Pulmonary and hepatic eosinophilic granulomas and epistaxis in a horse suggestive of multi‐systemic eosinophilic epitheliotropic disease

Multi‐systemic eosinophilic epitheliotropic disease (MEED) is a relatively uncommon disease characterised by eosinophilic infiltration of more than one organ system, with the skin and gastrointestinal tract most commonly affected. This case report describes a gelding that presented for weight loss, increased respiratory rate and effort and chronic intermittent epistaxis. During post mortem examination diffuse eosinophilic granulomatous lesions were identified in the lung and liver, leading to a diagnosis of MEED. Veno‐occlusive pulmonary remodelling was also discovered, believed to be the cause of the chronic epistaxis and a result of the pulmonary fibrosis and eosinophilic granulomas.     

A case of alveolar hydatid disease in a dog: domestic animals as rare incidental intermediate hosts for Echinococcus multilocularis

A 2-years old male Labrador retriever dog was presented with intermittent therapy-resistant diarrhoea, accompanied by vomiting, inappetence, apathy, and mild fever. The blood analysis showed an anaemia, neutrophilia, eosinophilia, and increased liver enzymes. Abdominal palpation was slightly painful. X-rays and echography revealed a severely enlarged liver with multiple cavernous structures. Histopathologic examination of liver biopsies showed a severe chronic granulomatous hepatitis with numerous parasitic cysts. Morphology of the cysts was compatible with the metacestode stage of Echinococcus multilocularis. The dog was only 2-years old at the time of diagnosis. Although alveolar hydatid disease of the liver is rare in dogs, it should be envisaged as a possible differential diagnosis in cases of space-occupying processes in the liver, even in young animals, as the incubation period of this disease in the dog can be considerably shorter than in humans.     

Mycobacterium tuberculosis infection in a dog from Africa

A 4-year-old male Boxer dog with a history of vomiting, diarrhea, and weight loss moved from West Africa to Lyon, France, where it was further evaluated. Radiographs revealed pleural effusion and enlargement of tracheobronchial lymph nodes and liver. Cytologic examination of the pleural effusion and a fine needle aspirate specimen of the liver showed mixed mononuclear inflammation with nonstaining rod structures within epithelioid histiocytes. At necropsy, the main gross pathologic findings were exudative pleuritis, nodular hepatitis, and infarcts and caseous nodules in the kidneys. The main histologic lesions were granulomatous hepatitis, granulomatous pneumonia, fibrinous leukocytic pleuritis, necrotic and fibro-calcified granulomatous lymphadenitis, and granulomatous nephritis. A Ziehl-Neelsen stain applied to both cytologic and histologic samples was positive for acid-fast bacilli. Bacterial culture of the pleural fluid was positive for Mycobacterium tuberculosis. Cytology is a valuable tool in the diagnosis of this important zoonotic disease.     

Extreme eosinophilia with disseminated eosinophilic granulomatous disease in a horse

Extreme eosinophilia with disseminated eosinophilic granulomatous disease is described in a 4-year-old Arabian mare. Clinical signs included weight loss, coughing, jugular distention, and ventral edema. Cutaneous lesions were not observed. Eosinophilic inflammation was observed in cytologic specimens from the respiratory tract, body cavities, and lymph nodes. At necropsy, a 20-cm diameter intrathoracic mass was observed. Smaller nodules were present in the lymph nodes, liver, spleen, adrenal glands, pancreas, and skeletal muscle. Histologically, these masses and nodules were characterized by infiltrates of eosinophils, macrophages, and multinucleated giant cells, reactive fibroplasia; and multifocal eosinophilic coagula. Microscopically, mild eosinophilic infiltrates were observed in sections of stomach, small intestine, colon, and pleura; however, gross lesions were not observed in these tissues at necropsy. The etiology of the extreme eosinophilia and disseminated eosinophilic granulomatous disease in this horse was not determined.     

Eosinophilic granulomatous pneumonia in a dog

An eosinophilic granulomatous pneumonia is described in a German shepherd dog. On thoracic radiographs and at post mortem examination disseminated pulmonary tumour-like nodules had been seen. Histologically the nodules consisted of macrophages, eosinophils, plasma cells and occasionally giant cells. In plasma cells and macrophages, large amounts of immunoglobulin G and immunoglobulin M could be demonstrated. An aetiology could not be determined, but vasculitis and cytology made an allergic reaction of type 1 and, or, type 3 most likely. The classification of pulmonary infiltration with eosinophilia (PIE-syndrome) is discussed.     

