1. Nematodes of Dogs & Cats

2. Toxocara sp.

3. Significance the most important parasites infection at birth
death: first two weeks (lung migration)
larval migration

4. Morphology
male = cm
female = cm

5. T. canis
cervical alae:
- long & narrow
- semilanceolate

6. cervical alae:
- broader
- arrow head

7. Life cycle modes of transmission: T. canis transplacenta
transcolostrum
direct ingestion
paratenic host

8. Direct life cycle 10-15 d tracheal migration prepatent period
4-5 weeks
age < 3 mths

9. Indirect life cycle prepatent period 3-5 weeks (neonates)
(age > 3 mths)
10-15 d
somatic migration
transplacenta
transcolostrum
paratenic hosts
> 42 d gestation

10. Life cycle Toxocara cati: direct ingestion paratenic host
no prenatal transmission

11. Effect on host adult: no clinical signs
puppies: severely affected, pneumonia

12. signs: vomiting, emaciation, potbelly, obstruction, dull coats
death: 2-3 weeks after birth

13. Diagnosis
T. canis T. cati

14. Infective stage
Ascarid egg

15. SEM differentiation large, coarse pitted surface
small, fine pitted surface
Uga et al., Vetrinary Parasitology 92(2000):

16. Treatment ivermectin dichlorvos fenbendazole febantel
pyrantel piperazine

17. Saprophytic soil fungi
Paecilomyces sp.
Ovicidal activity of T. canis
(Basualdo J.A., 2000)

18. Use of ivermectin during pregnancy
1) dose: 300 mcg/kg on day 0, 30, and 60 of gestation
- reduce # worms by 90%
- reduce # eggs by 99.8%

19. Use of ivermectin during pregnancy
2) dose: 300 mcg/kg on day 0, 30, 60 of gestation, 10 d post whelping
- reduce # worms by 100%
- no eggs were passed in environ.
(Payne P.A., 1999)

20. Selamectin dose: 6 mg/kg (6-12 mg/kg) reduce # adults by 93.9-98.1%
topical administration
dose: 6 mg/kg (6-12 mg/kg)
reduce # adults by %
reduce # eggs by 90-95%
(McTier T.L., 2000)

22. Control good sanitation regular deworming anthelmintics:
2, 4, 6 weeks of age

23. Public Health visceral larva migrans (T. canis):
children: chronic granulomatous
liver, lung, brain, eye
ocular larva migrans
choroidoretinitis

24. Toxascaris leonina (arrowhead worm)

25. head: lanceolate cervical alae
male: up to 7 cm
female: up to 10 cm

26. Life cycle transmission: direct ingestion paratenic host
no larval migration
prepatent period = 8-10 weeks

27. Effect on host
puppy: potbelly, intermittent diarrhea, poor condition, intestinal obstruction

28. Diagnosis
T. canis
T. leonina

29. febentel + praziquantel
Treatment
piperazine dichlorvos
pyrantel fenbendazole
febentel + praziquantel

30. Ancylostoma caninum (Hookworm)

31. Ancylostoma caninum Geographic distribution temperate climates
worldwide
Significance
very important
causes deaths (all ages)
causes heavy blood losses

32. Morphology worms: red or gray size: up to 1.6 cm
mouth: 3 pairs of prominent teeth

33. Life cycle modes of infection: 1. eating (infective eggs)
2. skin penetration (larvae)
tracheal migration

34. Life cycle modes of infection: intrauterine infection transcolostrum
paratenic host
prepatent period = days

35. H O K W R M S A N C Y L O S T M

36. Larval penetration
คัน!
moist eczema
&
ulceration

37. effect on dog
“pale mucous membrane”

38. effect on dog
“severe blood loss”

39. effect on dog blood vessels rupture & hookworms feed on the
released blood (0.25 ml/day)

40. Ancylostoma caninum

41. Clinical signs factors: dose, age, immune status dermatitis
puppy pneumonia
diarrhea: dark in color (blood & mucus)

42. Clinical signs severe blood loss: iron-deficiency anemia
edema, weakness, weight loss
poor coat condition

43. heavy infection: frequently fatal within 2 weeks of birth in puppies

44. Diagnosis clinical signs fecal examination: fresh direct smear
simple floatation
60 x 40 microns
ovoid, thin-shelled,
morulate embryo

45. Treatment supportive care: blood transfusions, iron supplement
anthelmintics: fenbendazole, ivermectin, tetrahydropyrimidine (pyrantel)

46. Ivermectin + pyrantel
ivermectin = 6 mcg/kg
pyrantel pamoate = 5 mg/kg
99.6 % reduction of adult hookworms
(Nolan T.J. et. al, 1992)

47. Doramectin
1 mg/kg on d30 of gestation reduce somatic larvae in bitches and adult hookworms in bitches and puppies
(Schnieder, T. et al, 1996)

48. Moxidectin
1 mg/kg on d55 of gestation (5-8 d before parturition): completely prevent lactogenic infections in puppies.
(Epe, C., 1999)

