Hypernatraemia in 39 hospitalised foals: clinical findings, primary diagnosis and outcome.

OBJECTIVE: To evaluate hypernatraemia in foals presenting as medical emergencies to an intensive care unit (ICU) to determine the prevalence, clinical findings, primary diagnosis and outcome. METHODS: Retrospective case study of records from Thoroughbred foals aged less than 3 months that presented to an ICU as medical emergencies in 2002-12. Data retrieved included signalment, clinical findings, laboratory results, primary diagnosis and outcome. Foals with hypernatraemia (serum sodium > 145 mmol/L) on admission laboratory data were identified and further evaluated. RESULTS: A total of 39 of 1718 foals (2.3%) were diagnosed with hypernatraemia; all foals were less than 7 days of age. The most common primary diagnoses in the foals with hypernatraemia were neonatal syndrome (19/39, 48.7%) and sepsis (15/39, 38.5%). Foals with hypernatraemia at presentation were more likely to die or be euthanased during their hospitalisation than foals with a normal serum sodium concentration on ICU admission (33.3% vs 16.1%; odds ratio, 2.3; 95% confidence interval, 1.2-4.6; P = 0.02). CONCLUSION: Admission hypernatraemia was an uncommon but important electrolyte abnormality in this population of hospitalised foals. Although the short-term outcome in survivors was most likely dependent on the underlying disease process, hypernatraemia was negatively associated with outcome in hospitalised foals.

Severe hyponatraemia in foals: clinical findings, primary diagnosis and outcome.

OBJECTIVE: To evaluate severe hyponatraemia in foals presenting as medical emergencies to an intensive care unit (ICU) in order to determine the prevalence, clinical findings, primary diagnosis and outcome. DESIGN: Retrospective case study of records from Thoroughbred foals aged less than 3 months presenting to an ICU as medical emergencies in 2002-12; foals with severe hyponatraemia (serum sodium <122 mmol/L) on admission laboratory data were identified. Data retrieved included signalment, clinical findings, laboratory results, primary diagnosis, treatment and outcome. RESULTS: Severe hyponatraemia was identified in 69/1718 Thoroughbred foals (4%) presenting to the ICU during the study period. Of the 69 foals, 11 (15.9%) presented with neurological signs attributable to hyponatraemic encephalopathy and 7 of these foals had seizures; other neurological signs included obtundation, ataxia and apparent blindness. The three most common primary diagnoses of the 69 foals with severe hyponatraemia were renal disease (18/69, 26.1%), enterocolitis (16/69, 23.2%) and uroperitoneum (15/69, 21.7%). Treatment was directed at the primary disease and correction of the hyponatraemia. A total of 50 of the 69 foals (72.5%) with severe hyponatraemia survived to hospital discharge and 38 of them (76%) survived at least 12 months following discharge. CONCLUSION: The prevalence of severe hyponatraemia in this study population was 4%. The majority of foals with severe hyponatraemia did not demonstrate direct clinical manifestations as a result of the low serum sodium concentration. The outcome of foals with severe hyponatraemia was mostly favourable.

Equine multinodular pulmonary fibrosis in three horses in Australia.

BACKGROUND: Equine multinodular pulmonary fibrosis (EMPF) is a recently described form of interstitial pneumonia associated with the presence of equine herpesvirus type 5 (EHV-5). Since 2007, several case reports from America, Europe and the United Kingdom have further characterised the clinical presentation and laboratory findings of this disease. CASE REPORTS: Three Thoroughbred broodmares were diagnosed with EMPF. Diagnosis was based on lung histopathology and positive identification of EHV-5 using PCR DNA amplification. There was multiple organ involvement in all three cases, including identification of EHV-5 in hepatic tissue in one case. Two of the three horses died. Treatment with acyclovir was unsuccessful in one horse and one horse survived without antiviral or corticosteroid treatment. CONCLUSION: This case series is, to the authors' knowledge, the first report of EMPF in Australia and adds to the clinical description of the disease.

