Prevention and treatment of gastrointestinal adhesions.

As with many aspects of clinical medicine, there is yet to be a single or definitive cure for postoperative adhesion formation. Current methods of prevention target risk factors predisposing horses to adhesion formation. Systemic pharmacologic therapies, such as antimicrobials, nonsteroidal anti-inflammatory drugs, Salmonella antiserum, and hyperimmune plasma, help to reduce abdominal inflammation and minimize the effects of endotoxemia. Intra-abdominal or systemic heparin aids in enhancing peritoneal fibrinolysis. Prokinetic therapy promotes early postoperative return of intestinal motility, minimizing the propensity for adhesion formation between apposing adynamic segments of intestine. Mechanical separation of potentially adhesiogenic serosal and peritoneal surfaces is commonly achieved with use of abdominal lavage, protective coating solutions, and barrier membranes. Ongoing and future research is directed toward a better understanding of the local effects of intestinal trauma and the corresponding response of the fibrinolytic system. Recognition of horses at high risk for adhesion formation helps to guide the equine surgeon to an appropriate perioperative and intraoperative plan for adhesion prevention, including good surgical technique and a combination of adjunct therapies.     

Antimicrobial therapy in neonatal foals

There are several differences in treatment of neonatal foals with antimicrobials, compared to mature horses. Firstly, the dose of many antimicrobials is different in the foal. For orally administered drugs, this may also affect their efficacy, due to different enteral absorption. Secondly, neonatal foals are not yet hindgut fermentors and this allows antimicrobials with a high propensity to cause colitis in mature horses to be used. Thirdly, toxicities are different and some antimicrobials used in mature horses, such as enrofloxacin, are not suitable for use in foals. Foal-specific information is therefore needed for their safe and effective treatment with antimicrobials.     

Antimicrobial use in the surgical patient.

Antimicrobials are often used in the surgical patient in an effort to prevent infection (prophylactic) or to treat established infection (therapeutic). To be effective, prophylactic antimicrobials at appropriate concentrations must be present in tissues at the surgical site at the time of contamination to prevent bacterial growth and subsequent infection. Therapeutic antimicrobials are used to treat established localized or systemic infection. Selection of antimicrobial agents for prophylactic or therapeutic use should be based on knowledge of expected flora, ability of the antimicrobial to reach the target tissue at appropriate concentrations, bacterial resistance patterns, drug pharmacokinetics, and culture and susceptibility testing results (therapeutic use). Failure of antimicrobial therapy to prevent or treat infection in the surgical patient may result from poor antimicrobial selection, inappropriate dosage or frequency, or inappropriate duration of therapy.     

Evaluation of Specific Infection Control Practices Used by Companion Animal Veterinarians in Community Veterinary Practices in Southern Ontario

This study evaluated specific infection control practices in community veterinary practices in southern Ontario. Environmental disinfection, management of infectious patients and antimicrobial use in clean surgical procedures were investigated. Community companion animal veterinary practices (n = 101) in Southern Ontario were recruited, and a questionnaire was administered to one veterinarian and one veterinary technician from each practice. The veterinarian questionnaire gathered data on clinic demographics, management of infectious patients, infectious diseases of concern, environmental disinfection and antimicrobial use in surgical procedures. The veterinary technician questionnaire gathered data on environmental disinfection. None of the veterinary practices had a formal infection control programme. Sixty‐five per cent (n = 66) of the veterinary practices did not have an isolation area and 61% (n = 40) of these practices did not employ any specific infection control measures for infectious cases. The products most frequently used for environmental disinfection were hydrogen peroxide based or quaternary ammonium compounds. Bleach was the agent most commonly used for environmental disinfection of infectious body fluids; however 60% of the veterinarians and 40% of the veterinary technicians did not identify a product for environmental disinfection of infectious body fluids. Twenty‐four per cent of the veterinarians reported using antimicrobials in animals undergoing elective sterilization surgeries and 60% reported using antimicrobials in other clean surgical procedures. There is a need for community veterinary practices to develop infection control programmes specific to their individual practice. In addition, veterinarians should discontinue the common use of antimicrobials for clean elective sterilization surgical procedures.     

