Aetiology of Bovine Abortion in Argentina

Necropsies were performed on 354 fetuses from dairy and beef herds submitted from 1994 to 2000 to the diagnostic laboratories at Instituto Nacional de Tecnología Agropecuaria, Balcarce, Argentina. Samples from the fetuses were examined for pathogenic organisms and processed for microscopic examination. An aetiological diagnosis was made for 161 (45.5%) of the fetuses. No diagnosis was made for 193 (54.5%) fetuses. Infectious agents were isolated from 122 (34.4%) of the fetuses, bacterial agents being involved in 80 (22.6%) of these. The most common bacterial agents isolated from the fetuses were Brucella abortus in 28 fetuses, Campylobacter fetus in 26 cases, and Escherichia coli in 9 cases. Bovine herpesvirus and bovine viral diarrhoea virus were found in 9 and 6 cases, respectively. Neospora caninum was detected by an immunohistochemical technique in 26 cases (7.3%). Congenital abnormalities, dystocia and mummifications were found in 8, 19 and 11 cases, respectively.     

The control of Streptococcus agalactiae mastitis by milking-shed hygiene,with particular reference to hibitane: A preliminary report

Extract

Since the advent of antibiotics, in particular penicillin, a great deal of experimental and field work on the control of Streptococcus agalactiae mastitis by these agents has been reported. The fact remains, however, that the incidence of mastitis seems as high as ever despite the marked advance in the treatment of clinical cases. This has led to the somewhat paradoxical situation where, on some dairy farms, more money is now being spent on penicillin than used to be lost through having to cull for mastitis or through the loss of quarters following infection.     

P‐81 A retrospective study of equine sarcoidosis

The purpose of this retrospective study was to evaluate six cases of equine sarcoidosis for initial presenting symptoms, response to therapy and actual outcome. Dermatologists and dermatopathologists from Europe, the United States, Australia and Canada were contacted to obtain these six cases, as this is a rare disease. Signalment, clinical signs, histological findings, clinical management and outcome were determined via a questionnaire and compared to former reports. There was no age or breed predilection, and four of six horses were geldings. Age of onset ranged from 3 months to 17 years. Onset of the disease was insidious or rapid. Interestingly, in five of six cases, scaling began on the trunk (girth and shoulder). Scaling, crusting and alopecia were seen in all six horses. In one horse, clinical signs of systemic disease were reported and included intermittent fever, prescapular lymphadenopathy, depression, poor body condition and nasal discharge. Treatment included phenylbutazone, deworming agents, antibiotics, short‐term low‐dose corticosteroids, and 1–1.5 mg/kg of prednisolone. One horse showed a partial response to trimethoprim and sulfonamide, and five of six went into clinical remission with corticosteroid treatment. Five of six horses were still alive 1 year after diagnosis; one horse was diagnosed <12 months ago. Two horses are in complete remission 4 and 8 years after diagnosis. In both horses, clinical signs recurred after cessation of therapy and went into remission again with reintroduction of treatment. Both of these horses have been in remission for several years without therapy. Funding: Self‐funded.     

In vitro antimicrobial activity of miconazole and polymyxin B against canine meticillin-resistant Staphylococcus aureus and meticillin-resistant Staphylococcus pseudintermedius isolates

Background – Meticillin‐resistant Staphylococcus aureus (MRSA) and meticillin‐resistant Staphylococcus pseudintermedius (MRSP) infections are increasingly reported in dogs, and these bacteria may be isolated from ear infections. Hypothesis/Objectives – The main aim of the present study was to investigate the in vitro antimicrobial activity of miconazole, polymyxin B and a combination of both against 24 canine MRSA and 50 canine MRSP isolates. The minimal inhibitory concentration (MIC) values of 12 other antimicrobial agents were also determined. Methods – All MIC values were determined according to a broth microdilution assay. Results – Acquired resistance was found to all tested agents, except for linezolid, miconazole and polymyxin B. The MIC values for miconazole and polymyxin B against MRSA were in the range of 4–8 and 8–64 μg/mL, respectively, while the MIC values for miconazole and polymyxin B against MRSP were in the range of 1–2 and 0.25–4 μg/mL, respectively. Using a combination of miconazole and polymyxin B, there was no evidence for enhanced in vitro activity of the combination (i.e. synergy) of both products. Nevertheless, MIC₉₀ values of the combination of these antimicrobial agents and of a commercial product containing both agents were at least 1000 times lower than the concentration present in the commercial product. Conclusions and clinical importance – These results indicate that the topical use of a combination of miconazole and polymyxin B in a 43.5:1 ratio may have potential for the treatment of MRSA‐mediated and MRSP‐associated otitis externa in dogs.     

