A critical assessment of antimicrobial treatment in uncomplicated Salmonella enteritis

The human and veterinary literature on the effect of antimicrobials on the clinical and bacteriological cure in uncomplicated Salmonella gastroenteritis is reviewed. Comparison of data on the efficacy of conventional antimicrobials (chloramphenicol, neomycin, ampicillin, amoxycillin, tetracycline, trimethoprim/sulfonamide combinations) and the newer fluoroquinolones indicate that quinolones may shorten the course of clinical disease in contrast to the conventional antimicrobials. Postconvalescent excretion of Salmonella was not affected by the conventional antimicrobials whereas the data on the fluoroquinolones in this respect are conflicting. The fluoroquinolones are the drugs of choice in human medicine for severe Salmonella infections and for the elimination of the carrier state. These drugs have not been evaluated in this respect in veterinary medicine. Well designed prospective placebo-controlled studies regarding the effect of antimicrobials, especially the fluoroquinolones, on the clinical cure and the postconvalescent shedding of Salmonella in animals are imperative to develop optimal therapeutic strategies.     

Metabolic and mitogenic activities of insulin-like growth factor-1 in interleukin-1-conditioned equine cartilage

OBJECTIVE: To determine response of interleukin-1alpha (IL-1alpha)-conditioned equine articular cartilage explants to insulin-like growth factor-1 (IGF-1). Sample Population-Cartilage from the trochlea and condyles of the femur of a clinically normal 4-year-old horse. PROCEDURE: Effects of IGF-1 (0 to 500 ng/ml) after addition of IL-1alpha were evaluated by assessing matrix responses, using a sulfated glycosaminoglycan (GAG) assay, matrix 35SO4 GAG incorporation, and release of GAG. Mitogenic response was assessed by 3H-thymidine incorporation into DNA and fluorometric assay of total DNA concentration. RESULTS: Human recombinant IL-1alpha (40 ng/ml) increased the amount of labeled GAG released and decreased labeled and total GAG remaining in explants, and IL-1alpha decreased mitogenic response. Addition of IGF-1 counteracted effects seen with IL-1alpha alone. In general, IGF-1 decreased total and labeled GAG released into the medium, compared with IL-1alpha-treated explants (positive-control sample). Values for these variables did not differ significantly from those for negative-control explants. A significant increase in total and newly synthesized GAG in the explants at termination of the experiment was observed with 500 ng of IGF-1/ml. Labeled GAG remaining in explants was greater with treatment at 50 ng of IGF-1/ml, compared with treatment with IL-1alpha alone. Concentrations of 200 ng of IGF-1/ml abolished actions of IL-1alpha and restored DNA synthesis to values similar to those of negative-control explants. CONCLUSIONS AND CLINICAL RELEVANCE: IGF-1 at 500 ng/ml was best at overcoming detrimental effects associated with IL-1alpha in in vitro explants. These beneficial effects may be useful in horses with osteoarthritis.     

Morphology and amplitude values of the electrocardiogram of Spanish-bred horses of different ages in the Dubois leads system

The aim of this work was to record the modifications of the form and amplitude of the electrocardiographic tracings during growth using the Dubois system and to study its sensibility to these physiological changes. This work was carried out on 179 healthy, young and adult Spanish-bred horses (98 females and 81 males). One electrocardiogram (ECG) was obtained from each horse using the Dubois leads system. The bifid shape deflection of the P wave was generally more frequent than the simple one in animals at 4 months of age or older. Amplitudes of the P2 component and of the simple positive wave presented significant differences (p < 0.01) between the age groups studied: animals up to 3 months in age and older than 2 years of age (highest amplitudes), and the rest of the animals (lowest amplitudes). Significant variations (p < 0.05) were found for the QS amplitude between animals of 1 month of age, and all the other groups. The multiple range analysis did not define a clear distribution of age groups for the amplitude of the T wave. It may therefore be concluded, that in the Spanish-bred horse up to 1 month of age, the form and amplitude of the QRS complex in the Dubois leads system differ from those of older animals. Thus, this study shows the sensibility of the Dubois leads system for detecting the electrocardiographic changes related to the growing process in the Spanish-bred horse. In addition, it provides standard values of electrocardiographic parameters in the Spanish-bred horse at different stages of growth.     

GnRH antagonist inhibition of gonadotropin and steroid secretion in boars in vivo and steroid production in vitro

The hormone GnRH has a stimulatory effect on gonadotropin synthesis and secretion. The objective of the first study was to evaluate concentrations of FSH and LH in plasma of boars after successive treatment with SB75, a GnRH antagonist. Thirteen boars greater than 1 yr of age (eight White Composite [WC] and five Meishan [MS]) were injected once daily with SB75 (10 microg/kg of body weight) for 4 d. Plasma concentrations of LH and testosterone (T) decreased after 1 h from the first dose of SB75. After 12 h of treatment, LH gradually returned to pretreatment concentrations, but T remained suppressed (< 2 ng/mL) until after the last injection of SB75. There was a modest, but significant, reduction in FSH during treatment with SB75. The prolonged inhibitory effect of SB75 on suppression of plasma T concentrations, in the presence of pretreatment concentrations of LH, implied direct effects of SB75 at the testis. In the second experiment, testicular tissue from adult boars was incubated in the presence of three doses of human chorionic gonadotropin (hCG; 0, .5, and 5 IU) with SB75 (250 ng/mL) or with Deslorelin, a GnRH agonist (500 ng/mL). Samples of media were collected every hour for 3 h, and concentrations of T and estrone (E1) were determined by RIA. Concentrations of T and E1 increased with time in response to treatment with hCG. Co-treatment with SB75 decreased media concentrations of T (P < .01) and E1 (P < .03) compared to controls (77.9 vs 85.7 +/- 2.0 and 4.7 vs 5.3 +/- .2 ng/g). In contrast, treatment with Deslorelin had no effect on the amount of T (P > .50) or E1 (P > .26) released with all dosages of hCG. These results indicate that a GnRH antagonist has a direct effect on the testis, decreasing amounts of T and E1 released from the Leydig cells; however, treatment with a GnRH agonist had no direct effect on release of these gonadal steroids. Thus, it remains unresolved whether the site of action of GnRH antagonist on testicular steroidogenesis is through a testicular GnRH receptor or through some other mechanism.     

