FAM II Lecture 22

Using too low of dose; #1 reason for anthelmintic resistance; record wts (scale, measurement); ^ stocking density

Toxins can degrade quickly; Tx challenging due to timeline; antitoxin earlier the better; Pen; vxn starting @ 6wk old

F. magna does not finish life cycle in SR; BW has eosinophilia, anemia, ^ liver enzymes + decreased protein

Monezia; often visible, not pathogenic; unless in large numbers in young animals (rare rupture + peritonitis)

M. avium spp. paratuberculosis; cattle strain, sheep strain, intermediate strain; Sheep can get sheep + intermediate

Underdosing common cause of parasite resistance; weigh whenever possible; when in doubt slightly over est. wts

Quantitative vs qualitative; eggs/gram; McMaster's, Modified wisconsin technique; once + repeat in 10-14d

Life cycle involves ingestion of infected mite; Tx: albendazole, fenbendazole, praziquantel; reinfection possible

Prevent intro of carriers; min/eliminate contamination of water/feed w/ fecal material; disinfection

Score amount of scouring; poor method to assess worm burden; other issues can cause scours; loss of production

Amprolium - thiamine analog; Decoquinate inhibits mitochondrial function; Ionophores alter ion transport in lipid memb.

Most important SR GI parasite in US; causes anemia (kids/adults), bottle jaw, chronic wt loss (adults), blood loss

Peracute to chronic; hypobiosis; dx: fecal exam; tx/prevention: fenbendazole, ivermectin; resistance genes

Survival ability (hypobiosis, weather resistance); frequent exposure to anthelmintics

Repeat scoring every 2wk during cool, moist seasons or prime survival for worm; repeat q 4-6wk; cull chronic offenders

Similar to cattle; rumen acidosis: ^ rapidly fermentable cabs, counsel pet goat owners!; free gas + frothy can occur

Larger egg (15-200um); seasonal "spring flush" in lambs; adults develop complete/near complete immunity

Fecundity: one worm on one farm can easily lead to millions of eggs being produced over several weeks-months

Not as well known in goats; more severe dmg to villus; tx similar to rotavirus; dysentery + d+ in calves/cattle

PE; Anemia via H. contortus; nasal discharge, submandibular edema, BCS, fecal staining of perineum, ocular MM color

Monensin tx + prevention, lasolacid prevention; Affected: fluids, electrolytes, sulfonamide or amprolium, ponazuril

Flukes: fasciola hepatica + fascioloides magna

Goals: minimize drug use; develop refugia: population of GI parasites not exposed to anthelmintics so it stays effective

Poor BCS; eval w/ objective system like FAMACHA; keep records - write everything down

Stress: weaning, feed changes, overcrowding; anorexia, dehydration, weakness, rough hair coat (d+ w/ constant straining)

Fecal egg count reduction tests; before: ideally greater than 95% reduction indicated clinically effective dewormer

Damage gut wall; less harmful than others by itself; can worsen damage caused by other worms

Black disease: C. novyi infection from damage to liver; Dx: eggs in feces for F. hepatica (sedimentation)

Fasting prior to deworming; NOT DIATOMACEOUS EARTH!; "food grade" does not mean meant to be fed (filter liquid food)

Absorption barrier +/- malabsorptive d+; wt loss w/ normal or ^ appetite; "bottle jaw", hypoproteinemia

Scores based on MM color; account for pigmentation, weather, flies; score animals from 1-5; treat 4s and 5s

Increasingly growing number of intestinal worms of sheep + goats resistant to anthelmintics

Small ruminants "waste away" + not always present w/ d+, chronic d+ ~20%; asymptomatic until 2-7y; emaciation @ necropsy

Nematodes: H. contortus, Nematodirus, Teladorsagia, Trichostrongylus, Cooperia; Cestodes: Monezia spp.

No tx!; Dx: PCR (fecal), ELISA, fecal culture; serology less predictable; vxn for cattle, utility in SR unknown

Treat 3s if >10% herd scored @ 4 or 5; young animal; pregnant or lactating, poor BCS; always tx w/ bottlejaw*

F. hepatic: tissue damage, adults in bile ducts; F. magna: does not mature in SR, continues to migrate - liver damage

Goats have cattle strain; FECAL-ORAL TRANSMISSION; also milk + placenta; gradual granulomatous thickening of intestines

Booster frequently; goats may respond less than sheep to vxn; keeping carb/energy levels consistent

Abx controversial; focus on preventing septicemia; trimeth sulfa until culture results; isolation and PPE!

Disinfectants (ammonia, bleach, formaldehyde); don't feed off the ground!

