A Cross‐Sectional Study Examining the Prevalence and Risk Factors for Anti‐Microbial‐Resistant Generic Escherichia coli in Domestic Dogs that Frequent Dog Parks in Three Cities in South‐Western Ontario,Canada

Anti‐microbial resistance can threaten health by limiting treatment options and increasing the risk of hospitalization and severity of infection. Companion animals can shed anti‐microbial‐resistant bacteria that may result in the exposure of other dogs and humans to anti‐microbial‐resistant genes. The prevalence of anti‐microbial‐resistant generic Escherichia coli in the faeces of dogs that visited dog parks in south‐western Ontario was examined and risk factors for shedding anti‐microbial‐resistant generic E. coli identified. From May to August 2009, canine faecal samples were collected at ten dog parks in three cities in south‐western Ontario, Canada. Owners completed a questionnaire related to pet characteristics and management factors including recent treatment with antibiotics. Faecal samples were collected from 251 dogs, and 189 surveys were completed. Generic E. coli was isolated from 237 of the faecal samples, and up to three isolates per sample were tested for anti‐microbial susceptibility. Eighty‐nine percent of isolates were pan‐susceptible; 82.3% of dogs shed isolates that were pan‐susceptible. Multiclass resistance was detected in 7.2% of the isolates from 10.1% of the dogs. Based on multilevel multivariable logistic regression, a risk factor for the shedding of generic E. coli resistant to ampicillin was attending dog day care. Risk factors for the shedding of E. coli resistant to at least one anti‐microbial included attending dog day care and being a large mixed breed dog, whereas consumption of commercial dry and home cooked diets was protective factor. In a multilevel multivariable model for the shedding of multiclass‐resistant E. coli, exposure to compost and being a large mixed breed dog were risk factors, while consumption of a commercial dry diet was a sparing factor. Pet dogs are a potential reservoir of anti‐microbial‐resistant generic E. coli; some dog characteristics and management factors are associated with the prevalence of anti‐microbial‐resistant generic E. coli in dogs.     

Haemostatic alterations in a group of canine cancer patients are associated with cancer type and disease progression

Background

Haemostatic alterations are commonly detected in human and canine cancer patients. Previous studies have described haemostatic dysfunction in canine patients with haemangiosarcomas and carcinomas, and haemostasis has been assessed in dogs with various malignant and benign neoplasias. Few studies have addressed the effect of cancer type and progression of disease on the presence of haemostatic alterations in canine patients. The objective of the present study was to evaluate haemostatic variables of coagulation and fibrinolysis in a group of canine cancer patients, and to compare haemostatic changes to the cancer type and progression of disease.

Methods

The study population consisted of 71 dogs with malignant neoplasia presented to the University Hospital for Companion Animals, Faculty of Life Sciences, University of Copenhagen, Denmark. The study was designed as a prospective observational study evaluating the haemostatic function in canine cancer patients stratified according to type of cancer disease and disease progression. The coagulation response was evaluated by thromboelastrography (TEG), platelet count, activated partial thromboplastin time (aPTT), prothombin time (PT), fibrinogen and antithrombin (AT); and fibrinolysis by d-dimer and plasminogen.

Results

Hypercoagulability was the most common haemostatic dysfunction found. Non mammary carcinomas had increased clot strength (TEG G), aPTT and fibrinogen compared to the other groups. When stratifying the patients according to disease progression dogs with distant metastatic disease exhibited significantly increased fibrinogen, and d-dimer compared to dogs with local invasive and local non-invasive cancers.

Conclusion

Hypercoagulability was confirmed as the most common haemostatic abnormality in canine cancer patients and haemostatic dysfunction in canine cancer patients was found related to the cancer type and progression of disease. Increase in TEG G, aPTT and fibrinogen were observed in non-mammary carcinomas and were speculated to overall represent a proinflammatory response associated with the disease. Dogs with distant metastatic disease exhibited increased fibrinogen and d-dimer. Future studies are needed to elucidate the clinical importance of these results.     

Scintigraphic Assessment of Deposition of Radiolabeled Fluticasone Delivered from a Nebulizer and Metered Dose Inhaler in 10 Healthy Dogs

Background

Aerosolized medications are increasingly being used to treat respiratory diseases in dogs. No previous studies assessing respiratory tract deposition of radiolabeled aerosols have been performed in conscious dogs.

Hypothesis/Objectives

Assess respiratory tract deposition of radiolabeled, inhalant corticosteroid (fluticasone propionate labeled with ^99mTc) delivered from a nebulizer and metered dose inhaler (MDI) to healthy dogs.

Animals

Ten healthy Foxhounds.

Methods

Prospective, randomized, cross‐over pilot study. Initial inhalation method (nebulizer or MDI) was randomly assigned. Treatments were crossed over after a 7‐day washout period. Treatments initially were performed using sedation. Dogs were imaged using 2‐dimensional planar scintigraphy, with respiratory tract deposition quantified by manual region‐of‐interest analysis. Deposition calculated as percentage of delivered dose. Six of 10 dogs were randomly selected and reassessed without sedation.