Ventral marsupialisation in the treatment of gastric dilatation-volvulus in two dogs

A ventral marsupialisation technique is described which was used successfully to manage gastric dilatation-volvulus (GDV) in two large breed dogs. The procedure allowed the stomach to be completely and rapidly emptied and lavaged without peritoneal contamination. Drainage was maintained in the postoperative period for both dogs and the technique was expected to result in a permanent ventral gastropexy.     

Pheasant ataxia: a new condition in pheasant poults

Between 1995 and 1997 a neurological condition in pheasant poults from 24 sites in England and Scotland was investigated. Affected birds showed varying degrees of ataxia and incoordinated movements and, in severe cases, recumbency, but generally remained alert with their heads held upright. The condition characteristically affected poults from seven weeks of age and the incidence on any one site was low. No significant bacteria were isolated consistently from brain tissue. The condition was characterised histologically by a non-suppurative meningoencephalitis, in which lesions were found predominantly in the cerebellum in 61 of 81 samples examined (75.3 per cent). A non-suppurative myelitis was recorded in 16 of 20 spinal cords examined. No lesions were recorded in peripheral neural tissue and lesions were rare in other tissues. The condition appeared not to have been recorded previously in pheasants. A viral aetiology was suspected but Newcastle disease virus was not involved.     

Use of a mucosal advancement flap for the treatment of nasopharyngeal stenosis in a cat

A three-and-a-half-year-old male neutered domestic short-haired cat was presented with a three-year history of stertor and intermittent open-mouth breathing. No airflow was detected from either nostril when checked using a cold slide test. Oropharyngeal swabs were positive for calicivirus, while skull radiographs were suggestive of a dorsal deviation of the soft palate. The diagnosis of nasopharyngeal stenosis was confirmed via cannulation of the nasal passages and direct examination of the oropharynx under general anaesthesia. A midline approach through the soft palate was used to excise the adhesions. The resulting defect was reconstructed by advancement of a mucosal flap elevated from the dorsal nasopharynx and laryngopharynx. The cat was free of clinical signs 28 months later.     

Radial carpal bone fractures in 15 dogs

Between 1977 and 1992, 15 adult dogs were presented to the Universities of Bristol, Glasgow, Liverpool and London with fractures of the radial carpal bone which had occurred without a known episode of violent trauma. Eleven of the dogs were boxers and the other breeds affected were a Pharaoh hound, rottweiler, springer spaniel and a greyhound. The condition was bilateral in three cases. Eleven dogs were treated surgically by cast immobilisation (four cases), fragment removal (one case), lag screw fixation (three cases), pan-carpal arthrodesis (one case) and lag screw reduction followed by pan-carpal arthrodesis (two cases). The remaining four dogs were treated conservatively with rest and tactical use of non-steroidal anti-inflammatory drugs. Follow-up periods ranged from two months to 11 years. Varying degrees of lameness, which tended to be exacerbated by exercise, persisted in all cases. The radial carpal bone appears to have at least three separate centres of ossification which eventually fuse; their planes of fusion correspond approximately to the two main fracture lines. These areas of fusion could be weak points within the radial carpal bone.     

Every man his own farrier in Australia: the origins and growth of a veterinary business in colonial New South Wales

The life and work is told of John Pottie (1832-1908), a Scotsman who graduated from Edinburgh Veterinary College in 1858. A year later, he contracted to provide veterinary care to a consignment of horses bound for Australia. Once there, he founded a firm that has survived to the present day, still marketing products that originated in his own veterinary remedies. John Pottie brought with him a European tradition of livestock care and treatment that was epitomised in Clater's title and book, Every man his own farrier. His career is of interest for several reasons. Firstly it is because he used this tradition to launch a business enterprise in a new and different market in Australia. Secondly, although his training lay in what may be termed the pre-scientific era of the profession's history, he was able to adapt old traditions successfully to the changes that came in the age of Pasteur and Koch. Finally, the manner in which he did this, besides demonstrating his business acumen, also shows how the professional veterinary qualification gained in value in a new age of science.     

Pythiosis with bone lesions in a pregnant mare

A 9-year-old pregnant mare was referred for evaluation of a nonhealing wound of 8 weeks' duration on the lateral aspect of the left forelimb. A soft tissue mass encircled the proximal two thirds of the metacarpus; radiography revealed a moderate periosteal reaction affecting metacarpal bone i.v. Histologic and immunohistochemical examinations revealed eosinophilic granulomatous inflammation and Pythium sp in the soft tissues. The mare was treated for 12 days with antimicrobials, medicated wound dressings, debridement, and i.v. administration of sodium iodide; radiography revealed progression of the bone lesions. The mare was treated by regional arterial perfusion with miconazole and excision of affected soft tissues and the distal two thirds of metacarpal bone i.v. The mare recovered without complications and gave birth to a healthy foal. Regional perfusion of antifungal agents provides high concentrations in soft and osseous tissues and permits use of low dosages of agents administered by other routes, which reduces cost, adverse effects, and teratogenic effects.