Investigation Of Intestinal Parasite Infections In Dogs In Taizhou And Studies Of Efficacy Of Drugs Against Canine Parasitic Diseases

With the rapid social and economic development,the number of breeding dogs has increased year by year,and the relationship between dogs and humans has become more and more intimate.It is very common that dogs are infected by many parasites,and gastrointestinal parasites of dogs are the most common.Gastrointestinal parasites of dogs often cause diarrhea,weight loss,anemia,growth retardation,resistance reduction,easily induce or spread subsequent diseases,and even cause death.Also,some of the canine parasites are important zoonotic parasites,such as Toxocara canis,Toxascaris leonina,Clonorchis sinensis,etc..Therefore,understanding the infection condition and the effect of anti-parasitic agents on gastrointestinal parasites is particularly urgent and important.These works can provide a basis for the clinical diagnosis and development of prevention and treatment measures against canine parasitic diseases,these can also protect the health of dogs,or reduce human infections with zoonotic disease,thus protecting human health.In view of this,this project investigated the infection of gastrointestinal parasites of dogs in Taizhou,and carried out molecular identification of the popular species of canine coccidian.Experiments were carried out on the efficacy of compound toltrazuril thixotropy suspension,the syrup-red to rid of vermin(Friend Baby)(mainly composed of sodium sulfamonomethoxine and dimethoprim)" and febantel Tablet(Drontal(?)plus flavor),ivermectin against canine coccidian and Toxocara canis,respectively.The results of this study laid an important foundation for the prevention and treatment of intestinal parasitic diseases in dogs in Taizhou.1.The investigation of gastrointestinal parasites of dogs in TaizhouA total of 621 canine feces samples collected from 5 dog farms,1 Tibetan mastiff breeding center,1 police dog breeding base,some pet clinic dogs,pet trading markets and free-range dogs in Taizhou were examined and identified by saturated saline floating method,nylon sifting method and water washing and sedimentation method.The results show that 9 species of gastrointestinal parasites were identified,They are T.cams,T.leonina,Ancylostoma spp.,T.vulpis,D.caninum,S.mansoni,C.sinensis,I.canis,I.ohioenais.The infection rate of gastrointestinal parasites of dogs was 33.01%(205/621).The dominant species were T.canis and Isospora spp.,and the infection rates were 19.16%and 11.27%respectively.The infection rate of puppies is significantly higher than adult dogs.The infection rate of canine parasites in puppies of 4 to 6 months old is the highest(54.39%,62/114),followed by puppies of 1 to 3 months old(43.88%).In the winter and early spring(December,January,February),the parasitic infection rate was significantly lower,and the infection rate in other seasons was more than 30%.The summer(From June to August)infection rate was the highest,reaching 43.52%.The parasitic infection rate of scattered dogs is slightly higher than that of captive dogs.Then,the infected dogs were selected and the infection intensity was measured.The infection intensity of several parasites was generally low.The average infection intensity of T.canis was 8.6×103,and the maxium infection intensity of Isospora spp.was 7.46×104.A necropsy of 10 free-range dogs and 4 captive dogs found that the parasite infection rate was higher,reaching 72.73%,and the infection rate of T.canis was the highest,reaching 45.45%.Conclusion:The infection of gastrointestinal parasites in dogs is directly related to the age,season and feeding methods.2.Molecular identification of coccidia species in dogsThe 18S,ITS1,5.8S,ITS2,and 28S rRNA sequences of one strain of I.canis(coded as TZ-IC)and two strains of I.ohioenais(coded as TZ-OS and TZ-OH,respectively)were amplified,cloned,sequenced,spliced,and sheared,then three sequences of about 2750 bp in length were obtained.The 18S,ITS1 and ITS2 sequences of the three Canine coccidia were subjected to homology comparison with CLUSTAL W of DNAstar software and their genetic similarity to GenBank were determined.Phylogenetic trees were constructed by the NJ method and the ML method using MEGA5.05 software.The results showed that the similarity rate of the 18S gene of the TZ-IC,TZ-OH and TZ-OS isolates were more than 99%,and the similarity rate of TZ-OH and TZ-OS isolates was 99.9%,and the homology was the highest.The similarity rate of TZ-IC isolate strain with TZ-OH and TZ-OS isolates were 99.4%and 99.3%,respectively.The homology of the three coccidia and Cysloisospora and Isospora is also very high,and the similarity is 98.4%?99.9%.The similarity of the TZ-IC isolate and C.canis(KT184360)is 99.8%.In the phylogenetic tree,three isolates and Cystoisospora,Isospora are located in the same branch.The TZ-IC isolate(TZ-IC18S)and C.canis(KT184360)form a small branch.The three isolates have the closest relationship with the Sarcocysae Cysloisospora,and have the distant relationship with Eimeria.The ITS1 sequence lengths of the isolates TZ-IC,TZ-OH and TZ-OS were 582 bp,586 bp and 584 bp,respectively.The ITS1 sequence of the two strains(TZ-OS and TZ-OH)were closely related,with a similarity of 98%,and the similarity between the