Investigations into the prevention of prenatal and lactogenic Toxocara canis infections in puppies by application of moxidectin to the pregnant dog

Aim of the investigation was to examine whether two administrations of moxidectin to pregnant dogs could prevent pre-natal and lactogenic infections of puppies with reactivated Toxocara canis larvae. Four pregnant beagles, infected experimentally with 20 000 embryonated eggs of T. canis, were treated subcutaneously with 1 mg moxidectin per kg body weight on days 40 and 55 of pregnancy (5-13 days before parturition). One further dam and its puppies served as untreated control. Two applications of moxidectin completely prevented pre-natal and lactogenic infections in the puppies. Neither intestinal stages nor somatic larvae were found in the dams or their corresponding puppies. All puppies and dams of the treatment group remained coproscopically negative until 42 days after parturition. The administration of moxidectin did not show any side effects in the dams. None of the puppies of the treated dams showed any pathological abnormalities. In the untreated dam one adult and 26 somatic larvae of T. canis were detected at necropsy. All puppies of the untreated dam showed a patent T. canis infection from day 28 post-natum (p.n.); 296 pre-adult and adult stages of T. canis were spontaneously eliminated and 51 intestinal stages and five somatic larvae of T. canis were recovered at necropsy. In contrast to the puppies of the treated dams all negative control puppies showed blood eosinophilia after parturition and elevated liver enzyme levels.     

Investigations into the prevention of neonatal Ancylostoma caninum infections in puppies by application of moxidectin to the bitch.

The aim of this investigation was to examine whether reactivated Ancylostoma caninum larvae can be eliminated by the administration of moxidectin to pregnant bitches. Four pregnant bitches infected experimentally with 20,000 third-stage larvae of A. caninum were treated subcutaneously with 1 mg moxidectin/kg body weight on day 55 of the pregnancy (5-8 days before parturition). Another four experimentally infected pregnant bitches served as controls. The single moxidectin treatment completely prevented lactogenic infections in the puppies. Neither intestinal stages nor somatic larvae could be found. The administration of moxidectin caused no local or systemic side-effects in the bitches. All 22 puppies of the treated bitches were born healthy and remained so during the whole trial period. Beginning during the third week after birth, all 20 puppies of the untreated bitches developed a severe microcytic, hypochromic anaemia and they revealed a total of 8649 intestinal stages of A. caninum after autopsy.     

Investigations into the Prevention of Neonatal Ancylostoma caninum Infections in Puppies by Application of Moxidectin to the Bitch

The aim of this investigation was to examine whether reactivated Ancylostoma caninum larvae can be eliminated by the administration of moxidectin to pregnant bitches. Four pregnant bitches infected experimentally with 20 000 third-stage larvae of A. caninum were treated subcutaneously with 1 mg moxidectin/kg body weight on day 55 of the pregnancy (5–8 days before parturition). Another four experimentally infected pregnant bitches served as controls. The single moxidectin treatment completely prevented lactogenic infections in the puppies. Neither intestinal stages nor somatic larvae could be found. The administration of moxidectin caused no local or systemic side-effects in the bitches. All 22 puppies of the treated bitches were born healthy and remained so during the whole trial period. Beginning during the third week after birth, all 20 puppies of the untreated bitches developed a severe microcytic, hypochromic anaemia and they revealed a total of 8649 intestinal stages of A. caninum after autopsy.     

Biology, pathogenicity, diagnosis and control of Ancylostoma caninum]

Infections with Ancylostoma caninum are transmitted orally or percutaneously. The transmission of infectious stages with the milk of particular importance for the distribution of the species. It occurs during the dissemination of larvae that follows every infection as well as after reactivation of resting somatic larvae in the bitch at the end of the pregnancy. The galactogenic transmission of larvae occurs even when, due to existing immunity, no patent infections develop in the bitch. Immunity does not or only to a low extent influence impatient infections or the migration of reactivated somatic larvae. It also allows a limited reestablishment of a deposit of larvae in the bitch. Following percutaneous infection dermatitis occurs in the area of larval penetration and the lung is affected by migrating larvae. Intestinal stages of Ancylostoma caninum damage the host by ingestion of the mucosa of the small intestine and withdrawal of blood. Main symptoms of ancylostomiasis are a mucous haemorrhagic diarrhoea and anaemia, that become visible 8 to 10 days post infection. The examination for impatient infections with Ancylostoma caninum can be done by immunofluorescence and ELISA. With both methods antibodies against third stage larvae can be detected from the first or second week post infection onward. Patent infections with Ancylostoma caninum can easily be detected by faecal examination for the presence of the characteristic oval, thin-walled eggs containing few blastomeres. Galactogenic infections with Ancylostoma caninum can be prevented or reduced by a regular treatment of the bitch with albendazole, fenbendazole or oxfendazole during the activation of larvae in the last third of the pregnancy or by repeated treatment with ivermectin shortly before and after birth. To prevent patent infections, galactogenic infected puppies have to be treated early and repeatedly.     