Methicillin-resistant Staphylococcus aureus in a population of horses in Australia.

OBJECTIVE: To evaluate if methicillin-resistant Staphylococcus aureus (MRSA) is present in the horse population in Australia. DESIGN: A two-part retrospective study of laboratory submissions of microbial culture results from horses. METHODS: Part A: medical records of 216 horses that had MRSA screening performed on nasal swabs collected over a 30-day period at admission to the Scone Equine Hospital Clovelly Intensive Care Unit were retrieved. Part B: laboratory records from 2004 to 2009 of culture submissions to the Scone Veterinary Laboratory were reviewed and cultures that grew MRSA were identified. The MRSA isolates from Parts A and B were genotyped over an 18-month period. RESULTS: MRSA screening of 216 horses identified eight (3.7%) positive samples. MRSA was isolated from cultures of 80 (0.002%) clinical bacteriology samples over a 6-year period. Genotypic analysis was performed on 36 isolates. All MRSA characterised had the same pulse field gel electrophoresis pattern (type 1), with eight closely related subtypes identified (subtypes A-F and H) and 66% of isolates classified as subtype D, which multilocus sequence and staphylococcal cassette chromosome mec typing analysis identified as ST612-MRSA-IVa, a clonal complex (CC) 8 S. aureus strain. Antimicrobial resistance to more than two classes of antimicrobials was common. CONCLUSIONS: MRSA was present in a population of horses in Australia. Genotypic analysis of the isolates identified the MRSA strain as CC8 S. aureus. Further research needs to be undertaken to evaluate MRSA infection and colonisation of horses and personnel in Australia.

Two-dimensional and M-mode echocardiographic findings in healthy Thoroughbred foals.

OBJECTIVE: The aim of this study was to establish reference values for a series of conventional two-dimensional (2-D) and M-mode echocardiographic variables in Thoroughbred foals at increasing age intervals. DESIGN: Nineteen healthy Thoroughbred foals (11 males, 8 females) were examined at 1, 2, 4, 8, 12 and 16 weeks of life. Auscultatory findings were recorded and echocardiographic examinations (2-D and M-mode) were performed. Descriptive statistical analyses, including mean, standard deviation and 95% confidence interval for the means, were used to summarise the data. The relationships between selected echocardiographic variables and age, body weight and heart rate were analysed. RESULTS: Reference values were determined for 12 routinely used 2-D and M-mode echocardiographic variables in healthy Thoroughbred foals at increasing age intervals. Linear relationships between echocardiographic variables and age (P < 0.001) and body weight (P < 0.001) were found, with the linear relationships between echocardiographic variables and body weight being stronger than those with age. Weak (R(2) ≤ 0.37) but significant (P < 0.001) correlations between the echocardiographic variables and heart rate were identified. CONCLUSIONS: Reference values for 2-D and M-mode echocardiographic variables in clinically normal Thoroughbred foals up to 4 months of age and approximately 190 kg body weight may assist in the interpretation of echocardiograms of Thoroughbred foals of similar age and body weight with suspected congenital or acquired cardiac disease.

Equine idiopathic cheek teeth fractures: part 3: a hospital-based survey of 68 referred horses (1999-2005).