two was 99.15%.The similarity of the strain of C,spp changchunl of the dog strain isolated is up to 99.5%.They form a branch with TZ-OH isolate strain.This branch,I.belli,C.rivolta and the three strains of C.ohioensis are located in the same branch.The IC strain forms a branch with C.felis(EU124689),which is far away from the genetic distance of the other two strains(TZ-OS and TZ-OH).The ITS2 sequences of TZ-IC,TZ-OH and TZ-OS were 435 bp,411 bp and 411 bp,respectively.The ITS2 sequence similarity between the TZ-IC strain and the other two strains was 91.1%,and the sequence similarity between TZ-OH and TZ-OS was 99.8%.In the phylogenetic tree,the TZ-OH and TZ-OS strains are located in the same branch as the C.ohioensis,which are close to each other relatively.Conclusion:The TZ-IC strain is I.canis or C.canis.Both TZ-OS and TZ-OH strains are isocysts of C.ohioensis,belonging to different strains of the same species.3,Experimental infection of I.canis and I.ohioenais oocystsTwelve 30 to 40-day-old puppies were divided into four groups of 3 dogs each.They were infected with the sporulated oocysts of I.canis and I.ohioensis by 1,500 per dose(low dose group)and 15,000(high dose group).After the infection,the clinical manifestations of the dogs were observed every day,The feces were examined with saturated sugar-saline floating method,and the number of oocysts per gram of feces(OPG)was counted to observe the excreting regulation of the coccidia.The newly released oocysts were collected for sporulation to observe the time required for oocyst sporulation.The results showed that dogs infected with 15,000 oocysts of I.canis showed symptoms such as loss of appetite,depression,mushy,grayish white feces,watery feces,and spray on the 9th day after infection.Dogs infected with 15,000 oocysts of I.ohioenais were more likely to develop diarrhea than 15,000 oocysts of I.canis.The clinical symptoms appeared on the 6th day after infection,and the degree of diarrhea is not as severe as the high dose group of I.canis.The low-dose group of the two species of coccidia had a mild diarrhea and a short diarrhea.The prepatent period of I.caniswas 7?9 days,and the patent period was 10?11 days(the low-dose group)and 21?22 days(the high-d ose group),respecticely The prepatent period of I.ohioena was 3-4 days,and the patent period was 11-13 days(the low-dose group)and 24-25 days(the high-dose group),respecticely.The sporulation time of both coccidia was 4 days.4.Efficacy of toltrazuril thixotropic suspension and the syrup-red to rid of vermin(Friend Baby syrup-red)against C.canis and C.ohioensisBy using the animal model of coccidia infection experimentally,the prevention group was treated during prepatency(2 days post infection)while dogs in the treatment group were treated individually after the onset of oocyst excretion of the respective coccidia species.The effects of toltrazuril thixotropy suspension and the syrup-red to rid of vermin(Friend Baby syrup-red)was compared against C.canis and C.ohioensis.The results showed that the toltrazepam thixotropy suspension did not show obvious diarrhea against prepatent infection with C.canis and C.ohioensis in dogs.Only one dog discharged a small number of oocysts in the two groups.The dogs in the toltrazuril thixotropy suspension treatment group only discharged a small amount of soft feces,and the number of days of diarrhea was also short.The symptoms of diarrhea disappeared after one day of treatment.The number of the oocysts in faces was zero within 3-4 days after treatment.After treatment with the syrup-red to rid of vermin(Friend Baby),the dogs infected with C.canis and C.ohioensis had different degrees of diarrhea,and the rates of diarrhea were 25.88%and 27.78%,respectively,but the degree of diarrhea was lighter than the infected non-treatment controlgroup.The effect of the syrup-red to rid of vermin(Friend Baby)against C.canis was the same as that of toltrazuril.The number of the oocysts in faces was zero in the 3rd day after treatment.However,the number of the oocysts in faces was zero in the 19th day after the syrup-red to rid of vermin(Friend Baby)against C.ohioensis.Conclusion:The toltrazuril thixotropic suspension has good prevention and treatment effects against canine coccidia.The syrup-red to rid of vermin(Friend Baby)is effective in treating coccidiosis of canine,but its preventive effect is weak.5.Efficacy of compound febantel Tablelelet(Drontal(?)plus flavor)and ivermectin against T.canisThe efficacy of compound febantel Tablelelet(Drontal(?)plus flavor)and ivermectin against T.canis was evaluated in naturally infected dogs.The reduction rate of eggs in the two groups on the 5th,10th,and 15th day after the first treatment exceeded 95.0%.However,the conversion rate of the eggs in the two groups could not reach 100%after 15 days of the first treatment.The disappearance rate of eggs reach 100%in the 5-10 days after the second treatment.The worm was mostly excreted on the 6th-8th day after treatment with ivermectin,and the worm was more than 2-4 days after treatment with Drontal(?)plus flavor.Both of groups can reach the 100%repellent rate after two treatment according to the result of necropsy.Conclusion:Ivermectin and compound febantel Tablelelet(Drontal(?)plus flavor)is highly efficacious against T.canis.