Central nervous system syndrome associated with Marek’s disease in Hubbard broilers

Marek’s disease (MD) has a high economic impact in poultry production worldwide. MD consists of several pathologic syndromes of which the most commonly encountered are lymphoproliferative syndromes such as acute MD. Sporadically, MD leads to central nervous system syndromes characterized by non-neoplastic brain pathology. In this case report, an onset of neurological signs on two different broiler farms, housing ‘slow-growing’ Hubbard JA 757 broilers, is described. On the first farm, clinical signs were observed from 42 days of age onwards and on the second farm, respectively from 42 (stable 1) and 30 days (stable 2) of age onwards. The neurological symptoms consisted of acute central nervous system signs, which started with flaccid neck paralysis. Histopathological examination revealed multifocal perivascular cuffing of CD3 positive mononuclear cells in the brain tissues. These findings pointed towards the development of transient paralysis. qPCR analysis confirmed the diagnosis. In broiler flocks, which only have a limited life span, vaccination is not common practice. In flocks of slow-growing breeds, outbreaks of MD might become more important again. Therefore, vaccination of slow-growing broilers against MD seems recommended.

Lungworm infection with Otostrongylus circumlitus in a free-ranging harbor seal (Phoca vitulina)

A young wild harbor seal (Phoca vitulina) was found stranded on the North Sea coast at Kok- sijde (Belgium)and was admitted to a rehabilitation center where it died one day later. Full ne- cropsy with histopathology was performed. Gross examination revealed severe diffuse hemorr- hagic and emphysematous pneumonia with the presence of 6-10 cm-large nematodes. The nema- todes were found in the trachea, large bronchi, right heart and pulmonary arteries, and subsequently identified as Otostrongylus circumlitus. Histologic examination demonstrated severe eosinophilic to granulomatous bronchointerstitial pneumonia with intralesional nematodes. It was concluded that the seal died of severe verminous pneumonia. In this case report, the importance of lungworm infection, which is a common and critical disease in young seals, is highlighted.

Oak leaf (Quercus spp.) intoxication in a sheep

A twenty-year-old ewe presented with acute lateral decubitus, tremor and dyspnea, followed by death. Post-mortem examination revealed a large amount of oak leaves in the rumen, reticulum and omasum. The duodenum had a focal hemorrhagic content and multifocal hemorrhages were present in several organs. Histopathological examination of the kidneys showed characteristic lesions of oak intoxication, such as intratubular hemorrhage, tubular degeneration and necrosis. This case report illustrates the importance to include oak intoxication in the differential diagnosis of acute death in sheep and the value of post-mortem and histopathological examination.

Infectious canine hepatitis, not only in the textbooks: a brief review and three case reports

Infectious canine hepatitis (IHC) caused by canine adenovirus 1 (CAdV-1) is a classic disease in dogs causing severe illness in non-vaccinated dogs. For this reason, CAdV-1 is incorporated in the standard core vaccination. Because of widespread vaccination, this disease is only rarely seen by the veterinary practitioner. However, ICH does occur in Belgium, especially when vaccination is not adequate. In this brief review, the authors intend to refresh the knowledge of ICH illustrated by three recent cases.

The use of equine chondrogenic-induced mesenchymal stem cells as a treatment for osteoarthritis: A randomised, double-blinded, placebo-controlled proof-of-concept study

BACKGROUND

There is a need to improve therapies for osteoarthritis in horses.

OBJECTIVES

To assess the efficacy of equine allogeneic chondrogenic-induced mesenchymal stem cells combined with equine allogeneic plasma as a novel therapy for osteoarthritis in horses.

STUDY DESIGN

Randomised, double-blinded, placebo-controlled experiment.