Results

Inhalation method had significant effect on respiratory tract deposition (P = 0.027). Higher deposition was achieved by nebulization with mean deposition of 4.2% (standard deviation [SD], 1.4%; range, 1.9–6.1%); whereas MDI treatment achieved a mean of 2.3% (SD, 1.4%; range, 0.2–4.2%). Nebulization achieved higher respiratory tract deposition than MDI in 7 of 10 dogs. No statistical difference (P = 0.68) was found between mean respiratory tract deposition achieved in dogs when unsedated (3.8%; SD, 1.5%) or sedated (3.6%; SD, 1.7%).

Conclusions and Clinical Importance

Study confirms respiratory tract deposition of inhalant medications delivered from a nebulizer and MDI in healthy dogs, breathing tidally with and without sedation. Respiratory tract deposition in these dogs was low compared to reported deposition in adult humans, but similar to reported deposition in children.     

An association study of 20 candidate genes with cryptorchidism in Siberian Husky dogs

Cryptorchidism (CO) as a common developmental defect in purebred dogs causes health concerns of reduced fertility and increases risk of testicular malignancies. A total of 49 single nucleotide polymorphisms (SNPs) discovered from 20 candidate genes was investigated to analyse their associations with CO in Siberian Huskies. The sibling‐transmission disequilibrium test on 38 discordant full‐sibs revealed seven SNPs in the collagen type II α 1 (COL2A1) gene were significantly (p < 0.05) or suggestively (p < 0.10) associated with CO. Further analyses showed that only one SNP (rs23358342) in this gene remained suggestively significant (p < 0.1) on a data set of full‐sibs with additional related dogs, but not significant on all 156 Siberian Huskies. Based on the statistical results and the involvement of COL2A1 in the testicle development and descent, we could not exclude COL2A1 as a potential candidate gene for CO in Siberian Huskies. Further studies are necessary to clarify these results from our relatively small sample size.     

Effect of renal denervation by radiofrequency catheter ablation on expression of aquaporins in dog kidneys

AIM: To investigate the effect of renal denervation (RDN) by radiofrequency catheter ablation on the expression of aquaporins (AQP) in dog kidneys.METHODS: Adult Chinese Kunming dogs (n=12) were randomly divided into RDN group and control group (6 for each group). The dogs in RDN group underwent bilateral RDN using radiofrequency catheter ablation, and radiofrequency catheter was positioned in bilateral renal artery without ablation in control group. The levels of norepinephrine (NE) and AQP1~3 in the renal tissues were detected 1 month after RDN, and blood pressure (BP) measurements were performed at baseline and 1 month after RDN.RESULTS: The level of NE in RDN group was significantly lower than that in control group (P<0.01). The expression of AQP1~3 in the renal cortex and medulla was lower in RDN group than that in control group. RDN also caused a substantial BP reduction (P<0.05). CONCLUSION: RDN substantially decreases the tissue levels of NE and AQP in dog kidneys, and also decreases BP significantly, which might be involved in the mechanism of BP reduction by RDN. Renal sympathetic nerve plays an excitatory role in the regulation of AQP in the kidney.     

The desmopressin stimulation test in dogs with Cushing's syndrome

Desmopressin is a synthetic analogue of the hypothalamic peptide vasopressin and binds to specific pituitary vasopressin (V3) receptors. The V3-receptor is overexpressed in pituitary corticotrope tumors and the injection of desmopressin induces a marked ACTH and cortisol release in human patients with pituitary- (PDH), but not adrenal tumor (AT) dependent hyperadrenocorticism. In this prospective study, we investigated the effects of desmopressin on serum cortisol levels in 80 dogs suspected of Cushing's syndrome. The aim was to find a sensitive and specific test to exclude AT. According to standard tests the dogs were divided into 3 groups (group 1=other disease, n=27; group 2=PDH, n=46; group 3=AT, n=7). Desmopressin was injected as an i.v. bolus of 4microg and serial blood samples were collected before and after 30, 60 and 90min. Desmopressin significantly stimulated cortisol release in dogs with PDH (median 51%, range -24 to 563%; p<0.0001), whereas no increase was seen in dogs with AT (median -12%, range -44 to 5%; p=0.063) and in controls (median +7%, range -36 to 196%; p=0.131). Using a cut off value of 10% increase over baseline, it was possible to exclude AT in 75% of patients. The results of this study suggest that the desmopressin test could be a useful tool in differentiating pituitary from adrenal dependent Cushing's syndromes. Additional dogs with adrenocortical tumor must be tested in order to recommend its use in clinical practice.     

Multiplex PCR-based identification of Streptococcus canis,Streptococcus zooepidemicus and Streptococcus dysgalactiae subspecies from dogs

Streptococcus canis (S. canis), Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) and Streptococcus dysgalactiae subspecies (S. dysgalactiae subspecies) are β-haemolytic Gram positive bacteria infecting animals and humans. S. canis and S. zooepidemicus are considered as two of the major zoonotic species of Streptococcus, while more research is needed on S. dysgalactiae subspecies bacteria. In this work, a multiplex-PCR protocol was tested on strains and clinical samples to detect S. canis, S. dysgalactiae subspecies and S. equi subspecies bacteria in dogs. All strains were correctly identified as S. canis, S. equi subspecies or S. dysgalactiae subspecies by the multiplex-PCR. The main Streptococcus species isolated from symptomatic dogs were confirmed S. canis. The multiplex-PCR protocol described is a rapid, accurate and efficient method for identifying S. canis, S. equi subspecies and S. dysgalactiae subspecies in dogs and could be used for diagnostic purposes and for epidemiological studies.