Exam 1 Flashcards
What drugs have the best activity and widest margin of safety against GI nematodes?
Pyrantel Pamoate Fenbendazole (FBZ) -Hookworms -Whipworms -Roundworms Plus Ingredient in Heartgard Plus -Ivermectin does not have significant efficacy against GI, unless ~200 ug/kg . Also, concern with MDR1 mutant dogs, young animals where BBB not fully developed. MDR1 good for treating parasites in other tissues and systems
What are some treatments and control drugs for parasitic infection in dogs and cats?
Prevention:
-Puppies dewormed at 2,4,6,8 weeks of age.
-Shorter than PPP or ERP
-Suppressive treatment
Drug choices:
-Pyrantel Pamoate (Strongyid) Fenbendazole (Panacur/Safeguard).
Prophylactic treatment:
-Interceptor: (Milbemycin) @ 4 wks of age for hookworms, roundworms, whipworms.
-HeartGard Plus (IVM + Pyrantel) @ 6 wks of age.
-Advantage Multi (Imidaclorip + Moxidectin) @ 7 wks of age.
Control of prenatal and Perinatal Parasitic Infections
Fenbendazole (FBZ)
-Daily treatment from 40th day of gestation through 14th day of lactation.
-Prevention of hookworm and roundworm
Ivermectin
-Single dose 4-9 days prior to whelping and 10 days post appear satisfactory, lactogenic Ancylostoma prevention
-Heroic tx @ day 20 and 42 for Toxocara canis in puppies
-Significant concern with MDR1 (multi-drug resistance genetic mutation)
What are some methods of disease and infection prevention?
- Remove feces from yard, play areas, sand boxes, etc
- Wash hands following pet contact
- Clean dogs promptly when they roll!
- Parasite control involves use of effective chemotherapy and attention to hygiene.
Ollulanus tricuspis
Feline stomach worm
-Small < 1mm Life cycle: Direct Infective Stage: Larvae in stomach becomes infective Transmission: ingestion of vomited larvae by susceptible host. Auto-infection PPP: Clinical signs: -Chronic gastritis -Induced vomiting -Auto-infection significant worm burden Dx: -Worms in vomitus Tx: FBZ (Panacur), clean up vomitus,
Physaloptera sp.
Canine Stomach Worm
-Stout: 13-48 mm
-Superficially resemble Ascarids
-Two lips
-Cuticle around anterior end
-Live in anterior portion of duodenum near gastric valve
Life cycle: Obligate indirect
I.H: mice, frogs
-Crickets, cock roaches, mice and frogs (paratenic hosts)
Infective Stage: Thick shelled, larvated ~ 50 um diameter. eggs passed in feces, ingested by Intermediate host
Clinical Signs:
-Chronic gastritis, anorexia, dark feces, weight loss, ulcers. Immature worms in vomitus of puppies
Tx: CATS
-Pyrantel repeat 2-3 weeks
-IVM repeat 2 weeks
Tx: Dogs
-FBZ once per day for 3 days.
-Pyrantel
-Ivermectin repeat 2 weeks
Spirocerca lupi
Canine esophageal worm
-Coiled, pinkish worm
-30- 80mm
-Superficially resembles Ascarids
-Three lips
-Occurs in fiberous nodules in the esophagus, stomach, aorta.
Life cycle: Obligate indirect life cycle
I.H: frogs, mice, lizards may serve as paratenic host
PPP: 5-6 mts
-Infective stage: eggs passed in feces. ~30x12 um. Resemble paper clip
Clinical signs:
-Dysphagia, vomiting, esophageal neoplasia, bleeding lesions may cause anemia.
-Aortic aneurysm, and rapture seen on necropsy
Tx:
-Milbemycin 7 and 28 days, and 6 mts
Strongyloides stercoralis Intestinal threadworm (dogs, humans)
-Small thread-like worms
-Small intestine
-Only females parasitic ~2.2 mm
-Parthenogenesis (lay fertilized eggs without males)
Life Cycle: Direct
-Homogonic: parthenogenic females
-Heterogonic: free living females and males
Transmission:
-Lactogenic
-Percutaneous
-Ingestion
-Auto-infection: accumulation of significant worm populations in short period of time.
Clinical signs:
-Coughing
-Verminous pneumonia
-Diarrhea
-Dehydration
-Death
Zoonotic Potential
Dx:
-1st Stage larvae: ~380 um
-Direct smear
-Larvated eggs ~50x35 um on fecal float
Tx:
IVM: repeat in 4 weeks
Nothing effective for tissue stages
Hygiene
Zoonotic potential
Trichuris vulpis
Canine Whipworm
-Small whip-like worms ~30-50mm
-Females always larger
-Tiny buccal capsule w/ long esophagus
Life Cycle: Direct
Infective stage: Larvated eggs in environment (3 weeks)
Larvae hatch and develops beneath intestinal lining. Migrate to large intestine.
