Ultrastructural analysis of platelets and megakaryocytes from a dog with probable essential thrombocythemia

Blood platelets and bone marrow megakaryocytes from a dog with essential thrombocythemia were analyzed by transmission electron microscopy and compared with those of control dogs. Platelets varied in size and shape and contained enlarged and dilated open canalicular systems. Megakaryocytes were dysmorphic and had evidence of abnormal maturation, with large numbers of megakaryoblasts containing alpha granules and poorly organized and reduplicated demarcation membranes. The fewer, more mature megakaryocytes lacked normal cytoplasmic organization. Most notable was the absence of well-demarcated "platelet fields," due to the excessive and disorderly array of demarcation membranes.     

Pathologic consequences of a severe influenza outbreak (swine virus A/H1N1) under natural conditions in the non-immune sow at the beginning of pregnancy

Pathological consequences of a severe outbreak of swine influenza (H1N1 virus) in the non immune sow at the beginning of pregnancy, under natural conditions. A sudden acute outbreak of fever, depression, anorexia and coughing in a group of nulliparous sows from a herd that was currently under epidemiological investigation lead to build a particular disposal of observation. The clinical signs were daily recorded including rectal temperature. Blood was taken from the sows at the beginning of the troubles and 3 weeks later for the detection of Aujesky's disease, coronavirus TGE-like, Influenza viruses A/H1N1 and A/H3N2 and Mycoplasma hyopneumoniae. Viral detection was attempted from nasal swabs and aborted fetuses during the acute phase. The clinical study showed fever reaching near 41 degrees C on most of the pigs and lasting usually from 2 to 5 days. The diagnosis of Influenza (virus swine H1N1) was established both on serology (massive seroconversion) and on the detection of the virus from the nasal swabs and from an aborted fetus. The control of the lungs of sows "not in pig" and culled showed extended lesions of bronchopneumonia and Pasteurella multocida was found. The technical consequences of this severe outbreak of Influenza on reproduction were mainly important at the beginning of pregnancy. Over 13 sows inseminated less than 1 week before the outbreak, only 3 farrowed (respectively 5.5 and 12 piglets); 7 returned to oestrus and 3 "not a pig" at 21 days (echotomography) did not show signs of heat and were culled. Over 8 pregnant sows (1 month of pregnancy), 6 farrowed normal litters and total embryonic resorption occurred in 2 sows. Over 18 pregnant sows (more than 45 days gestation) one aborted.     

Cardiac arrhythmia and suspect cardiomyopathy in a Boxer dog

A 3 year old Boxer dog was presented with a history of syncope and an irregular heart heat. An arrhythmia characterised by ventricular premature contractions was detected and was thought to cause the syncopal episodes. On the basis of the age, breed and the characteristic electrocardiographic findings, a diagnosis of Boxer Cardiomyopathy was made. The dog was treated with procainamide 500 mg every 8 hours to control the arrythmia and there were no further syncopal episodes in the subsequent 13 months.     

Viruses and virus-like particles detected during examination of feces from calves and piglets with diarrhea

A total of 763 fecal or intestinal samples from diarrheic calves and piglets were examined for viral content by immunofluorescence, electron microscopy or cell culture. Routine fluorescent antibody and cultural tests detected rotavirus (n=126), coronavirus (n=80) and bovine viral diarrhea virus (n=13). Electron microscopy detected rotaviruses (n=24) and coronaviruses (n=17) not identified by standard fluorescent antibody tests. Other viruses detected by electron microscopy included Breda virus-like particles (n=49), astroviruses (n=1), caliciviruses (n=1), rhabdoviruses (n=1), parvoviruses (n=2), enteroviruses (n=3), togavirus-like particles (n=2), and “chained” particles (n=5). Mixtures of several of the viruses were detected in a number of fecal samples.

The survey emphasized the value of electron microscopy as a broad-spectrum diagnostic tool.

     

Outbreaks of budgerigar fledgling disease in three aviaries in Ontario

Outbreaks of budgerigar fledgling disease (BFD) occurred in three budgerigar aviaries in Ontario. Acute death in seven to ten-day-old nestlings and feather abnormalities in birds over three weeks of age were common findings. Ascites, hepatomegaly and hydropericardium were prominent gross lesions. Histologically, basophilic intranuclear inclusions were seen in many tissues. A severe drop in hatchability occurred in one aviary—a finding not previously reported with BFD. Interruption of breeding controlled the disease in aviary 1, but failed in two consecutive attempts in aviary 2. A third outbreak occurred in aviary 2 after depopulation and restocking. In aviary 3, the spread of disease was very rapid; 90% of the nestlings died within a few weeks. A papovavirus similar to a previously described isolate was recovered in this outbreak.