CLINICAL VALUE OF FRUCTOSAMINE MEASUREMENTS AND FRUCTOSAMINE-ALBUMIN RATIO IN HYPOGLYCEMIC FERRETS (MUSTELA PUTORIUS FURO)

The objective of this preliminary study was to establish a reference range for plasma fructosamine concentration and fructosamine-albumin ratio in healthy ferrets and to compare these reference intervals to values obtained from hypoglycemic ferrets. Fructosamine concentration has been shown to reflect blood glucose concentration over the previous 1 to 2 weeks in other animal species, and may be a useful indicator of chronic hypoglycemia in ferrets diagnosed with insulinoma. Plasma fructosamine was measured with an automated colorimetric assay using nitroblue tetrazolium. Thirty-two clinically healthy and 5 hypoglycemic ferrets were included in the study. The reference interval in healthy ferrets for fructosamine was 110 (98 to 123) – 203 (191 to 218) μmol/L, and the reference interval for plasma fructosamine-albumin ratio was 5.1 (4.6 to 5.6) – 8.6 (8.2 to 9.0) μmol/g. Results for hypoglycemic ferrets were within the ranges for both fructosamine and fructosamine-albumin ratio. As there were no significant differences between the healthy and hypoglycemic ferrets, this study suggests that fructosamine concentration and fructosamine-albumin ratio are not likely to be useful in determining insulinoma-associated chronic hypoglycemia in ferrets.     

PHARMACOKINETICS OF SINGLE-DOSE BUPRENORPHINE,BUTORPHANOL, AND HYDROMORPHONE IN THE DOMESTIC FERRET (MUSTELA PUTORIUS FURO)

The objective of this study was to establish the clinical pharmacokinetic profile of 4 different opioid drugs (buprenorphine, butorphanol, hydromorphone, and morphine) in the domestic ferret (Mustela putorius furo). Twenty-four, approximately 1-year-old, male neutered purpose-bred domestic ferrets were used for this study. The ferrets were divided into 4 groups of 6, with a different opioid drug used for each group. A preopioid venous blood sample was obtained via cranial vena cava venipuncture. Following the initial blood collection, a single injection of opioid (hydromorphone 0.1 mg/kg, buprenorphine 0.04 mg/kg, butorphanol 0.3 mg/kg, and morphine 1 mg/kg) was given to each ferret, dependent on assigned drug group, intramuscularly (buprenorphine) or subcutaneously (hydromorphone, butorphanol, and morphine). Intramuscular injections were administered in the semimembranosis and semitendinosis muscles, whereas the subcutaneous injections were delivered in the intrascapular subcutaneous space. A venous blood sample was obtained at 5, 15, 30, 60, 120, 240, 360, 480, and 720 minutes postinjection from the ferrets in the buprenorphine, butorphanol, and hydromorphone groups. Mass spectrometry and liquid chromatography was performed to obtain plasma concentrations of the administered drugs. The mean maximum concentration of buprenorphine was 6.96 ng/mL, butorphanol was 48.6 ng/mL, and hydromorphone was 17.3 ng/mL. Maximum concentrations were achieved at a mean of 9 minutes after administration for buprenorphine, 13.3 minutes for butorphanol, and 8.33 minutes for hydromorphone. The mean half-life of buprenorphine was 219.1 minutes, butorphanol was 91.1 minutes, and hydromorphone was 24.7 minutes. Owing to severe complications arising within the morphine group, including hypersalivation and vomiting, the morphine study was discontinued prior to blood sample collection. Intramuscular injections of buprenorphine and subcutaneous injections of butorphanol or hydromorphone appeared to be well tolerated by all ferrets. The pharmacokinetics of buprenorphine, butorphanol, and hydromorphone of a single equipotent dose of each drug have been established through this research investigation and may be useful for further studies.     

