Natural transplacental infection of dairy calves with bovine immunodeficiency virus and estimation of effect on neonatal health

Many experimental infection studies with bovine immunodeficiency virus (BIV) have been conducted, but neither virus transmission under natural conditions nor longitudinal clinical effects of naturally occurring infections in non-experimental populations are well explored. We tested the hypotheses that BIV is transmitted across the placenta during gestation and that intragestionally infected calves are at increased risk of neonatal disease. A cohort of 59 dairy cows on one farm were enrolled at parturition and the BIV serostatus of the cows and their pre-colostral calves determined with an indirect fluorescent-antibody assay. Moreover, the enrolled calves were monitored thrice weekly for specific clinical signs through the duration of the 30 day neonatal period and the occurrence of clinical signs analyzed for association with calf pre-colostral BIV serostatus and dam BIV serostatus. Confounding due to calf passive immunity and season of birth were also explored. Forty percent of seropositive cows (14/35) gave birth to seropositive calves but no seropositive calves (0/19) were born to seronegative dams (estimated relative risk 16, 95% exact confidence interval 2.6–5.8×10²⁹). Calf pre-colostral BIV serostatus was not associated with the occurrence or frequency of clinical signs — but dam BIV serostatus was associated with the odds of occurrence of calf hyperthermia and with the frequency of occurrence of calf hyperthermia and hyperventilatory events. This study is inconclusive about the effects of prenatal BIV infection on neonatal health — but it does provide evidence for the natural occurrence of transplacental BIV infection.     

Clinical studies on daily low dose oxytocin in mares at term

The aim of this study was to test whether low dose oxytocin i.v. injection once a day to mares diagnosed as being ready for birth by mammary secretion calcium strip test measurements could be used as a reliable method to induce parturition and/or predict the mare would not foal during the following night if parturition did not occur within 2 h of treatment. Fifty-one near-term Haflinger mares were used and a single injection of 2.5 iu oxytocin was given between 1700 and 1900 h, including 10 mares used as controls which were administered a placebo. Administration of oxytocin resulted in the delivery of a normal foal within 120 min in 95% of mares. Twenty-four out of 38 (63%) treated animals foaled in response to the first oxytocin injection, 9 out of 38 (24%) in response to the second injection and 3 out of 38 (8%) in response to the third treatment. Two out of 38 (5%) treated mares foaled during the night irrespective of treatment whereas 7 out of 10 (70%) control mares foaled during the night. It was concluded that the major advantage of injecting a daily low dose of oxytocin appears to be that such a low dose induces delivery only in mares carrying a mature fetus and which are ready to foal.     

Ulcerative duodenitis with luminal constriction in two horses

Proximal enteritis was diagnosed on the basis of clinical signs of disease in 2 Standard-bred yearlings from the same farm. Large volumes of fluid were repeatedly obtained during gastric decompression. The horses did not respond to treatment with IV administered fluids, antimicrobial agents, cimetidine, and metoclopramide. Postmortem findings confirmed severe focal chronic active duodenitis with stricture formation. An etiologic agent was not identified.     

Veterinary and nonveterinary costs of disease in 29 California dairies participating in the National Animal Health Monitoring System from 1988 to 1989

Twenty-nine California dairy herds were studied over a 12-month period from 1988 to 1989 as part of the National Animal Health Monitoring System. Monthly interviews administered to dairy producers were used to measure the costs of all health-related expenditures and disease incidence in these herds. Of the total $1,523,558 reported, $1,355,467 (89%) was attributed to cost of disease events and $168,091 (11%) to cost of disease prevention. Most (78%) of the cost of disease events was attributable to death and culling losses. Veterinary services accounted for only $54,099 (4%) of total costs, 64% of which was used for disease prevention, compared with 36% for disease treatment. Udder disease was the most costly category of diseases reported at an average of $49.85/head at risk annually, followed by reproductive problems at $38.05. Through the use of sampling strategies less biased than those used in other surveys, the National Animal Health Monitoring System is designed to provide statistically-valid estimates of disease incidence and costs across broad geographic areas, potentially benefiting all those interested in the economics of livestock diseases in the United States.     

