VETERINARSKI ARHIV 68 (4), 121-125, 1998

ISSN 0372-5480
Printed in Croatia

Prevalence and chemotherapy of toxocariasis
in the dog in Faisalabad (Punjab), Pakistan

Azhar Maqbool1*, Syed Hasan Raza2, Choudary Sikandar Hayat1, and Mohammad Shafiq1

1Department of Clinical Medicine and Surgery, Faculty of Veterinary Science,
University of Agriculture, Faisalabad, Pakistan

2Department L&DD. Punjab Lahore, Pakistan

* Contact address:
Dr. Azhar Maqbool,
Department of Clinical Medicine and Surgery, Faculty of Veterinary Science, University of Agriculture, Faisalabad, House No. 20, Bilal Colony, Jail Road, Pakistan,
Phone: 92 41 30 281 281, Fax: 92 41 647 846

MAQBOOL, A., S. H. RAZA, C. S. HAYAT, M. SHAFIQ: Prevalence and chemotherapy of toxocariasis in the dog in Faisalabad (Punjab), Pakistan. Vet. arhiv 68, 121-125, 1998.


A total of 240 dogs were examined for the presence of Toxocara canis infestation. Through faecal examination, heavy infection of toxocariasis was confirmed in 80 dogs. These dogs were divided randomly into four groups A, B, C, and D (control group), each with 20 dogs. Dogs in groups A, B, and C were treated with ivermectin, pyrantel pamoate and levamisole hydrochloride, respectively. The efficacy of the drugs was calculated on the basis of the reduction in the number of ova discharged in faeces. Results showed that ivermectin and levamisole hydrochloride were 100% effective, whereas pyrental pamoate showed 95% efficacy after a single dose treatment.

Key words: toxocariasis, dog, chemotherapy, Faisalabad, Pakistan


Toxocariasis of dogs caused by Toxocara canis has been reported in nearly all parts of the world, with infection rates approaching 100% for some populations of pups. Dogs can become infected with T. canis through ingesting infective eggs, ingestion of infective larvae in tissues of paratenic hosts (mice, birds, pigs, earthworm and others); transplacental migration of larvae from a pregnant bitch to her developing pups; transmammary passage of larvae in milk from a lactating bitch to nursing pups, and ingestion of late-stage larvae or immature adults in the vomitus or faeces of infected pups (SPRENT, 1961). The parasites occur in the small intestine of all canine species. Heavy infestations are most commonly seen in kennels with poor hygiene conditions (JACOBS et al., 1977). Toxocariasis thus causes emaciation, anaemia, constipation, intermittent diarrhoea, a pot-bellied appearance and even death due to acute intestinal obstruction. A high percentage of stillbirths and deaths have been reported in puppies suffering from this disease.

In human beings, two distinct zoonotic syndromes of toxocariasis have been described, i.e., larva migrans (VLM) and ocular larva migrans (OLM) (WILDER, 1950; BEAVER et al., 1952; ZINKHAM, 1978; GLICKMAN and SCHANTZ, 1981). This disease can damage the liver, lungs, eyes and brain of children (DENT and CARRERA, 1967; SOULSBY, 1982). It has been reported that more than 80% of blood eosinophilia in human patients are infected with T. canis (CHAUDHURI and SAHA, 1959). Children become infected after ingesting infective Toxocara eggs found in the soil or on contaminated hands. Infection with this common contaminant may leave children with permanent visual or neurological impairment (SCHANTZ, 1989). The incidence of toxocariasis in children is increasing due to the fouling of footpaths, and by public unawareness of the danger of toxocariasis.

Bearing in mind the zoonotic importance of this disease, affected dogs must be treated with anthelmintics. The current study also included a comparison of the efficacy of ivermectin, pyrantel pamoate and levamisole hydrochlorides against toxocariasis in dogs. This will assist in selecting the most suitable and effective drug against toxocariasis in dogs.

Materials and methods

During the study period, from January 1992 to December 1992, a total of 240 dogs of multiple breeds (75 pups and 165 adults) were brought to the outdoor clinics of the Department of Clinical Medicine and Surgery, University of Agriculture Faisalabad, Pakistan for treatment purposes for various ailments. Eighty (60 pups and 20 adults) were found to be positive for toxocariasis. These dogs were selected for anthelmintics trials and were randomly divided into four groups, i.e., A, B, C, and D, each group with an equal number of dogs (N=20/group). The following drugs were used in these studies.