Surgical procedures for glaucoma: what the general practitioner needs to know

Glaucoma can be treated by medical and surgical options. Most ophthalmologists believe that patients with glaucoma are best treated with surgery. Early recognition of clinical signs and selection of the most effective type of surgery depending on the stage of glaucoma and the underlying cause are important factors in glaucoma surgery. Several surgical procedures exist for dogs with primary glaucoma, which may include a cyclodestructive technique or an aqueous outflow bypass procedure or a combination of both procedures. Salvage procedures such as enucleation, evisceration with an intrascleral prosthesis, or chemical intravitreal injection may be advised for chronically blind eyes with no hope of vision. Client compliance and expectations, therapeutic goals, status of vision (visual versus blind), financial constraints, surgical expertise, and underlying systemic disorders should be considered in the selection of the most appropriate surgical option for each patient.     

Bacterial septic arthritis in 19 dogs

OBJECTIVE: To provide information on the clinical features, diagnosis and treatment of bacterial septic arthritis in dogs. DESIGN: A retrospective study examining case records of all dogs diagnosed with bacterial septic arthritis at Murdoch University Veterinary Hospital between 1988 and 1997. RESULTS: Nineteen dogs were diagnosed with bacterial septic arthritis, which most commonly occurred after surgery involving the stifle joint. Haematogenous infection occurred in only five dogs. Diagnosis was based on clinical signs, joint fluid analysis, radiography, microbiology and/or response to treatment. Chronic lameness was the most common problem at presentation. Analysis of joint fluid invariably revealed large number of nucleated cells, which consisted primarily of neutrophils. In all but one case the neutrophils were nondegenerate. Culture of joint fluid was frequently successful. Staphylococcus spp were the most common bacteria isolated. Treatment involved antimicrobial drugs only in five dogs. Other dogs received antimicrobial drugs in combination with surgical procedures such as joint lavage and removal of nonabsorbable suture material (eight), arthrodesis (two) or amputation (one). Two dogs were euthanased. Most dogs responded well to treatment and were free of signs of septic arthritis at follow-up. CONCLUSION: Bacterial septic arthritis may often be mild and manifest as chronic lameness. Analysis of joint fluid will detect an inflammatory arthropathy but the presence of toxic neutrophils should not be relied on as an indicator of sepsis. Culture of infected joint fluid is likely to be successful if antimicrobials are not given prior to collection and if the sample is inoculated into enrichment broth. Treatment should involve antimicrobial drugs, open-joint lavage and removal of joint prostheses if the infection is associated with previous surgery.     

The treatment of diarrhoea in the adult horse

The priority in treating the equine patient with acute diarrhoea is to stabilise the haemodynamic aberrations secondary to the fluid and electrolyte losses. Once this has been initiated and the patient is stabilised ancillary treatments may be beneficial. Besides the well established effects of NSAIDs and polymixin B on systemic inflammation, recent studies suggest that the use of DTOS to bind bacterial toxins and Saccharomyces boulardii to reduce the severity and duration of diarrhoea may be beneficial. The justification for using probiotic products is scant. There is no evidence to suggest that systemic use of antimicrobials benefits equine patients with colitis, with the exception of metronidazole in cases of clostridial diarrhoea. In light of their potentially detrimental effects, their use can, in the opinion of the authors, not be advocated. Better understanding of the pathways of systemic inflammation and more selective anti‐inflammatory drugs may be of great benefit in the future.     

The welfare significance of the castration of cattle: A review

Castration is an ancient husbandry procedure used to produce docile cattle for draught work, to reduce unwanted breeding, and to modify carcass quality. All the physical methods used to castrate cattle have side-effects and cause pain. The plasma cortisol response to castration using Burdizzo clamps and, by inference, the acute pain experienced, is less than that caused by surgical, rubber-ring or latex-band castration. The cortisol response may be influenced by the age of the animal castrated, but this has not been well defined. Local anaesthesia virtually eliminates the cortisol response, and thus the acute pain, caused by rubber-ring or latex-band castration, but needs to be combined with a systemic analgesic such as the non-steroidal anti-inflammatory drug ketoprofen to eliminate the cortisol response to Burdizzo or surgical castration. When used alone, ketoprofen sometimes reduces the cortisol response to Burdizzo or surgical castration but may need to be accompanied by local anaesthesia to eliminate the pain-induced behaviour seen during the castration process itself. Thus, pharmacological methods are available to virtually eliminate the acute pain experienced by calves during the 12 h following castration. The use of these methods is an additional cost for farmers and may be limited by the availability of drugs for farmers to use and the scarcity of veterinarians in farm animal practice.     

