PubMed Health⌕ Search

Biomedical subjects

J L Hodgson

Publications and source records attributed to J L Hodgson.

At least 19 recordsLinked to original sources
PubMed2005

Snake envenomation in dogs in New South Wales.

OBJECTIVE: To obtain baseline data on the prevalence of elapid snake envenomation in dogs presented to veterinary practices in New South Wales and to assess attitudes of veterinarians to this clinical entity. PROCEDURE: A mailed questionnaire, sent to all veterinary clinics within New South Wales, was utilised to collect epidemiological information regarding elapid snake envenomation in dogs. RESULTS: A response rate of 68% was obtained and a yearly prevalence of snake envenomation in dogs across New South Wales veterinary clinics was estimated as 0.31%. The most common species reported to be responsible for envenomation within NSW was the Red Bellied Black snake (Pseudechis porphyriacus) followed by the Brown snake (Pseudonaja textilis) and then Tiger snake (Notechis scutatus). The reported envenomation syndromes caused by these common snake species were perceived to be similar for Brown and Tiger snakes but differed for Red Bellied Black snakes. Diagnosis of snake envenomation was based predominantly on the recognition of clinical signs. Specific diagnostic tests, such as venom detection kits, were used infrequently. The most common treatment was reported to be a combination of intravenous fluid therapy and antivenom, and monitoring of response to this treatment was usually through assessment of clinical signs. Survival after antivenom administration was reported to be highest for Red Bellied Black snake species. Survival was perceived to be associated with time between envenomation and presentation to the veterinary clinic and with antivenom administration. CONCLUSIONS: Current attitudes and perceptions of veterinarians have been defined. Diagnosis of species-specific snake envenomation is shown to be made on the basis of clinical signs which are, however, reported as similar for each species. Clearer definition of these envenomation syndromes and identification of accessible diagnostic testing procedures are needed.

Animals↗
PubMed2003

Comparison of tracheal aspirates and bronchoalveolar lavage in racehorses. 1. Evaluation of cytological stains and the percentage of mast cells and eosinophils.

OBJECTIVE: To compare a fast Romanowsky cytological stain (Diff-Quik) and Leishman's stain for the detection of mast cells in samples from the lower airways of racehorses, and to compare the proportion of mast cells and eosinophils in the total inflammatory cells in tracheal aspirate (TA) with those in paired bronchoalveolar lavage (BAL) samples. DESIGN: Retrospective case series of 48 young Thoroughbred and Standardbred racehorses. PROCEDURE: Fifty-one paired TA and BAL samples were collected after treadmill exercise from 48 horses with poor racing performance. Two slides were prepared from each sample; one was stained with Diff-Quik stain and the other with Leishman's stain. Differential cell counts of eosinophils and mast cells were recorded from each slide. Comparison of the suitability of the stains for the detection of mast cells, and comparisons of eosinophil and mast cell percentages in TA and BAL samples were analysed using the non-parametric Wilcoxon matched pairs test. RESULTS: Percentages of mast cells were significantly higher in Leishman than in Diff-Quik stained slides in both TA (P = 0.03) and BAL samples (P < 0.0001). Mast cell percentages were significantly higher in BAL than in TA samples using Leishman's stain (P < 0.0001). There was no significant difference in eosinophil percentages between TA and BAL samples (P = 0.07). CONCLUSIONS: Fast Romanowsky type stains (for example Diff-Quik) are not appropriate for the detection of mast cells in samples from the equine lower respiratory tract. Therefore, a metachromatic stain that reliably identifies mast cells (for example Leishman's) should be used if evaluation of mast cells in lower respiratory tract is undertaken. Mast cells are predominantly found in the distal small airways and alveoli sampled with a BAL. In contrast, eosinophils appear to be evenly distributed in the lower respiratory tract. However, high percentages of eosinophils are occasionally found only in TA samples. We recommend that both a TA and BAL be used for the evaluation of eosinophils and mast cells within the equine lower respiratory tract.

Animals↗
PubMed2003

Comparison of tracheal aspirates and bronchoalveolar lavage in racehorses. 2. Evaluation of the diagnostic significance of neutrophil percentage.

