Effect of canine parvovirus on erythroid progenitors in phenylhydrazine-induced regenerative hemolytic anemia in dogs

The effects of canine parvovirus (CPV) infection in dogs with hemolytic anemia was compared with the clinical effects of human parvovirus-induced aplastic anemia in human beings with chronic regenerative anemias. Phenylhydrazine was used to induce a transient, severe, hemolytic anemia in dogs to evaluate the effects of CPV infection on rapidly dividing bone marrow precursors. Erythrocyte colony-forming unit bone marrow cultures and cytologic examination of bone marrow were used to determine the effects of CPV infection on erythroid bone marrow precursors. The induced hemolytic anemia regenerated rapidly and although the bone marrow was infected, it was determined that CPV infection did not induce a detectable decrease in erythroid progenitors in dogs with severe hemolytic anemia.     

Bone marrow hypoplasia in a feminized dog with an interstitial cell tumor.

Bone marrow hypoplasia and feminization developed in a 10-year-old male German Shepherd Dog with interstitial cell tumor. Clinical abnormalities included pyrexia, pale mucous membranes, signs of abdominal pain, large left testis, atrophied right testis, and feminization. Abnormal laboratory findings included pancytopenia, bacteremia, bacteriuria, and pyuria. Results of cytologic examination of a bone marrow aspirate were consistent with aplastic anemia. Serum estradiol concentration was high, and serum testosterone concentration was low, compared with normal values for male dogs. The left testicular mass was identified as an interstitial cell tumor. Other causes of the aplastic anemia or feminization were not found.     

Hydranencephaly in a foal

Hydranencephaly is well recognised in several domestic animals, especially ruminants, but is virtually unknown in the horse. This case report describes a premature filly foal that on the day of delivery was found with a severe neurological disorder that initially improved but then progressively worsened. The foal was subjected to euthanasia on humane grounds and post mortem examination revealed somewhat asymmetric but bilateral destruction of the telencephalon identified as hydranencephaly. The possible causes of hydranencephaly in foals are discussed.     

Bullous emphysema with haemorrhage in a premature foal

A Warmblood foal was admitted at one day of age because of prematurity and seizures. Clinical and clinical pathology abnormalities were consistent with prematurity and suspected hypoxic seizures that responded to anti‐convulsive therapy. The foal stabilised after several days of intensive care but then developed an airway infection. Thoracic radiographs showed multiple cavitary lesions and ultrasound examination suggested intra‐cavital haemorrhage. The foal went on to develop septicaemia and was subjected to euthanasia. Post mortem examination revealed multiple bullous emphysema with haemorrhage. This disorder should be considered in the differential diagnosis of foals having air‐fluid filled cavities on thoracic radiographs.     

Idiopathic aplastic anemia in a dog

A case of idiopathic aplastic anemia in a dog was characterized by pancytopenia and bone marrow aplasia. Erythroid colony-forming units (CFU-E) were not detected in bone marrow culture. Addition of the dog's serum to CFU-E culture from control dogs failed to suppress colony formation, suggesting that humorally-mediated suppression at the CFU-E level was not a cause of the aplastic anemia.     

Aortic rupture causing cardiac tamponade in a 24‐day‐old Friesian colt with concurrent colonic Chlamydiosis and Balantidiasis

A 24‐day‐old Friesian colt died suddenly and a physical examination the morning the foal died showed no abnormalities and serum IgG levels >8.0 g/l. Necropsy examination revealed haemopericardium and a 2 cm transverse tear at the root of the aorta. The foal was also found to have Chlamydophila spp. in the epithelium and Balantidium coli on the mucosal surface of the large colon. An aortic rupture is a novel finding in a foal, colonic Chlamydiosis has not been previously reported in horses and Balantidium coli has not been reported in equids in North America.     

Chicken anemia agent.

Chicken anemia agent (CAA) is a small, spherical, non-enveloped virus containing a circular single-stranded DNA genome. CAA remains unclassified and probably should be classified in a new virus family. The chicken is the only recognized natural host for CAA. CAA was initially isolated in Japan and the associated disease chicken infectious anemia described in 1979. The virus has a world-wide distribution and is common in intensive poultry raising areas. Chicken infectious anemia is not a new disease but a newly recognized disease. CAA is now thought to play a key role in several multiple etiology disease syndromes; hemorrhagic syndrome; aplastic anemia, gangrenous dermatitis, hemorrhagic anemia syndrome, hemorrhagic aplastic anemia syndrome, anemia dermatitis and blue wing disease. The pathogenesis of chicken infectious anemia is described. Vertical transmission appears to be more important than horizontal spread. A yellow fatty bone marrow is the most characteristic lesion and thymic atrophy is the most consistent finding in CAA infection. Thymic and bone marrow intranuclear inclusion bodies occur with infection but are of limited value diagnostically and are very transient and rarely seen. Five different disease-producing scenarios that lead to clinical CAA infection in young chickens are presented.     

