Adherent-invasive Escherichia coli associated with granulomatous colitis and extraintestinal dissemination in a Sphynx cat.

This case report describes a case of granulomatous colitis (GC) associated with adherent-invasive Escherichia coli (AIEC) with extension to cecum and ileum and dissemination to multiple lymph nodes, the spleen, and brain in a 10-year-old, male Sphynx cat. The cat had an episode of diarrhea 4 months prior to consultation due to sudden blindness. Signs rapidly progressed to ataxia, seizures, and death. Gross and histologic findings were consistent with granulomatous inflammation in all affected organs. In situ hybridization confirmed the presence of intracellular E. coli within enterocytes and infiltrating macrophages, and whole genome sequencing identified virulence traits commonly linked to AIEC strain. This is the first characterization of GC in a cat associated to AIEC resembling the metastatic form of Crohn's disease in humans and GC of dogs. Extraintestinal involvement might provide evidence of the ability of AIEC to promote granulomatous inflammation beyond the gut.

Persistent fontanelles in Chihuahuas. Part I. Distribution and clinical relevance.

BACKGROUND: The Chihuahua dog breed is known for frequent occurrence of a bregmatic fontanelle on the dorsal skull. A common conception is that this skull defect is a clinically irrelevant finding. No studies, however, describe its prevalence or whether it is accompanied by other persistent fontanelles (PFs). Although Chihuahuas are predisposed to Chiari-like malformation (CM) and syringomyelia (SM), it is unknown whether PFs occur more commonly in dogs with clinical signs that are caused by CM or SM. HYPOTHESIS/OBJECTIVES: To describe the number and location of PFs at cranial sutures (CSs) and to compare the occurrence of these PFs in dogs with and without CM/SM-related clinical signs. We hypothesized that PFs also occur commonly at lateral and caudal cranial surfaces, affect a higher number of CSs, and are larger in dogs with CM/SM-related clinical signs. ANIMALS: Fifty client-owned Chihuahuas with or without CM/SM-related clinical signs. RESULTS: Of the 50 dogs evaluated, 46 (92%) had either 1 or several PFs. The mean ± SD number of PFs was 2.8 ± 3.0 (range, 0-13). A total of 138 PFs occupied 118 CSs with 57 (48%) located dorsally, 44 (37%) caudally, and 17 (14%) laterally. The number of CSs affected by PFs was significantly higher (P ≤ .001) and total PF area was significantly larger (P = .003) in dogs with CM/SM-related clinical signs. CONCLUSIONS AND CLINICAL IMPORTANCE: Persistent fontanelles are very common in this group of Chihuahuas and appear at dorsal, lateral, and caudal cranial surfaces. They are more numerous and larger in Chihuahuas with CM/SM-related clinical signs.

Persistent fontanelles in Chihuahuas. Part II: Association with craniocervical junction abnormalities, syringomyelia, and ventricular volume.

BACKGROUND: Persistent fontanelles (PFs) are, in Chihuahuas, almost ubiquitous. Furthermore, Chihuahuas are predisposed to other craniomorphological abnormalities, including syringomyelia (SM), ventriculomegaly, and craniocervical junction (CCJ) overcrowding resulting in neural tissue deviation. It is, however, undetermined if PFs are more common in dogs with these structural abnormalities, and their etiology is unknown. HYPOTHESIS/OBJECTIVES: Persistent fontanelles are more numerous and larger in Chihuahuas with low body weight, older age, SM, dilated fourth ventricle, ventriculomegaly, and CCJ overcrowding. ANIMALS: Fifty client-owned Chihuahuas. METHODS: Cross-sectional study evaluating the association of both the number of cranial sutures affected by PFs (NAS) and total fontanelle area (TFA), based on computed tomography with SM, fourth ventricle dilatation, lateral ventricle volume, and extent of neural tissue compression at the CCJ based on magnetic resonance images. RESULTS: The NASs was higher and TFA larger in dogs with low body weight (NAS: P = .007; 95% confidence interval [CI] = 0.384-0.861; TFA: P = .002; 95% CI = -1.91 to -0.478), larger lateral ventricles (NAS: P ≤ .001; 95% CI = 1.04-1.15; TFA: P ≤ .001; 95% CI = 0.099-0.363), and more severe neural tissue compression at the CCJ (NAS: P ≤ .001; 95% CI = 1.26-2.06; TFA: P = .03; 95% CI = 0.066-1.13). Similarly, dogs with SM (NAS: P = .004; 95% CI = 1.26-3.32; TFA: mean ± SD, 130 ± 217 mm2 ; P = .05) had higher NAS and larger TFA than did dogs without SM (43.7 ± 61.0 mm2 ). Age was not associated with NAS (P = .81; 95% CI = 0.989-1.01) or TFA (P = .33; 95% CI = -0.269 to 0.092). CONCLUSIONS AND CLINICAL IMPORTANCE: Persistent fontanelles are associated with small size, SM, ventriculomegaly, and CCJ overcrowding.