METHODS

In 12 healthy horses, osteoarthritis was induced in the metacarpophalangeal joint using an osteochondral fragment-groove model. Five weeks after surgery, horses were randomly assigned to either an intra-articular injection with chondrogenic-induced mesenchymal stem cells + equine allogeneic plasma (= intervention) or with 0.9% saline solution (= control). From surgery until the study end, horses underwent a weekly joint and lameness assessment. Synovial fluid was collected for cytology and biomarker analysis before surgery and at Weeks 5, 5 + 1d, 7, 9 and 11. At Week 11, horses were subjected to euthanasia, and the metacarpophalangeal joints were evaluated macroscopically and histologically.

RESULTS

No serious adverse events or suspected adverse drug reactions occurred during the study. A significant improvement in visual and objective lameness was seen with the intervention compared with the control. Synovial fluid displayed a significantly higher viscosity and a significantly lower glycosaminoglycan concentration in the intervention group. Other biomarkers or cytology parameters were not significantly different between the treatment groups. Significantly less wear lines and synovial hyperaemia were present in the intervention group. The amount of cartilage oligomeric matrix protein, collagen type II and glycosaminoglycans were significantly higher in the articular cartilage of the intervention group.

MAIN LIMITATIONS

This study assessed the short-term effect of the intervention on a limited number of horses, using an osteoarthritis model. This study also included multiple statistical tests, increasing the risk of type 1 error.

CONCLUSIONS

Equine allogeneic chondrogenic-induced mesenchymal stem cells combined with equine allogeneic plasma may be a promising treatment for osteoarthritis in horses. The Summary is available in Spanish - see Supporting Information.

Treatment of a malignant peripheral nerve sheath tumor by intravenous administration of combretastatin A4-phosphate in a dog

A fifteen-year-old, male, castrated American Staffordshire terrier was presented with a subcutaneous, ulcerated mass on the right carpal joint. Thoracic radiographs and abdominal ultrasound were both negative for metastatic disease. Punch biopsies revealed the histopathological diagnosis of a malignant peripheral nerve sheath tumor. Due to the extent of the primary mass, local excision was not possible, and amputation of the limb was not an option for the owner. The dog was treated with intravenous administration of combretastatin A4-phosphate, a vascular disrupting agent. A biopsy was taken before and after treatment and power-Doppler ultrasound and contrast-enhanced ultrasound were performed to assess pre- and posttreatment evaluation of the tumor vasculature. The treatment resulted in massive necrosis of the tumor.

A single dose of intravenous combretastatin A4-phosphate is reasonably well tolerated and significantly reduces tumour vascularization in canine spontaneous cancers

Combretastatin A4-phosphate (CA4P) is an anti-tumour vascular targeting agent which selectively blocks tumour blood flow. Research on CA4P in rodent tumour models is extensive; however, knowledge of its effect on spontaneous cancer is scarce. This study was conducted in canine patients with spontaneous solid tumours. The goal was to assess the toxicity and efficacy of CA4P in various spontaneous tumour types. Eight dogs with spontaneous tumours were enrolled and treated with a single dose of 75 mg m^-2 intravenous CA4P. The dogs were screened and monitored before and after injection. Pre- and post-treatment tumour blood flow was analysed in vivo by power Doppler ultrasound (PDUS) and contrast-enhanced ultrasound (CEUS). Vessel destruction and tumour necrosis were evaluated by histopathology. Clinically relevant toxicity was limited to one case of temporary tetraparesis; other adverse events were mild. Significant cardiovascular changes were mostly confined to changes in heart rate and cTnI levels. Macroscopic tumour size reduction was evident in 2 dogs. Based on PDUS and CEUS, CA4P induced a significant decrease in vascular index and tumour blood flow. Post-treatment, histopathology revealed a significant increase of necrotic tumoural tissue and a significant reduction in microvessel density in tumoural tissue. Anti-vascular and necrotizing effects of CA4P were documented in a variety of canine spontaneous cancers with only minimal side effects. This is the first study reporting the administration of CA4P to canine cancer patients with in vivo and ex vivo assessment, and a first step toward implementing CA4P in combination therapies in veterinary oncology patients. The use of CA4P in canine patients was approved and registered by the Belgian Federal Agency for Medicines and Health Products (FAMHP) (approval number 0002588, registration number 6518 ID 2F12).

