G.H. Collins

Studies on Sarcocystis species III: The macrocystic species of sheep.

Abstract Three forms of macrocyst were studied in sheep. On the basis of their dimensions and cyst-wall ultrastructure, thin cysts were found to be a separate species from fat and oesophageal cysts, but were also transmitted by cats. Sporocysts derived from fat and thin cysts had similar dimensions. It is proposed that the thin species be named S. medusiformis n.sp.

Studies on Sarcocystis species VI: a comparison of three methods for the detection of Sarcocystis species in muscle.

Abstract Twenty minutes peptic digestion was as senstitive as 2 hours digestion and three times more sensitive than histology in the detection of Sarcocystis in muscle. Ten of 25 red deer and 7 of 25 wild pigs were infected with Sarcocystis.

Studies on Sarcocystis species. II. Infection in wild and feral animals--prevalence and transmission.

Abstract Wild and feral animals in New Zealand were examined by a muscle-digest technique, and histology. Sarcocystis spp. were found in red deer, feral goats, feral pigs, rats, mice, and rabbits, and the prevalence of infection recorded. No Sarcocystis spp. were found in 8 wallabies and 62 possums. Sarcocystis spp. in rats and rabbits were transmitted to cats, and a species in goats to dogs.

Studies on Sarcocystis species: 1. Feral cats as definitive hosts for sporozoa.

Abstract A survey was carried out by means of questionnaires and correspondence on the distribution, feeding and breeding of feral cats in New Zealand. Altogether 950 specific sightings of feral cats were recorded and mapped: cats were recorded from almost all parts of the country in a wide range of habitats from sea-level to 1500 m. Eighty per cent of these sightings were 2 km or more from human habitation, 29% > 10 km. Evidence of breeding was recorded from all areas and categories of habitat. Cats were observed feeding on a wide range of animal remains; rabbits, opossums, sheep and birds were reported most commonly. Although they are probably an important source of sporozoan infections for domesticated animals, it is concluded that it would be neither practical nor justifiable to attempt to control feral cats on agricultural land.

Eperythrozoon wenyoni - a blood parasite of cattle. A first report in New Zealand.

Summary This paper records, for the first time in New Zealand, the occurrence of Eperythrozoon wenyoni in the blood of a cow. Inoculation of infected blood into two splenectomized calves resulted in a heavy parasitaemia with a moderate anaemia in one calf The other calf remained refractory to infection. The possible importance of E. wenyoni is discussed.Summary This paper records, for the first time in New Zealand, the occurrence of Eperythrozoon wenyoni in the blood of a cow. Inoculation of infected blood into two splenectomized calves resulted in a heavy parasitaemia with a moderate anaemia in one calf The other calf remained refractory to infection. The possible importance of E. wenyoni is discussed.

Studies on Sarcocystis species VII: the effect of temperature on the viability of macrocysts (Sarcocystis gigantea) of sheep.

Abstract Survival of Sarcocystis gigantea macrocysts was studied usingan oxygen electrode and by feeding to cats. Macrocysts were viable after 10 minutes at 52.5°C but not after 20 minutes at 55°C or 10 minutes at 60°C. Macrocysts survived 60 days at — 14°C and infected cats. After storage at 10°C for 13 days and 4°C for 20 days macrocysts still metabolised vigorously. Treatment of sheep meat at 60°C for at least 20 minutes should render it non-infective for cats.

Studies in Sarcocystis species V: A species infecting dogs and goats; observations on the pathology and serology of experimental sarcocystosis in goats

Abstract Eleven goats given dog-derived Sarcocystis sporocysts, showed illness from day 18. Doses of 5 × 106 sporocysts caused a progressive temperature rise, with peaks at 6,11 and 18 days. Necropsy at 18 and 19 days revealed multiple petechiation and schizogony in endothelial cells. In goats given smaller doses, Hb, PCV and TP levels fell from day 17. IFAT titres rose from day 28.

Studies on Sarcocystis species. IV: A species infecting dogs and goats; development in goats.

Abstract The development of a dog:goat species of Sarcocystis was studied experimentally in goats. Schizogony in vascular endothelium at 18 and 19 days after infection was associated with-pyrexia, anaemia, anorexia, depression and death. Clinical signswere dose-related and doses of 6 × 105 or more sporocysts were fatal. Muscle invasion took place before 34 days. At 129 days, sarcocysts were infective for dogs and the life cycle was completed. Sporocysts of this dog:goat species were not infective for sheep.

Sarcocystis in goats: prevalence and transmission.

Abstract Extract A limited survey to determine the prevalence of Sarcocystis species in goats was carried out during 1977. Feral goats (Capra hircus) are commonly found on farmland in certain parts of New Zealand and, in recent years, many have been captured and slaughtered for export. The goats we examined were part of a largegroup assembled from many properties in the Hawkes Bay area.

Filaroides osleri in a dog.

Summary The symptoms, diagnosis, treatment and necropsy findings in a Filaroides osleri infection in a dog are described. Changes in respiratory function before and after treatment are recorded and the possible significance of bronchospasm as a cause of dyspnoea is discussed. Although diagnosis was made initally by finding larvae in bronchial washings, endoscopy is considered the most reliable means of diagnosis. Treatment with thiabendazole, levamisole and fenbendazole appeared to suppress larval production but failed to kill adult F. osleri.