The welfare significance of the castration of cattle: a review

Castration is an ancient husbandry procedure used to produce docile cattle for draught work, to reduce unwanted breeding, and to modify carcass quality. All the physical methods used to castrate cattle have side-effects and cause pain. The plasma cortisol response to castration using Burdizzo clamps and, by inference, the acute pain experienced, is less than that caused by surgical, rubber-ring or latex-band castration. The cortisol response may be influenced by the age of the animal castrated, but this has not been well defined. Local anaesthesia virtually eliminates the cortisol response, and thus the acute pain, caused by rubber-ring or latex-band castration, but needs to be combined with a systemic analgesic such as the non-steroidal anti-inflammatory drug ketoprofen to eliminate the cortisol response to Burdizzo or surgical castration. When used alone, ketoprofen sometimes reduces the cortisol response to Burdizzo or surgical castration but may need to be accompanied by local anaesthesia to eliminate the pain-induced behaviour seen during the castration process itself. Thus, pharmacological methods are available to virtually eliminate the acute pain experienced by calves during the 12 h following castration. The use of these methods is an additional cost for farmers and may be limited by the availability of drugs for farmers to use and the scarcity of veterinarians in farm animal practice.     

Analgesia and sedation in the critically ill

Objective: To summarize the challenges to recognizing pain in critically ill patients, the rationale for treatment even in the absence of signs of pain, and the therapeutic options available in the intensive care environment. Etiology: Pain is one of many stressors challenging the critically ill patient, and may in turn be multifactorial in nature. Common causes include local and systemic inflammation, injuries, diagnostic and therapeutic procedures, immobilization, and thrombosis. Diagnosis: Critically ill animals with pain may not demonstrate overt behavioral or physiologic signs of distress. Therefore, pain must be assumed to be present for animals whose condition puts them at risk. Therapy: Currently available analgesic and sedative drugs and methods of delivery are described. Several useful analgesics and sedatives may be co‐administered as fluid additives to provide continuous therapy. Prognosis: There is growing evidence that the neuroendocrine stress response to severe injury or illness may become sufficiently intense to contribute to morbidity and mortality. Many therapeutic analgesic and sedation options provide good control of pain and stress, and in some circumstances this may improve the outcome of critical illness.     

Pancytopenia caused by bone marrow aplasia in a horse

Pancytopenia was evaluated in a mature Quarter Horse gelding. A diagnosis of bone marrow aplasia was made on the basis of bone marrow hypocellularity. History of drugs administered included penicillin, oxytetracycline, trimethoprim-sulfadiazine, phenylbutazone, dipyrone, flunixin meglumine, and isoxsuprine. Clinical remission was observed after treatment with glucocorticoids, androgens, and broad-spectrum antimicrobials.     

Nonsteroidal anti-inflammatory drugs in veterinary ophthalmology.

Uveitis is a common sequela to many ocular diseases. Primary treatment goals for uveitis should be to halt inflammation, prevent or control complications caused by inflammation, relieve pain, and preserve vision.Systemic and topical NSAIDs are essential components of the pharmaceutic armamentarium currently employed in the management of ocular inflammation by general practitioners and veterinary ophthalmologists worldwide. NSAIDs effectively prevent intraoperative miosis; control postoperative pain and inflammation after intraocular procedures, thus optimizing surgical outcome; control symptoms of allergic conjunctivitis;alleviate pain from various causes of uveitis; and circumvent some of the unwanted side effects that occur with corticosteroid treatment. Systemic NSAID therapy is necessary to treat posterior uveitis, because therapeutic concentrations cannot be attained in the retina and choroid with topical administration alone, and is warranted when diseases, such as diabetes mellitus or systemic infection, preclude the use of systemic corticosteroids.Risk factors have been identified with systemic and topical administration of NSAIDs. In general, ophthalmic NSAIDs may be used safely with other ophthalmic pharmaceutics; however, concurrent use of drugs known to affect the corneal epithelium adversely, such as gentamicin, may lead to increased corneal penetration of the NSAID. The concurrent use of NSAIDs with topical corticosteroids in the face of significant preexisting corneal inflammation has been identified as a risk factor in precipitating corneal erosions and melts in people and should be undertaken with caution[8]. Clinicians should remain vigilant in their screening of ophthalmic and systemic complications secondary to drug therapy and educate owners accordingly. If a sudden increase in patient ocular pain (as manifested by an increase in blepharospasm, photophobia, ocular discharge, or rubbing)is noted, owners should be instructed to contact their veterinarian promptly.     

