{'fraction_non_alphanumeric': 0.01734730755330683, 'fraction_numerical': 0.003614022406938923, 'mean_word_length': 4.7907949790794975, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Helminths of the dog: Treatment and control

Toxocara canis is the commonest helminth of the dog. It occurs in all types of canidae, from the fox to the most pampered pet. It should be assumed that virtually every litter of pups is affected to a greater or lesser degree. T canis usually causes little obvious clinical effect, but illthrift, pot belly, diarrhoea, vomiting and respiratory signs frequently accompany heavy infections in young pups, and there may be nervous signs and death. This is also the nematode that causes the greatest concern to the general public, because its zoonotic potential has received so much media coverage in recent times. The life cycle of T canis is complex and the features most important to the understanding of the epidemiology of toxocariasis in the domestic dog are summarised below. The eggs are sticky, resistant to most disinfectants and can survive for many months. Adult worms are spontaneously expelled from pups during the early months of life. However, small numbers of egglaying worms are found in about 10 per cent of adult dogs. Substantial numbers may be found in lactating bitches during the period of perinatal immunosuppression. Somatic migration will occur if embryonated eggs are ingested by man. Normally, human infections are apparently asymptomatic but disease can occur if massive numbers of larvae invade the body (visceral larva migrans) or if one larva comes to rest in the eye (ocular larva migrans). The former mostly affects children under the age of three and is usually associated with pica, while ocular larva migrans is seen in older children and sometimes adults. Figures (still awaiting official verification) indicate that 13 cases of toxocariasis were reported to the British medical authorities in 1982. However, it is not a notifiable disease and unreported or undiagnosed cases may also have occurred. In statistical terms the incidence of human disease is very low. Nevertheless it is clearly the responsibility of the veterinary profession to promote worm control as an integral part of responsible pet ownership. This will ensure that the zoonotic risk is kept to an absolute minimum. The development of Toxascaris leonina in the dog or cat is confined to the wall and lumen of the gastrointestinal tract and so there can be no prenatal or transmammary transmission. Infections tend, therefore, to be acquired later in life than in the case of T canis with the highest prevalence occurring in the six-to 12-month-old age group. Migration of T leonina larvae to the body tissues does occur in animals other than the dog or cat (or their feral relatives) following the ingestion of embryonated eggs. There is as yet no evidence to implicate T leonina as a cause of visceral larva migrans.