Pentalogy of Cantrell in Two Neonate Littermate Puppies: A Spontaneous Animal Model Suggesting Familial Inheritance.

Developmental anomalies are an important cause of stillbirth and early perinatal death in companion animals. Many of these disorders remain poorly understood and provide an opportunity as a spontaneous animal model for human disease. Pentalogy of Cantrell is a rare congenital syndrome described in human neonates. It is a ventral midline closure defect with a proposed familial inheritance in humans. This syndrome involves five defects, including the thoracoabdominal wall, sternal, diaphragmatic, pericardial and cardiac malformations. Diverse expressions of these defects have been described in humans and sporadically in domestic animals. This severe syndrome commonly harbors a poor prognosis, posing an ethical and surgical dilemma. To better understand this syndrome and its presentation in dogs, we describe two rare cases of Pentalogy of Cantrell in a litter of papillon dogs. The affected puppies had anomalies compatible with the Pentalogy of Cantrell, including thoracoabdominal schisis, ectopia cordis, sternal cleft, pericardial agenesis, and diaphragmatic defects. The diagnosis was confirmed by advanced imaging (computed tomography) and postmortem examinations. The family history of this litter was explored and other cases in domestic animals were reviewed. This is the first report of the complete Pentalogy of Cantrell with ectopia cordis in the dog and the only report on papillons. Similar to human cases, possible familial inheritance and suspected male gender bias were observed. Further research on this novel animal model, its pathogenesis and its hereditary basis, may be helpful in better understanding this rare developmental disorder.

Investigation of scan delays for CT evaluation of inner wall layering and peak enhancement of the canine stomach and small intestine using a 20 second fixed-injection-duration and bolus tracking technique.

Many gastrointestinal diseases affect the mucosal layer, suggesting that on computed tomography (CT) examination, detection of consistent inner wall layering of the gastrointestinal tract may aid in detection of disease. Changes in wall enhancement can also characterise specific diseases and provide prognostic information. The objectives of this mixed retrospective and prospective analytical study were therefore to identify the scan delays for peak detection of canine stomach and small intestinal inner wall layering and enhancement when using a 20 s fixed-injection-duration and bolus tracking technique. For each patient, 700 mg I/kg iohexol was administered intravenously. Bolus tracking was used to determine aortic arrival. Diagnostic scans were performed after a post-aortic arrival scan delay. Postcontrast CT series were grouped according to post-aortic arrival scan delay: 5 s (n = 17), 10 s (n = 18), 15 s (n = 23), 20 s (n = 10), 25 s (n = 6), 30 s (n = 14), 35 s (n = 17), 40 s (n = 24), and 180 s (n = 60). The stomach and small intestine were assessed for the presence of a contrast-enhancing inner wall layer and wall enhancement. Statistical modeling showed that the scan delays for peak inner wall layering and enhancement were 10 and 15 s for the small intestine, respectively, and 40 s for the stomach. For the injection protocol used in this study, assessment of the canine gastrointestinal tract may use scan delays of 10-15 s and 40 s.

Zinc toxicosis in a cat associated with ingestion of a metal screw nut.

Case summary: A 3-year-old female neutered domestic shorthair cat was presented for vomiting, inappetence and weight loss. The cat developed moderately regenerative anaemia, moderately increased alanine transaminase and alkaline phosphatase activities, hyperbilirubinaemia and prolonged activated partial thromboplastin time. Abdominal ultrasound identified gastric wall thickening and changes suggestive of pancreatitis. Gastroduodenoscopy identified a metal screw nut in the pylorus, which was removed with rat tooth forceps. Metal analysis and serum zinc concentration using leftover serum collected at admission were performed after screw nut removal. Serum zinc concentration was markedly elevated, confirming a diagnosis of zinc toxicosis. Metal analysis of the screw nut showed that the major metal component was zinc. The cat recovered after screw nut removal and supportive care. Clinical signs resolved and the serum zinc concentration reduced significantly after screw nut removal. Relevance and novel information: Reports of zinc toxicosis in cats are scarce, possibly due to the more discriminating eating habits of this species. To our knowledge, this is the first report of zinc toxicosis causing haemolytic anaemia, liver enzyme activity increases, gastrointestinal signs and pancreatitis in a cat associated with ingestion of a zinc-containing metal object.

