or Fat Intakes on Leptin, Growth Hormone and Luteinizing Hormone Secretions in Prepubertal Fat-Tailed Tuj Lambs

The aim of the current study was to evaluate the effects of high carbohydrate or fat diets, fed for 15 days at the end of breeding season, on leptin, GH and LH secretions in prepubertal fat‐tailed Tuj lambs. For that purpose, 9‐month‐old ram‐lambs were divided into three groups as control group (fed with basal ration, n = 4), high carbohydrate (HC) group, basal ration plus barley, n = 4), or high fat (HF) group (basal ration plus by‐pass fat, n = 4). For the measurement of leptin and GH, blood plasma samples were collected on days 1, 4, 9 and 14 of the experiment. For the measurement of LH pulse frequency, serial blood samples were collected every 15 min for 6 h on day 14. Lambs were weighed and body condition scored (BCS) on days 1 and 15. Body weight and BCS increased towards the end of the study (p < 0.05). The BCS was higher in high energy groups at the end of the experiment (p < 0.05). Diet affected plasma leptin concentrations (p = 0.002) but time did not. The GH concentrations were not affected by diet or time. The LH pulse frequency appeared to be higher in HC and HF groups but there were no statistical difference between the groups. There was a significant positive relationship between overall BCS and corresponding leptin concentrations (R² = 0.263; p = 0.010) and between LH pulse frequency and leptin concentrations (R² = 0.594; p = 0.003). In conclusion, the present study suggests that rather than type of energy, amount of energy intake and body energy reserves are much important regulators of plasma leptin concentrations and LH pulse frequency in fat‐tailed Tuj lambs.     

New Zealand sea lion (Phocarctos hookeri) epidemic 2002 (abstract)

The New Zealand sea lion is a threatened species and two unusual events contributed to a decrease in recruitment in 2002. The first was a marked reduction (20%) in the number of pups born at the principal Auckland Island rookeries. Secondly, the mortality rate for pups was significantly elevated and was 33% by the end of February, almost three times the mean for that time of the year. Counts of females at rookeries indicated that the lowered fecundity was possibly due to a scarcity of food resources, supported by the fact that male pups (n=50) in 2002 grew poorly with the lightest recorded liveweights for the previous 8 years. Lowered fecundity may also have resulted from infection leading to foetal death, seen in an adult by-catch female, or abortion. Necropsies were conducted on 126/133 pups that died at Sandy Bay and for many the cause of death was multifactorial and included stillbirth, trauma, malnutrition, and severe anaemia caused by hookworm (Uncinaria spp) infection. An unusual disease presentation seen for the first time in 2002 was characterised by systemic bacterial infection that caused suppurative polyarthritis, severe necrotising fasciitis, myositis and osteomyelitis, suppurative peritonitis, pleuritis, or meningitis. For 41 pups, this syndrome was the primary cause of death and for an additional 16 it was a contributing factor along with hookworm infection or trauma. A consistent isolate has been Klebsiella pneumoniae with frequent isolations of Salmonella spp.     

Reproductive performance of anoestrous high-producing dairy cows improved by adding equine chorionic gonadotrophin to a progesterone-based oestrous synchronizing protocol

This study sought to improve the reproductive performance of anoestrous high-producing dairy cows by including equine chorionic gonadotrophin (eCG) after progesterone-releasing intravaginal device (PRID) removal. In Experiment I, 806 cows at 51-57 days post-partum were randomly assigned to a PRID (treated with PRID), PRID-500 (treated with PRID plus 500 IU of eCG) or PRID-750 (treated with PRID plus 750 IU of eCG) group. In Experiment II, 422 cows showing a long anoestrus period (animals with no oestrus signs nor luteal tissue 35 days before treatment) were randomly assigned to the PRID, PRID-500 or PRID-750 groups. The dependent variables considered in binary logistic regression analyses for both experiments were the rates of oestrus, ovulation and conception after treatment, the cumulative conception rate on Day 120 post-partum and pregnancy loss. In Experiment I, interaction between treatment and season showed a significant effect on the oestrous response. Thus, during the warm season, PRID group cows were 8.9 times more likely to express oestrus than the remaining cows. Moreover, inseminated cows with two or more corpora lutea 8-14 days after treatment were more likely to become pregnant (by a factor of 2.4) than cows with a single corpus luteum. Finally, cows without luteal structures treated with PRID were 0.4 less likely to be pregnant on Day 120 post-partum, compared with the remaining cows. In Experiment II, cows in the PRID group treated during the warm or cool season were less likely to exhibit oestrus (by a factor of 0.06 or 0.2, respectively) or ovulate (by a factor of 0.004 or 0.14, respectively) than the remaining cows. In conclusion, in anoestrous cows in both experiments, the addition of eCG to the use of an intravaginal progesterone device to induce oestrus was beneficial. The recommended dose of eCG is 500 IU.     

Computed Tomography Atlas of the Normal Cranial Canine Abdominal Vasculature Enhanced by Dual‐phase Angiography

This study was performed to provide a detailed atlas of the normal arterial and venous canine vasculature in the cranial abdomen by dual‐phase computed tomographic angiography. Five adult beagles were positioned in dorsal recumbency on a multislice helical CT scanner. An unenhanced survey CT scan from the diaphragm to the pelvic inlet was performed. Bolus‐tracking software was used for the dual‐phase angiogram, and contrast medium was administered in a cephalic vein. The arterial phase was scanned from the mid‐abdomen to the cranial aspect of the diaphragm; the portal phase was scanned a few seconds after the arterial phase in the opposite direction. The DICOM studies from all dogs were analysed. Representative images were selected and anatomic structures labelled. Maximum intensity projections and three‐dimensional images were generated using software techniques. A detailed atlas of the venous and arterial vasculature of the cranial canine abdomen was created with the help of bolus‐tracking dual‐phase computed tomographic angiography (CTA). Practitioners can use this anatomic atlas with its detailed venous and arterial phase CT angiograms of the canine cranial abdomen to compare normal versus abnormal vascular anatomy.     