FC‐45 Mites as newly emerging disease pathogens in rodents and human beings

Different mite species generally found on animals may temporarily also infest humans. Consequently, these arthropods may be responsible for pruritic skin reactions that are often misdiagnosed. Mite dermatitis caused by the tropical rat mite Ornithonyssus bacoti occurs in several small mammals and rodents under tropical and temperate climatic conditions. According to various observations in Germany, O. bacoti appears in wild rodents more frequently than previously thought. In most cases, symptoms of mites are recognized only when they attack humans, but the diagnosis of rat mite dermatitis requires identification of the parasite, which is more likely to be found in the environment than on the hosts’ skin itself. Here, five different outbreaks from Bavaria are reported. A clinical example is the case of a 23‐year‐old medical student and several other residents inhabiting a rat‐ and mouse‐infested house in Munich. The arthropods originally came from an Italian restaurant and surrounding facilities. Mites were found in large numbers in the students’ flat. The patient was suffering from severe itching and papular urticaria. He consulted a dermatology clinic complaining of a pruritic dermatitis of 2‐weeks duration. Dermatitis was misdiagnosed as allergy and treatment with an anti‐inflammatory agent was unsuccessful. Eradication of rodents and treatment of the house with a pyrethroid were performed to prevent reinfestation. Ornithonyssus bacoti is a periodic haematophageous parasite and spends a relatively short time on the host. Causal therapy with antiparasitic agents on human patients is not necessary. If indicated, treatment should be symptomatic. Funding: Self‐funded.     

Principles of chemotherapy

Chemotherapeutic agents can be used to increase both the length and the quality of the lives of patients with a wide variety of neoplastic diseases. The therapeutic index for many of these agents is very narrow; thus, close attention must be paid to proper dosing and timing of treatment. Proper patient selection is also critical for successful chemotherapy treatment. If the clinician is familiar with the agents being used, then toxicities can often be anticipated and then treated, or in some cases prevented, to ensure continued quality of life. The purpose of this article is to review the basic principles for the safe and effective use of various chemotherapeutic agents in the treatment of neoplastic diseases.     

Chemotherapy of T b brucei infection: Use of DFMO, diminazene aceturate, alone and in combination

The therapeutic activity of diminazene aceturate, difluoromethylornithine (DFMO) and a combination of the two agents was investigated in experimental Trypanosoma brucei brucei infections in mongrel dogs. The criteria used in the assessment of the trypanocidal effect of these compounds included the examination of the blood for the parasite, as well as clinical and haematological changes at intervals following treatment. Diminazene aceturate (7 mg/kg intramuscularly), DFMO (300 mg/kg/day orally in three divided doses for six days) and the combination of diminazene aceturate (7 mg/kg intramuscularly) and DFMO (300 mg/kg/day orally for six days) produced an intermittent aparasitemia in the dogs. Relapse infection occurred in all the three groups, but the period of aparasitemia produced by the combination of the agents was longest. The packed cell volume, haemoglobin concentration and red cell count values decreased after the dogs were inoculated with the parasite. The values improved slightly following the treatments with the agents or their combination. The total white blood cell counts in the infected dogs indicated leucocytosis, but this improved with drug treatment.     

