Seasonality of canine leptospirosis in the United States and Canada and its association with rainfall

A retrospective study was undertaken to describe seasonal patterns of leptospirosis diagnosed at veterinary teaching hospitals in the United States and Canada, and to determine if occurrence of cases (diagnoses) was associated with rainfall. The veterinary medicine database (VMDB) was searched for records of dogs in which a diagnosis of leptospirosis was made, and average monthly rainfall recorded at the city where each hospital is located was calculated from historical data. Time-series analysis was used to identify the variables that best described occurrence of cases of leptospirosis. Three-hundred and forty dogs were diagnosed with leptospirosis at 22 veterinary teaching hospitals between 1983 and 1998. Most cases (n = 184) were diagnosed between August and November during each year of the study. A significant correlation (r = 0.41) was detected between the number of cases of leptospirosis diagnosed and average rainfall recorded 3-months prior to diagnosis. The best-fitting (Akaike's corrected information criterion = 2.01) regression on the leptospirosis case series included cases diagnosed in the previous month and 12-months previously, and rainfall recorded 3 months previously. Leptospirosis has a seasonal distribution (late summer to fall), and rainfall can be used to predict the occurrence of leptospirosis. Leptospirosis can affect the health of dogs seriously and its prevalence is increasing, but the disease is preventable by vaccination.     

Molecular carcinogenesis of canine mammary tumors: news from an old disease

Studies focusing on the molecular basis of canine mammary tumors (CMT) have long been hampered by limited numbers of molecular tools specific to the canine species. The lack of molecular information for CMT has impeded the identification of clinically relevant tumor markers beyond histopathology and the introduction of new therapeutic concepts. Additionally, the potential use for the dog as a model for human breast cancer is debatable until questions are answered regarding cellular origin, mechanisms, and cellular pathways. During the past years, increasing numbers of canine molecular tools have been developed on the genomic, RNA, and protein levels, and an increasing number of studies have shed light on specific aspects of canine carcinogenesis, particularly of the mammary gland. This review summarizes current knowledge on the molecular carcinogenesis of CMT, including the role of specific oncogenes, tumor suppressors, regulators of apoptosis and DNA repair, proliferation indices, adhesion molecules, circulating tumor cells, and mediators of angiogenesis in CMT progression and clinical behavior. Whereas the data available are far from complete, knowledge of molecular pathways has a significant potential to complement and refine the current diagnostic and therapeutic approach to this tumor type. Furthermore, current data show that significant similarities and differences exist between canine and human mammary tumors at the molecular level. Clearly, this is only the beginning of an understanding of the molecular mechanisms of CMT and their application in clinical patient management.     

Infectious canine hepatitis: an "old" disease reemerging in Italy

Four outbreaks of infectious canine hepatitis (ICH) occurring in Italy between 2001 and 2006 are reported. Three outbreaks were observed in animal shelters of southern Italy, whereas a fourth outbreak involved two purebred pups imported from Hungary few days before the onset of clinical symptoms. In all outbreaks canine adenovirus type 1 (CAV-1) was identified by virus isolation and PCR. In three outbreaks, other canine viral pathogens were detected, including canine distemper virus, canine parvovirus or canine coronavirus. The present study shows that CAV-1 is currently circulating in the Italian dog population and that vaccination is still required.     

Oncolytic gene therapy for canine cancers: teaching old dog viruses new tricks

The use of viruses to treat cancer has been studied for decades. With the advancement of molecular biology, viruses have been modified and genetically engineered to optimize their ability to target cancer cells. Canine viruses, such as distemper virus and adenovirus, are being exploited for the treatment of canine cancer as the dog has proven to be a good comparative model for human cancer research and proof of concept investigations. In this review, we introduce the concept of oncolytic viruses and describe some of the preliminary attempts to use oncolytic viruses for the treatment of canine cancer.     

Ovine footrot: new approaches to an old disease

Footrot is a bacterial disease that has substantial economic and welfare impacts in sheep and can be difficult to manage. Research is focussed on reducing the impact that footrot has on farmers and their flocks and better understanding the aetiology of the disease. Key areas of current research include, developing better vaccines, deploying tailored vaccines in a specific and targeted fashion on individual farms, analysing and developing better farm management practices to suit specific sheep farming environments, elucidating the virulence genes and bacterial population dynamics that drive footrot and using genetic testing in combination with selective breeding to produce stock that are more resilient to disease.     