The effect of CT and MRI with and without arthrography on the appearance of the feline carpal ligaments.

BACKGROUND: The current diagnosis of feline carpal injuries is based on radiographic examination including stress views and computed tomography; however, these techniques do not allow for direct evaluation of the carpal ligaments. The purpose of this cadaveric study was to assess the ability of CT arthrography (CTA) and MR arthrography (MRA) to provide this information using a single contrast mixture. A protocol for intra-articular injection of the feline carpus was also described. A contrast solution containing gadolinium and iohexol with a 50% gadolinium solution (Magnevist-gadolinium 0.5 mmol/mL diluted to a 0.05 mmol/mL solution) and 50% of iodine (Iohexol-iodine 300mgI/mL) was injected into the antebrachiocarpal and middle carpal joints of feline carpi using fluoroscopic guidance. RESULTS: CTA allowed for identification of intra-articular ligaments and the silhouette of select extra-articular ligaments when there was adequate joint distension, however it was not considered to be superior to MRI. MRA allowed for improved identification of the dorsal radiocarpal, accessorioulnocarpal, accessorioquartile, short ulnar and short radial collateral ligaments. CONCLUSION: In this ex-vivo study, combined CTA and MRA enhanced the appearance of the feline carpal ligaments and may provide a foundation for future studies in the diagnosis of carpal injuries.

Magnetic resonance imaging in dogs with neuroangiostrongyliasis (rat lungworm disease).

The magnetic resonance imaging (MRI) appearance of the brain and spinal cord in humans with neuroangiostrongyliasis (NA) due to Angiostrongylus cantonensis infection has been well reported. Equivalent studies in animals are lacking. This case series describes clinical and MRI findings in 11 dogs with presumptively or definitively diagnosed NA. MRI of the brain and/or spinal cord was performed using high-field (1.5 T) or low-field (0.25 T) scanners using various combinations of transverse, sagittal, dorsal and three-dimensional (3D) T1-weighted (T1W), transverse, sagittal and dorsal T2-weighted (T2W), T2W fluid-attenuated inversion recovery (FLAIR) and T2*-weighted (T2*W) gradient echo (GRE), dorsal T2W short tau inversion recovery (STIR) and post-gadolinium transverse, sagittal, dorsal and 3D T1W and transverse T2W FLAIR sequences. In 4/6 cases where the brain was imaged, changes consistent with diffuse meningoencephalitis were observed. Evidence of meningeal involvement was evident even when not clinically apparent. The spinal cord was imaged in 9 dogs, with evidence of meningitis and myelitis detected in regions consistent with the observed neuroanatomical localization. Pathognomonic changes of neural larva migrans, as described in some human patients with NA, were not detected. NA should be considered in the differential diagnosis of dogs with MRI evidence of focal or diffuse meningitis, myelitis and/or encephalitis, especially in areas where A. cantonensis is endemic. If not precluded by imaging findings suggestive of brain herniation, cerebrospinal fluid (CSF) collection for cytology, fluid analysis, real-time polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA) testing should be considered mandatory in such cases after the MRI studies.

Hepatic computed tomography and cholangiography by use of gadoxetic acid in healthy cats.