The effect of ivermectin on reactivated somatic larva of Ancylostoma caninum Ercolani 1859 (Ancylostomidae) in the pregnant dog

It was evaluated by means of a controlled test to what extent reactivated larvae of Ancylostoma caninum were influenced by single or double treatment with ivermectin. The investigations were done with a total of ten experimentally infected bitches. The single treatment of dams two to ten days ante partum with 0.5 mg or 1 mg ivermectin per kg bodyweight reduced the wormburden of their puppies on an average by 96.6% and 98.5%, respectively. The double treatment with 0.5 mg/kg bodyweight ante and post partum each with an interval of ten days completely prevented lactogenic infections with Ancylostoma caninum. Following a single application of 0.5 mg ivermectin per kg bodyweight the excretion of larvae was markedly delayed and remained on a low level. In addition the infections of the puppies of single treated dams became patent on an average 9.5 and 14.5 days later than the controls. In the bitches no side-effects, neither local nor general, were seen after the treatment with ivermectin. All forty puppies of the treated bitches were born without visible damages.     

First report of the use of meglumine antimoniate for treatment of canine leishmaniasis in a pregnant dog

Canine leishmaniasis during pregnancy is rarely reported, even in countries where the infection in dogs is endemic. The authors report a case of a 4 yr old bitch with leishmaniasis treated with meglumine antimoniate during pregnancy. The pregnancy and delivery were normal and the bitch presented improvement of the infection during treatment. Three puppies died within 2 days of birth and tested negative via real-time PCR for L. infantum. The two surviving puppies were followed clinically, serologically, and by real-time PCR until 1 yr of age with no evidence of congenital leishmaniasis. L. infantum DNA was detected with real-time PCR analysis of uterine tissue from the bitch at the time of ovariohysterectomy. PCR analysis was performed after an ovariohysterectomy of the bitch that was performed two months after parturition. Meglumine antimoniate use in the pregnant bitch may have prevented vertical transmission of leishmaniasis.     

Effects of host maturity and prior exposure history on the production of Neospora caninum oocysts by dogs

To investigate whether dogs shed Neospora caninum oocysts more than once, five dogs with a previous history of shedding oocysts were fed infected bovine tissues. Two of three dogs shed oocysts when they were re-exposed 18-20 months after the first challenge; two other dogs re-exposed earlier, only 8 months after the primary exposure, did not produce oocysts. These results suggest that dogs may become refractory to shedding N. caninum oocysts for a period approximately between 8 and 18 months after a primary infection; however, this possibility requires statistical validation by testing of more dogs. The development of a high antibody titer did not ensure that a dog would completely resist shedding oocysts after consuming an infected meal. Oocyst production was also compared between puppies and adult dogs with primary infections. Twelve puppies (three from the present study and nine from a previous study) shed significantly more oocysts (mean: 166,400) compared with five adult dogs following primary exposure (mean: 2900), indicating that a dog's age can influence N. caninum oocyst production (P=0.02).     

Patent Toxocara canis infections in previously exposed and in helminth-free dogs after infection with low numbers of embryonated eggs