REASONS FOR PERFORMING STUDY: There is limited information available on the more serious sequellae of idiopathic cheek teeth (CT) fractures. OBJECTIVES: To obtain information on clinical and ancillary diagnostic findings in referred horses with idiopathic CT fractures. METHODS: Details of all horses suffering from idiopathic CT fractures referred to the Equine Hospital at the University of Edinburgh 1999-2005 were examined, and information concerning fracture patterns, clinical and ancillary diagnostic findings, treatments and long-term response to treatments were obtained and analysed. RESULTS: A total of 60 maxillary and 17 mandibular idiopathic CT fractures were diagnosed in 68 horses. Fracture patterns included maxillary CT lateral slab fractures (45%), maxillary CT midline sagittal fractures (16%) and various other patterns of maxillary CT fractures (17%). In the mandibular CT, lateral slab fractures were found (12%) and various other CT fracture patterns were present in 10%. The more centrally positioned CT (maxillary and mandibular Triadan 08s and 09) were preferentially fractured. Clinical signs included quidding in 47% of cases; bitting and behavioural problems (28%); signs of apical infection, including bony swellings and nasal discharge (21%); anorexia/weight loss (15%); halitosis (13%); and buccal food impaction (12%). The treatment of all cases was conservative whenever possible and included corrective rasping of the remaining tooth (46% of cases); oral extraction of the smaller and loose dental fragment (32%) and extraction of the entire fractured tooth by oral extraction (28%) or by repulsion (13%). Prophylactic treatment of adjacent, nonfractured CT with carious infundibula was possibly of value in preventing further midline sagittal maxillary CT fractures. CONCLUSIONS: Horses referred with idiopathic CT fractures frequently have clinical signs of apical infection of the fractured CT and these teeth require extraction, orally if possible. More conservative treatment of idiopathic CT fractures without signs of gross apical infection can resolve clinical signs in most cases. POTENTIAL RELEVANCE: In the absence of apical infection, extraction of only the loose dental fragments of CT with idiopathic fractures is usually successful.

The impact of population pressure on conservation and development.

PIP: In many parts of the world high population levels and growth rates are responsible for hunger, disease, and poverty. Humans are not the only species suffering the consequences of the increasing numbers of people. The search for agricultural and grazing land, the depletion of forests and woodlands for timber and fuel, and the intensified use of chemicals for pest control, pasture improvement, and crop productivity all combine to degrade the environment, forcing the retreat and extinction of wild animals and plants. All organisms, including humans, depend upon environmental resources which are shared with other animals and plants. Overpopulation by 1 species inevitably depletes the resources of all of them. Many animals and plants have methods which prevent overcrowding and competition with other individuals of their own species. Humans have escaped many of nature's constraints by developing agriculture, industrialization, and medicine, bypassing the safety valves which regulate other species. Population growth in the industrial nations of the northern hemisphere since the industrial revolution frequently has been very high and has now stabilized at less than 1%. The environmental cost has been great and is still serious because of increasingly intensive use of the land. Many species have been severely reduced in numbers. Humans are the greatest single factor in the loss of species. In industrialized nations, powerful machines and chemicals change habitats and entire landscapes. In developing countries, a vast army of rural people do the same. The demands of populations are so great that even the basic need for firewood causes severe destruction of tropical woodlands and shrub formations. In 1980 the 1200 million people in the developing world who use wood as their primary fuel consumed wood faster than it was naturally replaced. Soil erosion, loss of fertility, and desertification follow. More species than ever before might become extinct as humans disrupt the most complex of all earth's biological communities--the equatorial rain forest. At the end of the century about 88% of the world's present rain forest area will remain, but most of it will be in the huge forests of Brazil and Zaire. Land hungry shifting cultivators are clearing 7.5 million hectares of closed canopy forest every year. With too many people on too little land, the traditional fallow periods are markedly fore-shortened and the forest cannot rebuild its store of nutrients. Some species adapt well. Yet, the number of endangered species could escalate to unprecedented proportions, many being familiar vertebrates. A table shows the number of extinctions of full species of birds and mammals alone between 1600 and 1970. Dependence upon wild species should not be underestimated. Resource conservation is essential for sustainable development.^ieng

The role of termites in the decomposition of wood and leaf litter in the Southern Guinea savanna of Nigeria.