Typhimurium, dublin, abortusovis, anatum, Montevideo; Zoonotic!; <1wk old; more likely acute death; >1wk diarrhea

Dx via acid fast stain or PCR; hx may have prolonged antimicrobial admin; no tx other than supportive care

5-10d old; does not require decal excretion + can become infective in gut; zoonotic; d+ (self limiting to severe)

Haemonchus: EPG <2000 EPG bucks + dry does; EPG >500 EPG young + lactating; 325 EPG dairy does; 10-12 random ideally

Enterotoxins; invasive, promote necrosis + inflam. in intestines; direct activation of Ca-dependent adenylate cyclase

EPG, tx, wait 2wk + repeat EPG; >95% reduction anthelmintic considered effective; <85% reduction resistance; cull repeat

Often introduced through new stock (quarantine protocol for new arrivals); changing wormers frequently (^ resistance)

Dx: electron microscopy, immunologic tech, ruminant d+ panel; Tx: hydration, electrolytes + acid-base recovery

High mortality; dx: fecal culture, serotyping K99 + F41 antigens; fluid therapy: oral, IV, electrolyte + bicarb

Abx controversial: may kill ETEC, may kill normal bacteria, trimeth sulfa, ampicillin, amoxi; NSAIDs for inflammation

Tx: clorsulon, combo w/ albendazole (does not kill entire burden); prevention: timing of tx, limit exposure to water

High carb ration; peracute: rapid onset abdominal pain, severe depression, d+, neuro signs (sudden death)

Animals w/ low fecal egg counts may not benefit from deworming; saves $

Dormant (hypobiotic) period where they form nodules in abomasum + wait to emerge in favorable spring conditions

~10d olf; most common 1-4d; d+: acidosis, dehydration, can die b4 d+; "Splash" in abomasum on auscultation

Prophylactic: amprolium, decoquinate, monensin, lasolacid; sulfameth, sulfaquin inhibit DNA synthesis via in. folic acid

Improve sanitation; avoid fecal contamination of food/water; reduce envir. oocyst burden; sunlight + dessication

Flunixin - caution if dehydrated; vxn of ewes/does w/ bovine produce to improve colostral antibodies; hygiene

Eggs/gram; thresholds are different for each parasite + can vary on production location + history; min of 6 animals

^ protein; nematode trapping fungi (duddingtonia spp.); high tannin plants; copper oxide wire particles

Abomasitis; some immunity can develop in adult sheep and goats

Ostertagia; 2nd most common; due to destruction of abomasal mucosa as opposed to anemia

F. hepatica + F. magna lifecycle requires aquatic snail; F. hepatic: immature fluke penetrates liver, blood loss

Eimeria spp.; 21-28d lifecycle; sexual + asexual stages; allows for continuous re-infection; 1-6m most susceptible

Group B commonly infect lambs/kids; infect villus tips of SI; d+ 2-14d of age; depression, dehydration

Vaccination not thoroughly evaluated in sheep and goats; intracellular bacteria (cure vs carrier)

Physiology based on toxins; tx is mostly supportive care: IV fluids, charcoal + sorbitol, +/- rumenotomy; "true" v+

Common in 2-4wk old lamb/kid; can shed cyst for wk after d+ resolves; zoonotic!; wet mount slide; fenbendazole

Acute: similar to peracute, less severe; chronic: d+, wt loss; Dx: culture + toxin typing (can be normal GI inhabitant)

Fever, depression, tenesmus, shock +/- blood in stool; Dx: Culture, PCR; supportive care (fluids, anti-inflammatories)

60-95% reduction is evidence of resistance or failure of deworming practices; evidence of ineffective dewormer

Only effective for Haemonchus; not to be used by itself!; aids in genetic selection for resilience, not resistance

Tx: supportive care; Prevention: severely affected flocks, vxn w/ bovine vxn may be useful

Enterotoxigenic (ETEC); fimbraie/pili attach + colonize villi (K99, F41); enterotoxin - d+; fecal-oral infection

Adults 1 month before kidding and breeding; kids at weaning; don't forget bucks; dry lot can be effective to break cycle

Emergence of merozoites causes sig. damage to gut; fluid, electrolyte, protein loss; Non-clinical: prophylactic tx

Tx + quarantine new arrivals + new additions to herd (consider dry lot); consider everything when eval anemic animals

Suffolk sheep only; sus dysautonomia; anorexia, wasting, right abdominal distention; tx unrewarding

C. perfringens; A, B, C, D all cause d+; D most common in US (epsilon); C common <3wk (beta); overeating disease