Trophoblast emboli in the lung of a snowshoe hare (Lepus americanus)

Spontaneous migration of placental trophoblasts into maternal blood vessels and embolization to other organs (ie, lung, adrenal gland, spleen, and liver) occurs in women and certain animals with hemochorial placentation. Although considered incidental in most species, increased incidence and numbers of trophoblast emboli are reported in women with gestational diseases with arterial hypertension (pre-eclampsia and eclampsia). To the best of our knowledge, trophoblast emboli have not been reported in lagomorphs. This case report describes the identification of trophoblast emboli in the lung of a wild snowshoe hare (Lepus americanus). Death of this hare was attributed to pulmonary hemorrhages and hemothorax, but a definitive cause for the hemorrhages was not determined. It is unclear whether trophoblast embolism normally occurs in this species and represents an incidental finding, or whether it possibly contributed to rupture of pulmonary or thoracic blood vessels leading to hemorrhage.

Presumptive fibrocartilaginous embolic myelopathy in a pot-bellied pig

A case of presumptive fibrocartilaginous embolic myelopathy in a pet pot-bellied pig is described in this report. This case, which was associated with a previous trauma, highlighted the importance of advanced diagnostic imaging in pigs with clinical signs consistent with a myelopathy.

Fibrocartilaginous Embolic Encephalopathy in a Pig

A 1-year-old boar was investigated after presenting with acute onset collapse and obtundance. No significant gross lesions were observed at post-mortem examination. Histopathological investigation revealed a severe bilateral and multifocal necrotizing encephalopathy with an amorphous material, which obstructed neuroparenchymal vessels in the metencephalon and mesencephalon. Alcian blue staining identified the material as of cartilaginous origin and a diagnosis of cerebral fibrocartilaginous embolism was established. No gross evidence of vertebral disc disease was detected and the origin of the embolic material was not found. Although cerebral fibrocartilaginous embolism has been reported in a human, and rarely in animals, it has not been reported previously in the pig.

Aortic thromboembolism in a basset hound-beagle crossbred dog with protein-losing nephropathy

A 12-year-old neutered male basset hound-beagle crossbred dog with a history of protein-losing nephropathy was presented because of acute weight-bearing right hind limb lameness with hind-end paresis and intermittent splaying. The condition was painful and progressed to non-ambulatory paraparesis. The dog was referred to an emergency and specialty hospital where a diagnosis of aortic thromboembolism was confirmed. This case illustrates the challenge in diagnosing and determining the cause of aortic thromboembolism in dogs.

Magnetic resonance imaging muscle lesions in presumptive canine fibrocartilaginous embolic myelopathy

This retrospective cohort study reports the observation of magnetic resonance imaging (MRI) epaxial muscle hyperintensity in dogs diagnosed with presumptive fibrocartilaginous embolic myelopathy (FCEM) (n = 61). It further reports the observation of vertebral column hyperesthesia lasting > 12 hours. The hypothesis tested was that the finding of MRI epaxial muscle hyperintensity correlated with dogs presenting with hyperesthesia. Client-owned dogs diagnosed with presumptive FCEM by specific MRI criteria were included. Statistical analysis was performed using Fisher's exact test. Twenty-three percent (14/61) of MRIs displayed abnormal muscle hyperintensity and 43% (26/61) exhibited vertebral column hyperesthesia. No relationship was found between muscle hyperintensity and pain persisting beyond 12 hours. The muscle hyperintensity remains of unknown significance. That 43% of presumptive FCEM cases have prolonged signs of pain is a higher prevalence than previously reported, and may affect clinical differential diagnoses. This is especially significant in cases in which MRI is not possible and a presumptive diagnosis must be based on the clinical signs.

Fibrocartilaginous Embolic Myelopathy in a Calf

A 5-month-old Angus heifer with a history of acute hindlimb paresis that quickly progressed to lateral recumbency was necropsied. Gross lesions included a 6-cm segment of gray to brown discoloration and softening of the right ventrolateral spinal cord between T2 and T3. Microscopically, there was liquefactive necrosis of ventrolateral white and gray matter, and multiple intravascular emboli partially or completely occluded many intralesional and adjacent spinal and meningeal arteries and veins. Emboli were alcian blue positive, consistent with fibrocartilage of the nucleus pulposus of the intervertebral disk. No gross abnormalities were detected in the vertebrae or intervertebral disks. Fibrocartilaginous embolic myelopathy appears to be very rare in cattle; however, it should be considered in cases of acute, nonprogressive spinal cord dysfunction.