OBJECTIVE: To determine whether diagnosis of airway inflammation, using cut-off percentages for neutrophils, differs when based on samples from tracheal aspirate (TA) and bronchoalveolar lavage (BAL) collected concomitantly from the same racehorse. DESIGN: Retrospective case series of 48 young Thoroughbred and Standardbred racehorses in race training, but showing poor performance. PROCEDURE TA and BAL samples were collected from all horses 1 to 2 h after high-speed treadmill exercise. Aliquots of the retrieved fluid were cytocentrifuged and smears stained with Diff-Quik. The mean percentage of neutrophils was calculated. Diagnostic cut-off points were set at 20% for TA samples and 5% for BAL samples. Agreement in the interpretations between the two techniques was analysed. RESULTS: In 19 of 51 paired samples (37%) there were differences in diagnostic interpretation between TA and BAL samples. Of these, airway inflammation was indicated only by the TA sample in 13 and only by the BAL in 6. CONCLUSION: TA and BAL samples give important information about different regions of the airway, but neither should be used alone for the diagnosis of inflammation of the entire lung. The limitations of these procedures mean that both samples should be collected when it is desired to cytologically evaluate the entire lower airway.

Animals↗
PubMed2002

Evaluation of tests for anthelmintic resistance in cyathostomes.

Resistance, especially to the anthelmintic benzimidazoles (BZ), has been reported in horse cyathostomes world-wide. Diagnosis of resistance has traditionally been made by faecal egg count reduction (FECR) trials, however, this technique has limitations. Some of the shortcomings may be resolved by refining the test or by using an in vitro test. FECR tests and the larval development assay (LDA) were performed on adult horses held on 15 different horse properties across a wide geographical area of NSW, Australia. FECR were measured before and 10-14 after days treatment with oxibendazole (OBZ), morantel (MOR) or ivermectin (IVM) at recommended dose rates. Eight properties were rejected following low pre-treatment egg counts, leaving seven in the study. On these, the majority of larvae recovered from faecal cultures were cyathostomes. Using a definition of resistance as a FECR of <90%, resistance to OBZ was present on six properties and to MOR on two properties. Resistance to IVM was not detected. An alternative method of calculating FECR based on individual horse egg counts pre- and post-treatment was developed and results from the same properties compared with the results of the LDA. For example, for the BZ, correlation coefficients of values of lethal concentration to kill 50% of population (LC50) on LDA and FECR percentages were -0.536 before and -0.704 after OBZ treatment. We conclude that the LDA has the potential to be a single visit test for detection of anthelmintic resistance in horse cyathostomes but requires further investigation and standardisation.

Animals↗
PubMed2002

Heart rate and blood lactate responses during exercise in preparation for eventing competition.

The aim of this study was to investigate the heart rate and blood lactate responses to exercise in event horses in normal training, and to compare them to those encountered in eventing competition. It was hypothesised that the responses during exercise in the course of training for CCI*** events would be significantly different from those of the Cross-Country day. Heart rates and blood lactate concentrations were measured in 13 elite event horses after intense exercise sessions conducted during the late stages of preparation for CCI*** or CCI**** 3-day-event competition. Mean +/- s.d. heart rate during exercise was 138 +/- 17 beats/min and mean blood lactate concentration after exercise was 1.0 +/- 0.6 mmol/l. These values were compared to heart rates and blood lactate concentrations recorded during and after a CCI*** Cross Country course using unpaired t tests (unequal variances) and 99.9% confidence interval analysis. Mean heart rates during and blood lactate concentrations after the competition were 195 +/- 8 beats/min and 10.2 +/- 4.2 mmol/l. The 99.9% confidence intervals were 183-207 beats/min and 7.7-12.6 mmol/l. Heart rates and blood lactate concentrations recorded during exercise sessions were significantly lower than competition values (P<0.001) and lay outside 99.9% confidence intervals for most horses. Only one horse achieved heart rates and blood lactate concentrations during exercise sessions that were similar to those occurring in competition. The intensity of exercise during normal training sessions was much lower than during competition, suggesting that many event horses are not appropriately trained.

Analysis of Variance↗
PubMed2001

Coughing in thoroughbred racehorses: risk factors and tracheal endoscopic and cytological findings.

A matched case-control study was made of 100 thoroughbred horses which were coughing and 148 control horses which were free of clinical signs of respiratory tract disease. The variables identified by multivariable conditional logistic regression as being significantly associated with coughing included age (the risk decreased with age), the stage of training (horses in early training were at greatest risk), the time since the last race (horses that had never raced were at greatest risk) and the time since they were last transported (horses transported more than 14 days previously were more likely to cough than those transported within the last week). The coughing horses were significantly more likely to have high scores for upper and lower tracheal mucus and pharyngeal lymphoid hyperplasia. In addition, the tracheal aspirates of the coughing horses had increased odds of neutrophilia and were more likely to have intracellular bacteria than the control horses. However, a considerable proportion of the control horses had cytological and/or endoscopic evidence of airway inflammation.