Aplastic anemia in cats - clinicopathological features and associated disease conditions 1996-2004

A retrospective study of 128 feline bone marrow reports identified 13 cases of aplastic anemia. Clinical diagnoses included chronic renal failure (n=5), feline leukemia virus infection (n=2), hyperthyroidism treated with methimazole (n=1) and idiopathic aplastic anemia (n=5). In some cats, starvation may play a role in the development of marrow aplasia. Some cats with aplastic anemia can have prolonged survival without resolution of the pancytopenia.     

Severe hyperkalaemia associated with renal dysplasia in a 2-day-old foal

A 2-day-old filly foal presented with signs of depression, recumbency and inappetence. Blood analyses revealed hypoalbuminaemia, hyperfibrinogenaemia, hyperglycaemia and hyperkalaemia. The foal deteriorated despite intensive treatment and was subjected to euthanasia. At post mortem examination, the urinary bladder, ureters and kidneys appeared normal grossly. Histologically both kidneys showed disorganised development with the presence of structures inappropriate for a foal of this age, including primitive glomeruli, immature renal tubules and persistent metanephric ducts. Based on these findings a diagnosis of bilateral renal dysplasia was made.     

An unusual cause of colic in a neonatal foal

A case of a neonatal foal with acute colic and respiratory distress is described. The foal presented with signs of acute colic and was treated medically. The foal did not respond to treatment and 2 h after admission the foal began to demonstrate signs of respiratory distress. Thoracic and abdominal radiographs were obtained and a diagnosis of a diaphragmatic hernia was made. Surgical repair of the hernia was recommended but the owner declined and the foal was subjected to euthanasia. Post mortem findings confirmed the diagnosis and revealed that the defect was of congenital origin. Congenital diaphragmatic hernia is an unusual cause of colic in a neonatal foal.     

Haemobartonellosis in the Domestic Cat

Post-mortem examination of two cases of natural Haemobartonella felis infection in the cat is reported. In both cases haemobartonellosis was confirmed on blood smears from the diseased animals. The most noticeable macroscopic finding was a pronounced general anemia.The microscopic examination revealed hyperplasia of the bone marrow and a moderate extramedullary hematopoiesis in case 1 and in case 2 a reduction of the M/E index in the bone marrow.Keyword: haemobartonellosis, Haemobartonella felis, Eperythrozoon felis, feline infectious anemia, blood diseases, anemia     

Distal aortic aneurysm presumed to be secondary to an infected umbilical artery in a foal

Abstract

CASE HISTORY:?A 3-month-old female Warmblood foal was presented after displaying signs of colic with pyrexia for 5 days.

CLINICAL AND PATHOLOGICAL FINDINGS:?The foal continued to show signs of colic, frequently passed urine, and was pyrexic with an elevated white blood cell count. The umbilical stalk was thickened but there was no evidence of purulent material. Exploratory laparotomy revealed an enlarged left umbilical artery remnant tightly adhered to the bladder wall. The left umbilical artery continued to an aneurysm involving the distal aorta. The foal was subject to euthanasia and post-mortem examination confirmed a spherical aortic aneurysm, in the dorsal midline caudal to the kidneys that contained a large thrombus. Histopathological examination revealed inflammation and necrosis of the tunica intima and tunica media of the left umbilical artery with suppuration and bacterial colonies evident in the periarterial tissues.

DIAGNOSIS:?Infected aortic aneurysm presumably caused by an umbilical artery infection.

CLINICAL RELEVANCE:?A previously undetected umbilical infection appears to have resulted in an unusual delayed complication causing signs of colic in a foal. Veterinarians should be aware of this condition, and the possibility that it may be a cause of signs of colic in foals. Diagnosis based on ultrasonography should be possible, but may require sedation, visceral analgesia and careful examination.     