[Fibrocartilaginous embolic myelopathy in dogs: a retrospective study]

The clinical aspects of 26 dogs suspected of fibrocartilaginous embolic myelopathy (FEM) were documented and compared to results from 2 studies published in the literature. The short-term recovery capacity of 15 of these patients was also evaluated during a 30 day period by giving a neurological score. We have observed, compared to other studies, a larger proportion of cervical localization (15.4%) as well as a larger variety of race sizes for FEM. We have established that, after 30 days, 67% of patients had improved and that 88% of non-ambulatory patients had regained their ambulatory capacity. Also, patients showing signs of grey matter lesions (inferior motor neuron--IMN) as well as those having white matter lesions (superior motor neuron--SMN) had shown signs of neurological progress. Therefore, we have observed that the recovery capacity of an animal suffering from FEM does not seem to be impacted by its initial ambulatory state, nor by its lesions to IMN or SMN, although the low number of cases does not allow us to positively confirm this situation.

Fibrocartilaginous Embolic Myelopathy in Five Cats

Five cats had clinical signs, radiographic findings, and cerebrospinal fluid analyses consistent with fibrocartilaginous embolic myelopathy. All cats had an acute onset of nonpainful, asymmetrical spinal cord signs (paresis or paralysis of one or more limbs). Magnetic resonance imaging was performed in three cats. On T2-weighted images, an intramedullary lesion was revealed that was hyperintense to normal spinal cord gray matter. On T1-weighted images, the lesion was isointense. Three of the cats were euthanized, and postmortem examination confirmed myelomalacia with intralesional fibrocartilaginous emboli. Two cats survived and were clinically improved within 3 weeks.

Suspected fibrocartilaginous embolism in a cat

A 12-year-old cat was presented to the University of Queensland's Small Animal Teaching Hospital with a 1-day history of left hemiparesis of acute onset, with no evidence of trauma or toxin exposure. Neurological examination findings were consistent with a lesion in the caudal left cervical spinal cord (C6 to C8), which was non-painful and had not progressed since the onset of clinical signs. No other abnormalities were found, although myelography showed a mild swelling involving the caudal cervical and cranial thoracic spinal segments. A diagnosis of suspected fibrocartilaginous embolism was made on the basis of the history, clinical presentation and diagnostic tests results, making this case the first report of a suspected fibrocartilaginous embolism in a cat that returned to normal function.

Magnetic resonance imaging findings in spinal cord infarction in three small breed dogs

Fibrocartilaginous embolization (FCE) of the spinal cord is a common disease in large breed dogs. There are only a few reports about this entity in small breed dogs and it has never been reported in chondrodystrophic breed. For definitive diagnosis histopathologic examination is necessary. Magnetic resonance imaging (MRI) as a potential diagnostic tool for intravitam diagnosis of FCE has been mentioned before, but results have not been reported so far. This report describes the neurological findings and MRI results in three small breed dogs, including a Pekingese dog, with FCE of the spinal cord. The disease was suspected in two animals based upon clinical and MRI-appearance and confirmed in the third by histopathological examination. In all three cases, similar focal intramedullary lesions, consisting of hyperintensive signals on T2-weighted images, were detected. Based on these findings, high-field MRI may be used as an antemortem tool for the diagnosis of FCE. It is also shown that FCE can occur in chondrodystrophic dogs.

Fibrocartilaginous embolism in a chondrodystrophoid breed dog

An 8-year-old intact male Shih Tzu dog was admitted with acute-onset tetraplegia. Magnetic resonance imaging showed an abnormality of the cervical intramedullary spinal cord. Histopathological examination of a spinal biopsy confirmed the presence of intravascular cartilaginous emboli. This is the first report of an antemortem diagnosis of fibrocartilaginous embolism in a chondrodystrophoid breed dog.

Fibrocartilaginous Embolic Myelopathy in a Horse

Fibrocartilaginous embolic myelopathy was diagnosed in a 11-year-old, male, Tennessee Walking Horse by histopathological examination of the spinal cord after the horse was killed because of severe neurological dysfunction. Both ventral funiculi of C6 and C7 cervical spinal cord had extensive necrosis with blood vessels containing fibrocartilaginous emboli. A similar fibrocartilaginous embolus was observed in a single large spinal artery adjoining the vertebral leptomeninges.

FIBROCARTILAGINOUS EMBOLIC MYELOPATHY IN A SUMATRAN TIGER (PANTHERA TIGRIS SUMATRAE)

An adult, captive-born Sumatran tiger (Panthera tigris sumatrae) had been ataxic for approximately 3 mo and had been self-mutilating after an acute onset of unilateral paresis and Homer's syndrome. Histologic lesions in the cervical spinal cord were consistent with fibrocartilaginous embolic myelopathy (FCEM), and they included the presence of cartilaginous occlusion of spinal blood vessels. This is the first reported case of FCEM in a large felid and specifically a Sumatran tiger.