49. Deworming program CDC recommendation:
bitch: fenbendazole in the 3rd trimester (kill migrating larvae)
pups: 2, 4, 6, and 8 weeks of age

50. Control feces elimination keep kennel-floor dry regular deworming
treat bitch with ivermectin

51. Effect on man Adult Ancylostoma caninum excretory/secretory antigens
causes hypersensitivity in man
human eosinophilic enteritis

52. Cutaneous larval migration

53. Cutaneous larval migration

54. Trichuris vulpis (whipworms)

55. Morphology
size: cm.
anterior part: 3/4 of body, long & slender

56. Life cycle location: caecum
infection: direct ingestion of infective egg

57. T R I C H U R I S
L I F E C Y C L E
prepatent period = weeks

58. Effect on host intestine: irritation of caecum & large intestine
profuse diarrhea, loss of weight, unthriftiness
anemia in heavy infection

59. Diagnosis
70-90 x microns
Lemon-shaped with bipolar plugs

60. Treatment mebendazole fenbendazole dichlorvos febantel
avermectins are not as effective.

61. Spirocerca lupi (esophageal worm)

62. Definitive host
dogs
Intermediate host
coprophagous beetles
lizards, chickens, mice (paratenic host)

63. morphology: red, coiled nematode
3-8 cm long

64. beetles encyst larvae esophagus thoracic aorta prepatent period
5-6 mths
coeliac artery
gastroepiploic artery
adults in nodule
(L1)
beetles
encyst larvae
(L3)

65. Effect on host larval migration: aorta haemorrhage granuloma, stenosis
aneurysm, rupture

66. Effect on host
adult: embedded in the walls of aorta, esophagus and stomach

67. Effect on host adult: nodules, tumor
nodules: interfere with swallowing, respiration and circulation

68. signs: persistent vomiting, wt. loss, hemoptysis
aneurysm burst
causes sudden death
“esophageal sarcoma”
10% of infected dogs

69. Diagnosis
floatation method
radiography
endoscopy
necropsy

70. Diagnosis egg: small, oblong in shape, thick-shelled, larva inside
30-38 x microns

71. Treatment
fenbendazole
avermectins

72. Control isolate infected animals dispose of the vomit and feces
keep dogs from eating beetles, paratenic hosts

73. Strongyloides stercoralis (threadworms)

74. Morphology parasitic stage: pathenogenetic female size: 2-9 mm. long
filariform esophagus

75. Life cycle host: dogs, cats, men
direct life cycle: free-living, parasitic
prepatent period = 7 days

76. Life cycle modes of infection: skin penetration ingestion (rare)
hyperinfection (mucosal migration)
autoinfection (perianal area)

77. Significance reinfection: kennel situation
causes severe disease only in young animals
heavy infection: death in puppies

78. Effect on host
skin: dermatitis

79. intestine: irritation, catarrhal inflammation, mucosal erosion, necrosis
signs: diarrhea (blood), low appetite, weight loss, dehydration, weakness, death

80. lung migration: alveoli destruction, ecchymotic hemorrhage, pneumonia

81. Diagnosis fecal examination larvae, eggs containing larvae
40-50 microns

82. Treatment Dichlorvos Fenbendazole
Control
clean & dry floor

83. Gnathostoma spinigerum

84. G. spinigerum size: 1-3 cm. long head bulb: “ballonets”
head & anterior part: spines

85. Life cycle prepatent period: 7 months 1st int. host: Cyclops
2nd int. host: fresh water fish, reptiles
location: stomach

86. Gnathostoma spinigerum nodule in the gastric wall
cats, dogs
nodule in the gastric wall
eggs (L1)
fish, frog, snake (L3)
man
Cyclops (L2)

87. Effect on host Cutaneous larva migrans:
cause intermittent, migratory, painful, priritus swelling

88. Effect on host visceral larva migrans: cough, hematuria,
ocular involment
eosinophilic meningtitsis
myeloencephalitis

89. Pathogenesis
larval migration: liver damage, mesentery, diaphragm, thoracic cavity
adult: migrate in stomach wall
cavity, pus, cyst

90. Diagnosis
egg: rare in feces
Treatment
no specific drug (albendazole)

91. Physaloptera praeputialis

92. Morphology size: 1.5-4.8 cm long body: large, thick, stout nematodes
egg: contain a larva when laid

93. Life cycle host: dogs, cats, other carnivores intermediate hosts:
crickets, cockroaches, beetles
prepatent period = days

94. location: stomach, duodenum
worldwide distribution

95. Effect on host
adult
irritation: firmly attach to the lining of the gastric mucosa
bleeding, mucosa erosion
digestion interference

96. Clinical signs loss of condition vomiting (possibly bloody, mucoid)
anorexia

97. Diagnosis fecal examination (floatation)
small, oblong eggs containing larvae
40-58 x microns

98. Treatment anthelmintics dichlorvos, benzimidazoles, avermectins
control pets’ eating habits