Anatomic characterization of the location of the esophageal ostium relative to the rima glottidis on CT in adult Labrador Retrievers.

OBJECTIVE: To characterize the anatomic location of the esophageal ostium relative to the rima glottidis in adult Labrador Retrievers with the use of CT. ANIMALS: 98 CT scans of 75 adult Labrador Retrievers. PROCEDURES: A search of the medical records database identified records of Labrador Retrievers that underwent CT of the head and neck between January 1, 2015, and December 31, 2018. Evaluators, blinded to each other's results, reviewed CT images and measured esophageal area at the level of the rima glottidis. For each dog, the left esophageal percentage (LEP) was calculated as the esophageal area left of the rima glottidis midline divided by the overall esophageal area at that level. Variables (age, sex, patient position, intubation status, and maxillary support during CT) were evaluated for association with LEP. The CT images of dogs that had multiple scans were assessed for within-patient variance. RESULTS: Mean LEP was 56.2 ± 18.1% for all dogs. Only right lateral recumbency was significantly associated with LEP, with a lower LEP for dogs positioned in right lateral recumbency (42.4 ± 12.7%), compared with left lateral (63.0 ± 7.4%) or sternal (57.3 ± 18.8%) recumbency. No association was detected between LEP and other variables assessed. Eleven dogs had multiple CT scans; within-patient variance for LEP was ± 26.6%. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that, although most dogs had an LEP > 50%, the esophageal ostium was fairly centrally located in most dogs and may be more mobile than previously thought. Additional research is warranted to assess this mobility and whether the esophageal ostium location, relative to the larynx, affects the incidence of aspiration pneumonia in dogs undergoing surgical treatment for geriatric-onset laryngeal paralysis and polyneuropathy.

A small scale study to evaluate the efficacy of microneedling in the presence or absence of platelet-rich plasma in the treatment of post-clipping alopecia in dogs.

BACKGROUND: Post-clipping alopecia often has a clinically poor response to therapy and prolonged alopecia is a source of anxiety for some owners. In humans and dogs, superficial microtrauma via a microneedling (MN) device induces mechanical stimulation of the hair follicle with resultant hair regrowth. Human studies suggest that concurrent application of platelet-rich plasma (PRP) with MN induces more rapid regrowth of better-quality hair than microneedling alone. HYPOTHESIS: Microneedling with PRP will induce more rapid regrowth of better quality hair. ANIMALS: Four unrelated client-owned dogs diagnosed with post-clipping alopecia. METHODS AND MATERIALS: This was a prospective study. The affected site was divided in half, with the first half treated with MN alone and the second half treated with MN + PRP. Hair regrowth was assessed by clinician and owner using a hair growth assessment scale (HGAS) at one, three, six and 12 months. RESULTS: At three months, all dogs had improved and three exhibited greater hair regrowth on the MN + PRP side. A similar response was noted bilaterally in three dogs, which had improved by 76-100% at six months and remained unchanged at 12 months. One dog improved by < 26% at six months, but had> 50% re-growth by 12 months. The small sample size precluded statistical analysis. CONCLUSIONS AND CLINICAL IMPORTANCE: In dogs with post-clipping alopecia, MN + PRP appeared to induce more rapid hair regrowth than MN; however, overall results were visibly equivalent by six months regardless of method. Both MN and MN + PRP proved successful for treating post-clipping alopecia.

Multimodality imaging of an azygous continuation of the caudal vena cava in a dog with pulmonary thromboembolic disease.

A 5-year-old spayed female English Bulldog was evaluated for acute anorexia, lethargy, respiratory distress, and syncope. Contrast-enhanced computed tomography revealed the vascular malformation of azygous continuation of the caudal vena cava with extensive thrombus formation and pulmonary arterial thromboembolic disease. The patient was hospitalized for supportive treatment and was prescribed long-term clopidogrel therapy. The patient survived to discharge and at last follow-up remained clinically stable. While this vascular malformation has been reported in canines, to the authors' knowledge, this is the first reported case of pulmonary thromboembolic disease in a canine concurrent with this condition.

Brucella canis sacroiliitis and discospondylitis in a dog.