Dissemination of brain emboli following captive bolt stunning of sheep: capacity for entry into the systemic arterial circulation

The epidemic of bovine spongiform encephalopathy in the United Kingdom and the recognition of a variant of Creutzfeldt-Jakob disease prompted revision of the guidelines for slaughter of cattle and sheep to prevent contamination of the edible parts of the carcass with central nervous system tissue. We previously showed that captive bolt gun stunning, which is routinely used for the slaughter of cattle and sheep, causes entry of fragments of central nervous system tissue into the jugular vein. To determine whether such tissue can traverse pulmonary capillaries to enter the systemic circulation, we introduced small volumes of brain tissue that had been disrupted by stunning with a captive bolt gun into the jugular vein of sheep sent for slaughter. We examined aortic blood samples by immunocytochemistry for neurofilament and S100 proteins and by enzyme-linked immunosorbent assay for glial fibrillary acidic protein and found fragments of neurofilament- and S100-immunopositive central nervous system tissue in samples from 2 of 11 sheep and elevated glial fibrillary acidic protein in 6 sheep. Our findings suggest that central nervous system tissue that is dislodged during routine captive bolt gun stunning and slaughter of sheep can enter the systemic arterial circulation and that, in some cases, this method of slaughter of an animal infected with bovine spongiform encephalopathy would be likely to contaminate edible parts of the carcass with infective material.

Emboli in bulls killed in Spanish traditional bullfighting

The finding of brain tissue fragments in blood and lungs of cattle stunned in slaughterhouses has raised concerns about food safety in the context of the bovine spongiform encephalopathy epidemic. In the present study, the possible occurrence of brain tissue emboli in animals killed in traditional Spanish bullfighting was investigated. Thorough histological analysis of multiple possible target organs was carried out in 434 bulls. No evidence of brain tissue embolism was obtained, but emboli from diverse sources were detected in pulmonary and hepatic tissue of a significant number of animals. These emboli seem to have been caused by the use of a long sword, which extensively disrupts intra-thoracic and intra-abdominal organs and vascular structures.

Fibrocartilaginous embolism in 75 dogs: clinical findings and factors influencing the recovery rate

The records of 75 dogs with fibrocartilaginous embolism of the spinal cord were evaluated retrospectively. The diagnosis was confirmed histopathologically in 21 dogs (group A) and remained suspected in 54 patients (group B). The two groups were compared. Particular emphasis was placed on the description of physiotherapy procedures, recovery rates and prognostic criteria. Results demonstrated that fibrocartilaginous embolism affected mainly middle-aged, large- or giant-breed dogs. Clinical signs were peracute in onset, non-progressive and often asymmetric. Cerebrospinal fluid analysis was normal in the majority of dogs. Intramedullary swelling was the only abnormality detected on myelograms of these patients. A positive correlation was found between a poor prognosis and the involvement of intumescences, symmetrical clinical signs and decreased deep pain sensation. However, physio/hydrotherapy instituted immediately after the diagnostic work-up seemed to have a major influence on the recovery rate.

Embolized mesothelial cells within mediastinal lymph nodes of three dogs with idiopathic haemorrhagic pericardial effusion

Embolized mesothelial-like cells were detected within pericardial lymphatics and mediastinal lymph nodes of three golden retrievers with idiopathic haemorrhagic pericardial effusion. Morphological, cytochemical, and immunohistochemical investigations indicated that the embolized cells most likely originated from the pericardial mesothelium. None of the dogs showed evidence of an underlying neoplastic disorder. Such findings have not been reported previously in animals, but so-called "benign mesothelial cell inclusions" have been reported in mediastinal lymph nodes of human patients with pleuritis and pericarditis but no history of neoplasia. The present findings in dogs indicate the need to distinguish between lymphatic emboli arising from reactive mesothelial cells and metastases arising from a mesothelioma.

Transvenous coil embolization of portosystemic shunt in dogs

This paper describes transvenous coil embolization of portosystemic shunt in 10 dogs. Clinical signs resolved in 4 dogs with extrahepatic shunt, and in 3 dogs with intrahepatic shunt. Two dogs of less than 3 kg died because of migration of coils to the level of the main pulmonary artery. One dog was euthanized when acute portal hypertension developed following transvenous coil embolization. Transvenous coil embolization seems to be a less invasive alternative to surgical ligation in dogs with a single intrahepatic portosystemic shunt.

