Clinical, neurological and clinicopathological signs, treatment and outcome of metaldehyde intoxication in 18 dogs

OBJECTIVES: To describe the clinical signs, clinicopathological abnormalities and outcome of metaldehyde intoxication in dogs. METHODS: Medical records of dogs presenting between 1989 and 2005 with a diagnosis of metaldehyde toxicity were reviewed retrospectively. Data obtained from the medical record included signalment, history, clinical signs, laboratory tests results, hospitalisation period length, treatments and outcome. RESULTS: Eighteen dogs fulfilled the inclusion criteria. The most prevalent clinical signs were seizures, hyperthermia, tachycardia and muscle tremors. Serum biochemistry abnormalities included increased serum muscle enzymes activities, acidaemia (six dogs) and decreased blood bicarbonate (eight dogs). Treatment was symptomatic and supportive. Hyperbilirubinaemia was observed in two dogs. Diazepam was the most commonly used anticonvulsant followed by phenobarbitone and pentobarbital. General inhalant anaesthesia was required in nine of 18 dogs with seizures unresponsive to anticonvulsants. The survival was 83 per cent (15 of 18 dogs). CLINICAL SIGNIFICANCE: This clinical study recorded, for the first time in the veterinary literature, several clinicopathological abnormalities from severely intoxicated dogs. Metabolic acidosis was common, while acute or delayed hepatotoxicity was an uncommon complication.     

Magnetic resonance imaging findings of neuroaxonal dystrophy in a papillon puppy

A 3.5-month-old papillon puppy was brought to our clinic with chief complaints of progressive quadriparesis, ataxia and head tremor. Lesions in the cerebellum, brainstem and spinal cord were suspected on the basis of a neurological examination. No abnormality was found in a clinicopathological examination or on magnetic resonance imaging. On the basis of these results differential diagnoses including an inflammatory disease, a degenerative condition or a storage disorder were considered. Subsequently, the signs progressed and glossoplegia and dysphagia developed at six months of age. At a second magnetic resonance imaging, severe atrophy of the entire brain was found. After these examinations, the puppy was euthanased and histopathologically diagnosed with neuroaxonal dystrophy. Because magnetic resonance imaging detected abnormal features that were characteristic of neuroaxonal dystrophy in this case, we speculate that magnetic resonance imaging can assist in the pre-mortem diagnosis of this disease.     

Clinical, humoral and IFNgamma responses of cattle to infection with Mycoplasma mycoides var. mycoides small colony and attempts to condition the pathogenesis of the infection

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides var. mycoides small colony (MmmSC), is one of the most important diseases of cattle in Africa. The role of innate or acquired cell mediated and humoral immunity in conferring protection against MmmSC infection has not yet been elucidated. On the other hand, the pathological lesions caused by the aetiological agent have been considered indicative of an immunopathological process. In this study ten na?ve cattle were exposed to in-contact infection with animals infected by intubation with a strain of MmmSC. Clinical signs, antibody response, IFNgamma release and pathological changes at necropsy were analysed and compared with the events following in-contact infection of an equal number of animals kept under daily treatment with cyclosporine for the entire observation period of 84 days. Cyclosporine is a suppressor of the immune response related to the T-cell system. Under the conditions of the experiment, cyclosporine appeared to condition the pathogenesis of CBPP by delaying the events that follow infection, bringing further support to the possibility that the immune response may have an impact on the disease outcome.     

Ticks (Acari: Ixodidae) collected from animals in three western, semi-arid nature reserves in South Africa

The objective of this study was to make an inventory of the ixodid tick species infesting wild animals in three western, semi-arid nature reserves in South Africa. To this end 22 animals in the Kgalagadi Transfrontier Park, 10 in the West Coast National Park and 16 in the Karoo National Park were examined. Fourteen tick species were recovered, of which Hyalomma truncatum, Rhipicephalus exophthalmos and Rhipicephalus glabroscutatum were each present in two reserves and the remainder only in one. The distributions of two of the 14 tick species recovered, namely Rhipicephalus capensis and Rhipicephalus neumanni, are virtually confined to the western semi-arid regions of southern Africa. Hyalomma truncatum, R. capensis and R. glabroscutatum were the most numerous of the ticks recovered, and eland, Taurotragus oryx, were the most heavily infested with the former two species and gemsbok, Oryx gazella, and mountain reedbuck, Redunca fulvorufula, with R. glabroscutatum.     

