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Investigations
into the efficacy of doramectin on reactivated somatic larvae of
Ancylostoma caninum Ercolani 1859 (Ancylostomatidae) in pregnant
bitches.
Schneider T, Heidemann R, Epe C, Stoye M
Institute of Parasitology, School of Veterinary Medicine, Hannover,
Germany.
The aim of this investigation was to examine whether reactivated somatic
Ancylostoma caninum larvae can be eliminated by the administration of
doramectin to pregnant bitches. Four pregnant bitches experimentally
infected with 20,000 third-stage larvae of A. caninum were treated
subcutaneously with 1 mg doramectin per 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 doramectin
treatment completely prevented galactogenic infections in the puppies.
Neither intestinal stages nor somatic larvae could be found. The
administration of doramectin caused no local or generalized side-effects
in the bitches. All 16 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. They had to be
killed between 17 and 35 days after birth. Post mortem, they revealed a
total of 8649 intestinal stages of A. caninum.
A study on the prevention of prenatal
and galactogenic Toxocara canis infections in pups by treatment of
infected bitches with ivermectin or doramectin
Epe C, Pankow WR, Hackbarth H, Schnieder T, Stoye M
Institute of Parasitology, School of Veterinary Medicine, Hannover,
Germany.
Investigations were carried out to test the efficacy of a two dose
treatment with ivermectin or doramectin on reactivated larvae of
Toxocara canis in bitches to prevent prenatal and galactogenic
infections of their pups. Thirty pregnant bitches were treated by
subcutaneous injection of ivermectin or doramectin on day 40 and 50 post
conception (p.c.) each with a dose of 1 mg/kg body weight. The efficacy
of the treatments was determined by faecal examinations and by comparing
the number of infected pups and the onset of patency in each group of
pups. 1. Patient infections with T. canis were seen in pups from
untreated bitches from day 21 after birth and all pups were
coproscopically positive one week later. To prevent severe clinical
symptoms all pups in this group were treated with anthelmintics on day
42 after birth. 2. Pups from ivermectin treated bitches occasionally
exhibited patent infections from day 28 after birth onwards; pups from
doramectin group exhibited infections from day 56 after birth. The
number of patently infected pups in both groups increased till 70 days
after birth, probably because of postnatal infections. 3. 28 days after
parturition, T. canis infections became patent in all untreated bitches.
Single bitches in the ivermectin and doramectin groups developed patent
infections after day 49 after parturition. All coproscopically positive
bitches had patently infected pups in their litters. 4. The
contamination of the environment with eggs of T. canis was calculated
from the results of the faecal examinations. (ABSTRACT TRUNCATED AT 250
WORDS)
Investigations into the prevention of
neonatal Toxocara canis infections in puppies by application of
doramectin to the bitch.
Schnieder T, Kordes S, Epe C, Kuschfeldt S, Stoye M
Institute of Parasitology, School of Veterinary Medicine, Hannover,
Germany.
The aim of this investigation was to examine whether the treatment of
bitches with doramectin is able to prevent pre-natal and galactogenic
infections with Toxocara canis in their pups. Five experimentally
infected beagle bitches were treated subcutaneously with 1 mg doramectin
per kg body weight on each of days 40 and 55 of their pregnancy. Another
infected bitch served as an untreated control. The efficacy of the
medication was examined by counting the intestinal stages and somatic
larvae in bitches and pups. The treatment did not completely prevent
perinatal infections with T. canis. Intestinal stages and/or somatic
larvae occurred in 16 of 20 pups. Seven pups developed patent
infections. Compared to the control pups, the average worm burden
(intestinal stages) of pups from treated bitches was less than 1%. No
impairment of condition or physical development was noticed in the pups
during the investigations. From the second week of life, the pups of the
non-medicated bitch showed signs of a severe toxocarosis. No side
effects were seen in the bitches after treatment with doramectin.
The efficacy of doramectin on arrested
larvae of Ancylostoma caninum in early pregnancy of bitches.
Schnieder T, Lechler M, Epe C, Kuschfeldt S, Stoye M
Institute of Parasitology, School of Veterinary Medicine, Hannover,
Germany.
The efficacy of doramectin treatment on arrested A. caninum larvae
during early pregnancy of bitches was examined. Four bitches were
percutaneously infected with 20,000 third-stage larvae of A. caninum on
the day of conception and treated subcutaneously with 1 mg doramectin
per kg body weight on day 30 of pregnancy. Four infected untreated
pregnant bitches served as controls. A single application of dormectin
substantially reduced the number of somatic larvae in bitches and the
number of intestinal stages in bitches and puppies. However, it did not
completely prevent lactogenic transmission of A. caninum larvae because
five out of 23 puppies from three litters of the treated bitches
harboured adult worms in their intestines, two of them shed eggs with
the faeces. Although clinical disease did not occur in puppies from
treated bitches the efficacy of the treatment was not satisfactory from
an epidemiological point of view. Despite the treatment puppies with
patent infections contaminated their environment with high numbers of
eggs thus producing an intolerable infection risk for dogs and humans.
No fetotoxic side-effects of the early treatment with doramectin were
seen.
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