Type 2 diabetes mellitus with pancreatic β cell dysfunction in 3 horses confirmed with minimal model analysis

Reasons for performing study: Type 2 diabetes mellitus (T2DM) is diagnosed rarely in equine practice although it may be under‐recognised. A greater awareness of the condition and therapeutic considerations would be to the benefit of such cases presenting in practice. More investigation into the pharmacological management of these cases is needed. Objectives: Three cases of diabetes mellitus were investigated using a specific test for insulin sensitivity and pancreatic β cell function in order to define accurately and characterise the existence of T2DM in all 3 subjects. Methods: The insulin‐modified frequently sampled i.v. glucose tolerance test was performed in each case and the data so obtained were subject to minimal model analysis of insulin‐glucose dynamics. Cases were then monitored following treatment using a combination of dietary modification, metformin, glibenclamide and pergolide. Results: Marked insulin resistance was identified in each case and, furthermore, severe pancreatic β cell dysfunction was present therefore classifying each case as end stage T2DM. Treatment was nevertheless associated with restoration of normoglycaemia in all cases. Conclusions: T2DM in horses may be more common than generally considered. In some cases individuals may respond to therapy aimed at restoring insulin sensitivity and pancreatic function. Drugs used in other species for the treatment of T2DM have not yet been adequately tested in horses. Potential relevance: T2DM should be considered as an important differential diagnosis in mature to elderly horses and ponies suffering from weight loss, polydipsia and polyuria. Clinicians should be encouraged to offer treatment and management advice when such cases are encountered.     

Enteric infections in veal calves: A longitudinal study on four veal calf units

Summary

Forty‐five calves on four veal calf units were monitored during the first four weeks after their arrival. Faecal samples were collected on alternate days and screened for the presence of rotaviruses, bovine coronavirus, Cryptosporidium oocysts, K99 positive strains of E. coli and Salmonella spp. Rotaviruses and Cryptosporidium were the most commonly detected agents (78% and 60% respectively of the calves). Bovine coronavirus was detected in the faeces of 18% of the calves, whilst K99 positive E. coli was only found in 2 samples from one calf. Salmonella spp. were not isolated from any of the 646 faecal samples examined. Shedding of rotaviruses occurred in a bimodal pattern beginning in the first week of the survey. Cryptosporidium oocysts were detected most frequently in the interval between the two peaks of rotavirus shedding. The presence of rotaviruses or Cryptosporidium oocysts in faeces was not strongly associated with scour, nor were combined infections with these agents or the cases of bovine coronavirus infection. The condition of the calves throughout the survey was generally satisfactory.     

Haemobartonella canis (Kiküth, 1928) in the blood of dogs with parvovirus disease

In the Tours area of the Val-de Loire, haemograms carried out in 40 dogs with canine parvovirus disease showed that in 30 cases the viral infection was complicated by canine haemobartonellosis. To the picture, typical of the former infection, were added very severe anaemia, fever, locomotor difficulties, arthralgia, adenopathy, respiratory difficulties (dyspnoea, polypnoea and anoxia) and circulatory disorders (tachycardia and capillary fragility). The blood picture was markedly abnormal, anisocytosis, poikilocytosis and anisochromia, being found together with alterations in the blood counts (neutrophils 85 to 90% high; leucocytes, 400 to 500 mm3; erythrocytes, 0·6 to 1·5 × 10⁶ mm³). Symptomatic treatment and serotherapy (equine hyperimmune serum against feline panleucopenia) were given for the parvovirus infection. Of the antimicrobial agents, only chloramphenicol, a spiramycin metronidazole association and sulphamethoxypyridazine gave good results. A high dose of intramuscular chlorpromazine (2 to 4 mg/kg b.w.) repeated 48 h later, followed by an 8-day course of oral treatment at a moderate dosage (1 mg/kg b.w. daily) produced complete clinical cure and disappearance of Haemobartonella canis from the peripheral blood. It is considered that these results support the view that an intercurrent infection may upset the balance existing between the host and parasite in carriers of H. canis and produce a virulent infection (see Fig. 1).     