Nonregenerative immune‐mediated anemia associated with a diffuse large B‐cell lymphoma in a captive jaguar (Panthera onca)

An 18‐year‐old male castrated jaguar (Panthera onca) was presented with anorexia and continuous bleeding from the oral cavity after a history of fighting with the partner animal. Clinical evaluation revealed ulcerating lesions on the gingiva and hard palate and a hematoma on the tongue. Computed tomography of the head and endoscopic examination of the esophagus and stomach were unremarkable. Hematology and clinical chemistry revealed severe nonregenerative anemia, mild thrombocytopenia, and moderate azotemia. Several PCRs for feline hemotropic mycoplasmas (Mycoplasma haemofelis, M heamominutium, M turicensis), Babesia felis, and Bartonella spp., as well as an FeLV antigen test were negative. The cytologic examination of a bone marrow aspirate was consistent with ineffective erythropoiesis, most likely due to immune‐mediated destruction of the erythroid precursor cells. Prednisolone therapy was initiated (1.25 mg/kg/day), and the CBC returned to normal 16 days after the initiation of the therapy. Anemia relapsed after 4 months and severe splenomegaly was noted. A repeat bone marrow aspirate revealed active erythropoiesis in the presence of erythroid precursor phagocytosis suggesting an immune‐mediated process. Splenic fine‐needle aspiration and tissue biopsies were taken, and all findings including histology and immunohistochemistry were consistent with a diffuse large B‐cell lymphoma (DLBCL). Five days later, the clinical condition deteriorated and the jaguar died. Histopathology following necropsy showed infiltration with neoplastic lymphoblasts in the spleen, liver, and abdominal lymph nodes. This case report describes a nonregenerative immune‐mediated anemia associated with a DLBCL in a jaguar.     

Fibrinous pericarditis and cardiac tamponade in a 3‐week‐old pony foal

A 3‐week‐old Pony of the Americas foal presented with a history of respiratory distress presumed to result from Actinobacillus equuli pleuropneumonia and septic arthritis. Failure of transfer of passive colostral immunity was suspected, but not confirmed, based on a history of the foal being separated from its dam shortly after parturition. Transient improvement was noted following thoracocentesis and removal of approximately 600 ml of pleural fluid but progressive clinical signs of congestive heart failure developed. Fibrinous pericarditis with evidence of cardiac tamponade was subsequently diagnosed via thoracic ultrasonography. Early clinical signs of cardiogenic shock were identified and fibrinopurulent exudate removed through a catheter placed with ultrasound guidance into the pericardium. The foal experienced cardiorespiratory arrest during the procedure and died despite resuscitative efforts. Post mortem examination identified extensive hypertrophy of the pericardium, septic arthritis, mild pleural effusion and focal bronchopneumonia. This report details the clinical evaluation, haematology, treatment and post mortem pathology of a foal with Actinobacillus equuli associated fibrinous pericarditis, as well as a brief review of cardiac tamponade.     

Myelophthisic pancytopenia in a pony mare

Myelophthisic pancytopenia was diagnosed in a 10-year-old pony mare with a history of recurring colic and anemia. Physical findings were unremarkable, with the exception of pale mucous membranes. Hematologic analysis revealed nonregenerative pancytopenia. Testing for equine infectious anemia and antiglobulin (Coombs) yielded negative results. The mare was treated with antibiotics, boldenone undecylenate, and corticosteroids, but a regenerative bone marrow response was not seen. Postmortem examination revealed severe myelofibrosis and multiple sites of extramedullary hematopoiesis. Myelophthisic pancytopenia develops when a space-occupying lesion destroys sufficient bone marrow or disturbs marrow architecture, resulting in decreased production capacity. Pancytopenia in the pony of this report resulted from inadequate production of blood cellular components secondary to replacement of the bone marrow by myelofibrosis. Cause of the myelofibrosis was not identified.     

Abdominal aortic thromboembolism and subsequent pelvic limb myositis secondary to colitis and septicaemia in a 5-day-old Oldenburg colt

