P-glycoproteins (P-gp) are transmemebrane glycoproteins associated with the multidrug resistance (MDR) phenotype. The P-gp functions as an ATP-dependent transporter of a diverse xenobiotic and pharmologic compounds to effectively lower their intracellular concentration. As such, P-gp is believed to be a significant component of the blood-brain-barrier (BBB) in mammals. We carried out a study to investigate whether P-gp could be detected in normal and in horses afflicted with equine motor neuron disease (EMND). Fresh samples were harvested at necropsy from seven horses diagnosed with EMND and three control horses and immediately frozen in liquid nitrogen until processing. The samples included tissues from the adrenal gland, kidney, liver, small intestine, brain stem, and spinal cord. These tissues were evaluated for P-gp immunoreactivity using monoclonal antibody (C494). Normal and EMND afflicted horses expressed the P-gp at similar levels in the adrenal cortex (100%), the renal proximal tubules (57%), and small intestinal enterocytes (60%). There was no significant difference in the P-gp expression rates between the EMND affected horses and controls. None of the liver and central nervous tissue samples exhibited any P-gp staining. The overall results of our investigation indicate that abundant P-gp expression can be detected in some of the equine tissues using the immunohistochemical methods. The ability to detect P-gp in equine tissues might help in determining its specific role in the etiology of EMND.
Two groups of jumping horses in activity were studied to evaluate the nutritional value and digestibility of the combinations of two feeds and three roughages each administered for 20 days. Group P (4 horses) was fed a pellet feed associated with traditional hay in Trial 1, haylage in Trial 2 and dehydrated alfalfa in Trial 3. Group C (4 horses) received a crushed feed and the same three roughages in the same order. After an adaptation period of 15 days, the faeces of each subject were collected twice a day for 5 days and the digestible utilisation coefficient (DUC) was determined using the AIA method. The three different roughages had similar digestibility coefficients of crude protein in combination with both feeds; in particular, dehydrated alfalfa yielded identical results in association with both the pellet and the crushed feed. Haylage showed a lower coefficient of digestibility of crude protein and ether extract with both feeds. The combination of the pellet and the traditional hay gave the best result of DUC. The energy coefficient of digestibility was higher with all three roughages combined with the P feed, even though the greater absolute amount of feed ingested by group P, by increasing the rate of transit, would have been expected to reduce the coefficient of utilisation. These results suggest the importance of analysing the quality of diets and of evaluating feed processing and the effect of combining different feeds.
We summarized the data from a mutual relief livestock insurance program, an insurance system applied under the Law of Compensation for Agricultural Damage, to determine the incidence of equine acute abdomen in the Hidaka district, a major horse-breeding region of Japan. A retrospective survey was conducted over a three year period, from January 2001 to December 2003. During this time, the number of cases of acute abdomen was 8,481 out of a total of 53,756 cases of diagnosed diseases (15.8%). During the same period, the number of cases of death due to acute abdomen was 306 out of a total of 1,106 deaths (27.7%). When a provisional population was calculated from the number of horses insured in November 2002 (45,624), the annual rates of "disease or injury" and "death or disuse" due to acute abdomen were 18.6% and 0.7%, respectively for the three year period. The most common forms of acute abdomen were intestinal tympany and constipational colic (5,455 cases, 64.3% of all acute abdomen cases); and volvulus was the most frequent cause of death (108 cases, 35.3% of the number of deaths due to acute abdomen). The incidence of intestinal obstruction, intestinal narrowing, intussusception and volvulus was highest from May to August (79 cases, 53.4% of a total of 179 cases). The mortality rate of acute abdomen was highest in those horses older than 21, followed by the range in age from 16 to 20. The removal of the factors associated with acute abdomen which are indicated in this report may be useful for prevention of acute abdomen.
To examine the association of equine herpesvirus types 1 (EHV-1) and 4 (EHV-4) with neonatal death of foals in Turkey, DNA detection of EHV-1 and EHV-4 from pooled organs of neonatal dead foals collected in Istanbul from 1998 to 2003 was conducted by PCR. EHV-1 DNA was detected in 5 foals (13.8%), but no viral DNA of EHV-4 was detected in 36 foals examined in this study. This report describes the first detection of EHV-1 DNA in neonatal dead foals by using the genetic method in Turkey.