Two cats were diagnosed with Dirofilaria immitis infection in West Tottori. Case 1 had vomiting and dyspnea. Antigen testing for D. immitis yielded negative results, so the initial diagnosis in this case was pneumonia. The clinical signs resolved following administration of antibiotics. However, symptoms similar to those seen on the first visit were noted on a subsequent consultation after 348 days. On this occasion, antigen testing for D. immitis yielded positive results. Palliative therapy, including steroids, was initiated, but the cat died suddenly one week later. The initial diagnosis in Case 2 was pleural effusion secondary to heart failure. The animal was treated by another veterinary hospital, but there was no improvement. Antigen testing for D. immitis yielded positive results, and evidence of adult worms within the right atrium and right ventricle was provided by echocardiography. Following a diagnosis of caval syndrome, three female worms were removed by string brush via the left jugular vein. One day postoperatively, the clinical signs had resolved. This cat has subsequently been examined periodically and administered an appropriate prophylactic agent for D. immitis. Diagnosis of feline D. immitis infection is not straightforward. When a definitive diagnosis cannot be provided, it is important to interpret clinical findings very carefully, and to obtain informed consent for subsequent treatment, periodic reinspection, and prevention.
An 8-year-old cavalier King Charles spaniel that had not passed feces for 7 days was referred to our hospital. Contrast-enhanced computed tomography revealed a mass in the small intestine and a filling defect of contrast agent in the spleen. Fine-needle aspiration biopsy of the intestinal mass revealed lymphoid cells. Surgery to remove the intestinal mass and spleen was performed on day 19. PCR using DNA isolated from the intestinal mass showed T-cell clonality. A provisional diagnosis of alimentary lymphoma was made, based on T-cell clonality and cytological observation, but the histopathological diagnosis was alimentary mast cell tumor.
A 2-year-old male dog with weakness, anorexia, and purpura of the right groin was referred to our hospital. This dog was diagnosed with idiopathic aplastic anemia based on our examinations. Treatment was initiated with steroid pulse therapy and the granulocyte colony-stimulating factor, mycophenolate mofetil. On day 20, a slight increase in the number of platelets and increase in the number of neutrophils was seen, but the packed cell volume (PCV) had dropped to 11%. Following the finding of a large number of spherical red blood cells in blood smear, a complication of immune-mediated hemolytic anemia (IMHA) was diagnosed. Immunoglobulins are used as rescue therapy in human IMHA, and with mycophenolate mofetil having proven ineffective in this case, therapy was changed to azathioprine. PCV and neutrophil and platelet numbers subsequently normalized, and the dog recovered.
Two cats presented with the chief complaints of abdominal distention, anorexia, and respiratory distress. Echocardiography showed left ventricular dilatation and a marked reduction in left ventricular fraction shortening (FS), leading to a diagnosis of dilated cardiomyopathy (DCM). Although both cats responded to medical treatment, they died following deterioration in their general condition. The autopsy findings shortly after death showed diffuse suppurative granulomatous inflammation of several organs. In addition, diffuse inflammatory cell infiltration, myocarditis, and myocardial fibrosis were found in the heart. Based on these findings, feline infectious peritonitis (FIP) was retrospectively diagnosed in both cats. The echocardiographic findings of DCM suggested FIP virus-induced myocarditis. A variety of diseases, including viral infections, are considered the cause of pathologies similar to DCM. We must, therefore, differentiate among diseases that are likely to result in pathologies similar to DCM, based not only on ultrasonography findings, but also on a range of examination results.