Ivermectin (Inj. Ivomec-MSD) given subcutaneously at a rate of 200 µg/kg body mass to 20 dogs in group A. Pyrantel pamoate (Tab. Combantrin-Pfizer) given orally at a rate of 5 mg/kg body mass to 20 dogs in group B. Levamisole, L-tetramisole hydrochloride (HCL) (Tab. Ketrax-ICI) given orally at a rate of 15 mg/kg body mass to 20 dogs in group C. No treatments was given to the dogs in group D, which acted as a control group.

Fresh faecal samples were examined on the 3rd, 7th, 14th and 21st day post-treatment, and eggs counts were made by McMaster egg counting technique (COLES, 1984). The side effects of drugs (if any) were also noted.


Of 240 dogs (75 pups and 165 adults) examined for parasitic infection, 80 dogs of various age groups (60 pups and 20 adults) showed heavy infection of T. canis. The incidence rate was 33.3%. The efficacy of various chemotherapeutic agents (anthelmintics) used in this study is given in Table 1.

It was evident that ivermectin and levamisole were 100% effective, whereas Pyrantel pamoate was 95% effective. Two dogs treated with levamisole developed diarrhoea soon after medication. None of the drugs used caused any detrimental effects, even among pregnant animals. On the whole, the general body condition of dogs improved gradually after treatment. In untreated controls (group D), a gradual rise in eggs per gram was observed until the end of the study period.

Table 1. Efficacy of ivermectin, pyrantel pamoate and levamisole hydrochloride against toxocariasis in dogs in Pakistan

(20 per group)

Drug used and its dose rate

Efficacy in percentage after treatment

3rd day

7th day

11th day

21th day


Ivermectin, 200 µg/kg b.m., subcutaneously






Pyrantel pamoate, 5 mg/kg b.m., orally






Levamisole hydrochloride, 15 mg/kg b.m., orally






Untreated control






Roundworm T. canis is a common intestinal helminth among dogs and is capable of infection and inducing disease (larva migrans syndromes) among human beings. Treating dogs affected with toxocariasis can control larva migrans. In the present study, the incidence of T. canis infection was recorded as 33.3% (80 out of 240 pups and adults were infected). MAQBOOL et al. (1994) and UMAR et al. (1986) also recorded similar results.

Results regarding the efficacy of levamisole hydrochloride, pyrantel pamoate and ivermectin against toxocariasis in dogs indicated that levamisole and ivermectin were 100% effective, whereas pyrantel pamoate was 95% effective. Similar results on drug efficacy have been reported by the researchers. PANICHI and VALLE (1975), ROLLO (1975) and UMAR et al. (1986) found that levamisole was 95-100% effective against toxocariasis in dogs. UMAR et al. (1986), NOLAN et al. (1992) and CLARK et al. (1992) observed that pyrantel pamoate was 90-95% effective. Ivermectin was found to be highly effective against toxocariasis in dogs in the present study. ANDERSON and ROBERTSON (1982), CLARK et al. (1992), NOLAN et al. (1992) and CAMACHO et al. (1993) also recorded similar results.

It is interesting to note that an average size dog passes 136 grams of faeces per day (OMER, 1991) and high T. canis infection results in 10,000 eggs per gram of faeces. Faeces containing Toxocara eggs are discharged in the streets and on the land. Some of these eggs may find appropriate conditions for survival in the ground and remain infective, possibly for years, and are responsible for causing larva migrans syndromes in children. It was noted that pet owners did not take proper care of their dogs. Uncared-for dogs live miserable lives and are a danger and a nuisance to human beings.


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Received: 10 January 1998
Accepted: 13 May 1998

MAQBOOL, A., S. H. RAZA, C. S. HAYAT, M. SHAFIQ: Proširenost i kemoterapija toksokaroze pasa u Faisalabadu (Punjab) u Pakistanu. Vet. arhiv 68, 121-125, 1998.


Pregledano je ukupno 240 pasa na invadiranost oblicem Toxocara canis. Koprološkim pretragama utvrdena je jaka invazija u 80 pregledanih pasa. Ti psi su nasumicno podijeljeni u 4 skupine: A, B, C i D (kontrolna skupina) s po 20 pasa u svakoj. Psi iz skupine A su tretirani ivermektinom, skupine B pirantel pamoatom i skupine C levamisol hidrokloridom. Ucinak danih sredstava je izracunat na osnovi smanjenja broja jajašaca nadenih u izmetinama. Istrazivanja su pokazala da su nakon jednokratne upotrebe ivermektin i levamisol hidroklorid bili 100% ucinkoviti, a pirantel pamoat 95%.

Kljucne rijeci: toksokaroza, pas, kemoterapija, Faisalabad, Pakistan