Ruminant Endo and Ecto Parasites

Large Lungworm (Dictycalus Filaria)

• Least common, most pathogenic

• Direct Lifecycle – does not require intermediate host

Small Lungworm (Muellerius Capillaries)

• Most common, least pathogenic

• Indirect Lifecycle- requires intermediate host to complete lifecycle 

Lungworm (Verminous Pneumonia)

• Clinical Signs: most severe in younger animals

  • Coughing 

  • Labored breathing

  • Reduced milk production , low growth rate, weight loss

  • Secondary bacterial infection 

• Diagnosis : Not by normal fecal float, Baermann testing 

• Treatment :

  • Most broad spectrum dewormers are effective

  • Macrocyclic lactones (ivermectin) recommended

  • Repeat treatment recommended

Meningeal Worm (Deer Worm)

• Parelophostrongylus tenuis 

• Natural host is the white-tailed deer, effects small ruminants (sheep and goats)

• Lifecycle: 

  • Small ruminants ingest -> migrate from the abomasum to the spinal cord -> damaging the central nervous system

• Clinical Signs:

  • Chronic skin itch 

  • Hind end weakness 

  • Total limb paralysis

• Diagnosis: 

  • No fecal testing available 

  • Post-mortem (after death) – finding live worms in nervous tissue 

• Treatment: 

  • Stop the worm: Fenbendazole (Safeguard) crosses the Blood Brain Barrier 

  • Reduce inflammation and damage to the nervous tissue: Steroids, NSAIDS 

Liver Fluke (Traumatic Hepatitis)

• Fasciola hepatica 

• Broad host range – cattle, sheep, alpacas, llamas

• Ingestion by host ->young flukes excyst in the duodenum -> penetrate the intestinal wall -> enter the peritoneal cavity -> migrate to the liver 

• Clinical Signs: 

  • Painful abdomen 

  • Anemia 

  • Sudden Death / Chronic Liver Damage

• Diagnosis: Fecal sedimentation test, ELISA 

• Treatment: Albendazole, Triclabendazole * (only drug that can kill all stages of fluke

Barber Pole Worm

• Haemonchus contortus

• Direct blood loss from parasites actively feeding on blood in the abomasum and C3 (llamas and alpacas) 

• Clinical Signs: NO DIARRHEA 

  • Anemia 

  • Submandibular Edema – Bottle Jaw 

• Diagnosis: Fecal Egg Counts – McMasters 

• Treatment: Ivermectin, Fenbendazole – Extremely resistant 

• Prevention: 

  • Pasture Management: rotational grazing

  • Strategic Deworming: FAMACHA Scoring 

Famacha Scoring

1. Cover

2. Push

3. Pull

4. Pop

Crypto (C. parvum)

• Most likely 7-21 days

• Watery-brown to green fees; blood/mucus possible

Coccidia

• Eimeria spp. 

• Protozoan / single celled parasites effecting the GI tract

• Species specific, 12 identified in cattle, 9 in chickens, 17 in goats 

• Clinical signs:

  • Severe Diarrhea

• Diagnosis: Fecal McMasters 

• Treatment/ Prevention: 

  • Coccidiostat

  • Cleanliness / Feces Removal

Cryptosporidium

• Protozoan parasites effecting the GI tract- 19 species 

• Zoonotic – always wear gloves when dealing with diarrhea in younger animals 

• Transmission: oocysts in the feces, fecal oral

• Clinical Signs: 

  • Diarrhea – prolonged nonresponsive to treatment

  • Anorexia 

  • Dehydration

• Treatment: 

  • Supportive Care- fluids for dehydration 

  • Nutritional Support

Biting/Chewing Lice

• Found on multiple ruminant species/ different genotypes: cattle, sheep, goats

• Affected animals rub on fencing and pens (fomites)-> cause excoriations on skin

• Clinical Signs: 

  • Itching

  • Hair Loss / Fleece and Hide damage

  • Dermatitis 

  • Trauma and secondary bacterial infections

Sucking Lice

• Blood feeding species 

• Clinicals Signs: 

  • Anemia : less than the normal amount of healthy red blood cells 

• Treatment: 

  • Insecticides : pour on and injectable : permethrin 

  • Maintain clean environments / Husbandry – overcrowding 

  • Grooming

Quarantine new arrivals (minimum 14 days)

Mange Mites

• Diagnosis: *state reporting / federal reporting

  • Skin Scraping

    • Demodex: Deep skin scraping

• Treatment: Multifactorial 

  • Insecticides: Macrocyclic Lactones

  • Treatment of animal, fomites, environment

  • Quarantine Period : minimum 2 weeks