Hypocellular marrow and extramedullary hematopoiesis in a dog: hematologic recovery after splenectomy

Nonregenerative anemia, poikilocytosis, thrombocytopenia, and splenomegaly were found in a 6-year-old dog. Marrow aspiration did not yield marrow particles, and microscopic examination of a marrow-core biopsy indicated hypocellular marrow. Marked extramedullary hematopoiesis was found in liver and spleen biopsy specimens. After splenectomy, the clinical and hematologic abnormalities resolved. The dog subsequently developed hemolytic anemia caused by Haemobartonella canis, which was resolved with oral tetracycline treatment. The dog remained healthy without recurrence of cytopenias or hypocellular marrow for 2 years after splenectomy. The clinical, hematologic, and microscopic findings in this dog were compatible with hypersplenism.     

Granulomatous disease associated with Bartonella infection in 2 dogs

Shortly after removal of an engorged tick from the left ear, a 4-year-old Greyhound was referred for evaluation of fever and a rapidly enlarging mass in the region of the left submandibular lymph node. Histopathologic evaluation of the lymph node resulted in a diagnosis of severe granulomatous lymphadenitis. An 11-year-old mixed-breed dog was referred for evaluation of a 6-week history of serous nasal discharge. Histologic examination of a surgical biopsy from a nasal mass indicated multifocal granulomatous inflammation with fibrosis. Serum samples obtained from both dogs were reactive by immunofluorescent assay to Bartonella vinsonii subsp. berkhoffii antigens (reciprocal titers of 128). Although Bartonella organisms were not isolated by lysis centrifugation blood culture, Bartonella DNA was amplified from tissue samples obtained from each dog (lymph node biopsy from dog 1 and nasal biopsy from dog 2) using primers that amplify a portion of the 16S rRNA gene followed by Southern blot hybridization using a genus-specific probe. Additionally, restriction fragment length polymorphism (RFLP) analysis of a Bartonella-specific citrate synthase gene product obtained from dog 2 resulted in a restriction pattern identical to B. vinsonii subsp. berkhoffii. This is the 1st report of granulomatous disease in dogs associated with Bartonella infection.     

Cytologic identification of fungal arthritis in a Labrador Retriever with disseminated Talaromyces helicus infection

An 8‐year‐old, neutered male Labrador Retriever presented with acute forelimb lameness. Clinical signs progressed over one week. On physical examination, right cubital joint effusion and bilateral axillary lymphadenomegaly were noted, and severe internal lymphadenomegaly was observed ultrasonographically. Granulomatous lymphadenitis with intralesional fungi was noted cytologically, and the dog was ultimately diagnosed with disseminated Talaromyces helicus infection via PCR of a pure isolate. Extensive medical therapy was pursued, and months later, an arthrocentesis was performed due to continued lameness and severe cubital joint effusion. The synovial fluid contained increased numbers of neutrophils, macrophages, and multinucleated giant cells. Frequent fungal hyphae were found both intracellularly and extracellularly. These basophilic organisms were 2‐4 µm in width with internal eosinophilic granules, roughly parallel walls, and occasional to frequent septa. Round to oval yeast‐like forms with thin, clear halos were also occasionally identified. Due to the severity of clinical signs, the right thoracic limb was amputated. Histologic examination of the cubital joint revealed marked granulomatous synovitis, fasciitis, panniculitis, and osteomyelitis, all with intralesional fungi. Talaromyces helicus is a very rare cause of disease, reported only in one other dog. Granulomatous lymphadenitis appears to be a feature of this disease, but this report is the first to describe a significant synovial component.     

Idiopathic ocular and nasal granulomatous inflammatory disease in a dog

A young female Akita presented for ocular and nasal lesions. Examination showed bilateral 360 degree limbal masses that extended onto the peripheral cornea. In addition, intranasal granulomatous masses were observed by rhinoscopy. Histopathologic examination with immunohistochemical staining showed that these masses were almost identical and were classified as an idiopathic, T-cell rich, granulomatous inflammation. The dog responded well to anti-inflammatory medication and the disease remains in remission 2 years after the initial presentation.     

Visceral leishmaniasis in a dog: clinical, hematological and pathological observations.

