Isolation of oxfendazole resistant Cooperia oncophora in cattle

A field strain of Cooperia oncophora resistant to oxfendazole was isolated from a commercial cattle rearing property in Waikato, New Zealand. Resistance to oxfendazole was assessed by means of a faecal egg count depression test and an in vitro egg hatch test. This is the first documented case of anthelmintic resistance in Cooperia spp. and the first report of anthelmintic resistance in cattle in New Zealand.     

Prevalence of dog-derived Sarcocystis spp. in some New Zealand lambs

Pepsin: hydrochloric acid digestion and histological examination of the myocardium of 51 hearts from five to nine month-old lambs from the southern half of the North Island, showed that 47 (92%) were infected with microscopic sarcocysts that are presumed to be dog-derived. Of 157 sarcocysts detected histologically, 32 corresponded morphologically with Sarcocystis ovicanis and 120 with Sarcocystis tenella (Syn. S. arieticanis). The remainder could not be identified as to type.     

Parapoxvirus infections in New Zealand farmed red deer (Cervus elaphus)

Outbreaks of infection due to a parapoxvirus were reported on eight New Zealand deer farms. Scabby lesions were seen variably on the muzzle, lips, face, ears and neck of red deer (Cervus elaphus) with morbidity rates reaching 100%. On three farms multifocal lesions were also present on the velvet. Deaths were reported on two properties where the lesions were extensive and secondary bacterial infections had occurred. On one of these farms multifactorial disease was suspected. Poxvirus particles were seen by negative contrast electron microscopy in scab material from all eight properties. Morphologically the deer virus resembled a parapoxvirus, but restriction endonuclease analysis showed its DNA fragment patterns were distinct from those of orf (contagious ecthyma) virus.     

The effects of artificially-induced fly-strike on food intake and liveweight gain in sheep

A single, artificially-induced fly-strike with Lucilia sericata larvae was associated with a rapid (decline in food intake in sheep, with a consequent reduction in liveweight. Loss of weight ranged from 0.5 to 5.5 kg over four to six days and recovery to pre-infestation liveweight took three to 36 days. Pair-fed, uninfested partners of these sheep also showed a reduction in liveweight, whereas uninfested sheep in some experiments fed ad libitum showed either little change or a gain in liveweight over the same period. In general, maggot infested sheep took less time to regain weight than did their pair-fed partners although the weight lost as a proportion of initial weight was similar in both groups. Loss of appetite alone would appear to account for these events.     

Dyserythropoeisis, sideroblasts/siderocytes and hemoglobin crystallization in a dog

Dyserythropoiesis characterized by enhanced intramedullary destruction, pathologic sideroblasts and siderocytes, and hemoglobin crystallization was detected in a female Cocker Spaniel presented for poor exercise tolerance. Examination of peripheral blood revealed intraerythrocytic crystals, granulation of erythrocytes, nucleated erythroid cells, reticulocytosis and marked variation in erythrocyte morphology in the absence of anemia. Bone marrow examination revealed sideroblasts, a low M:E ratio and evidence of enhanced intramedullary destruction of erythroid cells. Electron microscopy of peripheral blood and bone marrow confirmed pathologic mitochondrial iron accumulation in erythroid cells and the presence of intraerythrocytic hemoglobin crystals. A cause for the hematologic changes was not identified. After the animal became clinically normal, siderocytes disappeared from peripheral blood but intraerythrocytic crystals and reticulocytosis persisted.     

Effects of heartworm and intestinal parasitic infections on hematology and peripheral lymph node cytology in louisiana dogs

Hookworm infected dogs had higher blood basophil counts than hookworm negative dogs. Dogs with occult heartworm infection (i.e., without microfilaremia) had higher blood neutrophil counts than heartworm negative dogs. The percentage of eosinophils in peripheral lymph nodes was higher in heartworm infected, microfilaremic dogs than in both occult infected dogs and heartworm negative dogs. Heartworm or intestinal parasitic infection had no other significant effects on hematologic parameters or peripheral lymph node cytology.