A review of topical therapy for skin infections with bacteria and yeast

Background – Cutaneous infections with bacteria and yeasts are common in small animal practice. Treatment with systemic antibiotics or antifungal agents may not be ideal, because of the increasing development of multiresistant organisms, the cost and the possible adverse effects. Topical antimicrobials may be used as adjunctive therapy to systemic treatment or as sole therapy instead of systemic treatment. Objective – This literature review evaluated studies on topical antimicrobial treatment of skin infections. Methods – In vitro and in vivo studies evaluating topical antimicrobial agents were identified using a number of electronic and manual searches of textbooks and articles. Studies were evaluated, and the evidence for or against the use of the topical agents was extracted. Results – There is good evidence for the efficacy of chlorhexidine and, to a lesser degree, benzoyl peroxide in canine bacterial skin infections. There is limited evidence for the efficacy of silver sulfadiazine and medical honey against bacterial skin infections in the dog, and for the efficacy of hydrogen peroxide and stannous fluoride in the horse. Good evidence supports the use of a combination of chlorhexidine and miconazole in dogs with cutaneous Malassezia infections. There is insufficient evidence to recommend any other topical therapy for use in cutaneous infections. Conclusions and clinical importance – Although many antimicrobial topicals are marketed in veterinary dermatology, the efficacy has been reported for only a minority of agents. Randomized controlled trials evaluating various topical treatments are therefore urgently needed.     

Detection of Ureaplasma diversum in the upper airways of Australian feedlot cattle

Bovine respiratory disease (BRD) exerts a major impact on the beef cattle industry nationally and worldwide, with a range of aetiological factors impacting its pathogenesis. Previous research has focussed on an increasing number of bacteria and viruses that have been shown to play a role in eliciting disease. Recently, additional agents have been emerging as potential contributors to BRD, including the opportunistic pathogen Ureaplasma diversum. To determine if U. diversum was present in Australian feedlot cattle and if that presence was linked to BRD, nasal swabs were collected from a cohort of 34 hospital pen animals and compared to 216 apparently healthy animals sampled contemporaneously at feedlot induction and again after 14 days on feed at an Australian feedlot. All samples were subjected to a de novo polymerase chain reaction (PCR) assay targeting U. diversum in combination with other BRD agents. U. diversum was detected at a low prevalence in cattle at induction (Day 0: 6.9%, Day 14: 9.7%), but in a significantly greater proportion of cattle sampled from the hospital pen (58.8%). When considering the presence of other BRD-associated agents, co-detection of U. diversum and Mycoplasma bovis was most common in hospital pen animals receiving treatment for BRD. These findings suggest that U. diversum may be an opportunistic pathogen involved in the aetiology of BRD in Australian feedlot cattle, in combination with other agents, with further studies are warranted to identify if a causal relationship exists.     

Old Friends in New Places: Exploring the Role of Extraintestinal E. coli in Intestinal Disease and Foodborne Illness

The emergence of new antibiotic‐resistant Escherichia coli pathotypes associated with human disease has led to an investigation in terms of the origins of these pathogens. According to the Centers for Disease Control and Prevention, unspecified agents are responsible for 38.4 million of the 48 million (80%) cases of foodborne illnesses each year in the United States. It is hypothesized that environmental E. coli not typically associated with the ability to cause disease in humans could potentially be responsible for some of these cases. In order for an environmental E. coli isolate to have the ability to cause foodborne illness, it must be able to utilize the same attachment and virulence mechanisms utilized by other human pathogenic E. coli. Recent research has shown that many avian pathogenic E. coli (APEC) isolated from poultry harbour attachment and virulence genes also currently found in human pathogenic E. coli isolates. Research also suggests that, in addition to the ability to cause gastrointestinal illnesses, APEC may also be an etiological agent of foodborne urinary tract infections (FUTIs). The purpose of this article was to evaluate the evidence pertaining to the ability of APEC to cause disease in humans, their potential for zoonotic transfer along with discussion on the types of illnesses that may be associated with these pathogens.     