Results of myelography in seven dogs with myelomalacia

Myelomalacia is a hemorrhagic infarction of the spinal cord that can occur as a sequel to acute spinal cord injury. Myelomalacia may be focal or diffuse; the diffuse form is typically associated with cranial migration of neurologic signs ("ascending syndrome") and is often fatal. In a retrospective study of seven affected dogs, diffuse myelomalacia was associated with intervertebral disc extrusion in five dogs, focal myelomalacia was associated with fibrocartilagenous embolus in one dog, and had no apparent cause in one dog. The myelographic signs included a variable degree of contrast medium infiltration into the spinal cord in six dogs (86%) and/or spinal cord swelling in six dogs (86%). In one dog with focal myelomalacia, the only myelographic sign was spinal cord swelling.

Liver blood perfusion as a possible instrument for fetal growth regulation

Placental and fetal liver blood perfusions are reduced in intrauterine growth-restricted human fetuses. We hypothesized that changes in fetal liver blood supply can alter fetal growth. In nine ewes with twin pregnancies at a gestational age of 119+/-2 days, a stent (4 mm) was placed into the ductus venosus of one twin (DV(stent) group). Alternatively, in 17 near term sheep with twin (n=11) or singleton (n=6) pregnancies, a DV was blocked with an embolization coil (DV(coil) group) for about one week. The cell proliferation rate (pKi-67) was determined in the liver, heart, skeletal muscle, kidneys and placenta. The dilatation or occlusion of the DV did not change placental perfusion on the first day or later after surgery. The liver blood supply was decreased in the DV(stent) group by more than half from 499+/-371 to 278+/-219 ml min(-1) (mean+/-s.d., n=4), and increased two-fold in the DV(coil) group (P< 0.05). The percentage of liver/body weight was decreased from 3.9+/-0.6 per cent in control twin to 3.0+/-0.2 per cent (n=3) in the DV(stent) group. Occlusion of the DV lead to an increase in the percentage of liver/body weight from 3.4+/-0.8 per cent to 4.3+/-0.8 per cent (n=11, P< 0.05). Reduced liver blood supply in the DV(stent) group was associated with a decrease of cell proliferation in the liver from 12.43+/-2.31 to 6.5+/-0.62 (nuclei microm(2) 10(-4), n=3, P=0.058), in heart from 1.14+/-0.03 to 0.93+/-0.02 (nuclei microm(2) 10(-4), P< 0.05), and in skeletal muscle from 0.82+/-0.05 to 0.54+/-0.01 (nuclei microm(2) 10(-4), P< 0.05). The increased liver blood perfusion following occlusion of the DV increased cell proliferation sixfold in the liver, (n=9, P< 0.005) and twofold in heart muscle, skeletal muscle and the kidneys (P< 0.05), whereas no significant difference was seen in the placenta. The expression of mRNA for IGF-I and IGF-II in the liver was increased in the DV(coil) group. In conclusion, these results suggest that liver blood perfusion can regulate fetal growth.

Tetraparesis in a cat with fibrocartilaginous emboli

An 8-year-old cat, with a history of ataxia that progressed to tetraparesis over a 5-day period, was evaluated. A lesion was localized to the sixth cervical (C6) to second thoracic (T2) spinal cord segments based on physical and neurological examination findings. Blood work was unremarkable, as was survey radiography of the thoracic and abdominal cavities. Cerebrospinal fluid analysis showed moderate neutrophilic inflammation. A definitive diagnosis was not made until necropsy, at which time intravascular fibrocartilaginous embolization (FCE) of the cervical spinal cord was identified. This is only the third published report of FCE in the feline species and the first such case involving the cervical spinal cord.

Long-term cannulation of the vena cava of rats for blood sampling: local and systemic effects observed by histopathology after six weeks of cannulation

A cannulation system with fixation by a metal cuff around the tail was used for blood sampling. The cannula was guided subcutaneously and positioned in the vena cava after entering the body via the femoral vein. Histopathology was performed after long-term cannulation of up to 35 and 45 days. The presence of the cannula in the vena cava induced endothelial hypertrophy and hyperplasia accompanied by stromal hypertrophy. The endothelial activation was not limited to the vena cava but was also observed in both the cannulated vena iliaca and the contralateral control vena iliaca, the latter showing only minor alterations. In the lung, thrombi were noted in the larger lung arteries; and foreign body emboli, probably situated in the alveolar septi, could be detected occasionally. Inflammatory reactions in the tail at the site of cuff fixation consisted of a mixture of acute and chronic inflammatory responses. The chronic inflammation extended into the tail muscles, as shown by the presence of fibrous tissue associated with muscle degeneration. In conclusion, prolonged venous cannulation in rats resulted in local alterations in the veins, small emboli in the lungs and a moderate to marked inflammation in the tail. However, the procedure itself was well tolerated by the animals.

