Protozoa

Question 1

What are the definitive hosts of Giardia species?

Answer 1

dogs (G. duodenalis) and cats

• referred to as “assemblages” that can infect different animals

Question 2

What are some common clinical signs associated with Giardia infection?

Answer 2

• diarrhea + other signs of colitis
• weight loss, anorexia

Question 3

How is Giardia transmitted?

Answer 3

fecal-oral by ingestion of cyst

• contaminated water or feces
• thorough self-grooming
• fomites
• NO INTERMEDIATE HOST

Question 4

What are 4 options for diagnosing Giardia infections?Why is diagnosis commonly difficult?

Answer 4

1. direct smear using a saline mount
2. fecal flotation using centrifugation
3. fecal Giardia ELISA for antigen detection
4. PCR

intermittent shedding of organisms is common –> repeated and various types of tests recommended

Question 5

What are the 2 most common treatments for Giardia infection?

Answer 5

1. Fenbendazole
2. Metronidazole
   - re-test after medication period to ensure there is no evidence of treatment failure

(not technically approved)

Question 6

How can Giardia infections be reduced? Is it zoonotic?

Answer 6

cysts are resistant in the environment, so environmental control is important

not established

Question 7

What are the domestic small animal hosts of coccidia?

Answer 7

• CATS - Cystoisospora felis, C. rivolta
• DOGS - C. canis, C. ohioensis, C. neorivolta, C. burrowsi

Eimeria spp. are not true parasites –> considered a pseudoparasite

Question 8

What clinical signs are associated with coccidiosis in dogs and cats?

Answer 8

• diarrhea and other signs of colitis
• weight loss
• dehydration

Question 9

How is coccidiosis transmitted?

Answer 9

fecal-oral

• ingestion of infected sporulated oocysts from the environment
• ingestion of infected transport hosts

Question 10

How is coccidiosis diagnosed?

Answer 10

fecal flotation

Question 11

What is the only approved treatment for coccidiosis? What are 2 other not approved options?

Answer 11

Sulfadimethoxine

1. Ponazuril
2. TMS

Question 12

What is the most common cause of Tritrichomonas infection in cats? Where do they reside?

Answer 12

T. blagburni

colon and cecum of cats

Question 13

How is Tritrichomonas infection transmitted?

Answer 13

fecal-oral

Question 14

What clinical signs are indicative of Tritrichomonas infection in cats?

Answer 14

• chronic/intermitted diarrhea
• other signs of colitis

Question 15

What are 3 diagnostic options for Tritrichomonas infection in cats? How can they be differentiated from Giardia?

Answer 15

1. direct fecal smear
2. PCR
3. culture

T. blagburni has random and jerky movements while Giardia has more of a “falling leaf” movement

Question 16

What treatment is most commonly used for Tritrichomonas infection?

Answer 16

Ronidazole - not technically FDA approved

• neurotoxicity side effects and resistance are possible!

Question 17

What is the domestic small animal host of Toxoplasma gondii? What are 3 modes of transmission?

Answer 17

cats

1. ingestion of infective oocysts
2. ingestion of infected tissue containing bradyzoites
3. passage of tachyzoites from dam to offspring via transplacental or transmammary transmission

Question 18

What are 3 diagnostics used for Toxoplasma gondii infection?

Answer 18

1. fecal flotation - recovers oocysts, limited usefulness
2. IFA, ELISA - rise in IgG over 2-3 weeks or high IgM
3. PCR

Question 19

What are 3 treatment options for Toxoplasma gondii infection?

Answer 19

1. Clindamycin - treatment of choice
2. Trimethoprim-sulfonamide
3. Pyrimethamine + sulfonamide

Question 20

What significance does Toxoplasmosis in cats have in humans?

Answer 20

serious zoonotic risk that can cause congenital defects

• pregnant women must avoid contact with soil, cat litter, raw meat, and cats excreting oocysts

Question 21

What is the domestic small animal host of Neospora caninum? What are 3 methods of transmission?

Answer 21

dogs

1. ingestion of infective sporulated oocysts
2. consumption of cattle tissues containing bradyzoites
3. transplacental transmission of tachyzoites from dam to offspring

Question 22

What are the clinical signs associated with Neospora caninum infection in younger and older dogs?

Answer 22

YOUNG - ascending paralysis

OLD - neurologic, respiratory, and/or dermatologic signs

Question 23

What are 4 options for diagnosing Neospora caninum infection?

Answer 23

1. fecal flotation - recovers oocysts, rarely detected
2. IFA, direct agglutination, ELISA - rise in IgG over 2-3 weeks or high IgM
3. PCR
4. cytologic or histologic exams

Question 24

What 2 treatments are recommended for Neospora caninum infection?

Answer 24

1. Clindamycin
2. Trimethoprim sulfadiazine + pyrimethamine

Question 25

What Cryptosporidium species infect dogs, cats, and ruminants?

Answer 25

DOG = C. canis

CAT = C. felis

RUMINANT = C. parvum

Question 26

How is Cryptosporidium transmitted? What are 4 options for diagnosis?

Answer 26

fecal-oral via sporulated oocysts

1. complete fecal examination - fecal float + direct smear, due to shedding pattern it may be of limited diagnostic usefulness
2. ELISA
3. fluorescent antibody tests to visualize oocysts in feces
4. molecular methods done in special labs

Question 27

What are 4 possible treatment options for Cryptosporidium infections?

Answer 27

1. Nitazoxanide (Alinia)
2. Paromomycin
3. Tylosin
4. Azithromycin