Age Factors↗
PubMed2001

Cardiovascular, haematological and biochemical responses after large volume blood collection in horses.

To determine whether removal of 20 mL/kg of blood (approximately 25% of blood volume) resulted in adverse physiological effects in donor horses, we removed this volume of blood from five horses and selected cardiovascular, haematological and biochemical variables measured during collection and for 31 days thereafter. We found that alteration in most variables occurred, although the changes in values usually remained within published reference ranges. Also, recovery of these alterations to pre-collection values was rapid, occurring within 24--48 h in most instances. We concluded that volumes of blood less than or equal to 20 mL/kg when collected appropriately from healthy donor horses result in no adverse acute or chronic physiological changes. These results suggest that horses undergo adequate physiological compensation when approximately 25% of blood volume is removed for the purposes of blood donation or production of plasma.

Acid-Base Equilibrium↗
PubMed2001

Peritonitis associated with Actinobacillus equuli in horses: 51 cases.

OBJECTIVE: To review the clinical findings, diagnosis and treatment of 51 horses with peritonitis attributed to Actinobacillus equuli. DESIGN: Retrospective study of clinical cases. METHODS: Breed, age and gender of horse, history, physical examination findings, treatment and outcome were determined from the hospital records of 51 horses in which a diagnosis of peritonitis attributed to A. equuli was made between January 1993 and June 1999. Results of abdominal fluid cytology and bacteriology, antimicrobial sensitivity patterns, haematology and faecal egg counts, when performed, were also retrieved. RESULTS: There was a variety of breeds of horses affected. There were 35 male and 17 female horses, aged from 9 months to 22 years, presented. Lethargy, signs of depression with mild to moderate signs of abdominal pain and inappetence were the most common reasons for presentation. Most horses had elevated heart and respiratory rates, an elevated rectal temperature and reduced intestinal borborygmi heard on auscultation of the abdomen. Abnormal colour with an elevated protein were features of an abdominal fluid sample in 98% of horses and a marked elevation in nucleated cell count was present in all samples. Pleomorphic gram-negative rods were seen on cytology in 53% of samples and a positive culture of A. equuli was returned in 72% of samples. Other laboratory findings in some horses included mild haemoconcentration, hypoproteinaemia, an elevated circulating nucleated cell count with a left shift, an elevation in fibrinogen concentration and an elevated faecal egg count. All horses demonstrated a rapid response to treatment with procaine penicillin alone, or a combination of procaine penicillin and gentamicin sulphate. Where antimicrobial sensitivity tests were performed, all but two isolates were sensitive to procaine penicillin. All horses responded to antimicrobial and supportive therapy and were discharged from hospital. CONCLUSION: Horses with A. equuli peritonitis present with similar clinical signs as horses with other causes of abdominal pain. However, these signs, when evaluated in conjunction with the results of abdominal fluid analysis and response to treatment, are characteristic of A. equuli peritonitis. Pleomorphic gram-negative bacteria may be seen on a cytological preparation of the abdominal fluid sample, and a positive bacterial culture may be obtained in some, but not all, cases. Most isolates are sensitive to procaine penicillin, so treatment with procaine penicillin and gentamicin sulphate is recommended until antimicrobial sensitivity is known.

Actinobacillus↗
PubMed2001

A case-control study of respiratory disease in Thoroughbred racehorses in Sydney, Australia.

In order to investigate the role of infectious agents in the aetiology of lower respiratory tract disease in Thoroughbred racehorses, a matched case-control study was conducted. Cases were identified by the presence of coughing, and were compared to a control population matched on time of sample collection and location within the same training establishment. Tracheal wash samples were collected from 100 cases and 148 controls. Case horses were more likely than controls to have endoscopic and cytological evidence of airway inflammation. There was no significant association between serological evidence of infection by commonly implicated respiratory viruses and coughing. Similarly, mycoplasma were rarely isolated and were not associated with disease. In contrast, there was a strong association between isolation of greater than a total of 10(3) colony-forming units/ml of tracheal wash and coughing. Individual bacterial species associated with disease included Streptococcus zooepidemicus, Streptococcus pneumoniae, Streptococcus suis, Streptococcus sanguis, Pasteurella spp and Bordetella bronchiseptica. This study provides evidence of the role of bacterial infection in the aetiology of lower respiratory tract inflammation in racehorses. However, in 58% of cases, few or no bacteria were isolated. Hence, at the time of identification of disease, there was no evidence of viral, bacterial or mycoplasmal infection in the majority of coughing horses. The aetiology of the signs observed in these horses requires further investigation.