Visceral leishmaniasis was diagnosed in a dog that had been living with his owners in Spain for two years. Clinical diagnosis was somewhat delayed as the disease is largely unknown to Canada and was manifested by a nonresponsive anemia which was not easily explained on peripheral blood evaluation alone, and concomitant interstitial nephritis. On post mortem examination splenomegaly was the main gross pathological finding. Light microscopic examination of bone marrow aspirates and subsequent electron microscopic examination of splenic and hepatic tissues revealed numerous Leishman-Donovan bodies in cells of the reticuloendothelial system. Parasitized reticuloendothelial cells were seen singly or forming granulomata. These latter did not contain giant cells and were confined mainly to the liver and spleen, being sparse and single in the first but extremely numerous and coalescing in the latter. Accumulation of intrafollicular hyaline material was seen in a small number of splenic follicles. Leishman-Donovan bodies on electron microscopic examination had a trilaminar periplast, a large round nucleus with heavy blocks of marginated chromatin and two nucleoli, a short flagellum and a kinetoplast. Lymph nodes and bone marrow had numerous parasitized macrophages but no granulomata. Leishman-Donovan bodies were not detected in the lungs and kidneys both of which exhibited a chronic intersitital reaction. The comparative hematological profile as well as the importance of bone marrow and electron microscopic examinations of the spleen and liver in diagnosis are discussed. The potential public health hazard of leishmaniasis to North America and particularly to Canada is considered.     

Peliosis hepatis-like lesion in a pekingese dog. A case report

Peliosis hepatis (PH) is a rare condition characterized by dilatation of hepatic sinusoids and the presence of blood-filled spaces within the liver. The disease occurs mainly in subjects exposed to toxic substances or estrogens, and is often asymptomatic. A 9 year-old pekingese female dog was sent to Division of Pathology for autopsy because of sudden death of unclear cause. Autopsy revealed severe hydroperitoneum (1500 ml of transsudate), dilatation of heart ventricles, passive hyperemia of lungs, spleen and kidneys. The liver was enlarged, with slightly wrinkled surface, with many red spots, of different size and shape. Microscopic examination of the liver revealed the presence of areas with severe dilatation of hepatic sinusoids, and multiple cystic spaces filled with blood. Some of these spaces were lined with endothelium and other were not. Spaces were different in shape and size and were localized in the areas between dilated sinusoids. Based on the macroscopic and microscopic examination, the liver lesions were identified as severe hepatic sinusoidal dilatation with formation of peliosis hepatis-like structures.     

Oral conidiobolomycosis in a dog

Conidiobolomycosis was diagnosed via culture from an oral lesion in a 1.5-year-old German Shepherd dog. Clinically, the lesion consisted of a large, irregularly shaped, ulcerative focus on the caudal hard palate. Microscopically, the lesion was characterized by an eosinophilic granulomatous stomatitis with hyphal organisms surrounded by eosinophilic sleeves (Splendore–Hoeppli material) suggestive of an entomophthoramycosis. The fungus was cultured and identified with features consistent with Conidiobolus sp. Treatment with itraconazole at 10 mg kg⁻¹ twice daily for 61 days resulted in clinical and radiographic resolution of the lesion.     

Listeriosis in a raccoon dog (Nyctereutes procyonoides) associated with canine distemper

A wild raccoon dog (Nyctereutes procyonoides) that manifested severe illness and died was examined. Necropsy revealed severe emaciation, systemic icterus and petechial hemorrhages on the mucous membranes. Histopathologically, necroses were seen in the liver and brain stem associated with meningitis. Eosinophilic intranuclear inclusion bodies were observed in the spleen and intestinal mucosa, and eosinophilic intracytoplasmic inclusion bodies were seen in transitional epithelium in the bladder. Listeria monocytogenes 4b was isolated from the liver, spleen, kidneys and lungs, and the pathogen was also detected in the liver and brain stem immunohistopathologically. The disease was diagnosed as listeriosis associated with canine distemper virus infection in a raccoon dog.     

Disseminated eosinophilic disease resembling idiopathic hypereosinophilic syndrome in a dog

True idiopathic hypereosinophilic syndrome has been described in human beings and cats, but not in dogs. The syndrome is characterised by prolonged unexplained peripheral mature eosinophilia, the infiltration of many organs by eosinophils, organ dysfunction and a fatal outcome. This paper describes an idiopathic disseminated eosinophilic disease in a dog involving various organs, manly the heart and the lungs, accompanied by a leukemoid eosinophilic response, and a fatal outcome. The histopathological findings included the infiltration of the myocardium, lung parenchyma, liver, spleen, lymph nodes and skeletal muscles with eosiniphils.     

Bicavitary eosinophilic effusion in a dog with coccidioidomycosis

This is a case of coccidioidomycosis in a dog, examined for vomiting and labored breathing. Physical examination and thoracic and abdominal imaging revealed pleural and peritoneal effusions, both of which exhibited neutrophilic inflammation with a substantial eosinophilic component. The dog had positive IgM and IgG coccidioidomycosis titers at initial evaluation. The eosinophilic component of the inflammation was attributed to coccidioidomycosis. The dog underwent approximately 6 months of fluconazole treatment, with both effusions and clinical signs improving after 6 weeks. Three months after cessation of antifungal treatment, the dog developed a mid-diaphyseal lytic and proliferative lesion in the left radius caused by Coccidioides spp. This case illustrates the importance of consideration of coccidioidomycosis when an eosinophilic cavitary effusion is present in dogs that live in or have traveled to endemic regions.     