This is part of a study on the litter dynamics of Southern Guinea savanna, with special reference to the role of termites (Isoptera) as decomposers of wood and leaves.The biomass of accumulated wood litter on the 6 ha study area varied from 2.299 to 3.488 t ha-1, with a mean of 2.821 t ha-1 Leaf litter biomass varied from 0.290 to 1.643 t ha-1, with a mean of 0.903 t ha-1. The measured decomposition constant for wood of 51% a-1 agreed well with a calculated value of 49% a-1. Leaf decomposition was calculated as 264% a-1. Termites removed an estimated 835.5 kg ha-1a-1 of wood litter (60% of annual wood-fall), and 68.4 kg ha-1a-1 of leaf litter (3% of annual leaf-fall), i.e. 24% of total annual litter production. Conversely, the annual bush-fire removed 1.173 t ha-1a-1 (49%) of annual leaf-fall but only 3 kg ha-1a-1 (0.2%) of annual wood-fall, i.e. 31% of total annual litter production. Baiting studies showed that the fungus-growing Macrotermitinae took 95% of the litter removed by termites (23% of annual litter production).The ability of the Macrotermitinae to utilise fresh litter is a diagnostic feature of decomposition processes in Southern Guinea and other savanna ecosystems. Their fungus combs produce a processed diet which allows the Macrotermitinae to feed in a seasonally arid environment where the curtailment of free fungal and microbial activity inhibits feeding by other decomposer invertebrates.

The distribution of soil macrofauna on the west ridge of Gunung (Mount) Mulu, Sarawak.

The macrofauna of the soils on the west ridge of Gunung Mulu in 4th Division, Sarawak, were sampled during February and March 1978. The eleven sampling sites ranged from near the base of the mountain at 130 m a.s.1. to the summit at 2.376 m.Altitudinal changes from lowland rain forest (mixed dipterocarp forest) to lower montane and upper montane rain forests are concomitant with changes in soil from red yellow podzolics and regosols to peaty gley podzolics and organic peats.The abundance of the total macrofauna declined from 2,579 individuals m-2 at 130 m to 145 m-2 at 2,376 m. Declining population densities of ants and termites correlated significantly with increasing altitude but the effect on other groups was variable. Changes in total biomass were erratic and varied from 4.1-6.2 g m-2 (alc. w.w.) in the dipterocarp forest soils to 5.8 g m-2 in the lower montane, 9.3-20.2 g m-2 in the upper montane (tall facies) and 1.9-9.5 g m-2 in the upper montane (short and summit facies). Only the decline in the biomass of termites and ants correlated significantly with altitude. Other groups remained fairly constant, varied erratically or increased in the middle altitudes.The dipterocarp forest soil macrofaunal biomass was dominated by termites, beetles and earthworms (Megascolecidae and Moniligastridae), with ants the dominant predators. The lower montane forest was a transitional and ill-defined zone on the mountain and the soil macrofauna was also transitional to some extent. Termite biomass fell substantially and earthworms replaced them as the dominant detritivores, with beetles in a secondary role. Formicidae remained as the major predators. With the inception of peats in the upper montane forest (tall facies), the macrofauna was dominated by Coleoptera with earthworms, Diptera larvae and Blattodea in lesser roles. With increasing exposure in the upper montane forests (short and summit facies), several major groups disappeared altogether. The soils were dominated by Blattodea with Coleoptera and Megascolecidae of lesser importance. Chilopoda and Arachnida replaced Formicidae as the dominant predators.

Vegetation and litter production in Southern Guinea savanna, Nigeria.

This study examines the woody vegetation, annual leaf-fall and annual wood-fall in Southern Guinea savanna near Mokwa, Nigeria. There were 1425±402 (95% limits) trees ha-1 of which Caesalpiniaceous legumes made up 53%. Annual leaf-fall was 2.387 t ha-1 a-1 equivalent to 11,238,932 kcal ha-1 a-1 and was highly seasonal, peaking from November to February, with a maximum in January after the annual bush fires. Annual wood-fall was 1.391 t ha-1 a-1 equivalent to 7,598,256 kcal ha-1 a-1 and was less seasonal but with two peaks, one from January to March after the fires and another from May to July in the rainy season.The litter-fall data currently available from West Africa are reviewed and indicate a negative correlation between litterfall and latitude (P<0.001). Litter production is found to be positively correlated with rainfall (P<0.001) and it is suggested that seasonal distribution of rainfall may also be a factor contributing to the limits of litter production.