Comparative pharmacokinetics of marbofloxacin in healthy and Mannheimia haemolytica infected calves

The pharmacokinetics of marbofloxacin were investigated in healthy (n=8) and Mannheimia haemolytica naturally infected (n=8) Simmental ruminant calves following intravenous (i.v.) and intramuscular (i.m.) administration of 2 mg kg(-1) body weight. The concentration of marbofloxacin in plasma was measured using high performance liquid chromatography with ultraviolet detection. Following i.v. administration of the drug, the elimination half-life (t(1/2 beta)) and mean residence time (MRT) were significantly longer in diseased calves (8.2h; 11.13 h) than in healthy ones (4.6 h; 6.1 h), respectively. The value of total body clearance (CL(B)) was larger in healthy calves (3 ml min(-1) kg(-1)) than in diseased ones (1.3 ml min(-1) kg(-1)). After single intramuscular (i.m.) administration of the drug, the elimination half-life, mean residence time (MRT) and maximum plasma concentration (C(max)) were higher in diseased calves (8.0, 12 h, 2.32 microg ml(-1)) than in healthy ones (4.7, 7.4 h, 1.4 microg ml(-1)), respectively. The plasma concentrations and AUC following administration of the drug by both routes were significantly higher in diseased calves than in healthy ones. Protein binding of Marbofloxacin was not significantly different in healthy and diseased calves. The mean value for MIC of marbofloxacin for M. haemolytica was 0.1+/-0.06 microg ml(-1). The C(max)/MIC and AUC(24)/MIC ratios were significantly higher in diseased calves (13.0-64.4 and 125-618 h) than in healthy calves (8-38.33 and 66.34-328 h). The obtained results for surrogate markers of antimicrobial activity (C(max)/MIC, AUC/MIC and T > or = MIC) indicate the excellent pharmacodynamic characteristics of the drug in diseased calves with M. haemolytica, which can be expected to optimize the clinical efficacy and minimize the development of resistance.     

Pre-partum monensin supplementation improves body reserves at calving and milk yield in Holstein cows dried-off with low body condition score

The objective of this study was to determine the effect of a monensin controlled-release capsule administered intraruminally at drying-off on body condition score (BCS) at calving, milk yield, fertility and concentration of energy-related blood metabolites in Holstein cows dried-off with low BCS (< or = 3.0, scale 1 to 5 with a 0.25 point of increment). Between July and August, 2001, 220 cows from parity 2 or more and dried-off 50-70 days before expected parturition, with a BCS < or = 3.0 were randomly assigned to either a treatment group (n=110; oral capsule of monensin releasing 335 mg/day for 95 days) or a control group (no capsule, n=110). At assignment, on day 21 before expected parturition, at calving, and at 7, 14, and 21 days in milk a blood sample was obtained from a random sub sample of 10 cows per group. Effects of monensin on serum NEFA, BHBA and glucose were measured. Milk yield, milk fat and protein content (%) at DHIA test days during the entire lactation, 305 ME milk production and reproductive responses were compared. Monensin significantly improved BCS at calving, increased milk yield at test days 4 and 8, decreased the percentage of milk protein, did not change the percentage of milk fat, and decreased NEFA and BHBA during the post-partum period.     