Ovine ceroid-lipofuscinosis is a proteolipid proteinosis

The pathogenesis of the ceroid-lipofuscinoses, inherited storage diseases of children, was studied in an ovine model. This was shown to have clinical and pathological features most in common with the late infantile and juvenile human forms of the disease. The ability to study sequential changes allowed the retinal lesions to be described as a dystrophy of photoreceptor outer segments which preceded loss of the photoreceptor cells. An early decrease in amplitude of the c-wave electroretinograph was attributed to a decrease in the transpigment epithelial component. The decreased a- and b-wave amplitudes were attributed to the changes in and loss of, photoreceptor cells. The chemical components of isolated storage cytosomes were analyzed and shown to consist mostly of protein. Sequence analysis of the dominantly stored protein showed that it was identical to the DCCD reactive proteolipid or subunit c of mitochondrial adenosine triphosphate synthase and that it comprised approximately 50% of storage material. Based on the adage that the dominantly stored species should reflect the underlying biochemical anomaly, it was concluded that it was of pathogenic significance. This highly hydrophobic protein tends to extract with lipids in chloroform/methanol and is thus known as a proteolipid. Some of the remainder of the stored proteins also had this characteristic. It was concluded that ovine ceroid-lipofuscinosis was a proteinosis, more specifically a proteolipid proteinosis and as such it forms the prototype of a new class of storage diseases. Recognition of the nature of the dominantly stored chemical species has helped understanding of a variety of chemical and physical characteristics attributed to the whole pigment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Primary intestinal lymphangiectasia in three dogs: a morphological and immunopathological investigation

Morphological and immunological findings of three dogs with primary lymphangiectasia are described and compared with three normal dogs. Scanning electron microscopy showed distended and fused intestinal villi in dogs with intestinal lymphangiectasia, and morphometric evaluation revealed deeper crypts in the small intestine of dogs with intestinal lymphangiectasia. Although plasma cells of all classes were diminished in the cranial parts of the small intestine, there was an absolute and relative increase of immunoglobulin G-containing plasma cells in the caudal small intestine in dogs with intestinal lymphangiectasia.     

Soil and foliar phosphorus as indicators of sustainability for Pinus radiata plantation forestry in New Zealand

We investigated how multiple-crop forestry has influenced the magnitude and variability of soil and plant phosphorus (P) fertility and site disturbance. Kinleith Forest, on Mamaku Plateau, covers >100,000 ha and comprises mainly plantation Pinus radiata. Three study areas in the forest were chosen to represent natural state (native forest), first crop of P. radiata (24 years growth), and second crop of P. radiata (4 years growth of second crop). The adjacent areas have similar relief and climate, and the soils are all the same age, being predominantly Andic Haplohumods developed in 1770 calendar-year-old non-welded tephra (Taupo Ignimbrite, ca. 0.5–0.8 m in thickness) and overlying a buried paleosol on earlier tephric material.

Soil properties were compared using a random geometric sampling scheme stratified in a 40-m grid. Soil samples (0–20 cm) were taken at 1.5, 4.5 and 13 m spatial intervals in random directions away from each primary node, providing 192 sample sites for each study area. Additionally at selected sites, samples of the current year's foliage from the upper crowns were collected, the thickness of Taupo Ignimbrite (i.e. depth to buried paleosol) was recorded by augering, and site disturbance was assessed using a new six-point scale based on change relative to a modal soil profile. Geostatistics and geographical information systems (GIS) were used to assess variability and effects of forest management on the measured properties. Soil Bray-2 P concentrations were below guidelines for satisfactory growth (12 mg kg⁻¹) at all sites, and no differences were recorded between the different management areas. However, the amount of within-site variability in Bray-2 P increased with the number of crops. Foliar P concentrations were only marginally deficient in both the first and second crops, indicating that P is currently not significantly limiting growth. The lack of difference in foliar P between first and second crops indicates no crop-to-crop decline in foliar P status and suggests that no site P fertility decline has occurred. The soils have an unusual ability to continue releasing P through successive sequential extractions in the Bray-2 P test, indicating a strong buffering capacity, and this may explain the apparent lack of deficiency even with Bray-2 P values of <12 mg kg⁻¹. The site disturbance index increased and the spatial distribution of P data became increasingly variable with crop rotation.

GIS, inverse-distance weighting and kriging proved useful in illustrating the trends between crops. The spatial variability of results indicated that there was no obvious pattern to the variability and that more site-specific forest management in the region would be difficult. However, there was some evidence that less disturbance during harvesting may minimise variability of soil P supply.