The Post‐Cervical Insemination does not Impair the Reproductive Performance of Primiparous Sows

The study evaluated the reproductive performance of primiparous sows submitted to post‐cervical insemination (PCAI) compared with cervical artificial insemination (CAI). Difficulty with catheter introduction, the occurrence of bleeding or semen backflow during insemination, and volume and sperm cell backflow up to 60 min after insemination were also evaluated. Sows were homogenously distributed, according to body weight loss in lactation, lactation length, weaned piglets, weaning‐to‐oestrus interval and total born in previous farrowing, in two treatments: PCAI (n = 165) with 1.5 × 10⁹ sperm cells in 45 ml (2.4 ± 0.04 doses per sow) and CAI (n = 165) with 3 × 10⁹ sperm cells in 90 ml (2.5 ± 0.04 doses per sow). During PCAI, sows were inseminated in the absence of boars. Transabdominal real‐time ultrasonography was performed at oestrus onset, immediately before the first insemination and at 24 h after last insemination. There was no difference (P > 0.05) between treatments in farrowing rate (91.5% × 89.1%) and litter size (12.5 × 11.9 piglets born, respectively for PCAI and CAI sows). Successful passage of the intrauterine catheter in all the inseminations was possible in 86.8% (165/190) of sows initially allocated to PCAI treatment. Difficulty of introducing the catheter in at least one insemination did not affect the reproductive performance of PCAI sows (P > 0.05). Bleeding during insemination did not affect (P > 0.05) the farrowing rate in both treatments, but litter size was reduced in CAI and PCAI sows (P ≤ 0.06). Percentage of spermatozoa present in backflow within 1 h after insemination was greater in CAI than PCAI sows (P < 0.01). More than 85% of primiparous sows can be successfully post‐cervical inseminated with doses containing 1.5 × 10⁹ sperm cells in the absence of the boar during insemination without impairing the reproductive performance.     

Anemia amelioration by lactose infusion during trypanosomosis could be associated with erythrocytes membrane de-galactosylation

African trypanosomosis is a potentially fatal disease that is caused by extracellular parasitic protists known as African trypanosomes. These parasites inhabit the blood stream of their mammalian hosts and produce a number of pathological features, amongst which is anemia. Etiology of the anemia has been partly attributed to an autoimmunity-like mediated erythrophagocytosis of de-sialylated red blood cells (dsRBCs) by macrophages. Lactose infusion to infected animals has proven effective at delaying progression of the anemia. However, the mechanism of this anemia prevention is yet to be well characterized. Here, the hypothesis of a likely induced further modification of the dsRBCs was investigated. RBC membrane galactose (RBC m-GAL) and packed cell volume (PCV) were measured during the course of experimental trypanosomosis in mice infected with Trypanosoma congolense (stb 212). Intriguingly, while the membrane galactose on the RBCs of infected and lactose-treated mice (group D) decreased as a function of parasitemia, that of the lactose-untreated infected group (group C) remained relatively constant, as was recorded for the uninfected lactose-treated control (group B) animals. At the peak of infection, the respective cumulative percent decrease in PCV and membrane galactose were 30 and 185 for group D, and 84 and 13 for group C. From this observed inverse relationship between RBCs membrane galactose and PCV, it is logical to rationalize that the delay of anemia progression during trypanosomosis produced by lactose might have resulted from an induction of galactose depletion from dsRBCs, thereby preventing their recognition by the macrophages.     

Pharmacokinetics of erythromycin in nonlactating and lactating goats after intravenous and intramuscular administration

The objectives of this work were to compare the pharmacokinetics of erythromycin administered by the intramuscular (i.m.) and intravenous (i.v.) routes between nonlactating and lactating goats and to determine the passage of the drug from blood into milk. Six nonpregnant, nonlactating and six lactating goats received erythromycin by the i.m. (15 mg/kg) and the i.v. (10 mg/kg) routes of administration. Milk and blood samples were collected at predetermined times. Erythromycin concentrations were determined by microbiological assay. Results are reported as mean +/- SD. Comparison of the pharmacokinetic profiles between nonlactating and lactating animals after i.v. administration indicated that significant differences were found in the mean body clearance (8.38 +/- 1.45 vs. 3.77 +/- 0.83 mL/kg x h respectively), mean residence time (0.96 +/- 0.20 vs. 3.18 +/- 1.32 h respectively), area under curve from 0 to 12 h (AUC(0-12)) (1.22 +/- 0.22 vs. 2.76 +/- 0.58 microg x h/mL respectively) and elimination half-life (1.41 +/- 1.20 vs. 3.32 +/- 1.34 h); however, only AUC(0-12) showed significant differences after the i.m. administration. Passage of erythromycin in milk was high (peak milk concentration/peak serum concentration, 2.06 +/- 0.36 and AUC(0-12milk)/AUC(0-12serum),6.9 +/- 1.05 and 2.37 +/- 0.61 after i.v. and i.m. administrations respectively). We, therefore, conclude that lactation affects erythromycin pharmacokinetics in goats.