PPP: 90 days post infection adults in large intestine.
Clinical Signs:
-Dysorexia (anorexia?)
-Weakness
-Weight loss
-Intermittent vomiting, diarrhea
-Fluid brown diarrhea w/ mucus (flecks of red blood) in severe infections
-Electrolyte imbalance
-Hyponatremia, hyperkalemia
-Decreased sodium/potassium ratio
-Pseudo-Addison’s disease
Dx:
-fecal flotation eggs ~90x40 um
Tx:
-FBZ (panacur)
-Febantel
-Milbemycine
-Moxidectin
Prevention:
-Remove feces daily
-Monthly suppressive treatment
Capillaria sp.
-Small worms with whip like anterior
-Resembles Trichuris but smaller
Hosts:
-Reptiles, birds, mammals, fish
Life Cycle:
-Simple direct
-Facultative indirect
-Obligate indirect with intermediate host
Clinical signs/importance:
-Capillaria puttori: Cats, mustelids Alimentary tract
-Capillaria boehmi: respiratory tract/sinuses
-Capillaria plica, Feliscati: urinary tract
Species of zoonotic significance:
-C. hepatica, C. philippinensis
Trichinella sp.
Trichina worm
-Small worms 1.4-1.6 mm
-Tiny buccal capsule w/ long esophagus approximately equal to rest of the body
Life Cycle:
-Direct
-Occurs in small intestine of a wide variety of mammals including humans
-Infective larvae encyst in tissue of D.H.
-Larvae rapidly develops into adults and mate within 2 days
Transmission:
Ingestion of encysted larvae from infected meat
Zoonotic disease of humans
-Most current infections from contaminated bear meat ingestion
Ascarids
Roundworms
General
-Dioecious, sexually dimorphic, females larger
-Occupy small intestine of vertebrate hosts. Humans, dogs, cats, livestock, reptiles
-Feed on host ingesta
-Blockage of intestinal lumen
-Inflammatory response of the host
-Development of infective stage in the environment
-
Toxocara canis
Ascaris
Roundworm
-Large stout worms 7-18 cm
-Mouth with three lips
-Buccal capsule
Life cycle: Direct basic
Infective stage: Larvated eggs passed in feces 2-3 weeks development in environment
-Tracheal migration
-Larvae enter the hepatic blood supply
PPP: Adults 4-5 weeks
Arrested development in somatic tissue
D.H: dog
P.H: rat
Transmission:
-Vertical
-In utero 42 days of gestation
-Lactogenic
-Mother with sequestered larvae pass infection up to 385 days to puppies
Facultative indirect: “bridge an ecologic gap” Rodents P.H. larvae encysts in tissue
Patent infections: puppies < 3 mts Clinical signs: -Hyper infection: immune naive animals -Mechanical damage from migration through the alveoli leading to pneumonia -Irritation in gut as worms mature -vomiting, anorexia, and diarrhea -Hypo-proteinemia, pot belly Dx: -Worms in feces/vomitus young puppies -Older puppies > 3mts Dull haircoat -Poor BCS -Emaciated -Eggs: 75-90 um diameter, albuminous coat, pitted shell Tx: -Pyrantel pamoate 2,4,6,8 -Monthly prophylactic for 1st year of life -ERP: 21 days -Interceptor (Milbemycin) @ 2wks -HeartGard Plus (IVM + Pyrantel) @ 6 wks -Advantage multi (Imidacloprid + Moxidectin) @ 7 wks Most zoonotic disease in Iceland Potential for dog pet as host or transport vector for larvated eggs
Toxocara cati
Ascarids
Roundworms
-Prominent cervical alae
-Projections or cuticle
Life cycle:
-Direct: Ingestion of larvated eggs passed in feces 42-49 days post infection. Arrive in alimentary tract via tracheal migration. Eggs hatch and migrate in hepatic blood supply
-Facultative indirect: adult cats eat infected paratenic host (infected meat larvae activated and travel to small intestine)
-Vertical transmission:
-No in utero infection
-Lactogenic when queen is acutely infected during late gestation
May be zoonotic threat
Clinical signs:
-Coughing, gagging, like chocking on a hair ball.
-Worms in feces/vomitus of infected host
Dx:
-Eggs: round pitted shell, sticky albuminous coat. ~60-70 um diameter.
Tx:
-Pyrantel pamoate suspension, no FDA approval
-Pyrantel/Praziquantel (Drontal) FDA approved
-Selemectin, Ivermectin, other drugs also effective
Toxocaris leonia
Ascarids
Roundworms
-Dogs and Cats similar to T. canis, and T. cati Life Cycle: Direct Infective stage: larvated eggs or ingestion of paratenic/intermediate host. -No tracheal migration -No in utero infection -No lactogenic transmission Minor zoonotic significance Clinical signs: -Worms in feces, vomitus Dx: -Eggs: round to slightly oval. Light translucent single cell embryo. 85-90 um diameter
