General Characteristics

Cat Spray No More

How to stop cats spraying in the house

Get Instant Access

COMMON NAME: New World hookworm (archaic).

GEOGRAPHICAL DISTRIBUTION: Western hemisphere.

PATHOGENESIS: Inflammation of intestinal mucosa, anemia (chronic nutritional deficiency type) diarrhea, pneumonitis, eosinophilia, erythemia, dyspnea. Same as A duodenale

HABITAT: Small intestines.

INTERMEDIATE HOST: None.

RESERVOIR HOST: None.

INFECTIVE FORM: Filariform larva.

MODE OF INFECTION: Active penetration.

SPECIMEN OF CHOICE: Feces.

Figure 4-15. Life cycle of Necator americanus.

Same as A. duodenale

Necator Americanus Common Name
Figure 4-16. Stages of Necator americanus. Continued)

ADULT

SIZE: Smaller than A. duodenale. Male: 5 to 9 mm. FEMALE: 9 to 11 mm. SHAPE: Cylindrical; head is sharply dorsally curved. COLOR: Grayish-white.

BUCCAL STRUCTURES: Prominent ventral and dorsal semilunar cutting plates. COPULATORY BURSA: Male.

PAIRED COPULATORY SPICULES: Fused with a terminal barb. SMALL PAIRED DORSAL RAYS: Bipartite.

RHABDITIFORM LARVAE

SIZE: 250 mcm.

BUCCAL CAVITY: large (longitudinal parallel lines). GENITAL PRIMORDIUM: Small (inconspicuous). TAIL: Slender, long, and tapering.

Figure 4-16. Stages of Necator americanus. Continued)

Figure 4-16. Stages of Necator americanus. Continued)

Necator Americanus Common Name

Figure 4-16. Stages of Necator americanus. (concluded)

GENERAL CHARACTERISTICS

COMMON NAME: Threadworm. GEOGRAPHICAL DISTRIBUTION: Worldwide.

PATHOGENESIS: Chronic gastrointestinal inflammation, eosinophilia, anemia, recurrent diarrhea, secondary bacterial infections, biliary and pancreatic inflammation. HABITAT: Small intestine. INTERMEDIATE HOST: None. RESERVOIR HOST: Perhaps dogs and apes. INFECTIVE FORM: Filariform larva. MODE OF INFECTION: Active penetration. SPECIMEN OF CHOICE: Feces.

Generic Myxozoan Life Cycle
Figure 4-17. Life cycle of Strongyloides stercoralis. Parasitic and Free Living Cycles

Rarely seen; similar to Hookworm species eggs; may contain a larva.

ADULT

SIZE

MALE: Less than 1 mm; seen only in free living cycle. FEMALE: 1 mm for the free living; 2 mm for the parasitic. SHAPE: Very slender, threadlike, male has a curved tail. COLOR: Colorless; semitransparent. BUCCAL STRUCTURES: Short buccal cavity. COPULATORY BURSA: Absent. SPICULES: Two.

RHABDITIFORM LARVA

SIZE: 250 mcm. BUCCAL CAVITY: Short.

GENITAL PRIMORDIUM: Large and conspicuous. TAIL: Short and stubby.

SHORT BUCCAL WVtTr

SHORT BUCCAL WVtTr

Figure 4-18. Stages of Strongyloides stercoralis.

B. Tissue Dwelling Nematodes

ORGANISM 1: Toxocara species (T. canis and T. cati)

GENERAL CHARACTERISTICS

COMMON NAME: Visceral larval. GEOGRAPHICAL DISTRIBUTION: Worldwide migrans. PATHOGENESIS: Granulomatous lesions of liver, lungs and other organs, eosinophilia, anemia, hepatosplenomegaly, pneumonitis, dermatitis, neurologicaldisturbances, tumors of eyes, spinal cord and heart in severe cases.

HABITAT

MAN: Any organs and tissues of the body. DEFINITIVE HOST: Small intestines of dogs and cats. INTERMEDIATE HOST: None.

RESERVOIR HOST: Same as definitive host, dogs and cats.

INFECTIVE FORM: Embryonated egg.

MODE OF INFECTION: Ingestion.

SPECIMEN OF CHOICE: Tissue biopsy and serological.

LIFE CYCLE

larva mature to adults in the small intestine swallowed into esophagus amd reach intestine adults in small intestines of dogs amd cats

enter bflonchial spaces akd reach trachea i immature eggs deposited in intestinal LUMENj larva molt in alveoli of lungs immature eggs passed with host feces

Was this article helpful?

0 0

Post a comment