Cystoisospora in Dogs & Cats

Sporogony

process of making infectious sporozoites within oocysts from unsporulated oocysts

Merogony

process of making merizoites (asexual reproduction) within a parasitophorous vacuole

Gametogony

process of making gametes (sexual reproduction) where Macrogametocytes becomes macrogamete and microgametocyte becomes microgamete

Just the four species of concern of Cystoisospora.

C. Canis: dogs (Large)

C. Felis: cats (Large)

C. Rivolta: cats (medium)

C. Ohioensis complex: dogs (Medium)

What is the paratenic host of Cystoisospora spp?

rodents

Location of Cystoisospora

Small Intestines

Morphology of coccidia oocysts

Fresh Feces: oocysts have single round cell that is unsporulated

Sporulated: oocysts have 2 sporocysts that have 4 banana shaped sporozoites

Coccidia: Infective Stage

Sproulated Oocysts

General Life Cycle of Coccidia

1. Ingestion of sporulated oocysts or monocyte cyst in paratenic host.

2. Sporozoites released in small intestine and enter enterocytes.

3. Undergo merogony in enterocytes until the meront is large enough to destroy it. Occurs 2-4 times

4. Merozoites develop into gamonts which result in microgametes and macrogametes.

5. Macrogametes and microgametes fuse and form an unsporulated oocysts.

6. Becomes sporulated in environment.

True or False: Pathogenesis of coccidia depends on the number of sporulated oocysts ingested.

TRUE

Clinical Signs of Coccidia.

• <1year old puppy

• Catarrhal enteritis with mucous diarrhea (can precede oocyte production)

• Rectal Prolapse

Diagnosis of Coccidia

• Fecal Centrifugation - BEST

• ELISA - detects antigen

• PCR - detects DNA

Treatment of Coccidia

• Sulfadimethoxine (Albon)

• Ponazuril