Caniene cutane mastceltumoren

Caniene cutane mastceltumoren (cMCT) zijn een vaak voorkomende neoplasie in de eerstelijnspraktijk. In 96% van de gevallen kunnen cMCT worden gediagnosticeerd via cytologie. Het stellen van een prognose is echter geen evidentie omwille van hun variabel biologisch karakter. Aan de hand van verschillende factoren, zoals tumorlocatie, de aanwezigheid van systemische klachten en metastasen, histologische en cytologische gradering, proliferatiemerkers, KIT-lokalisatiepatroon, KIT-mutatie en de tumorvrije randen, wordt de prognose ingeschat. De gekozen behandeling is gebaseerd op het resultaat van deze prognostische factoren, het klinisch stadium en de lokalisatie van de tumor. Mogelijke behandelingen zijn chirurgie, radiotherapie, chemotherapie, elektrochemotherapie, tyrosine-kinasereceptorinhibitor, cryotherapie en intraregionale behandeling met gedeïonizeerd water.

Embryonal Rhabdomyosarcoma of the Oesophagus in a Young Dog

A 15-month-old great Dane dog, showing clinical signs related to hypertrophic osteopathy, was diagnosed radiographically with a mass in the region of the thoracic oesophagus. Exploratory thoracotomy revealed an extensive, highly vascularized and locally invasive oesophageal mass and the presence of nodules in adjacent lung lobes. The dog was humanely destroyed intra-operatively. Histological examination revealed that the mass was an embryonal rhabdomyosarcoma. This is the first report of rhabdomyosarcoma of the oesophagus of a dog. Rhabdomyosarcoma should be considered a differential diagnosis when a mass adjacent to the oesophagus is diagnosed.

Intratumoural interleukin 12 gene therapy stimulates the immune system and decreases angiogenesis in dogs with spontaneous cancer

Interleukin 12 (IL-12) is a powerful immunostimulatory cytokine with a strong antitumoural activity. In this work, the immunological, anti-angiogenic and clinical effects of three consecutive intratumoural IL-12 electrogene therapy (EGT) treatments were evaluated in nine dogs with spontaneous cancer. In all the dogs, tumour biopsies and blood samples were taken prior, during and after the intratumoural IL-12 EGT (on days 1, 8, 35 and 1, 3, 8, 15, 35, respectively). An initial decrease in immune cells was followed by an increase above baseline 1-3 weeks after treatment initiation. Interestingly, the decrease in peripheral leukocytes 2 days after the first intratumoural IL-12 EGT coincided with erythema and tumour swelling. Transient increases of IL-12 and interferon γ were measured in the serum and the tumour tissue, whereas IL-10 transiently increased only in the serum. The effect of intratumoural IL-12 EGT on the levels of IL-24 and vascular endothelial growth factor in the sera and tumour biopsies differed per dog. Via contrast-enhanced ultrasound (US) (on days 1, 8 and 35), we demonstrated that intratumoural IL-12 EGT resulted in a significant decrease of the relative blood volume and blood flow speed in the tumour compared with baseline. Metastases were present in two dogs. In one of these dogs, IL-12 EGT of the primary tumour caused a transient partial regression of the metastases, but not of the primary tumour. The second dog with metastases did not survive long enough to complete the entire treatment cycle. Despite encouraging immunostimulatory and anti-angiogenic effects after intratumoural IL-12 EGT, no clinically relevant outcomes were observed in this study, as persistent tumour regression could not be obtained. On the other hand, the laboratory and US results hold great promise for combinatorial strategies of intratumoural IL-12 EGT with conventional antitumour (immuno)therapies.