Update on canine and feline fungal diseases.

Systemic fungal diseases cause significant morbidity and mortality in dogs and cats. Blastomycosis, histoplasmosis, coccidiomycosis, and cryptococcosis represent the four most common systemic fungal diseases. Young adult, large breed dogs generally are predisposed; cats usually do not have predictable predispositions. Intact cell-mediated immunity is essential to initial resistance to infection and response to treatment in animals. Several body systems can be affected. Diagnosis can be confirmed on the basis of clinical signs and demonstration of the causative organism. Serology is helpful with coccidiomycosis and cryptococcosis. Treatment is complicated by limited availability of fungicidal antimicrobials and the necessity of long-term treatment with expensive drugs.     

Anesthetic Considerations for Amphibians

The popularity of amphibians in research, zoological exhibits, and as pets is on the rise. With this increased popularity comes a need for veterinarians to develop methods for managing these animals for various diagnostic and surgical procedures. For many of these procedures, the provision of anesthesia is a must. Fortunately, there are a number of different anesthetics available to the veterinary clinician for anesthetizing amphibians, including tricaine methanesulfonate, clove oil, propofol, isoflurane, and ketamine. In addition to the variety of anesthetics at our disposal, there is also a wider range of methods for delivering the anesthetics than are generally available for higher vertebrates, including immersion, topical, and intracoelomic routes of delivery. The purpose of this article is to review the different methods that can be used to successfully manage an amphibian patient through an anesthetic event.     

Nocardiosis

Two dogs with systemic nocardiosis are presented and the pathobiology, diagnosis, and treatment of nocardial infections are discussed. Both dogs had nonspecific respiratory signs and depression. The diagnosis was made by isolation of the organism only after surgical drainage was established and appropriate tissues were cultured. The response to surgical drainage and antimicrobial therapy was dramatic in both dogs, but one dog experienced a drug reaction to trimethoprim-potentiated sulfonamide. Although systemic nocardial infections traditionally have had a grave prognosis, through early diagnosis, surgical intervention, and the use of newer, safer and synergistically acting antimicrobials, the prognosis has improved. This article reviews current human and veterinary literature regarding the microbiology, pathogenesis, and treatment of nocardiosis and reports on the successful treatment of systemic nocardiosis in two dogs.     

Multi-drug-resistant Enterococcus spp. as a cause of non-responsive septic synovitis in three horses

Abstract

CASE HISTORY: Three Thoroughbred horses, a 6-week-old filly (Case 1), a 15-year-old broodmare (Case 2) and a yearling filly (Case 3), sustained synovial sepsis secondary to trauma.

CLINICAL FINDINGS: Case 1 presented with a heel bulb laceration communicating with the distal interphalangeal joint. Arthroscopic lavage was performed and treatment commenced using systemic and local broad spectrum antimicrobial drugs. A pure growth of multi-drug-resistant (MDR) Enterococcus gallinarum was cultured from samples of synovium and joint fluid. Antimicrobial treatment was changed according to the susceptibility results. Response to treatment was poor and despite repeat arthroscopic lavage and intra-osseous regional perfusion of antimicrobials the filly was subject to euthanasia 24 days after the initial injury. Post-mortem examination confirmed septic synovitis, cartilage degeneration and osteomyelitis.

