Search

Fecal survey of Eimeria oocysts and parasite eggs was conducted for 219 fecal samples of free-ranging Grus japonensis in Kushiro district in Hokkaido in April 2003. Positive rate and mean oocysts (or eggs) per gram in positive samples were 26% (57/219) and 8.8 (0.2-136) in oocysts of Eimeria reichenowi, 18.3% (40/219) and 320 (100-1,000) in trematode eggs, 0.1% (2/219) and 0.2 (0.2-0.3) in eggs of Nematoda A, and 4.1% (9/219) and 0.8 (0.2-3.6) in eggs of Nematoda B, respectively.

To determine the effects of ozone on the phagocytosis of bovine polymorphonuclear leukocytes (PMNs), ozone gas was administered in vitro on the blood and milk of healthy lactating cows, cows with acute mastitis, and cows with milk fever. In the blood of healthy dairy cattle, although there was no significant effect of ozone gas on the viability of the leukocytes, phagocytosis of PMNs significantly decreased. In contrast, ozone gas administration in vitro significantly increased phagocytosis of PMNs from the blood of cows with acute mastitis and milk fever, and from mastitic milk. These findings showed that ozone administration in vitro has positive and negative effects on bovine PMN phagocytosis, depending on the health status of the animal.

The prevalence of Cryptosporidium infection was examined in 480 healthy cattle (0-39 months old) in the Tokachi district in Hokkaido during the period from June to September in 2000 and from June to July in 2001. C. parvum oocysts were detected in 6 of 50 cattle (0-2 months old) in 2001; while C. muris was detected in 2 of 56 cattle (6-8 months old) in 2001, in 1 of 15 cattle (9-11 months old) in 2001, in 1 of 88 cattle (15-17 months old) in 2000, in 4 of 89 cattle (18-21 months old) in 2000 and in 2 of 53 cattle (21-23 months old) in 2000.

The purpose of this study was to evaluate seasonal influences on thyroid hormone levels of healthy outdoor dogs in Hokkaido. We surveyed serum basal total thyroxine (tT4), free thyroxine (fT4), and canine thyroid-stimulating hormone (cTSH) levels, and tT4 levels after administration of TSH for a year. Basal tT4 levels decreased in January, and increased in August and September. fT4 levels increased in January and November. No significant seasonal variation was found in cTSH. tT4 levels after administration of TSH in August and November increased. These results suggested that the thyroid gland may have been activated in November. We should take seasonal variation into consideration when thyroid function is tested.

Fifteen healthy castrated male dogs were separated into three treatment groups that were administered etodolac, aspirin and a placebo orally, respectively. All treatments were continued for 28 days. The animals were examined endoscopically on days 0, 3, 7, 10, 14, 17, 21, 24 and 28. There were no gastrointestinal mucosal lesions in either the etodolac or the placebo group, whereas some gastric lesions developed in the aspirin group after day 17. We considered that etodolac could be used for long-term treatments in dogs with fewer side-effects on the gastric mucosa than aspirin.

Maximum serum thyroxine (T4) and triiodothyronine (T3) levels of healthy calves were seen at 1 day after birth, and thereafter rapidly decreased until 5 days after birth. They stabilized until 2 weeks after birth, then gradually decreased until 4 weeks after birth. Serum T4 levels of calves with endemic goiter tended to be lower than those of healthy ones, but showed similar levels to those of adult cows. T3 levels of calves with goiter were similar to those of healthy ones, but showed higher variation. T4/T3 ratio of calves with goiter were significantly lower than those of healthy ones and adult cows. While individual levels of serum T4 and T3 at just after birth could not be considered as a diagnostic index, the T4/T3 ratio could be adopted as a diagnostic index of endemic goiter.

Sporozoites of Toxoplasma gondii preincubated with lactoferricin showed decreased activity in penetration of mouse embryonal cells. Mice inoculated with 10(5) sporozoites preincubated with lactoferricin showed a higher survival rate than those inoculated with the same number of untreated sporozoites. Likewise, sporozoites of Eimeria stiedai preincubated with lactoferricin also showed decreased activity in penetration of rabbit hepatobiliary cells. Rabbits inoculated with 10(5) sporozoites preincubated with lactoferricin shed fewer oocysts than those inoculated with the same number of untreated sporozoites. These results indicate that lactoferricin is effective to reduce the infectivity of sporozoites of Toxoplasma gondii and Eimeria stiedai.

A field trial was conducted to evaluate the efficacy of a topical formulation of ivermectin administered at the dose of 500 micrograms/kg against horn flies (Haematobia irritans) in cattle. Eighty-eight cattle in four herds naturally exposed to horn flies were used in the trial. Replicates were formed of two herds. Within replicates, one herd was randomly allocated to the untreated control and the other to the ivermectin treatment group. Horn fly counts were taken on the treatment day (Day 0) and on Days 7, 14, 21, 28, and 35 post-treatment. There were no horn flies on any cattle in the treatment group, whereas all the control cattle were continuously infested by horn flies on each examination day.