Treatment of oromaxillary fistulae in nine standing horses (2002–2006)

Reasons for performing study: There is minimal published information on equine oromaxillary fistulae that are unrelated to cheek teeth (CT) repulsion or on the conservative treatment of these atypical fistulae. Objectives: To report equine oromaxillary fistulae unrelated to CT extraction and describe their management in standing horses. Methods: Case details of oromaxillary fistulae of atypical aetiology occurring at 2 referral centres between 2002–2006, including their treatment and response to treatment were examined. Results: Nine cases of oromaxillary fistula were recorded, mainly in aged horses (median 22 years). Fistulae were associated with CT diastemata in 7 cases, fractured CT in one and a central defect in a worn CT in another. After removing food and exudate from the sinuses, 6 cases were treated successfully by filling the diastema or dental defect with polymethylmethacrylate (PMMA). Following dental extraction, the other 3 cases were treated successfully by use of PMMA alveolar packing. Conclusion: Older horses can spontaneously develop oromaxillary fistulae, usually secondary to CT diastemata. In the absence of apical infection, this disorder can usually be treated successfully in standing horses by treating the sinusitis and sealing the oral aspect of the diastema with PMMA. Potential relevance: Older horses with sinusitis should be assessed for the presence of CT diastemata and oromaxillary fistulae. If detected, these disorders can be treated successfully in the standing horse.     

Pneumocystis carinii in the miniature dachshund: Case report and literature review

This article reviews Pneumocystis carinii and presents four cases in the miniature dachshund. The cases presented with hyperpnoea, tachy-pnoea and exercise intolerance. There were also clinical signs suggestive of immune incompetence in all the dogs. P carinii pneumonia was diagnosed in all four cases on transtracheal aspirate cytology. Immunological studies showed low globulin levels on serum electrophoresis, decreased lymphoblast transformation response (in the two cases that were tested) and a deficiency of immunoglobulins A, G and M. Light and electron microscopy as well as anti-canine immunoglobulin G immunoperoxidase staining studies were performed on one case which had died because of the disease. From these four cases, it appears that P carinii pneumonia in the miniature dachshund may be the result of an immunodeficiency. It does not, however, appear to be a classic primary severe combined immunodeficiency syndrome as the dogs appeared to respond to treatment, did not show growth failure and did not manifest overwhelming commensurate bacterial infections.     

Prevalence and Antimicrobial Resistance of Salmonella spp. in Non‐diarrhoeic Dogs in Trinidad

The estimated prevalence and antimicrobial resistances of Salmonella spp. in non‐diarrhoeic dogs across Trinidad was determined. The serotypes of Salmonella spp. isolated were also identified. Of a total of 1391 dogs sampled, 50 (3.6%) were positive for Salmonella spp. with 28 different serotypes, the predominant serotypes were Javiana (12), Newport (6), Arechavaleta (5) and Heidelberg (5). Fifty‐seven (85.1%) of 67 isolates exhibited resistance to one or more antimicrobial agents. Of eight antimicrobial agents tested, resistance was exhibited to streptomycin (80.6%), cephalothin (37.3%), neomycin (38.8%) and gentamicin (9.0%). All isolates were sensitive to ampicillin, norfloxacin, choramphenicol and sulphamethoxazole/trimethoprim. It was concluded that the isolation of the Salmonella spp. from non‐diarrhoeic dogs could pose health hazard to their owners as most serotypes are known to be virulent. Furthermore, the prevalence of resistance to antimicrobial agents amongst the Salmonella isolates from these animals indicates susceptibility testing may influence chemotherapeutic choices when treating these isolates.     

A new aid to the diagnosis of Vibrio foetus infection in cattle

This paper describes poisonings that occurred when two cows were fed, small quantities of minced white clover per rumen fistulam over a two-hour period. One animal died; the other survived following treatment with a specific antidote. The level of cyanide found in the leaf material was 200 /g greentissue. It seemsclear from calculations based on this result that the intake of glucosides was sufficient to account for the results observed. Aspects of these cases are discussed in relation to findings of other workers. These cases demonstrate the potential dangers of the high levels of cyanogenetic glucosides in N.Z. white clovers.     