Testiculaire aandoening van seksuele differentiatie (78,XX SRY-negatief) bij een vrouwelijke Franse buldog

Een tien maanden oude, vermeend vrouwelijke, intacte Franse buldog werd op de Faculteit Diergeneeskunde te Merelbeke (UGent) aangeboden met een vergrote clitoris en purulente vaginale uitvloei. Als therapie werd voorgesteld om de vergrote clitoris te verwijderen om verdere irritatie te vermijden en tegelijkertijd een gonadectomie uit te voeren aangezien de eigenaars geen fokplannen hadden. Intraoperatief werd een afwijkende genitaaltractus vastgesteld, waarbij macroscopisch een normaal uitziende baarmoeder aanwezig was maar waarbij de gonaden testes leken in plaats van ovaria. Histologisch onderzoek van het verwijderde weefsel toonde aan dat het inderdaad over bilaterale testes aansluitend op een normale baarmoeder ging. Karyotypering en de moleculaire analyse van het SRY-gen resulteerden in een 78,XX SRY-negatief karyotype. Bij de Franse buldog werd bijgevolg finaal een 78,XX SRY-negatief testiculaire aandoening van seksuele differentiatie, i.e. “disorder of sex development” (DSD) gediagnosticeerd.

Haemangiosarcoma in a captive Asiatic lion (Panthera leo persica)

A 2.7-year-old male captive Asiatic lion (Panthera leo persica) died unexpectedly without preceding symptoms. Gross necropsy revealed liver and lung tumours, which proved to be haemangiosarcomas by histopathology. Some of the liver tumours were ruptured, leading to massive intra-abdominal haemorrhage and death. Haemangiosarcomas are rare in domestic and exotic felids, occurring in skin, thoracic-abdominal cavity and bones. Although these tumours mainly appear to be occurring in older cats, they are sometimes observed in younger animals, as in the present case. This is the first description of haemangiosarcoma in a young Asiatic lion.

Canine mammary tumours, an overview

Canine mammary tumours (CMTs) are the most common neoplasms in intact female dogs. Although the prevalence of these tumours decreases in regions where preventive ovari(ohyster)ectomy is performed, it remains an important disease entity in veterinary medicine. Moreover, treatment options are limited in comparison with human breast cancer. Nevertheless, recent human treatment protocols might have potential in bitches suffering from CMTs.

Morphological changes in the small intestinal smooth muscle layers of horses suffering from small intestinal strangulation. Is there a basis for predisposition for reduced contractility?

REASONS FOR PERFORMING STUDY

Intestinal strangulation often leads to enterectomy after which ileus can develop. This has prompted research to look into possible pathophysiological processes triggering equine ileus. However, morphological changes of the small intestinal smooth muscle in relation to equine colic have not yet been studied.

OBJECTIVES

The presence of some smooth muscle proteins was morphologically assessed and quantified in control and colic horses. In addition, the up- or down-regulation of heat shock proteins (HSP20 and HSP27) influencing the contractility of smooth muscles was studied.

METHODS

Cranial resection margins of 18 strangulated small intestinal samples were collected. Small intestinal control samples were collected from 11 horses subjected to euthanasia for other than gastrointestinal-related reasons. Formaldehyde-fixed tissue was paraffin-embedded and processed for conventional staining and immunohistochemistry. Snap-frozen full-thickness biopsies were collected for western blot analyses.

RESULTS

Evaluating the muscle layer microscopically, colic samples showed significantly more signs of degradation than controls (P = 0.026) of which vacuolar degeneration was most prominent (P = 0.009). In colic samples, myosin protein levels were decreased (P = 0.022) whereas desmin (P = 0.049) and HSP20 protein levels (P = 0.005) were elevated.

CONCLUSIONS

In colic samples, microscopic lesions at the level of the muscle layer indicate a stress response. In addition, modified amounts of structural proteins such as myosin and desmin together with increased HSP20 levels could perhaps provide a basis for explaining the malfunctioning of the intestinal muscle layer.