The outcome of Toxocara canis infections in the canine host depends on the migratory pathway of parasite larvae (somatic or tracheal) which is considered to be related to the host's age and its immune status. However, field studies attest high prevalences of patent T. canis infections in adult animals. The controlled induction of patent infections with low doses of embryonated eggs was investigated in 18 beagles in a 7-month study until their 16th life month. The animals were assigned to three groups, each consisting of three vertically infected dogs (with a short patent infection as pups before anthelmintic treatment) and three helminth-free dogs. At study days 10 and 40, the animals of groups 1 and 3 were given each 100 embryonated T. canis eggs. In each case, group 1 was treated 10 days post-infection with Milbemax, while dogs of group 3 remained untreated. Control group 2 was not experimentally infected but treated as group 1. Two weeks after first egg administration, a sharp increase of specific antibody reactions in ELISA and increased eosinophilic counts indicated larval invasion in all infected dogs. 42-56 days following first infection, patent infections were detected coproscopically in all animals of group 3, but in none of the uninfected dogs (group 2) or the infected and treated dogs (group 1). Following a 3-month observation period, all animals of the three groups were treated with piperazine citrate to eliminate intestinal infections and all were administered 100 embryonated eggs. Subsequently, patent infections developed in animals of all groups: in one of the infected and treated animals of group 1, in five of the so far not infected control group 2 and in four of the dogs with previous patent infections (group 3). Susceptibility to patent infections was not significantly altered in T. canis-free dogs compared to dogs with previous patent infection (vertically acquired or experimentally induced). However, dogs of group 1 treated with Milbemax after repeated egg administration developed a significantly increased resistance to patent infections as compared to control dogs (group 2). Observed prepatency periods were between 40 and 56 days and did not differ in the three groups. Even in urban areas, facing high infection pressure with Toxocara eggs maintained by a high dog and fox population, dogs of all ages are at risk to develop patent T. canis infections.     

Diagnostic significance of Neospora caninum DNA detected by PCR in cattle serum

A nested PCR that successfully detected Neospora caninum DNA in serum of cattle was used for investigation of selected abortion cases and in a study of healthy pregnant cows at an abattoir. N. caninum DNA was not detected in serum from antibody positive dams that aborted due to N. caninum, but was present in serum of some antibody negative dams that aborted due to other causes. N. caninum DNA was also found in the serum of about half of the animals that aborted of undetermined cause, but was not detected in cow sera from two beef cattle herds in Western Australia with no recent history of abortion. In the abattoir study of 79 dams and their foetuses N. caninum DNA was found in serum of 3 dams and in material from 11 foetuses. The majority of the cows and all foetuses were antibody negative. Our findings suggest that there is no obvious relationship between the presence or absence of N. caninum DNA in serum and the presence of antibodies to N. caninum in dams, the presence of N. caninum DNA in foetuses or abortion due to N. caninum. This is the first report of the detection of N. caninum DNA in serum of cattle rather than the white blood cell fraction. It indicates the presence of free tachyzoites and/or parasite DNA in circulation. The results suggest that persistent infection in the absence of antibodies is a possible outcome of N. caninum infection. Infection of foetuses in the absence of antibodies supports the possibility of persistent infection due to immunotolerance to an early in utero infection. It is therefore important to test for N. caninum DNA as well as antibodies for the detection of exposed and/or infected animals. However, the presence or absence of N. caninum antibodies or DNA did not support nor exclude N. caninum as the cause of abortion. Additional criteria are required for a positive diagnosis of abortion caused by N. caninum.     

Field trials of the anthelmintic efficacy of nitroscanate and mebendazole in dogs

The efficacies of nitroscanate and mebendazole against nematodes and Dipylidium caninum were compared by the examination of the faeces of 155 dogs. In unweaned puppies nitroscanate acted significantly faster and was significantly more effective than mebendazole against Toxocara canis. In adult dogs, both drugs had a low efficacy against Trichuris vulpis but a similarly good efficacy against other nematodes, with a tendency for nitroscanate to be more effective in reducing the prevalence of Ancylostoma caninum. Nitroscanate reduced the prevalence of D caninum infections considerably more than mebendazole.     

Ascarid infections of cats and dogs

The ascarids Toxocara canis, Toxocara cati, and Toxascaris leonina are probably the most common gastrointestinal helminths encountered in small animal practice. Both T. canis and T. cati can cause serious disease in kittens and puppies; T. leonina is generally less pathogenic. Prenatal transmission assures that virtually all puppies are born infected with T. canis. Transmammary transmission is probably the major route of infection for kittens with T. cati. In addition, all three species of worm produce resistant eggs and use paratenic hosts to facilitate transmission. Much is now known about the complex biology and life history of T. canis. However, many questions, such as those concerning the mechanisms of larval survival within host tissues and of larval reactivation and migration during pregnancy, await further study. The mechanism of resistance to ascarid infections in cats and dogs has not been clearly defined. Ascariasis is traditionally thought to be a disease of young animals, with older animals being considered immune. However, at least in the case of T. canis, adult dogs can be repeatedly infected. A wide range of anthelmintics is available with extremely high efficacy against patent ascarid infections. The problem of prenatal infection with T. canis may be overcome by strategic use of the newer benzimidazole-carbamates, and the production of ascarid-free puppies now seems possible. However, complete larvicidal activity against somatic stages has not been convincingly demonstrated. Visceral larva migrans-like syndromes are now being recognized in dogs and cats. In addition, visceral larva migrans in children due to T. canis continues to be a significant zoonotic disease in North America and underscores the need for the veterinary profession to control ascarid infections in cats and dogs at every opportunity.     