Microscopic detection of Leptospira bacterial organisms in urine sediment from a young dog with leptospirosis and a review of the pathobiology and diagnosis of canine leptospirosis

Samples collected from an 11-month-old Dachshund-mix dog with a history of acute azotemia, fever, and enlarged and irregular kidneys were received at the Colorado State Veterinary Diagnostic Laboratory (CSU VDL). The submitting veterinarians were concerned about lymphoma versus acute nephritis/pyelonephritis. The CSU clinical pathology laboratory received urine for urinalysis and kidney aspirates for cytologic evaluation. Urine had also been submitted for aerobic culture and Leptospirosis PCR, and serum was submitted for Lepto-5 microscopic agglutination testing (MAT). Upon examination of a wet mount of the urine sediment, technical staff noted “vibrating” clumps of granular-appearing material throughout the slide, which prompted the preparation of a stained sediment slide for pathologist review. Very small, faintly staining organisms were observed, and an attempt was made to picture-match these with published reports of Leptospira in dog urine, but none could be found. In addition, some references claimed that Leptospira organisms are not seen in urine with light microscopy. The suspicion that these organisms were Leptospira sp. was supported by the MAT results and later confirmed by PCR. The organisms subsequently exhibited strong positive immunolabeling for the Leptospira antigen. This case report provides a searchable record of Leptospira organisms visualized by routine light microscopy in dog urine during natural infection and a review of canine leptospirosis pathobiology and diagnosis.     

Induction of VEGF by tepoxalin does not lead to increased tumour growth in a canine osteosarcoma xenograft

The purpose of this study was to determine the impact of the non-steroidal anti-inflammatory drug tepoxalin on canine tumour cell growth and describe the changes associated with tepoxalin treatment. In vitro experiments were performed to assess tepoxalin-associated alterations in tumour cell growth. Clinically achievable tepoxalin concentrations did not significantly alter tumour cell growth in vitro. Vascular endothelial growth factor (VEGF) production and hypoxia-inducible factor-1α dose-dependently increased in vitro in the presence of tepoxalin. A canine osteosarcoma xenograft was used to determine in vivo effects of tepoxalin on tumour growth and angiogenesis. Despite increased VEGF in vitro, there was a significant growth delay associated with tepoxalin treatment. Normal dogs were administered tepoxalin to assess effects on systemic VEGF production, but not found to have significantly increased VEGF. These data suggest that tepoxalin may moderately inhibit tumour growth and may be administered as an analgesic to tumour-bearing dogs.     

Heterozygote detection in a family of Lapland dogs with a recessively inherited metabolic disease: canine glycogen storage disease type II

The control of recessively inherited inborn errors of metabolism may benefit from quantitative biochemical screening assays enabling the identification of heterozygous individuals. Based on the principle of partial enzyme deficiency in heterozygotes, an attempt was made to identify heterozygous animals in a Lapland dog family with canine glycogen storage disease type II (acid alpha-glucosidase deficiency). Acid alpha-glucosidase activity was determined in peripheral blood leucocyte extracts of 12 related Lapland dogs, two of which were obligate heterozygotes. The use of an antiserum against acid alpha-glucosidase was necessary to increase the specificity of the assay. Twice the obligate heterozygous enzyme level was assumed to indicate the homozygous normal level. Five dogs were designated as presumptive heterozygotes, and five as presumptive normal homozygotes. The results in two dogs were inconclusive. The information obtained in this preliminary investigation may be helpful in the control of the disease in the Lapland dog breed.     

Zinc–carnosine and vitamin E supplementation does not ameliorate gastrointestinal side effects associated with ciclosporin therapy of canine atopic dermatitis

Chelated zinc–carnosine and vitamin E [GastriCalm^® (GCM); Teva Animal Health] is marketed as an anti‐emetic supplement for dogs to assist the repair of damaged stomach and intestinal mucosa. The purpose of this prospective, double‐blinded, placebo‐controlled trial was to determine whether GCM reduced the frequency of vomiting, diarrhoea and appetite changes during initiation of ciclosporin (Atopica^®; Novartis Animal Health) therapy for the treatment of canine atopic dermatitis. Sixty privately owned dogs diagnosed with atopic dermatitis were randomly assigned to GCM (n = 30) or placebo (n = 30) groups. All dogs received ～5 mg/kg ciclosporin (range, 3.5–5.8 mg/kg) once daily. Dogs <13.6 kg received half a tablet of GCM or placebo; dogs ≥13.6 kg received one tablet once daily. GastriCalm^® or placebo was administered 30 min prior to eating, and the ciclosporin was administered 2 h after feeding. Owners recorded episodes of vomiting, diarrhoea and appetite changes. Dogs were examined on days 0 and 14. Forty‐one of 60 dogs (68.3%) had at least one episode of vomiting, diarrhoea or appetite change, leaving nine placebo dogs (30%) and ten GCM dogs (33.3%) free of adverse events (AE). Twenty‐seven of 60 dogs (45%) vomited, and 15 of 60 (25%) had diarrhoea. There was no significant difference in episodes of individual AEs, but the placebo group had a significantly lower total AE score (summation of episodes of appetite change, vomiting and diarrhoea; P = 0.022). Small dogs (<6.82 kg) had significantly fewer total AEs in both treatment groups and tolerated ciclosporin better than larger dogs (P < 0.05).     