CORRELATIVE IMAGING FINDINGS IN SEVEN DOGS AND ONE CAT WITH SPINAL ARACHNOID CYSTS

Information regarding 7 dogs and 1 cat with a spinal arachnoid cyst is presented. All patients were evaluated with survey radiographs and myelography. Computed tomography (CT) following myelography, magnetic resonance (MR) imaging, and sonography, were used in some of the patients. These imaging techniques were evaluated to determine their efficacy in diagnosing arachnoid cysts, ascertaining the extent and internal cyst architecture and detecting associated spinal cord abnormalities. Survey radiographs were nondiagnostic in all patients. Myelographically, the arachnoid cyst was visible in all patients, with partial blockage to flow of contrast medium. CT provided additional information on localization and lateralization of the cyst, and allowed measurement of the degree of spinal cord compression. MR imaging enabled identification of an associated syringomyelia. Sonography was useful for defining the cyst wall and characterizing the internal architecture of the cyst cavity and adjacent spinal cord. Measurements of the degree of spinal cord compression could be made and were similar to measurements made from CT. Additionally, sonography was considered a useful technique for orientating the surgeon to the location and extent of the cyst. In the absence of the availability of CT or MR imaging for evaluating patients with an arachnoid cyst, sonography is considered a valuable technique for directly assessing the spinal cord for associated disease. Decompressive surgery was performed on 4 dogs and 1 cat, all with successful outcomes.     

MESENTERIC HETEROTOPIC OSSIFICANS IN A FERRET (MUSTELA PUTORIUS FURO): A RARE CAUSE OF SOFT TISSUE OSSIFICATION

Heterotopic ossification (HO) is a rare condition characterized by abnormal bone production in soft tissue. Very few cases of HO have been reported in animals (e.g., dogs and horses) and this disease process is often a consequence of a traumatic incident. A 5-year-old, male European ferret (Mustela putorius furo) was referred for anorexia, generalized weakness, and weight loss. Clinical examination revealed multiple abdominal masses. An explorative laparotomy identified omental, white/tan, nodular to coalescing hard lesions. The omentum and spleen were surgically removed during the surgical procedure, with both subsequently submitted for histopathologic evaluation. Microscopically, the omental masses were composed of a meshwork of lamellar and woven bone admixed with islands of cartilage and lacunae containing either blood, fat, and/or bone marrow. Multifocal mineralization and bone lamellae were also present in the grossly normal omentum. The finding of multiple bone nodules containing bone marrow and/or adipose tissue, with no Harversian system, and minimal intratrabecular connective tissue favored a diagnosis of HO.     

MR IMAGING FINDINGS IN A DOG WITH LUMBAR GANGLION CYSTS

Intraspinal cysts of the L6-L7 and L7-S1 articular process joints in a six-year-old neutered female German Shepherd Dog were diagnosed using magnetic resonance (MR) imaging. Histopathology provided a diagnosis of ganglion cysts. Clinical, laboratory, radiographic and MR imaging findings are described. Briefly, radiographic findings revealed lumbarization of the first sacral vertebra, and fusion of the first caudal vertebra to the sacrum. In addition, spondylosis and articular process osteoarthrosis occurred at L6-L7 and L7-S1. MR imaging revealed multiple, well encapsulated structures ranging in size from 3-10 mm in diameter which were found to arise from the L6-L7 and L7-S1 articular process joints. These cysts had signal intensities that varied from hyperintense to the cerebrospinal fluid (CSF) on T1 weighted images to isointense to CSF on T2 weighted images. Decompressive surgery in conjunction with arthrodesis of these joints resulted in resolution of clinical signs. The dog remained pain-free 1 1/2 years following surgical therapy.     

IMAGING DIAGNOSIS—VERTEBRAL POLYOSTOTIC LYMPHOMA IN A GERIATRIC DOG

A 9‐year‐old spayed female Scottish terrier presented with an 8‐day history of progressive paraparesis. Neurological examination suggested a painful T3‐L3 myelopathy. Multifocal uniform contrast‐enhancing masses involving the vertebral bodies, pedicles, laminae, and spinous processes of two vertebrae and compressing the spinal cord were present on MRI. Fluoroscopic‐guided fine needle aspiration of one of the vertebral lesions revealed a predominantly lymphoblastic population of cells compatible with a diagnosis of lymphoma. To the authors’ knowledge, this represents the first published case of canine lymphoma with vertebral involvement, characterized with MRI.     