Prenatal and transmammary infections of Toxocara canis in dogs: effect of benzimidazole-carbamate anthelmintics on various developmental stages of the parasite

Fenbendazole and albendazole, given at a dose rate of 150 mg/kg for 3 days, produced a 90 per cent reduction in the numbers of second stage larvae of Toxocara canis present in the tissues of dogs although no reduction in the number of larvae found in the brains of infected dogs occurred with this treatment. The results suggest that a course of 3 day therapy with these anthelmintics should prevent prenatal infections in puppies. However, if infection is acquired by bitches during late pregnancy or early lactation, the transmammary route of infection becomes important. Therefore, anthelmintic treatment of the bitch prior to pregnancy will not prevent transmission of infection to her puppies should the bitch acquire a new infection of T. canis during pregnancy or early lactation. Alternatively, infection with T. canis can be controlled through the treatment of neonatal puppies for migrating larvae of T. canis. Treatment of newborn puppies with fenbendazole, albendazole or oxfendazole at a dose of 100 mg/kg for 2–3 days produced a 91–99 per cent reduction in the number of adult parasites found. In addition, a single dose of fenbendazole, given at a dose rate of 40 mg/kg, eliminated 93–96 per cent of adult T. canis from the intestines of 4–5-week-old puppies. These latter treatments would need to be repeated to eliminate completely the infection from puppies.     

Population genetic analysis of the new dog breed Elo

The breeding of the dog breed Elo was started in 1987. This dog breed was established by using 16 dogs of nine different breeds. All pedigree information of the dogs from 1987 to 2002 was included for the analysis of the proportion of genes of the different founder breeds, of the inbreeding coefficient, and relationship coefficients. Additionally, the number of died puppies per litter were investigated. The Eurasian dog breed contributed about 48% of the genes in the whole Elo dog population. Old English sheepdog and Chow Chow contributed about 23% and 10% of the genes. The other dog breeds were of minor importance. The mean inbreeding and relationship coefficients of the whole Elo dog population were 12.04% and 19.22%, respectively. With the exception of 3.5% of animals, all Elo dogs were related to each other. The mean litter size was 6.39 puppies. The percentage of stillborn puppies per litter averaged at 9.47%. The inbreeding coefficients of the puppies and of their dams, the age of the sire and the dam at the time of birth of the puppies, the litter size, the puppies' year of birth and the proportion of genes of the Chow Chow showed a significant effect on the number of stillborn puppies per litter. The heritability for the frequency of stillborn puppies was estimated using a linear animal model. After transformation of the linear estimates to the underlying liability scale, the heritability amounted to h2 = 0.15.     

Canine parvovirus infections in a colony of dogs

A serological study of canine parvovirus (CPV) infections in a colony of dogs was conducted over a period of 8 months. Twenty-two of 24 adult dogs sampled initially had significant antibody titres to CPV. Nine litters of puppies wer e bled at fortnightly intervals and the sera tested for antibodies to CPV. Twenty-nine of 35 natural CPV infections observed were subclinical. A puppy in one litter developed vomiting and diarrhoea during the same period as seroconversion to CPV. Four puppies from a further litter developed histologically confirmed myocarditis. Serological testing of this latter litter indicated that the virus infections occurred between 2 weeks prior to and 1 week post whelping, and that clinical disease developed 20–40 days after viral infection. The mean half life of the decline of passively derived immunity to CPV was 8.3 days.     