Animals↗
PubMed2000

Attitudes of Australian veterinarians about the cause and treatment of lower-respiratory-tract disease in racehorses.

A questionnaire was administered to members of the Australian Equine Veterinary Association to investigate their attitudes and behaviours regarding the cause, diagnosis and treatment of lower-respiratory-tract disease in racehorses. The most-important perceived risk factors related to the level of exposure and resistance to infectious agents, whereas factors associated with racing and climatic factors were lower ranked. By far the most-commonly implicated primary cause of disease was respiratory viruses. However, specific diagnostic tests (such as viral serology or virus isolation) were rarely performed. By far the most-common diagnostic procedure was auscultation (without a rebreathing bag). The relative importance of diagnostic procedures was influenced by the proportion of total workload comprising horse work. Many respondents believed that bacteria become secondarily involved in disease; accordingly, antibiotic therapy was the most-commonly reported therapy. However, bacteriology of lower-airway-fluid samples was not commonly performed. The most-commonly used antibiotics were the potentiated sulphonamides (either alone or in combination with mucolytics or bronchodilators), followed by procaine penicillin and penicillin combined with gentamicin. Mainly, treatment would appear to be based on empirical beliefs rather than exhaustive investigation of individual cases.

Adrenal Cortex Hormones↗
PubMed2000

Issues associated with the application to veterinarians of a mailed questionnaire regarding lower respiratory-tract disease in racehorses.

This study evaluated a questionnaire investigating the attitudes and behaviours of veterinarians regarding the cause, diagnosis and treatment of lower respiratory-tract disease in racehorses. The questionnaire was sent to all non-student members (648) of the Australian Equine Veterinary Association: two mailings and a single telephone contact (each separated by four weeks). Subsequent phases were only administered to those who had not responded to earlier phases. In total, 467 (72.1%) of the 648 mailed questionnaires were returned. Of these, 354 were usable. The remaining 113 respondents gave various reasons for not completing the questionnaire; the most common (68%) was that horses were not a component of their practice. Those respondents working primarily with horses required fewer phases to return the questionnaire. Although deviating from previously described questionnaire designs, the described protocol provided a reasonable response rate.

Animals↗
PubMed2000

Characterization of hemolysin of Moraxella bovis using a hemolysis-neutralizing monoclonal antibody.

A concentrated bacterial culture supernatant from the hemolytic Moraxella bovis strain UQV 148NF was used to immunize mice and generate monoclonal antibodies (MAbs). One, MAb G3/D7, neutralized the hemolytic activity of M. bovis and recognized a 94-kDa protein by Western blot analysis in hemolytic M. bovis strains representing each of the different fimbrial serogroups. Exposure of corneal epithelial cells to M. bovis concentrated culture supernatants demonstrated a role for an exotoxin in the pathogenesis of infectious bovine keratoconjunctivitis, while neutralization of hemolytic and cytotoxic activities by MAb G3/D7 implies that these activities are related or have common epitopes. The action of M. bovis hemolysin was further characterized in sheep erythrocyte preparations with a binding step and Ca(2+) required for lysis to proceed, similar to the RTX family of bacterial exotoxins. Neutralization of lytic activity in vitro is evidence for the presence of M. bovis antigens, which may be capable of protecting cattle from the development of infectious bovine keratoconjunctivitis.

Animals↗
PubMed1999

Bone marrow response to large volume blood collection in the horse.

Evaluation of erythropoietic regeneration in horses is difficult unless serial bone marrow aspirates are performed. To investigate the acute and chronic erythropoietic regenerative response of equine bone marrow following acute removal or loss of blood, sequential bone marrow aspirates over 4 weeks were taken from the sternum of five horses from which 20 ml kg(-1)of blood had been removed. We found that the total number of erythroid cells counted (expressed as a percentage of the total number of erythroid and myeloid cells counted) expanded initially by 13.7 per cent within 3 days after blood removal, the erythroid response peaking by 9 days with a further 13.5 per cent increase. This peak coincided with the lowest M:E ratio. Concomitantly, a shift from proliferative phase cells to maturing phase cells occurred, which appeared to persist beyond 31 days post collection. Thus, we found that the equine bone marrow mounted a regenerative erythropoietic response more slowly than previously determined and, also, regeneration of the erythroid compartment was incomplete 31 days after blood removal of this magnitude.