IMAGING FINDINGS IN DOGS WITH CAUDAL INTERVERTEBRAL DISC HERNIATION

The radiographic and magnetic resonance imaging (MRI) findings for four dogs with herniation of the Cd1–Cd2 intervertebral disc are described. All dogs were 7 years of age at the time of presentation, with one neutered male and three neutered females. Breeds included one Beagle, one Bassett hound, and two large, mixed breed dogs. All dogs had tail pain on manipulation, two had pain during defecation, and two maintained an abnormal tail position. Three dogs had radiographs in which mineralization within the disc space was apparent. Two of these dogs also had mineralization within the vertebral canal. Three dogs underwent MRI, which was characterized by varying degrees of disc herniation and nerve root compression at Cd1–Cd2. Mobility may be a factor predisposing to disc herniation in the cranial aspect of the caudal spine. We documented that caudal disc herniation does occur occasionally in dogs and that radiography and MRI may be used to identify this disease. Caudal intervertebral disc herniation should be considered as a differential for dogs with caudal vertebral pain, pain with tail manipulation, pain during defecation, or abnormal tail carriage.     

MAGNETIC RESONANCE IMAGING FINDINGS IN 25 DOGS WITH INFLAMMATORY CEREBROSPINAL FLUID

To describe the signs that may be associated with intracranial inflammatory conditions, magnetic resonance (MR) images of 25 dogs that had inflammatory cerebrospinal fluid (CSF) were mixed with those of a control group of 40 dogs that had CSF negative for inflammatory disease and reviewed without knowledge of the clinical signs or diagnosis. CSF was considered inflammatory if the protein level was > 0.25 g/l and the white cell count was > 5 mm(-3). Abnormalities were found by MR imaging in 19 (76%) dogs with inflammatory CSF. Two dogs had focal lesions, 10 had multifocal lesions, and seven had diffuse lesions. Lesions affected all divisions of the brain. Mass effect was identified in seven (28%) dogs, including one that had a choroid plexus carcinoma. Lesions were hyperintense in T2-weighted images in 18 dogs and hypointense in T1-weighted images in six dogs. Multifocal or diffuse intraaxial lesions that were hyperintense in T2-weighted images were observed in 17 (68%) dogs with inflammatory CSF. Administration of gadolinium resulted in enhancement of intraaxial lesions in nine (36%) dogs and enhancement of meninges in seven (28%) dogs. Six (24%) dogs with inflammatory CSF had images interpreted as normal.     

MAGNETIC RESONANCE IMAGING FINDINGS IN HORSES WITH SEPTIC ARTHRITIS

Fourteen horses with septic arthritis underwent high‐field (1.5 T) magnetic resonance imaging (MRI). Septic arthritis was diagnosed based on results from historical and clinical findings, synovial fluid analyses and culture, and radiographic, ultrasonographic, arthroscopic, and histopathologic findings. MR findings included diffuse hyperintensity within bone and extracapsular tissue on fat‐suppressed images in 14/14 horses (100%), joint effusion, synovial proliferation, and capsular thickening in 13/14 horses (93%), bone sclerosis in 11/14 horses (79%), and evidence of cartilage and subchondral bone damage in 8/14 horses (57%). Intravenous gadolinium was administered to five of the 14 horses and fibrin deposition was noted in all horses. Other findings after gadolinium administration included synovial enhancement in 4/5 (80%) horses, and bone enhancement in 1/5 (20%) horses. The MR findings of septic arthritis in horses were consistent with those reported in people. MRI may allow earlier and more accurate diagnosis of septic arthritis in horses as compared with other imaging modalities, especially when the clinical diagnosis is challenging. It also provides additional information not afforded by other methods that may influence and enhance treatment.     

MAGNETIC RESONANCE, COMPUTED TOMOGRAPHIC AND RADIOLOGIC FINDINGS IN A DOG WITH DISCOSPONDYLITIS

Magnetic resonance (MR), computed tomographic and radiographic imaging were conducted in a dog with discospondylitis. The MR findings were increased T2 and decreased T1 signal intensity of the soft tissues ventral to vertebral bodies, the end plates of the same vertebral bodies and the intervertebral disc, and are similar to those described in human with discospondylitis.     