Experimental infection of dogs (Canis familiaris) with sporulated oocysts of Neospora caninum

Neospora caninum is widely distributed in the world and this parasite is one of the major causes of abortion in cattle. Dogs and coyotes are definitive hosts of N. caninum and several species of domestic and wild animals are intermediate hosts. Dogs can become infected by the ingestion of tissues containing cysts and then excrete oocysts. It is not yet known whether sporulated oocysts are able to induce a patent infection in dogs, i.e. a shedding of N. caninum oocysts in feces. The objective of this study was to experimentally examine the infection of dogs by sporulated oocysts. The oocysts used in the experiment were obtained by feeding dogs with brain of buffaloes (Bubalus bubalis) positive for anti-N. caninum antibodies by indirect fluorescent antibody test (IFAT ≥200). Oocysts shed by these dogs were confirmed to be N. caninum by molecular methods and by bioassay in gerbils, and sporulated N. caninum oocysts were used for the oral infection of four dogs. The dogs were 8 weeks old and negative for antibodies to N. caninum and Toxoplasma gondii. Dogs 1 and 4 received an inoculum of 10,000 sporulated oocysts each; dog 2 an inoculum of 5000 sporulated oocysts and dog 3 received 1000 sporulated oocysts of N. caninum. The total feces excreted by these dogs were collected and examined daily for a period of 30 days. No oocysts were found in their feces. The dogs were monitored monthly for a 6-month period to observe a possible seroconversion and when this occurred the animals were eliminated from the experiment. Dogs 1 and 4 seroconverted 1 month after the infection with titer, in the IFAT, of 1600 and 800, respectively; the other two dogs presented no seroconvertion during the 6-month period. Dogs 1 and 2 were euthanized 180 days after infection and were examined for the detection of N. caninum in tissues (brain, muscle, lymph node, liver, lung, heart and bone marrow) by immunohistochemistry and PCR with negative results in both techniques. Bioassay in gerbils with brain of these dogs was also performed and again the results were negative. In conclusion, dogs infected with sporulated oocysts of N. caninum were not able to shed oocysts in feces. However, a higher dose of infection stimulated the production of antibodies against N. caninum in the dogs.     

A review of maternal behaviour in dogs and potential areas for further research

Here we review information on maternal behaviour in dogs, defined as a combination of all the acts of the mother towards her offspring, which begins before parturition and continues until weaning. In dogs, maternal care is measured using the most commonly observed behaviours, such as the time spent in contact, licking/grooming and nursing of the puppies. Since newborn puppies have a very limited capacity for movement, maternal interaction is essential to their survival, nourishment and protection. It is also an important element of the bonding process between puppies and the bitch and is thought to play a role in the social development of the puppies. Nevertheless, some questions still need to be clarified, such as the best way to quantify factors that may interfere with maternal behaviour. In recent studies, maternal care, or maternal style, was measured using a scoring system and found to be influenced by factors such as litter size, breed and parity, or even human interaction. However, the impact of the emotional state of the bitch and the quality of maternal behaviour on puppy survival and development remain unclear. The long-lasting effects of mother–puppy interactions on puppy behaviour during their adult life are still poorly understood, despite their importance for breeders who wish to prevent future problem behaviours.     

Influence of inbreeding on litter size and the proportion of stillborn puppies in dachshunds

In the present study, factors influencing the litter size of puppies and the number and the proportion of stillborn puppies per litter were analysed in normally sized German dachshounds. Data was available for litters registered from 1987 to 2002 in the German dachshound kennel club. The records studied here contained 42,855 litters. The mean litter size was 5.22 +/- 2.01 puppies. The proportion of puppies born dead per litter was 6.6%. The age of dam, the puppy's year and month of birth, the hair type and the inbreeding coefficients of the puppies, the sire and the dam were significant on the litter size and the number and the proportion of puppies born dead. The litter size decreased and the percentage of puppies born dead increased with increasing inbreeding coefficients of the puppies, dams and sires. The increase of the inbreeding coefficient of the puppies by 1% led to a 0.06% higher percentage of puppies born dead per litter. The increase of the inbreeding coefficients of the dam and the sire by 1% resulted in 0.02% and 0.007% higher percentages of puppies born dead. Young and older dams had smaller litter size than middle-aged dams. The percentage of puppies born dead per litter increased with an increasing age of the dam. In the recent birth years, the litter size and the percentage of puppies born dead increased in German dachshounds.     