Fibrocartilaginous embolic myelopathy in miniature schnauzers

In large- and giant-breed dogs, fibrocartilaginous embolic myelopathy (FCEM) is a well-recognized syndrome of acute spinal cord infarction caused by embolization of fibrocartilage. The miniature schnauzer is reportedly the most frequently affected small breed, although clinical data from only six miniature schnauzers with FCEM is available in the literature. The purposes of this study were to determine the relative frequency of FCEM compared to other causes of myelopathy in miniature schnauzers, to characterize the clinicopathological features of FCEM in 38 miniature schnauzers, and to directly compare FCEM and intervertebral disk herniation in miniature schnauzers with respect to age at diagnosis; gender; neuroanatomical localization; and progression, asymmetry, and severity of neurological deficits. Fibrocartilaginous embolic myelopathy was the most common cause of myelopathy in miniature schnauzers. Age at diagnosis, asymmetry and severity of neurological deficits, and lack of progression of clinical signs after 24 hours assisted in distinguishing FCEM from intervertebral disk herniation. Fibrocartilaginous embolic myelopathy-related mortality in miniature schnauzers was significantly lower than mortality rates reported for affected large and giant breeds. Only 22% of miniature schnauzers were euthanized because of their disease, although the vast majority of survivors failed to achieve complete neurological recovery.

Jugular venous emboli of brain tissue induced in sheep by the use of captive bolt guns

Emboli of central nervous tissue were detected in the jugular venous blood of two of 15 sheep stunned with a conventional cartridge-operated captive bolt gun and in two of 15 sheep stunned with a pneumatically activated gun. No emboli were detected in arterial blood from these sheep or in venous blood from sheep stunned electrically. Emboli from an animal with BSE could transmit the disease to people.

Obstruction of ductus venosus stimulates cell proliferation in organs of fetal sheep

In growth restricted fetuses, hepatic blood flow is reduced. This suggests the hypothesis that liver blood flow controls fetal growth. In 11 near term sheep the ductus venosus was blocked with an embolization coil in one fetus (experimental) and left patent in the twin (control). Arterial catheters were placed in both fetuses. After termination [mean (s.d.) 5 days (2) after surgery] the fetal body and organs were weighed. The cell proliferation rate (pKi-67) was determined in tissue samples of the liver, heart, skeletal muscle, kidneys and placenta (n=6). Blood flow through the umbilical vein measured by Doppler ultrasound did not differ in control and experimental fetuses [experimental: 600 (101) ml/min; control: 626 (89) ml/min]. In experimental fetuses, blood flow through the ductus venosus was negligible (colour Doppler), and thus hepatic blood flow was increased. Absolute and relative (percentage of body weight) liver weights were increased in experimental fetuses [liver weight: 119 (34) g versus 84 (17) g; relative liver weight: 4.3 (0.8) per cent versus 3.4 (0.8) per cent;P=0.002, n=11]. The cell proliferation rate was increased significantly (twofold) in heart muscle, skeletal muscle and kidneys, and sixfold in liver. It is concluded that increases of hepatic blood flow stimulate cell proliferation in major organs of the ovine fetus.

Fibrocartilaginous embolism of the spinal cord (FCE) in juvenile Irish Wolfhounds

This study describes the occurrence of fibrocartilaginous embolism of the spinal cord (FCE) in eight juvenile Irish Wolfhounds that were presented within a period of 16 months (1996-1997). The dogs, seven males and one female between eight and 13 weeks of age, were presented because of an acute onset of abnormal locomotion. Five dogs were euthanized and FCE was diagnosed by the histomorphological presence of focal myelomalacia and Alcian blue-positive-nucleus-pulposus material in the spinal cord vasculature. Three dogs, which were thought to have FCE because of their clinical symptoms, improved with partial or almost complete return to normal locomotion. Although the observed high incidence may be a coincidence, oral information from breeders and lay reports of similar cases in journals for dog breeders from various countries suggest that FCE is a common disorder in young Irish Wolfhounds.

Fibrocartilaginous embolism in dogs

Fibrocartilage embolism originating from the intervertebral disk nucleus pulposus may induce acute spinal cord infarction. The main characteristics of this syndrome (acute, nonprogressive transverse myelopathy) are well known by the clinician. However, the impression that this disease is more commonly encountered in giant breeds of dogs, with intumescence involvement and loss of nociception may have been skewed relative to published data. A review of the vascularization peculiarities of the spinal cord explains the still hypothetical pathogenesis and helps to understand the diversity of the clinical presentation.

Fibrocartilaginous emboli in a tayra (Eira barbara): a case report

An 8-yr-old male tayra (Eira barbara) was presented with acute onset of pelvic limb paralysis. Radiography was unremarkable. Neurologic examination showed signs consistent with an intramedullary lesion between the second thoracic and fifth lumbar spinal cord segments. The animal's condition did not improve after 4 days of aggressive glucocorticoid therapy, and euthanasia was performed. Histologic examination of the spinal cord showed amorphous emboli suggestive of cartilaginous fragments within spinal veins. A diagnosis of fibrocartilaginous emboli was made, the first known case in a mustelid.