IMAGING DIAGNOSIS—RADIOGRAPHY AND ULTRASONOGRAPHY OF BILATERAL CONGENITAL URETEROVESICAL JUNCTION STENOSIS CAUSING HYDRONEPHROSIS AND HYDROURETER IN A FERRET (MUSTELA PUTORIUS FURO)

An 8‐month‐old neutered male ferret was presented for vaccination and preventive treatment for adrenal gland disease. Abdominal ultrasound revealed severe bilateral hydronephrosis and hydroureter. Excretory urography and negative contrast cystography showed bilateral ureterovesical junction stenosis. Positive retrograde cystography demonstrated right ureteral reflux. A subcutaneous ureteral bypass was placed in the left kidney; however, it had to be removed 3 months later due to an obstruction and persistent urinary tract infection. Bilateral ureteroneocystotomy was performed. Although congenital strictures are uncommon in veterinary patients, they should be included in the differential diagnosis in ferrets presenting with hydronephrosis and hydroureter of undetermined cause.     

MAGNETIC RESONANCE IMAGING AND PATHOLOGIC FINDINGS ASSOCIATED WITH NECROTIZING ENCEPHALITIS IN TWO YORKSHIRE TERRIERS

Two young adult Yorkshire terriers had neurologic signs consistent with forebrain and brainstem involvement or forebrain involvement alone. On magnetic resonance imaging studies there were asymmetric bilateral lesions mainly in the cerebral cortex, and in the diencephalon. These areas were hyperintense on T2-weighted and FLAIR images, but hypointense or isointense on T1-weighted images. Lesions had a varying degree of contrast enhancement. Areas which were isointense on T1-weighted images had no contrast enhancement or only foci of contrast enhancement. Lesions with hypointensity in T1-weighted images had no enhancement or more frequently ring-like enhancement around the lesion. Necrotizing encephalitis was confirmed pathohistologically in both dogs. The degree of contrast enhancement appeared to be related to the degree of lymphohistiocytic inflammation on histologic examination.     

MAGNETIC RESONANCE IMAGING FINDINGS IN HORSES WITH RECENT ONSET NAVICULAR SYNDROME BUT WITHOUT RADIOGRAPHIC ABNORMALITIES

Seventy-two horses with recent onset of navicular syndrome and normal radiographs were assessed. Horses underwent magnetic resonance (MR) imaging of both front feet. All abnormalities were characterized and the most severe abnormality identified, if possible. Abnormal signal intensity in the navicular bone was the most severe abnormality in 24 (33%) horses. Pathologic change in the deep digital flexor tendon was the most severe abnormality in 13 (18%) horses. Pathologic change in the collateral sesamoidean ligament was the most severe abnormality in 11 (15%) horses. Pathologic change in the distal sesamoidean impar ligament was the most severe abnormality in seven (10%) horses. Multiple abnormalities were observed in 13 (18%) horses in which an abnormality that was more severe than the others could not be determined. Abnormalities were not observed in the navicular bone or its supporting soft tissues in four (5%) horses. Fifty-six horses had abnormalities that were most severe in one limb; in 52 (93%) horses, the most severe abnormalities were in the foot of the most lame limb. In 7% (4/56) of horses, the most severe findings were in the opposite limb, and in 16 horses, the findings on both limbs were similar. MR imaging is a useful technique for evaluating horses with navicular syndrome and can differentiate between multiple abnormalities. This provides a more specific diagnosis which affects further treatment of the horse. Pathologic changes in different locations in the foot can cause similar clinical signs that, before MR imaging, were categorized as one syndrome.     

COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING OF CAVERNOUS SINUS ENLARGEMENT IN A DOG WITH UNILATERAL EXOPHTHALMOS

Computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) were performed on a dog with a two year history of unilateral exophthalmos occurring two years following head trauma. On CT images, an expansile enhancing mass was present along the right intracranial cavernous sinus and extended through the orbital fissure into the retrobulbar space. With MRI, the structure appeared as a signal void due to the presence of rapidly flowing blood. Gadolinium enhancement of the adjacent brain was not present. A vascular origin of the lesion was confirmed with MRA. Based on the CT and MRI findings, the enlarged cavernous sinus and associated ophthalmic plexus were believed to represent an arterialized aneurysm, most likely the result of traumatic arteriovenous fistulization. Treatment consisted of surgical enucleation. At the time of this report, 29 mouths later, the dog remains free of clinical signs.     

MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY CHARACTERISTICS OF INTRACRANIAL INTRA-ARACHNOID CYSTS IN 6 DOGS

Magnetic resonance imaging (MRI) and computed tomographic imaging (CT) characteristics of intracranial intra-arachnoid cysts in six dogs are described.Of the six dogs, three were less than one year of age and 4 were males. Five of the six dogs weighed less than 11 kg. Five cysts were located in the quadrigeminal cistern.On CT images, the intracranial intra-arachnoid cysts had sharply defined margins, contained fluid isodense to CSf and did not enhance following IV administration of contrast. On MRI images, the intracranial intra-arachnoid cysts were extra-axial, contained fluid isointense with CSF and did not enhance following IV contrast. While spinal arachnoid cysts of dogs have been reported in the literature, other than the six dogs contained in this report, intracranial intra-arachnoid cysts have not to our knowledge been described in animals. These six dogs have a similar age, sex, arachnoid cysts.     

MAGNETIC RESONANCE IMAGING OF INTRACRANIAL TISSUE ACCUMULATIONS IN DOMESTIC DUCKS (Anas platyrhynchos f. dom.) WITH FEATHER CRESTS

The crested breed of domestic duck (Anas platyrhynchos f. dom.) has been described as a variety which has high pre- and postnatal mortalities, malformations in skull and brain anatomy, and several central nervous deficiencies. In addition, intracranial tissue accumulations have been diagnosed in purebred Crested ducks. The incidence, heredity and inheritance of these accumulations as well as their pathogenesis are still generally unknown. The aims of this study were to examine the head of Crested ducks, plain-headed duck breeds, and their crossbreeding relating to the incidence of intracranial alterations. These examinations were performed using magnetic resonance imaging. We found a high incidence of intracranial tissue accumulations in domestic ducks with feather crests. Creasted ducks had more intracranial tissue deposits than plain-headed ducks (p < 0.001). In the present study a correlation between the volume of the crest cushion and the volume of the intracranial tissue deposit could not be found (r = 0.014). Some of the Crested ducks had encephaloceles in addition to the crest cushion.     

IMAGING DIAGNOSIS—CONCENTRIC PERIRADICULAR LIPOMA CAUSING LUMBAR NERVE ROOT COMPRESSION IN A DOG

An 11‐year‐old, male neutered Jack Russell Terrier was presented with a nerve root signature of the right pelvic limb. Magnetic resonance imaging revealed a well demarcated, ovoid, extramedullary mass at the level of the L7 vertebral body. This showed, compared to normal spinal cord, hyperintense signal on T1‐ and T2‐weighted images, which was suppressed on gradient echo short tau inversion recovery (GE‐STIR) images. Additionally, the mass was characterized by a fat density on computed tomography images. Histopathology of the surgically excised mass was consistent with concentric periradicular lipoma, which has not been described in domestic animals yet.     

REVIEW OF DIAGNOSTIC IMAGING OF EAR DISEASES IN THE DOG AND CAT

Diagnostic imaging techniques (conventional radiography, computed tomography and magnetic resonance imaging) are an essential tool in the diagnostic work-up of ear diseases. Conventional radiography is commonly used, but often lacks sensitivity. Computed tomography (CT) and magnetic resonance (MR) are complementary imaging studies of the middle ear, labyrinth, internal auditory canal and their contents. CT provides excellent images of bony structures and is indicated where osseous changes are of greatest diagnostic importance. MR is superior in imaging soft tissue components including intralabyrinthine fluid. Therefore, more than one of these imaging techniques may be required in order to make a diagnosis.