Recent advances in understanding the epidemiology of Neospora caninum in cattle

INTRODUCTION: Neospora caninum is the most frequently diagnosed cause of cattle abortion in New Zealand and is an important pathogen worldwide. The parasite has been found in aborted bovine foetuses and in puppies with neurological disease. Recent developments have provided new insights into the epidemiology of the disease that are reviewed in this article. TRANSMISSION: Transplacental infection is of major importance in the spread of N. caninum overseas. Most congenital infections result in the birth of apparently healthy calves. Seroepidemiological studies indicate introduced point-source infections are also likely, as do investigations of abortion outbreaks in cattle herds attributed to N. caninum. Horizontal transmission is an important determinant of the stability of infection prevalence in a herd. Two potential sources of horizontal transmission that have recently been reported are: via a canine definitive host and; cow-to-calf transmission through pooled colostrum or milk. Transmission parameters for the organism have been estimated using mathematical modeling, to explore the epidemiology and options for control of N. caninum infection in dairy cattle in the absence of precise epidemiological data. LIFE-CYCLE: Seroepidemiologic studies, combined with the knowledge that dogs can be a definitive host, provide evidence supporting a dog-cattle life-cycle. The importance of dogs in the epidemiology of bovine neosporosis is not yet clear. It is likely that N. caninum oocysts in dog faeces could serve as a source of infection for cattle and recent studies have shown that the canine and bovine isolatesflare the same organism. Infection of cattle orally exposed to oocysts has been demonstrated experimentally but not in nature. It is not known if other wild carnivores may serve as definitive hosts of N. caninum. CONCLUSION: Despite active research for over a decade, very little is known about the mechanisms of transmission of N. caninum. Vertical transmission is well documented but horizontal spread and the pathogenesis of abortion from this disease need further investigation. It is evident that, even with a very high probability of vertical transmission, some form of horizontal transmission is required for the disease to persist in a herd.     

Seronegative conversion in four Neospora caninum-infected cows, with a low rate of transplacental transmission

Four Neospora-seropositive pregnant cows (prebreeding indirect fluorescent antibody (IFA) titers between 1:400 and 1:1600) were confined and observed until parturition. All cows gave birth to normal calves. Selected tissues were tested for NC by histopathology, immunohistochemical (IHC) and polymerase chain reaction (PCR). Parasite isolation was attempted in vero cell cultures. At parturition, all cows were seronegative at 1:200 and two of four cows had a titer of 1:100 when further tested. Three of four calves were not infected, as determined by negative results of precolostral serology (1:25 cut-off), histopathology, IHC and PCR. One calf was congenitally infected, as shown by the presence of a thick-walled cyst labelled by IHC in its brain, positive PCR of brain and a precolostral IFA titer of 1:100. It was concluded that NC antibody titers may drop or convert to seronegative status in chronically infected cows by the time of parturition and this finding in four of four cows indicates that this could be a common occurrence. Similarly, the finding of an infected calf with a low antibody titer indicates that precolostral serology may not be a fool-proof means of identifying calves with congenital Neospora caninum infections. These findings call into question conclusions of other studies that have estimated rates of congenital transmission of this parasite based on serological tests at calving. This study is the first confirmed report of congenital NC infection in a calf in Thailand.     

Toxocara canis infection induces antigen-specific IL-10 and IFNgamma production in pregnant dogs and their puppies

Toxocara canis (T. canis) is originally a parasite of canine bitches and their pups. The pathogenicity of T. canis infection is enhanced during pregnancy and puppyhood. The aim of this study was to investigate if modification of IFNgamma and IL-10 secretion occurs during infection in pregnant dogs and puppies. Analysis of cytokines secreted could let us hypothesize a role for IL-10 and/or IFNgamma in T. canis infection. We tested T. canis-specific production of IFNgamma and IL-10 by lymphocytes of pregnant dogs and their puppies after in vitro re-exposure to purified excretory/secretory antigen (ESAg) from T. canis. Blood mononuclear cells (BMC) isolated from pregnant dogs and their puppies were cultured in the presence of ESAg. Cultures' supernatants were tested for cytokine levels by ELISA. Results obtained showed that IL-10 concentrations increased during pregnancy in infected animals and in the meantime IFNgamma production decreased. In puppyhood, we observed that, IL-10 concentration decreased with the age of puppies mainly in infected animals while IFNgamma increased. In conclusion, our data suggests that BMC of infected dogs have a particular modification of IL-10 and IFNgamma synthesis. These data could be the basis to design immunotherapeutic approaches.