POTENTIAL RELEVANCE

Post operative ileus, following small intestinal strangulation and resection, could be related in part to a dysfunctional muscle layer. In addition to microscopic signs of degeneration, myosin and HSP20 were affected. Pharmacological interventions might alter HSP20 expressions and thus serve a protective effect.

The use of slaughterhouse-obtained small intestinal tissue as control material in histological studies should be applied with prudence

This study aimed to evaluate the reliability of slaughterhouse-obtained small intestinal tissue as control material in equine colic research where molecular stress responses in small intestinal tissue are investigated. For this purpose, small intestinal samples from colic horses were collected during surgery or immediately after euthanasia at the oral border of strangulation resection sites and routinely processed for histopathology (i.c. rinsed with 4°C Krebs' solution, fixated overnight with 4% neutral buffered formaldehyde (FH) at room temperature). Control samples consisted of pieces of mid-jejunum, collected at the slaughterhouse and routinely processed for histopathology under 4 different conditions. The 4 conditions differed with regard to incubation and fixation temperature and whether or not oxygenated Krebs' solution was used. Histological scoring revealed that slaughterhouse samples had a higher mean lesion score (P<0.001) than colic samples. In addition, more slaughterhouse samples had a higher mean inflammation score than colic samples (P=0.001). The inflammatory cells in the small intestine consisted mostly of eosinophils and as such were very suggestive for parasitic infestation. Hypoxia-inducible factor-1α (HIF1α) nuclear immunoreactivity was more pronounced in slaughterhouse tissue, probably as a result of the delay between slaughter and sampling (P=0.034). The histopathological score (P=0.291), the inflammation score (P=0.248) and the HIF1α nuclear immunoreactivity (P=0.538) did not differ between the different collection protocols. It is concluded that slaughterhouse-obtained small intestinal tissue shows distinct alterations and that its use as control tissue when evaluating molecular stress responses should be applied with prudence.

Morphological data indicate a stress response at the oral border of strangulated small intestine in horses

Strangulation colic often leads to surgery. We aimed to document the molecular response in the non-resected intestine in these horses using quantitative Western blot analysis, and immunohistochemistry. The expression of hypoxia-inducible factor 1-alpha (HIF1α) was investigated together with two molecular pathways initiated after protein destruction: proteasome degradation via ubiquitin chain formation and protein restoration via molecular chaperones such as inducible heat shock protein 70 (HSP70). In addition, the expression of c-fos and c-jun could indicate an early proinflammatory response. Ubiquitin, HSP70, c-jun and c-fos protein levels did not differ between the control and colic samples nor were they related to the clinical outcome in case of strangulation colic. However, the immunohistochemical distribution of several of these proteins (ubiquitin, HSP70 and c-jun) differed significantly between colic and control samples. The elevated presence of ubiquitin in the enterocytes' nucleus, of HSP70 in the smooth muscle cells' nucleus and of c-jun in enteric neurons suggest protective and degenerative pathways are activated in the apparently healthy non-resected tissue in case of strangulation obstruction, perhaps providing a molecular and morphological basis for the development of complications like post-operative ileus.

Tracheal carcinosarcoma (true malignant mixed tumour) in a Belgian Blue heifer

This report describes a case of a carcinosarcoma or true malignant mixed tumour (salivary gland type) of the trachea in a Belgian Blue heifer. At post-mortem examination a nodular, well-circumscribed, firmly attached mass was found in the tracheal wall, severely compressing the tracheal lumen. Histologically the tumour was biphasic, with varying proportions of epithelial elements dispersed throughout a matrix showing varying degrees of myxo-chondroid and cartilaginous differentiation. The histological features of the tumour were consistent with a combination of an adenoid cystic carcinoma and a chondrosarcoma. Immunolabelling demonstrated smooth muscle actin in the cytoplasm of both the epithelial and mesenchymal components, thus fulfilling the diagnostic criteria for a mixed tumour. To our knowledge this is the first report of a mixed tumour of the trachea in a domestic animal.