Intravascular cartilaginous emboli in the spinal cord of turkeys

A flock of 15-wk-old tom turkeys experienced an acute onset of paresis and ataxia in 75% of the birds after handling. Cartilaginous emboli were found in the spinal cord vasculature from one of five turkeys at this initial presentation. Most of the flock recovered within 6 days, but 3% remained paretic. Myelomalacia was present in three turkeys that failed to recover. Two of these turkeys had cartilaginous and osseous emboli within the medullary spaces of the vertebral bodies, internal vertebral venous sinuses, and spinal cord. The third turkey had vascular and spinal cord necrosis consistent with thrombosis and resultant ischemia. These changes suggest that turkeys may be susceptible to a syndrome analogous to fibrocartilaginous embolism of the spinal cord in mammals. The articular cartilage of the vertebral body endplate may be the source of the emboli. The turkeys with emboli had articular cartilage defects consisting of matrix eosinophilia, chondrocyte loss, multicellular cluster formation, cartilage detachment, and cartilage clefts. Cartilaginous emboli in the spinal cord should be considered as a potential cause for acute paresis and ataxia, especially in flocks with preexisting abnormalities of the vertebral articular cartilage surfaces.

Conditions of the thoracolumbar spine

Neurological deficits suggesting trauma to the spinal cord in the thoracolumbar area are the most common clinical presentation of neurosurgical conditions. By far, the most common cause of thoracolumbar spinal cord dysfunction is intervertebral disc disease. Disc herniation and subsequent spinal cord compression usually requires prompt medical treatment, then referral for high detail radiographs, myelogram, and surgical decompression. Other causes of thoracolumbar spinal cord dysfunction include neoplasia, discospondylitis, fibrocartilaginous embolism, and degenerative myelopathy.

Fibrocartilaginous embolism of the spinal cord in dogs: review of 36 histologically confirmed cases and retrospective study of 26 suspected cases

Clinical features of 36 dogs with histologically confirmed fibrocartilaginous embolism (FCE) were contrasted with those of 26 dogs in which FCE was suspected based on characteristic clinical findings and the absence of compressive spinal cord disease on myelography. Dogs with confirmed and suspected FCE were of similar signalment, and had acute, nonprogressive dysfunction, often associated with trauma or exercise. The "suspected" group included fewer giant breeds and more often had asymmetric lesions, intact nociception, and upper motor neuron involvement. Dog size and severity of clinical signs probably contributed to owners choosing euthanasia in dogs with confirmed lesions. Accordingly, data from such patients may be skewed relative to these clinical features.

Fibro-cartilaginous embolism in a cat

A nine-year-old cat was presented with a history of an acute onset of paraplegia. On the basis of the neurological examination, the lesion was localised between the fourth lumbar and third sacral segments (L4 to S3) of the spinal cord. Investigations included radiography, myelography, cerebrospinal fluid analysis, routine haematology and biochemistry, feline leukaemia virus testing and urinalysis. A definitive diagnosis was not achieved and the cat was euthanased 12 days after presentation. Post mortem examination revealed infarction of the spinal cord secondary to fibrocartilaginous embolisation. This is the first reported case of fibrocartilaginous embolism in the cat in the UK.

Canine transfusion reactions and their management

There is a wide range of mechanisms by which transfusion reactions may occur. These reactions typically are categorized as immune- or nonimmune-mediated and also as to whether they are acute or delayed in nature. The type and severity of clinical signs vary according to the specific reaction present. Many reactions can be prevented with the use of standard and appropriate transfusion medicine procedures. These methods include careful collection and storage of blood products, adequate screening and blood typing of donor dogs, crossmatching donor and recipient blood, use of component therapy, correct administration of blood products, and the use of pretransfusion prophylaxis when appropriate. Because many reactions are dose dependent, careful monitoring of transfusions cannot be overemphasized. Rapid recognition of a transfusion reaction and immediate discontinuation of the transfusion, along with appropriate supportive therapy, is essential for the successful treatment of transfusion reactions. A summary of transfusion reactions including clinical signs, diagnosis, and basic treatment protocols is given in Table 4. When used appropriately, transfusion of blood products can be a highly beneficial, low-risk form of therapy.