Salmonella Infection in Illegally Imported Spur‐Thighed Tortoises (Testudo graeca)

The prevalence of Salmonella infection was determined in a group of spur‐thighed tortoises (Testudo graeca) seized during two smuggling attempts and in a population of captive Hermann’s tortoises (Testudo hermanni) sheltered in a wildlife rescue centre. Salmonella spp. was isolated in 81 of 220 (36.8%) and in 17 of 67 (25.4%) cloacal swabs collected from the T. graeca and T. hermanni tortoises respectively. Overall, a total of 21 different Salmonella serotypes were found. Some of these serotypes are common to terrestrial chelonians while others have never been reported. All cultured serotypes were non‐typhoidal but nonetheless many of these have been previously reported as source of human outbreaks of reptile‐related salmonellosis. Eighty‐two per cent and 5.3% of the isolates were resistant to two and three anti‐microbial agents respectively. However, the isolates were highly susceptible to the anti‐microbials of choice for the treatment of salmonellosis such as cephalosporins and fluoroquinolones. Our findings confirm that tortoises can be considered a reservoir for Salmonella and that care should be employed when handling and breeding these animals. Tight surveillance should be enforced to avoid illegal importation and prevent the trading of live tortoises, carriers of zoonotic pathogens.     

Prevalence and antimicrobial susceptibility of Campylobacter in broiler flocks in Japan

Campylobacter was isolated from 67 (47.2%) of 142 broiler flocks between September 2009 and February 2010. The prevalence of Campylobacter in broiler flocks was significantly lower during January and February than it was from September to December. Campylobacter colonization was more common in flocks that were not provided with a disinfected water supply, which was consistent with the findings of a previous study. The prevalence of antimicrobial drug‐resistant Campylobacter spp. was investigated, and the minimum inhibitory concentrations of eight antimicrobial agents were determined for 122 Campylobacter jejuni isolates and 46 Campylobacter coli isolates from broiler flocks between 2007 and 2010. In this study, 29.5% (36/122) of C. jejuni isolates and 41.3% (19/46) of C. coli isolates were resistant to enrofloxacin (ERFX), whereas all isolates were susceptible to erythromycin. Furthermore, the ERFX‐resistant isolates were tested for susceptibility to other classes of antimicrobial agents, and 55.6% (20/36) of ERFX‐resistant C. jejuni isolates and 47.4% (9/19) of ERFX‐resistant C. coli isolates were resistant to at least one of aminobenzyl penicillin, dihydrostreptomycin and oxytetracycline. To avoid an impact of antimicrobial drug‐resistant Campylobacter spp. on the efficacy of antimicrobial treatment for human campylobacteriosis, prudent use of antimicrobial agents is a requisite. The use of antimicrobial agents should be accompanied by various approaches such as prevention of Campylobacter colonization in broiler flocks with the aim of lowering the occurrence of Campylobacter infection in humans.     

Validating an empiric sulfadiazine–trimethoprim dosage regimen for treatment of Escherichia coli and Staphylococcus delphini infections in mink (Neovison vison)

Antimicrobial agents are used extensively off‐label in mink, as almost no agents are registered for this animal species. Pharmacokinetic (PK) and pharmacodynamic (PD) data are required to determine antimicrobial dosages specifically targeting mink bacterial pathogens. The aims of this study were to assess, in a PKPD framework, the empirical dosage regimen for a combination of trimethoprim (TMP) and sulfadiazine (SDZ) in mink, and secondarily to produce data for future setting of clinical breakpoints. TMP and SDZ PK parameters were obtained experimentally in 22 minks following IV or oral administration of TMP/SDZ (30 mg/kg, i.e. 5 mg/kg TMP and 25 mg/kg SDZ). fAUC/MIC with a target value of 24 hr was selected as the PKPD index predictive of TMP/SDZ efficacy. Using a modeling approach, PKPD cutoffs for TMP and SDZ were determined as 0.062 and 16 mg/L, respectively. By incorporating an anticipated potentiation effect of SDZ on TMP against Escherichia coli and Staphylococcus delphini, the PKPD cutoff of TMP was revised to 0.312 mg/L, which is above the tentative epidemiological cutoffs (TECOFF) for these species. The current empirical TMP/SDZ dosage regimen (30 mg/kg, PO, once daily) therefore appears adequate for treatment of wild‐type E. coli and S. delphini infections in mink.