The weather determines the number of cases of tick paralysis in dogs and cats in eastern Australia,caused by Ixodes holocyclus,the eastern paralysis tick

We studied over 222,000 cases of emergency veterinary consultations in four regions along the eastern coast of Australia. We found that cases of tick paralysis (TP) caused by the eastern paralysis tick, Ixodes holocyclus, accounted for 7.5% of these cases: >16,000 cases. The season of TP and the number (prevalence) of TP cases varied among regions and over the years. Our study of the association between weather and (i) the start of the season of TP, and (ii) the number of TP cases revealed much about the intricate relationship between the weather and I. holocyclus. We studied the effect of the hypothetical availability of isoxazoline-containing tick-preventative medicines and found that an increase in the availability of these medicines had significantly contributed to the decrease in TP cases. We found that the weather in winter accounted for the time of the year the season of TP starts whereas the weather in summer accounted for the number of TP cases in the TP season. Last, through a study of the effects of shifts in the climate under four hypothetical scenarios (warmer/cooler and drier/wetter than average), we propose that the start of the season of TP depends on how soon the weather in winter becomes suitable for the activity (e.g. host-seeking) and the development of I. holocyclus nymphs, and that the number of TP cases during the TP season depends on how many engorged female ticks and their eggs survive during summer.     

Bovine mycotic abortion and pneumonia

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Sir,—We should like to take this opportunity to congratulate Messrs Cordes, Dodd and O'Hara (1964 Cordes, D. O., Dodd, D. C. and O'Hara, P. J. 1964. N.Z. vet J., 12: 95–95. [Taylor &; Francis Online] , [Google Scholar]) on their excellent article on bovine mycotic abortion and pneumonia in New Zealand, and at the same time mention certain complementary features of these conditions as noted in Tasmania.     

Preparation of gastro-intestinal tracts for submission to the laboratory: A preservation technique

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Sir, — Diagnostic parasitologists are often required to examine autolysed gastro-intestinal tracts. Such specimens are aesthetically unpleasant and fragmentation of worms may have occurred, making it impossible either to identify or count them. Autolysis often occurs following collection while the specimen is in transit to the laboratory.     

Demonstration of a herpesvirus from piglets with lesions of Aujeszky's disease in New Zealand

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Sir, — Four suckling piglets have been examined at this laboratory from a Taranaki herd in which sudden death, chorea and convulsions were the clinical features.     

Dark ground microscopy of leptospira in tissue sections

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Sir, — Recently I read with interest a letter by Fowler in the January–February 1976 issue of the Journal.     

The brown dog tick (Rhipicephalus sanguineus) on an imported dog

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Sir, — We wish to record the presence of the tick Rhipicephalus sanguineus on a dog imported from Australia. This tick is mainly parasitic on dogs although on rare occasions it has been collected from non-canine hosts (Roberts, 1965 Roberts, F. H. S. 1965. The taxonomie status of the species of the genera Rhipicephalus (Koch) and Boophilus (Curtice) occurring in Australia. Aust. J. Zool., 13: 491–523.  [Google Scholar]). Experimentally it has been shown capable of transmitting a wide variety of serious diseases but its role as a natural vector of many of them is unknown. In Australia it has been demostrated as being naturally infected with Coxiella burnetii (Smith, 1942 Smith, D. J. W. 1942. Studies on the epidemiology of Q Fever. Aust. J. exp. Biol. med. Sci., 20: 295–296.  [Google Scholar]) and is recorded from all continents and some oceanic islands lying between latitudes 50°N and 36°S (Roberts, 1970 Roberts, F. H. S. 1970. Australian ticks, 87–87. CSIRO.  [Google Scholar]). Auckland falls within this boundaries and therefore it is not unreasonable to suggest that R. sanguineus could become established in New Zealand.     

A request for sheep with testicular feminization

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Sir,—I should like to make a request to interested veterinarians for live specimens of the rare condition in sheep — testicular feminization.