Vascular pattern of a metastatic liver tumor in a dog:--a scanning electron microscopic study of resin casts

Metastasis of a malignant mixed tumor occurring in the abdominal wall was found in the liver of a 15-year-old dog male. The vascular system of the metastatic lesion was examined by scanning electron microscopy using the resin cast technique. The existence of arterio-portal shunts was confirmed. The shunts arose from branches of the hepatic artery in retrograde or vertical direction and merged into the capillary plexus replacing the branches of the portal vein, forming the so-called thread and streaks vessel in the field of hepatic angiography. Vessels with the thread and streaks appearance histologically represented tumor emboli growing in the lumen of a large branch of the portal vein. There were capillaries running inside along the portal vein and forming a longitudinal dense network in the vein. Branches of the hepatic artery feeding the metastatic lesion were well developed and formed a coarse arterial network in their course. Tributaries of the hepatic vein from the lesion were also well developed.

Non-steroidal anti-inflammatory drugs in domestic animals: II Disposition and clinical indications

Most non-steroidal anti-inflammatory drugs (NSAID's) have similar absorption and disposition characteristics. Absorption after oral administration is good, extensive plasma protein binding results in a small volume of distribution, and excretion of metabolites occurs mainly in the urine after hepatic biotransformation of the active drug. The main clinical indications for use of NSAID's are anti-inflammatory, analgesic and antipyretic, and an increasing list of new indications are continually being found. The disposition, pharmacokinetics and clinical indications of non-steroidal anti-inflammatory drugs in domestic animals are reviewed.

Fibrocartilaginous emboli

Fibrocartilaginous embolism (FCE) is an acute ischemic myelopathy, primarily of large or giant breed dogs, which results from occlusion of blood vessels within the spinal cord parenchyma or the adjacent leptomeninges by masses of fibrocartilage. Lateralizing and asymmetric neurologic deficits are very suggestive of spinal cord infarction. The diagnosis of FCE is made by eliminating causes of acute compressive myelopathy such as trauma and intervertebral disc herniation. Patients with lower motor neuron deficits secondary to FCE have a more guarded prognosis than those with upper motor neuron deficits. In most instances, if recovery is to occur, improvement will be evident within the first 10 days after the onset of clinical signs.

Effects of treatment with ticlopidine in heartworm-negative, heartworm-infected, and embolized heartworm-infected dogs

Ticlopidine hydrochloride was evaluated for its effectiveness in inhibiting platelet aggregation and serotonin release in 5 laboratory Beagles before and after heartworm implantation with 7 adult Dirofilaria immitis, and after embolization with 7 dead heartworms to mimic what happens after heartworm adulticide treatment. Five other laboratory Beagles, similarly implanted and embolized with heartworms, were used as nonmedicated controls. During the heartworm-negative stage, the dosage of ticlopidine that inhibited adenosine diphosphate (ADP)-induced platelet aggregation in 5 dogs by at least 50% after 5 days of treatment was 62 mg/kg of body weight once a day. In the same dogs implanted with 7 adult heartworms 21 days previously, mean (+/- SD) ticlopidine dosage required to obtain similar results was 71 (+/- 13) mg/kg given once daily. During the 21 days after dead heartworms were implanted in heartworm-infected dogs, mean ticlopidine dosage was 108 (+/- 35) mg/kg (range, 62 to 150 mg/kg). Ticlopidine treatment was associated with increased platelet numbers in all 5 dogs during the heartworm-negative stage and in 4 of 5 dogs during the heartworm implantation and heartworm embolization stages. Mean platelet volume tended to decrease as platelet numbers increased. At necropsy, gross and histologic pulmonary lesions were less severe in ticlopidine-treated dogs than in nonmedicated control dogs.

Effects of treatment with aspirin or aspirin/dipyridamole combination in heartworm-negative, heartworm-infected, and embolized heartworm-infected dogs

To determine the drug dose required to inhibit platelet reactivity by at least 50%, 2 drug regimens were evaluated in heartworm-negative, heartworm-infected, and heartworm-infected dogs embolized with dead heartworms. Aspirin, or a combination of aspirin and dipyridamole, were administered to 2 groups of Beagles (n = 5 each) for 5 to 9 days; a third group of 5 Beagles served as nontreated controls. For heartworm-negative dogs, mean (+/- SD) aspirin dosage that inhibited collagen-induced platelet reactivity by at least 50% was 6 (+/- 2) mg/kg of body weight given once daily. The aspirin/diphridamole combination dosage was 1 mg of each drug/kg given every 12 hours. All dogs (n = 15) were implanted with 7 adult heartworms each and remedicated (or not treated) beginning at 21 days after heartworm implantation. In heartworm-infected dogs, mean aspirin dosage required to inhibit collagen-induced platelet reactivity greater than or equal to 50% was 10 (+/- 6) mg/kg. Mean dosage of aspirin/dipyridamole combination was 1.6 +/- (0.5) mg of each drug/kg given every 12 hours. When platelet reactivity in response to collagen was determined to be inhibited by at least 50% in all medicated dogs, each dog (n = 15) was embolized with 7 dead adult heartworms to mimic heartworm adulticidal treatment. Platelet reactivity was monitored for 21 days after treatment, and drug dose was adjusted to maintain platelet inhibition by at least 50%. In embolized dogs, mean aspirin dosage was 17 (+/- 14) mg/kg given once daily. Mean dosage of the aspirin/dipyridamole combination was 2.8 (+/- 1.3) mg of each drug/kg given every 12 hours. All dogs (n = 15) were euthanatized 21 days after heartworm embolization. Each lung lobe was evaluated for severity of lesions and presence of organized or fibrinous thrombi. Lesion severity in the aspirin- and aspirin/dipyridamole-treated dogs was not significantly different from that in control dogs.