Equine herpesvirus 2-associated granulomatous dermatitis in a horse

Granulomatous dermatitis in horses has been linked to many etiologies, including various parasites, fungi, and bacteria. Idiopathic forms of granulomatous inflammation-producing diseases, some of which are localized to the skin, also have been reported in horses. Herein we describe a case of recurrent equine granulomatous skin disease characterized by intranuclear viral inclusions within macrophages and giant cells. The histologic changes were primarily noted in the deep dermis and included multifocal to coalescing areas of necrosis marked by histiocytic cell infiltration and presence of giant cells. Electron microscopic examination revealed intranuclear and intracytoplasmic viral particles consistent with herpesvirus. Sequence results of the polymerase chain reaction product were consistent with equine herpesvirus 2, adding another possible etiology to the list of differentials in cases of equine granulomatous skin disease.     

Hyalinizing pancreatic adenocarcinoma in six dogs

Exocrine pancreatic carcinoma is a particularly malignant neoplasm of the dog. Clinical and pathologic findings of an unusual variant of exocrine pancreatic neoplasia termed hyalinizing pancreatic adenocarcinoma were evaluated in 6 dogs. On microscopic examination, neoplasms were composed of tubules and acini of epithelial cells, with bright eosinophilic granular apical cytoplasm. Tubular lumina and tumor stroma contained abundant hyaline material that resembled amyloid. The hyaline material was not congophilic, and tumor cells and hyaline material were immunohistochemically negative for amyloid A, immunoglobulin light chains (kappa and lambda), amylin (islet amyloid polypeptide), laminin, and alpha(1)-antitrypsin. Two patients survived longer than 15 months after diagnosis; one of these dogs was untreated and had grossly evident metastasis at the time of diagnosis. The deaths of the other 4 dogs occurred as a result of poor recovery after partial pancreatectomy or in association with other concurrent life-threatening conditions. Two dogs were diagnosed with panniculitis, a condition rarely associated with pancreatic disease. Further evaluation is needed to determine the composition and biologic significance of intratumor hyaline material. Studies that associate exocrine pancreatic carcinoma grade and histologic subtype with prognostic outcomes in the dog are warranted such that appropriate therapy can be elected.     

Generalised granulomatous disease in a horse

A 6-year-old gelding was referred with a 3-month history of recurrent fever, inappetance, lethargy and weight loss. On clinical examination major findings were depression, thin condition, thrombophlebitis, nodules on the scrotal skin, leukocytosis, hyperfibrinogenaemia and hyperglobulinaemia. Pleural fluid and areas of lung consolidation were seen on ultrasonographic examination of the thorax. A diagnosis of chronic respiratory disease was made. Initially there was a response to antibiotic therapy but the horse was presented 3 months later with continued weight loss, recurrent fever and multifocal skin lesions, characterised by scales, crusts and nodules, affecting the nasal bridge, jugular grooves, ventral neck, withers, scrotum, prepuce, and medial gaskins. Histological evaluation of skin biopsies indicated a granulomatous reaction. On ultrasonographic examination of the thorax multiple hypoechoic lesions consistent with granulomas were seen in both lungs. A diagnosis of generalised granulomatous disease was made. The horse was euthanased at the owner's request. On necropsy examination the main findings were multiple nodules of fibrotic granulomatous inflammation in the lung, heart, liver, gastrointestinal tract and mesenteric lymph nodes, supporting the diagnosis of generalised granulomatous disease.     

Clinical remission of idiopathic hypereosinophilic syndrome in a Rottweiler

Idiopathic hypereosinophilic syndrome (HES) is a rare syndrome for which Rottweilers appear to over-represent the canine cases. A 6-month-old female entire Rottweiler presented with seizures following a traumatic incident. The dog was identified as having a marked, sustained eosinophilia and investigations did not identify an underlying cause. Concurrently, the dog had chronic eosinophilic hepatitis with impaired liver function and mesenteric eosinophilic lymphadenitis. The dog went on to have spontaneous resolution of HES and normal liver function was subsequently documented. To date, the dog is still alive, more than 4 years after initial presentation. The diagnosis of idiopathic HES in Rottweilers may not carry a poor prognosis and the condition may spontaneously resolve, even in cases with documented organ damage.