Seizure-precipitating factors in dogs with idiopathic epilepsy.

BACKGROUND: Stress, sleep deprivation, and infectious diseases are important seizure-precipitating factors in human epilepsy patients. However, these factors have not been thoroughly studied in epileptic dogs. OBJECTIVE: Seizure-precipitating factors are common in dogs with idiopathic epilepsy and the occurrence of these factors associate with the dogs' signalment, personality, and epilepsy-related factors. ANIMALS: Fifty dogs with diagnosed idiopathic epilepsy from the hospital populations of University Veterinary Teaching Hospital of University of Helsinki and Referral Animal Hospital Aisti. METHODS: In a retrospective cross-sectional observational study, owners were interviewed about their dogs' possible seizure-precipitating factors according to a predefined questionnaire. The dogs were identified and selected by searching the medical records of the participating animal hospitals. RESULTS: The prevalence of seizure-precipitating factors in the study population was 74% (37/50). The most frequently reported factors included stress-related situations, sleep deprivation, weather, and hormonal factors. In dogs with focal onset seizures, the number of precipitating factors was 1.9 (95% CI 1.1-3.4) times higher compared to dogs with generalized seizures. CONCLUSIONS AND CLINICAL IMPORTANCE: Seizure-precipitating factors are common in dogs with idiopathic epilepsy, and the nature of these factors is consistent with those of human patients. Aside from antiepileptic medication, acknowledging and avoiding seizure-precipitating factors could help veterinarians achieve better treatment outcomes.

Craniometric Analysis of the Hindbrain and Craniocervical Junction of Chihuahua, Affenpinscher and Cavalier King Charles Spaniel Dogs With and Without Syringomyelia Secondary to Chiari-Like Malformation.

OBJECTIVES: To characterize and compare the phenotypic variables of the hindbrain and craniocervical junction associated with syringomyelia (SM) in the Chihuahua, Affenpinscher and Cavalier King Charles Spaniel (CKCS). METHOD: Analysis of 273 T1-weighted mid-sagittal DICOM sequences of the hindbrain and craniocervical junction from 99 Chihuahuas, 42 Affenpinschers and 132 CKCSs. The study compared 22 morphometric features (11 lines, eight angles and three ratios) of dogs with and without SM using refined techniques based on previous studies of the Griffon Bruxellois (GB) using Discriminant Function Analysis and ANOVA with post-hoc corrections. RESULTS: The analysis identified 14/22 significant traits for SM in the three dog breeds, five of which were identical to those reported for the GB and suggest inclusion of a common aetiology. One ratio, caudal fossa height to the length of the skull base extended to an imaginary point of alignment between the atlas and supraoccipital bones, was common to all three breeds (p values 0.029 to <0.001). Associated with SM were a reduced occipital crest and two acute changes in angulation i) 'sphenoid flexure' at the spheno-occipital synchondrosis ii) 'cervical flexure' at the foramen magnum allied with medulla oblongata elevation. Comparing dogs with and without SM, each breed had a unique trait: Chihuahua had a smaller angle between the dens, atlas and basioccipital bone (p value < 0.001); Affenpinschers had a smaller distance from atlas to dens (p value 0.009); CKCS had a shorter distance between the spheno-occipital synchondrosis and atlas (p value 0.007). CONCLUSION: The selected morphometries successfully characterised conformational changes in the brain and craniocervical junction that might form the basis of a diagnostic tool for all breeds. The severity of SM involved a spectrum of abnormalities, incurred by changes in both angulation and size that could alter neural parenchyma compliance and/or impede cerebrospinal fluid channels.