A 1.5-year-old neutered male Labrador retriever dog was presented with a 1-month history of pelvic limb lameness. Physical examination revealed lumbosacral and pelvic pain. Diagnostic imaging findings were consistent with discospondylitis and bilateral sacroiliitis. Brucellosis was definitively diagnosed with rapid slide agglutination (RSAT) and agar gel immunodiffusion (AGID) tests. Brucella canis has not been associated with sacroiliitis and should be included as a differential diagnosis for dogs presented with clinical or radiographic signs of sacroiliitis.

Sacro-iliite et discospondylite à Brucella canis chez un chien. Un chien mâle castré de race Labrador âgé de 1,5 ans fut présenté avec une histoire de boiterie du membre pelvien ayant débuté 1 mois plus tôt. L'examen physique révéla une douleur lombo-sacrée et pelvienne. Les trouvailles d'imagerie étaient cohérentes avec une discospondylite et une sacro-iliite bilatérale. La brucellose fut diagnostiquée de manière définitive par un test d'agglutination rapide sur lame (RSAT) et un test d'immunodiffusion en gel (AGID). Brucella canis n'a pas été associé avec une sacro-iliite et devrait être inclus dans le diagnostic différentiel de chiens présentant des signes cliniques ou radiographiques de sacro-iliite.(Traduit par Dr Serge Messier).

Factors associated with tick bites and pathogen prevalence in ticks parasitizing humans in Georgia, USA.

BACKGROUND: The incidence and emergence of tick-borne diseases has increased dramatically in the United States during the past 30 years, yet few large-scale epidemiological studies have been performed on individuals bitten by ticks. Epidemiological information, including disease development, may provide valuable information regarding effectiveness of tick bite prevention education, pathogen transmission, human-disease dynamics, and potential implications for under reporting of tick-borne diseases. METHODS: Ticks found attached to Georgia residents were submitted for identification and polymerase chain reaction (PCR) testing for Francisella tularensis, Ehrlichia, Anaplasma, Borrelia, and Rickettsia spp. Tick bite victims were interviewed three weeks after the tick bite to identify various epidemiologic factors associated with infestation and if signs suggestive of a tick-borne disease had developed. Fisher's exact test of independence was used to evaluate associations between various factors evaluated in the study. A multivariable logistic regression model was used for the prediction of non-specific illness post-tick bite. RESULTS: From April 2005-December 2006, 444 participants submitted 597 ticks (426 Amblyomma americanum, 142 Dermacentor variabilis, 19 A. maculatum, 7 Ixodes scapularis, 3 Amblyomma sp.) which originated from 95 counties. Only 25 (34 %) of 74 interviewed individuals purposely took tick bite prevention measures. Ticks that were PCR positive for bacterial organisms were attached to 136 participants. Of the 77 participants who developed non-specific illness, 50 did not have PCR positive ticks, whereas 27 did have PCR positive tick (s). Of those 27 individuals, 12 fit the criteria for a possible tick-borne illness (i.e., tick attached >6 h [if known], ≥4 day incubation period, and the individual exhibited clinical symptoms typical of a tick-borne illness without exhibiting cough, sore throat, or sinus congestion). Ticks from these individuals were positive for R. amblyommii (n = 8), E. ewingii (n = 1), R. montana (n = 1), R. rhiphicephali (n = 1), and Rickettsia sp. TR-39 (n = 1). CONCLUSIONS: Although illnesses reported in this study cannot definitively be connected with tick bites, it does provide insight into development, diagnosis, and treatment of possible tick-borne diseases post-tick bite. The study also provided data on pathogen prevalence, and epidemiologic factors associated with tick bites, as well as tick presence by county in Georgia.

Evaluation of standard magnetic resonance characteristics used to differentiate neoplastic, inflammatory, and vascular brain lesions in dogs.

