Neurologic Disease of Sheep and Goats

Tetanus (Lockjaw)

• Clostridium tentani

• History

Tetanus Pathogenesis

Wound + tissue necrosis —> Bacterial multiplication —> Neurotoxin released —> toxin absorbed by moto nerves and passes up the nerve tract to spinal cord —> Ascending tetanus —> spasmodic, tonic contractions of the voluntary muscles b/c of interference at the NMJ

More toxin released than can be absorbed —> Toxin travels by lymph and blood to brain —> Descending tetanus

Transmission: Tetanus (lockjaw)

Wound contamination

Clinical signs: Tetanus

Treatment and Prevention: Tetanus

Treatment

• Penicillin

• Wound care

• Tranquilizers

• Dark, isolated area

• Supportive care

• Slow recovery

Prevention

• Tetanus toxoid

• Tetanus antitoxin

Caprine Arthritis-Encephalomyelitis (CAE)

• Retrovirus

• All goats affected

Transmission: Caprine Arthritis-Encephalomyelitis (CAE)

• Oral via colostrum/milk

• Direct contact

Clinical Signs on Kid: CAE

• Posterior weakness/paresis

• Encephalopathy-rare

• Mild pneumonia

Clinical Signs on Adult: CAE

Treatment and Prevention: CAE

Treatment

• CNS signs- none

• Arthritis- NSAIDs

Prognosis- poor

Prevention/Control

• Serologic testing

• In infected herd

  • Depopulate

  • Test and cull

Scrapie

• Progressive infection of sheep/goats that is characterized by fatal encephalitis

• Prion: transmissible spongiform encephalopathies (TSE)

• Mature sheep

Other TSEs

• Bovine Spongiform Encephalopathy (BSE)

  • “Mad Cow”

• Chronic Wasting Disease (CWD)

  • White-tailed deer, mule deer, elk, moose

• Transmissible Mink Encephalopathy (TME)

  • Ranch-raised

• Creutzfeldt-Jakob

  • Humans

Transmission: Scrapie

• Brain tissue ingestion

• Nasal secretions

• Fecal shedding

• Placental fluids

Clinical Signs: Scrapie

• “spongy” appearance

Treatment and Prevention: Scrapie

Treatment

• NONE

Prevention

• Do not feed sheep by-products

• Reportable disease

Nervous Coccidiosis

• Eimeria spp.-

• Winter

• Asso with enteric Coccidia

  • Neurotoxin production

Transmission: Nervous Coccidiosis

Fecal-oral

Clinical Signs: Nervous Coccidiosis

• Diarrhea, tenesmus, blood

• Prolapsed rectums

• Depression, incoordination, twitching and hyperesthesia

• Recumbency, opisthotonos, tremors, nystagmus, frothing, bellowing, seizures

Diagnosis

• Fecal

Treatment and Prevention: Nervous Coccidiosis

• Sulfamethazine or amprolium

• Control seizures

• High mortality (72%)

Enterotoxemia (Overeating; Pulpy kidney disease)

• Clostridium perfringens type D produces toxin

• Normal microflora of the intestine

• Excessive grain or milk

• Toxin —> high vascular permeability, causes edema (lungs, kidney, brain)

Clinical Signs: Enterotoxemia

• Sudden death

• Incoordination and convulsions

• Diarrhea

• Head pressing

• Opisthotonos

Treatment and Prevention: Enterotoxemia

Treatment

• If caught early, type D= antitoxin

• Oral antibiotics

• Feed hay

Prevention

• Introduce slowly to concentrates

• Vaccination