一种新的人畜共患病毒病——亨德拉病

亨德拉病 ( Hendra disease,HD)是由亨德拉病毒 ( Hendra Virus,He V)引起的一种新的人畜共患病毒性疾病 ,于 1 994- 1 995年期间在澳大利亚昆士兰州布里斯班郊区的亨德拉首次被发现。目前该病仅发生于澳大利亚 ,主要感染马和人。本文就该病的研究概况作一介绍。1　发病历史1 994- 1 995年期间 ,在澳大利亚昆士兰发现了一种新的地方性流行疾病 ,后来用该病的发病地名命名为亨德拉病 ( Hendra Disease)。 1 994年 9月 ,昆士兰州布里斯班郊区的亨德拉首次暴发本病 ,在 2 0多天时间里 2 0匹感染马中有 1 3匹马死于急性呼吸道病[1] 。在这次…     

An investigation of the role of immunologic factors in anemia associated with canine heartworm disease

Direct Coombs' antiglobulin tests were performed on 80 dogs with patent Dirofilaria immitis infection and 170 dogs negative for microfilaria of D. immitis. Presence or absence of anemia was determined by hematocrit in 55 of the heartworm negative dogs and 68 of the dogs with heartworm disease. Heartworm infected dogs showed a higher incidence (37%) of anemia than noninfected dogs (14.5%). Anemia was most prevalent in two groups of dogs with heartworm infection, one group showing vena caval syndrome (91%) and the other occult dirofilariasis (62.5%). These latter two groups of dogs also showed a significantly higher number of positive Coombs' reactions at 37 degrees C than other dogs with heartworm disease and the noninfected dogs. The number of positive Coombs' reactions at 4 degrees C among the total of 80 dogs with heartworm infection was significantly higher than that for dogs without heartworm disease. However, there was no positive correlation between anemia and the outcome of the Coombs' test at either temperature. These findings do not suggest that immunologic factors play a major role in the pathogenesis of anemia in dogs with heartworm disease.     

Haemolytic anaemia and bilateral uveitis associated with leptospirosis in a 6‐year‐old Quarter Horse gelding

A 6‐year‐old Quarter Horse gelding was presented for bilateral uveitis resulting in vision loss as well as icterus. Anaemia with autoagglutination was consistent with a presumptive immune‐mediated haemolytic anaemia. Urinary PCR was positive for Leptospira spp. and microscopic agglutination test (MAT) titres were elevated to multiple serovars supportive of a diagnosis of leptospirosis. Treatments included broad spectrum antibiotics and aggressive anti‐inflammatory medications. While the horse was hospitalised, the development of bilateral corneal ulcers precluded the use of topical ophthalmic anti‐inflammatories for a number of days. The corneal ulceration resolved, vision returned in both eyes and the immune‐mediated haemolytic anaemia resolved. After 9 days of hospitalisation, oral minocycline was administered for 2 weeks at home as well as low dose oral flunixin meglumine and topical ophthalmic diclofenac and atropine. This case represents the first published case of haemolytic anaemia associated with leptospirosis in a horse.     

Treatment of canine nasal aspergillosis with a new non-invasive technique. Failure with enilconazole

A new, non-Invasive technique recently described for the treatment of canine nasal aspergillosis was performed on four dogs. The antimycotic agent used was a 10 per cent enilconazole suspension, with the drug left in situ for a period of one hour. None of the dogs responded to single treatment. One dog died from an acute septic response secondary to pyelonephritis and bacterial endocarditis eight days after a second treatment. A second dog responded completely to a second treatment and remained free of fungal disease for a follow-up period of H months. In the remaining two dogs, extensive and profuse fungal growth was seen on rhinoscopic reexamination. Conventional treatment, with tube Implantation into the frontal sinuses and nasal irrigation for two weeks, was performed. Successful resolution of infection was obtained. Although the new, non-invasive technique was simple to carry out and well tolerated by the dogs, instillation of 10 per cent enilconazole appears to have poor therapeutic efficacy and exacerbated fungal growth in two of the animals.