This case report describes the clinical progression of a 5-day-old Oldenburg colt presented for acute severe right hindlimb lameness. The foal had diarrhoea at presentation, and over the next 24 h became tachycardic and febrile with cold extremities in the hindlimbs and began to bear weight on the dorsum of both hind fetlocks. Diagnostic work-up included physical examination, radiography, ultrasonography and clinicopathological testing. Treatment consisted of antibiotics, anti-inflammatories, gastroprotectants, oral di-tri-octahedral smectite, hyperimmune plasma and isotonic crystalloid fluids for diarrhoea. Bandages and splints were applied to the hindlimbs to assist ambulation and prevent weightbearing on the dorsum of the fetlocks. The foal developed oedema of both hindlimbs, and ultrasonographic evaluation revealed gas pockets within the subcutaneous tissues. An ultrasound-guided aspirate of the right hindlimb oedema was submitted for cytology, which revealed presumed Clostridial spores, and culture, which yielded heavy growth of Escherichia coli. Surgical fenestration of the hindlimbs was performed due to suspected Clostridial myositis. The foal continued to decline clinically and was humanely subjected to euthanasia. Post-mortem evaluation revealed septicaemia and thromboembolism of the terminal abdominal aorta resulting in partial obstruction of blood flow to the pelvic limbs with resultant bacterial myositis (Clostridium [suspected] and Escherichia coli [confirmed]). In summary, thrombosis is a potential sequela to coagulopathy seen in septicaemia and should be considered a differential diagnosis in neonatal foals presenting for lameness.     

Renal hypoplasia and dysplasia in an American miniature foal

Diagnostic imaging, including computed tomography, of a two-month-old foal with renal failure indicated that its right kidney was probably absent and that its left kidney was abnormal in shape. The foal was stabilised and released, but three days later its clinical signs recurred. Postmortem examination revealed renal hypoplasia and dysplasia, the first reported case of this condition in an American miniature horse.     

Meningoencephalomyelitis in a foal due to Salmonella agona infection

CASE HISTORY: A neonatal Thoroughbred foal was presented with rib fractures and left forelimb lameness secondary to dystocia.

CLINICAL FINDINGS: The foal developed a head tilt, seizures and watery diarrhoea during hospitalisation and died at 7 days of age. Histological examination of the brain and spinal cord revealed a suppurative meningoencephalomyelitis with vasculitis, and numerous intralesional, gram-negative bacilli. Similar microscopic lesions were noted in the lungs, renal medullary interstitium, and umbilicus. Bacilli in the brain, spinal cord and umbilicus were identified immunohistochemically as Salmonella group B. Salmonella agona was isolated in pure culture from the brain, lung, liver, kidney, and intestine.

CONCLUSION: This is the first report of meningoencephalomyelitis and septicaemia due to Salmonella infection in an equine neonate.     

Imaging diagnosis and clinical presentation of a Chiari malformation in a Thoroughbred foal

A newborn Thoroughbred foal was presented to the clinic with ambiguous neurological deficits, spinal anomalies and a soft tissue swelling dorsal to the lumbar vertebral column. The foal was alert but unable to rise and stand. With radiography, ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) a lumbar dysraphic anomaly, cerebellar herniation and coincidental skeletal abnormalities were documented. Finally, a meningomyelocele was defined and, in context with the cerebellar herniation through the foramen magnum, the foal was diagnosed to have a Chiari malformation. The MRI examination corresponded best with the post mortem findings. Although 3‐dimensional imaging methods have been considered superior regarding full and detailed assessment of the congenital malformation, radiography and ultrasonography also provide essential information to diagnose dysraphic lesions at reduced costs and efforts. A Chiari malformation should be considered as a differential diagnosis in foals with neurological deficits.     

Blood smear from a cat: features to "dys"cover

A 4-year-old, spayed female, domestic shorthair cat was presented for lethargy, nonregenerative anemia, and inappetence. Results of a CBC included macrocytic, normochromic, nonregenerative anemia and a glucocorticoid-associated leukogram. On blood smear examination, neutrophils had abnormal features including hyposegmentation and a diffuse chromatin pattern with nuclear filament formation and nuclear blebbing. Microscopic examination of a roll preparation of bone marrow revealed hypolobulated megakaryocytes with asynchronous maturation of nuclei. The granulocytic to erythrocyte (G:E) ratio was 76. Segmented neutrophils had asynchronous maturation and dysplastic features. The entire erythroid lineage was markedly decreased for the degree of anemia and rare dysplastic features were noted in erythroid precursor cells. The interpretation of bone marrow findings was erythroid hypoplasia, megakaryocytic dysplasia, and granulocytic hyperplasia with dysplasia. Histopathologic examination of a bone marrow core sample also revealed myeloid hyperplasia and erythroid hypoplasia. The result of a direct immunofluorescence assay for FeLV performed on the bone marrow roll preparation was positive. A diagnosis of dysmyelopoiesis associated with FeLV infection was made. This case was unique in that the dysplastic changes occurred in cell lines that did not have associated cytopenias. The dysmyelopoiesis most closely resembled myelodysplastic syndrome with refractory cytopenia (MDS-RC); however, secondary dysmyelopoiesis could not be ruled out.