Magnetic resonance (MR) imaging characteristics are commonly used to help predict intracranial disease categories in dogs, however, few large studies have objectively evaluated these characteristics. The purpose of this retrospective study was to evaluate MR characteristics that have been used to differentiate neoplastic, inflammatory, and vascular intracranial diseases in a large, multi-institutional population of dogs. Medical records from three veterinary teaching hospitals were searched over a 6-year period for dogs that had diagnostic quality brain MR scans and histologically confirmed intracranial disease. Three examiners who were unaware of histologic diagnosis independently evaluated 19 MR lesion characteristics totaling 57 possible responses. A total of 75 dogs with histologically confirmed intracranial disease were included in analyses: 51 with neoplasia, 18 with inflammatory disease, and six with cerebrovascular disease. Only strong contrast enhancement was more common in neoplasia than other disease categories. A multivariable statistical model suggested that extra-axial origin, T2-FLAIR mixed intensity, and defined lesion margins were also predictive of neoplasia. Meningeal enhancement, irregular lesion shape, and multifocal location distinguished inflammatory diseases from the other disease categories. No MR characteristics distinguished vascular lesions and these appeared most similar to neoplasia. These results differed from a previous report describing seven MR characteristics that were predictive of neoplasia in dogs and cats. Findings from the current study indicated that the high performance of MR for diagnosing canine intracranial diseases might be due to evaluator recognition of combinations of MR characteristics vs. relying on any one MR characteristic alone.

Genetic variation and exchange in Trypanosoma cruzi isolates from the United States.

Trypanosoma cruzi, the causative agent of Chagas disease, is a multiclonal parasite with high levels of genetic diversity and broad host and geographic ranges. Molecular characterization of South American isolates of T. cruzi has demonstrated homologous recombination and nuclear hybridization, as well as the presence of 6 main genetic clusters or "discrete typing units" (DTUs). Few studies have extensively investigated such exchange events and genetic diversity in North American isolates. In the current study, we genetically characterized over 50 US isolates from wildlife reservoirs (e.g., raccoons, opossums, armadillos, skunks), domestic dogs, humans, nonhuman primates, and reduviid vectors from nine states (TX, CA, OK, SC, FL, GA, MD, LA, TN) using a multilocus sequencing method. Single nucleotide polymorphisms were identified in sequences of the mismatch-repair class 2 (MSH2) and Tc52 genes. Typing based on the two genes often paralleled genotyping by classic methodologies using mini-exon and 18S and 24Sα rRNA genes. Evidence for genetic exchange was obtained by comparing sequence phylogenies of nuclear and mitochondrial gene targets, dihydrofolate reductase-thymidylate synthase (DHFR-TS) and the cytochrome oxidase subunit II- NADH dehydrogenase subunit I region (COII-ND1), respectively. We observed genetic exchange in several US isolates as demonstrated by incongruent mitochondrial and nuclear genes phylogenies, which confirms a previous finding of a single genetic exchange event in a Florida isolate. The presence of SNPs and evidence of genetic exchange illustrates that strains from the US are genetically diverse, even though only two phylogenetic lineages have been identified in this region.

Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida.

Ticks were collected from 38 black bears (Ursus americanus floridanus) from northwestern Florida (n = 18) from 2003 to 2005 and southern Georgia (n = 20) in 2006. Five species (Amblyomma americanum, A. maculatum, Dermacentor variabilis, Ixodes scapularis, and I. affinis) were collected from Florida bears, and 4 species (A. americanum, A. maculatum, D. variabilis, I. scapularis) were collected from bears in Georgia. Ixodes scapularis was the most frequently collected tick, followed by D. variabilis, A. americanum, A. maculatum, and I. affinis. The collection of I. affinis from a Florida bear represents a new host record. A subset of ticks was screened for pathogens and putative symbionts by polymerase chain reaction (PCR). The zoonotic tick-borne pathogens Ehrlichia chaffeensis and Rickettsia parkeri were detected in 1 of 23 (4.3%) A. americanum and 1 of 12 (8.3%) A. maculatum, respectively. The putative zoonotic pathogen "Rickettsia amblyommii" was detected in 4 (17.4%) A. americanum and 1 (8.3%) A. maculatum. Other putative symbiotic rickettsiae detected included R. bellii and R. montanensis in D. variabilis, a Rickettsia cooleyi-like sp. and Rickettsia sp. Is-1 in I. scapularis, and Rickettsia TR39-like sp. in I. scapularis and A. americanum. All ticks were PCR-negative for Anaplasma phagocytophilum, Panola Mountain Ehrlichia sp., E. ewingii, Francisella tularensis, and Borrelia spp.