新疆部分地区生乳中金黄色葡萄球菌的分离鉴定及耐药性分析

【目的】探明新疆部分地区生乳中金黄色葡萄球菌流行情况及耐药性,为该地区生乳中金黄色葡萄球菌的监测及保障生乳质量安全提供理论依据。【方法】试验随机从南北疆规模化奶牛场采集110份生乳样品。采用增菌培养、分离纯化、革兰氏染色、生化鉴定及PCR法对奶样中金黄色葡萄球菌进行分离鉴定,并利用微量肉汤稀释法及PCR方法对金黄色葡萄球菌进行16种抗菌药物的耐药表型及耐药基因分析。【结果】从110份奶样中分离出18株金黄色葡萄球菌,分离株呈浅黄色、光滑凸起的圆形菌落,革兰氏染色镜检呈紫色、短链状排列的革兰氏阳性菌,生化试验结果符合金黄色葡萄球菌生化特点,经16S rDNA及nuc基因PCR扩增鉴定为金黄色葡萄球菌,分离率为16.36%(18/110)。药敏试验结果显示,金黄色葡萄球菌分离株对氨苄西林、青霉素及磺胺异噁唑具有较高的耐药性,耐药率分别为100%、83.33%和77.78%,而对万古霉素、复方新诺明、苯唑西林、头孢噻吩、头孢噻呋、利福昔明及环丙沙星7种抗菌药物高度敏感,敏感率分别为100%、100%、94.44%、94.44%、94.44%、94.44%和94.44%。其中有14株金黄色葡萄球菌为多重耐药菌,多重耐药率为77.78%。耐药基因检测结果显示,大环内酯类耐药基因ermB检出率最高,为50.00%,其次为β-内酰胺类耐药基因mecA,检出率为27.28%,磺胺类耐药基因Sul1的检出率为22.22%。【结论】新疆奶牛场生乳中分离的金黄色葡萄球菌的流行及耐药情况仍较严重,且存在多重耐药现象,因此,对生乳中金黄色葡萄球菌耐药性的监测有重要意义。     

Genetic and non-genetic factors influencing KLH binding natural antibodies and specific antibody response to Newcastle disease in Kenyan chicken populations

This study aimed at investigating the influence of genetic and non-genetic factors on immune traits to inform on possibilities of genetic improvement of disease resistance traits in local chicken of Kenya. Immune traits such as natural and specific antibodies are considered suitable indicators of an individual's health status and consequently, used as indicator traits of disease resistance. In this study, natural antibodies binding to Keyhole Limpet Hemocyanin (KLH-NAbs) was used to measure general disease resistance. Specific antibodies binding to Newcastle disease virus (NDV-IgG) post vaccination was used to measure specific disease resistance. Titers of KLH-NAbs isotypes (KLH-IgM, KLH-IgG and KLH-IgA) and NDV-IgG were measured in 1,540 chickens of different ages ranging from 12 to 56 weeks. A general linear model was fitted to determine the effect of sex, generation, population type, phylogenetic cluster, line, genotype and age on the antibody traits. A multivariate animal mixed model was fitted to estimate heritability and genetic correlations among the antibody traits. The model constituted of non-genetic factors found to have a significant influence on the antibody traits as fixed effects, and animal and residual effects as random variables. Overall mean (±SE) concentration levels for KLH-IgM, KLH-IgG, KLH-IgA and NDV-IgG were 10.33 ± 0.04, 9.08 ± 0.02, 6.00 ± 0.02 and 10.12 ± 0.03, respectively. Sex, generation and age (linear covariate) significantly (p < 0.05) influenced variation across all the antibody traits. Genotype effects (p < 0.05) were present in all antibody traits, apart from KLH-IgA. Interaction between generation and line was significant (p < 0.05) in KLH-IgM and NDV-IgG while nesting phylogenetic cluster within population significantly (p < 0.05) influenced all antibody traits, apart from KLH-IgA. Heritability estimates for KLH-IgM, KLH-IgG, KLH-IgA and NDV-IgG were 0.28 ± 0.08, 0.14 ± 0.06, 0.07 ± 0.04 and 0.31 ± 0.06, respectively. There were positive genetic correlations (0.40–0.61) among the KLH-NAbs while negative genetic correlations (−0.26 to −0.98) were observed between the KLH-NAbs and NDV-IgG. Results from this study indicate that non-genetic effects due to biological and environmental factors influence natural and specific antibodies and should be accounted for to reduce bias and improve accuracy when evaluating the traits. Subsequently, the moderate heritability estimates in KLH-IgM and NDV-IgG suggest selection possibilities for genetic improvement of general and specific immunity, respectively, and consequently disease resistance. However, the negative correlations between KLH-NAbs and NDV-IgG indicate the need to consider a suitable approach that can optimally combine both traits in a multiple trait selection strategies.