Case 2 sustained a full thickness wound to the carpus which was sharply debrided and closed. The wound dehisced with effusion within the tendon sheath. Drainage was established and treatment included systemic broad spectrum antimicrobials, topical lavage with povodine-iodine and manuka honey infusion. A mixed infection including MDR Enterococcus faecalis was cultured from the synovial fluid. Antebrachiocarpal joint effusion developed 21 days after initial injury and joint sepsis was confirmed. Arthroscopic lavage and tendon sheath debridement were performed, followed by treatment with systemic and local antimicrobials. The mare improved and was discharged. Three months later lameness recurred and corticosteroids were administered intra-articularly. The mare became non-weight bearing lame and was subject to euthanasia. Post-mortem examination confirmed joint sepsis of the antebrachiocarpal and intercarpal joint.

Case 3 presented with a complete articular open fracture of the tibial crest. Under general anaesthesia the fracture was stabilised and the wounds debrided and closed. Systemic broad-spectrum antimicrobials were administered. Six days later the wound dehisced and a bone fragment was removed. Three weeks post-surgery the wound deteriorated with a purulent discharge. Culture of the discharge revealed a mixed bacterial infection, including a MDR Enterococcus faecalis. Femoropatellar joint involvement was confirmed, and treatment included joint lavage, local and systemic antibiosis, and manuka honey instilled into the wound. The filly initially improved, and then deteriorated such that euthanasia was performed.

DIAGNOSIS: All three cases had synovial sepsis with MDR Enterococcus spp.

CLINICAL RELEVANCE: Increased awareness of MDR pathogens in equine wound infections is essential. Prompt diagnostic testing, appropriate therapy, infection control strategies and on-going monitoring and management are vital to limit the clinical impact of these organisms.     

Osteoarticular Allogeneic Bone Grafting in Dogs

A review of the clinical and pathologic evaluation of allogeneic bone grafts is presented with particular emphasis upon partial joint replacement. The histologic evaluation of cortical bone transplantation is reviewed. Radiographic evaluation of cortical bone transplants is presented in an attempt to understand the normal events that take place in incorporation of the graft by the host. The histologic and radiographic correlation is related to the healing process. Current methods of graft collection and storage are reviewed. While collection of the graft is fairly uniform, there are many varied treatment and storage procedures. General surgical procedures used in performing full cortical bone grafts are reviewed. The clinical use of an osteoarticular allogeneic bone graft in the elbow of a dog is presented, with a review of the operative and postoperative evaluation of the clinical patient.     

Responsible antimicrobial use in critically ill adult horses

Due to increasing antimicrobial resistance, pressure on veterinarians is mounting to adhere to responsible use of antimicrobial drugs. Antimicrobials are frequently included in the treatment of systemically ill horses due to the strong likelihood of an infection and the innate difficulties in differentiating systemic inflammation secondary to noninfectious from infectious causes. In light of increasing antimicrobial drug resistance and the potential negative impact of antimicrobials on equine patients, every attempt should be made to identify noninfectious disease, choose first-line antimicrobials and discontinue treatment as soon as possible. In most cases, a short duration of antimicrobial therapy ranging from a single dose (e.g. preoperatively) to 24–72 h might be sufficient with long-term treatment being rarely required. This article aims to provide practical guidelines for antimicrobial drug usage in critically ill adult horses by describing ancillary diagnostic aids that can help establishing whether or not an infection is present, discussing commonly encountered pathogens and their typical antimicrobial drug sensitivity patterns, and providing some guidance how to safely shorten the duration of antimicrobial therapy.     

Treatment of a metallic foreign body in the cranial cervical region of a horse

Ingestion of foreign bodies is uncommon in horses when compared with indiscriminate grazers such as cattle. This case report describes the diagnosis and treatment of a cervical abscess in a Thoroughbred racehorse thought to be associated with ingestion of wire. Radiographic and ultrasonographic examination provided a diagnosis, and conservative treatment of the lesion with antimicrobials initially allowed the lesion to localise closer to the skin for safer surgical exploration. Intra-operative ultrasonographic imaging facilitated surgical access, removal of the foreign body, and drainage. While surgical treatment is usually necessary to resolve an abscess, initially conservative therapy may help to improve the prognosis by simplifying surgical access and reducing the risk of surgical complications.