Acute pelvic limb paralysis induced by a lumbar fibrocartilaginous embolism in a sow

A diagnosis of fibrocartilaginous embolism was made in a mature mixed-breed sow with a history of an acute onset of pelvic limb paralysis. Within a single section of lumbar spinal cord, there was severe focally-extensive infarction of the right ventral gray horn. Within affected white matter, there was dilatation of multiple myelin sheaths with concurrent axonal swelling. A smaller focus of infarction was present on the contralateral side. Arteries at the periphery of both lesions contained a blue-gray material with staining characteristics similar to that evidenced by the nucleus pulposus present within intervertebral discs. Grossly, no abnormalities were present within the vertebral column.

Fibrocartilaginous embolism

Fibrocartilaginous embolism (FCE) is an acute myelopathy that affects primarily dogs and human beings, and occasionally other mammalian species. It is frequently associated with trauma or vigorous exercise; in dogs it tends to affect mature non-chondrodystrophoid and giant breeds. Signs are acute and frequently indicate a very lateralized or focal lesion within the spinal cord, with resultant disparities in sensory and motor function. Lower motor neuron disease is common and hyperesthesia is unusual. The primary differential diagnoses are concussive trauma and intervertebral disc herniation, but the acute onset of strongly lateralizing spinal cord deficits without hyperesthesia in a breed at risk is strongly suggestive of the FCE syndrome. Attention must be given to other systemic diseases that might also give rise to emboli in the absence of FCE. Diagnosis is based on history, clinical signs, and elimination of other differential diagnoses. Treatment is largely supportive, although high doses of methylprednisolone may be beneficial early in the course of the disease. Affected patients may make a functional recovery if deep pain sensation is preserved and there are not complete lower motor neuron signs in affected limbs or sphincters.

Multifocal ischaemic encephalomyelopathy associated with fibrocartilaginous emboli in the lamb

Multifocal, arterial, fibrocartilaginous embolism of the cervical spinal cord, medulla oblongata and cerebellum is described in a neonatal lamb. The emboli contained mucosubstances which, by the Alcian blue critical electrolyte concentration method, were identified as mainly keratan sulphate. This composition indicates the probable origin of emboli from the nucleus pulposus of intervertebral discs. Possible modes of entry of such material into the spinal cord vasculature are reviewed and a mechanism proposed to explain the localization of emboli in spinal cord, brain stem and cerebellar arteries in this case.

Fibrocartilaginous embolism and ischemic myelopathy in a four month old German shepherd dog

Clinical signs and postmortem findings are described in a four month old German Shepherd dog with fibrocartilaginous embolism of the spinal cord. Ischemic myelopathy involved spinal cord segments C7 to L1. No evidence of degeneration or herniation of intervertebral discs was found at necropsy.

Platelet-fibrin embolism in a rhesus macaque: angiographic and pathologic studies comparing fluorescein and indocyanine green

A male rhesus macaque was found to have what appeared to be numerous platelet-fibrin emboli in retinal vessels in the perimacular area. Indocyanine green (ICG) dye fluorescence and fluorescein angiograms of the fundus demonstrated leakage of fluorescein, but not ICG, from the involved arterioles. Histopathologic changes in the eyes included occlusion of retinal and choroidal vessels with platelet-fibrin emboli, inner retinal ischemia, ischemic injury to the parafoveal capillary bed distally to occlusion of precapillary arterioles, and retinal exudate limited to the regions of capillary damage. Differential leakage of fluorescein may be explained by the difference in binding affinities of the 2 dyes to blood protein: 20% to 40% of the circulating fluorescein is unbound, and 98% of ICG is bound to serum albumin. Simultaneously or serially performed angiograms with fluorescent probes of different sizes might be used to obtain a qualitative measure of vascular integrity in persons with embolism, diabetic retinopathy, sickle cell retinopathy, vasculitis, and other disorders known to produce focal retinal and choroidal vascular occlusion.