OBJECTIVE: To evaluate 3 doses of gadoxetic acid (Gd-EOB-DPTA) for hepatic CT and cholangiography in cats and to determine optimal timing for hepatobiliary image acquisition and evaluation of the contrast-enhanced hepatobiliary anatomy. ANIMALS: 6 healthy cats. PROCEDURES: Cats were anesthetized; sequential CT scans were performed 0, 5, 25, 45, 65, and 85 minutes after IV administration of Gd-EOB-DTPA at low (0.0125 mmol/kg), medium (0.1 mmol/kg), and high (0.3 mmol/kg) doses. Hepatobiliary enhancement for each dose was objectively assessed over time and by use of a subjective semiquantitative visual assessment score. RESULTS: No contrast-related adverse effects were detected. Each increase in dose of contrast medium resulted in a significant increase in HU across the hepatobiliary system. The liver had a significantly higher number of HU at 45 minutes, with homogenous enhancement at all doses of contrast medium. Contrast-enhanced cystic and bile duct HU were significantly higher and maximal at 65 minutes. Contrast-enhanced gallbladder HU did not plateau by 85 minutes. At a high dose of contrast medium, 12 of 60 (20%) biliary tract scores indicated no enhancement, 34 (57%) indicated poor enhancement, and 14 (23%) indicated moderate enhancement. No cat had excellent enhancement of the biliary tract at any dose. CONCLUSIONS AND CLINICAL RELEVANCE: Gd-EOB-DTPA-enhanced hepatic CT and cholangiography in cats were safely performed and provided good hepatic enhancement but poor to moderate enhancement of the biliary tract. This technique may be useful for assessing the liver parenchyma in cats, but its value for assessing the biliary tract is questionable.

High field magnetic resonance imaging anatomy of feline carpal ligaments is comparable to plastinated specimen anatomy.

Feline carpal ligament injuries are often diagnosed indirectly using palpation and stress radiography to detect whether there is instability and widening of joint spaces. There are currently no reports describing normal feline carpal ligament anatomy and the magnetic resonance imaging (MRI) appearance of the carpal ligaments. The objective of this prospective, anatomic study was to describe normal feline carpal ligament anatomy using gross plastinated specimens and MRI. We hypothesized that MRI could be used to identify the carpal ligaments as previously described in the dog, and to identify species specific variations in the cat. The study was conducted using feline cadaver antebrachii that were radiographed prior to study inclusion. Three limbs were selected for MRI to confirm repeatability of anatomy between cats. The proton density weighted pulse sequence was used and images were acquired in transverse, dorsal, and sagittal planes. Following MRI, the limbs were plastinated and a collagen stain was used to aid in identification of carpal ligament anatomy. These limbs were sliced in sagittal section, and a further six paired limbs were included in the study and sliced in transverse and dorsal planes. Anatomic structures were initially described using MRI and then subjectively compared with gross plastinated specimens. Readers considered the transverse MRI plane to be most useful for visualizing the majority of the carpal ligaments. Findings indicated that MRI anatomy of the carpal ligaments was comparable to plastinated anatomy; therefore MRI appears to be a beneficial imaging modality for exploration of feline carpal pathology.

Use of gadoxetic acid for computed tomographic cholangiography in healthy dogs.

OBJECTIVE To evaluate the effect of gadoxetic acid (contrast) dose on biliary tract enhancement, determine the optimal time after contrast injection for CT image acquisition, and assess the feasibility of CT cholangiography in sedated dogs. ANIMALS 8 healthy dogs. PROCEDURES The study had 2 parts. In part 1, 4 dogs were anesthetized and underwent CT cholangiography twice. Gadoxetic acid was administered IV at a low dose (0.025 mmol/kg) for the first procedure and high dose (0.3 mmol/kg) for the second procedure. Serial CT scans were obtained at predetermined times after contrast injection. In part 2, 4 dogs were sedated and underwent CT angiography 85 minutes after IV administration of the high contrast dose. Contrast enhancement of the biliary tract on all scans was objectively assessed by measurement of CT attenuation and qualitatively assessed by use of a subjective 4-point scoring system by 3 independent reviewers. All measurements were compared over time and between contrast doses for the dogs of part 1. Subjective measurements were compared between the sedated dogs of part 2 and anesthetized dogs of part 1. RESULTS Enhancement of the biliary tract was positively associated with contrast dose and time after contrast injection. Optimal enhancement was achieved 65 minutes after contrast injection. Subjective visualization of most biliary structures did not differ significantly between sedated and anesthetized dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated CT cholangiography with gadoxetic acid was feasible in sedated dogs. The high contrast dose provided better visualization of biliary structures than the low dose; CT scans should be obtained 65 minutes after contrast injection.