Animals↗
PubMed1999

Comparison of bacteriology and cytology of tracheal fluid samples collected by percutaneous transtracheal aspiration or via an endoscope using a plugged, guarded catheter.

Cytological and bacteriological results from tracheal fluid samples obtained endoscopically using a telescoping, plugged catheter (TPC) were compared with results from samples collected by percutaneous transtracheal aspiration (PTA). The TPC technique and PTA were performed in random order on 9 healthy Standardbred geldings. Three weeks later the procedures were performed on the same horses in the reverse order. The presence of oropharyngeal contamination was determined by quantitative bacteriology and quantification of squamous epithelial cells (SEC)/ml sample. The relative numbers of macrophages, haemosiderophages, giant cells, neutrophils, lymphocytes and eosinophils did not differ between techniques. The number of SEC/ml was greater in samples with more colony forming units/ml indicating that quantification of SEC provides evidence of the probable degree of oropharyngeal contamination. Fifteen out of the 18 TPC samples were free of contamination, indicating that the TPC can provide adequate samples for bacteriology. The results also indicate that tracheoscopy sometimes results in oropharyngeal contamination of the trachea, but that this does not affect the results of the TPC sample.

Animals↗
PubMed1998

Serum gentamicin concentrations in compromised neonatal foals.

Twenty-one compromised neonatal foals hospitalised at the Rural Veterinary Centre (RVC) during 1993 were studied to determine i) serum gentamicin concentrations obtained when gentamicin was administered at 3.3 mg/kg bwt twice daily i.m.; ii) factors which contributed to inter-foal variation in serum gentamicin concentrations achieved and iii) clinical efficacy of gentamicin therapy in foals with confirmed septicaemia. Septicaemia was confirmed in 7 foals with positive blood cultures and suspected in 8 foals with a sepsis score > 11. Peak serum concentrations (Ps) were > 6 microg/ml in all foals and > 8 microg/ml in 60% of foals. Trough serum concentrations (Ts) were < 2 microg/ml in all foals. Factors found to produce inter-foal variation in the Ps achieved included age (< 24 h; decreased), bodyweight (< 38 kg; decreased) and severity of dehydration (8-12% bodyweight; increased). Clinical response was not associated with achievement of Ps > 8 microg/ml, but was negatively influenced by the severity of clinical signs of depression. None of the foals in this study developed septic arthritis or pneumonia during or after therapy. No serum biochemical evidence (i.e. elevated serum creatinine concentrations) of gentamicin-induced nephrotoxicity was noted during therapy.

Animals↗
PubMed1997

Failure of passive transfer in foals: incidence and outcome on four studs in New South Wales.

OBJECTIVE: To determine the regional incidence and effectiveness of treatment of failure of passive transfer (FPT) in foals. DESIGN: A study of disease incidence. ANIMALS: Eighty-eight foals and 57 mares from four studs in the practice area of the Rural Veterinary Centre were tested. PROCEDURE: Foals were tested for their serum IgG and total serum protein (TSP) concentration within the first 72 hours of life. Colostrum was collected from mares and specific gravity determined. FPT and partial failure of passive transfer (PFPT) of immunoglobulins was diagnosed when serum IgG concentrations were < 4 g/L and 4 to 8 g/L respectively. Owners of foals diagnosed with FPT were offered treatment with 1 to 2 L plasma (TSP > 70 g/L); 9 (64%) of the affected foals were treated. RESULTS: Fourteen foals (16%) had FPT whereas 15 (17%) had PFPT. There were significant differences between the mean TSP concentration in foals with FPT (42.6 +/- 4.2 g/L), PFPT (48.1 +/- 3.9 g/L) and those acquiring adequate passive immunity (58.9 +/- 5.5 g/l) (p < 0.01). Sixteen (29%) mares had pre-suck colostral specific gravity < 1.060 and 12 (71%) foals raised by these mares had FPT or PFPT. The incidence of severe disease (categorised by a sepsis score > 11, positive culture of bacteria from blood or disease requiring hospitalisation) in all foals in the first 2 months of life was 10%. However, none of the nine foals with FPT that received plasma experienced severe disease. In contrast, foals with PFPT had an increased susceptibility to severe disease (p < 0.001) when compared with normal foals. CONCLUSION: Treatment of foals with FPT may reduce the subsequent incidence of severe disease. Pre-suck colostral specific gravity and foal TSP may be used to predict the likelihood of FPT and PFPT. Even though the number of foals studied is small the results highlight the importance of optimal management practices in reducing the incidence of FPT and disease associated with this process.

Animals↗