Equine Vaccines and Common Diseases

Flashcards about Equine Vaccines and Common Diseases

Core Vaccines

Protect against diseases endemic to a region, highly contagious, pose a risk of severe disease, have potential public health significance, and/or are required by law.

1.Tetanus- Clostridium tetani

2.Rabies virus

3.Eastern and Western Equine Encephalitis (EEE/WEE) Venezuelan EE is risk-based

4.West Nile virus

Tetanus

 Causative agent: Clostridium tetani, lives in soil, enters through open wounds, horses highly susceptible

 Clinical signs: Sawhorse appearance, recumbent; and dyspnea

 Diagnosis: Clinical signs, history

 Treatment: Supportive and antitoxin

 Prevention:  Vaccination with tetanus toxoid yearly and booster if they get a wound

Rabies

 Causative agent: rhabdovirus, transmitted through a bite wound from an infected animal

 Clinical signs: GI symptoms, neurologic deficits, ataxia, lameness, and loss of bladder control

 Diagnosis: Examination of brain and spinal cord (post mortem), Reportable

 Treatment: None

 Prevention: Annual vaccination

Encephalomyelitis (EEE/WEE/VEE)

 Also known as “Sleeping Sickness”

 Causative agent: Equine alphaviruses (three variants), spread by mosquitoes

 Clinical signs: Fever, ataxia, anorexia, paralysis, circling, head pressing, and hyperexcitability

 Diagnosis: Presumptive before death, PCR from a tissue sample (post mortem), Reportable

 Treatment: No specific, supportive care (high mortality rate)

 Prevention:  Yearly vaccination (WEE/EEE), may be more frequent for year-long mosquito season—VEE is risk based

West Nile Virus

 Causative agent: Equine Flavivirus, spread by mosquitoes who have bitten infected avian species (reservoir)

 Clinical signs: Fever, ataxia, anorexia, paralysis, circling, colic, and hyperexcitability

 Diagnosis: ELISA testing of serum or CSF, PCR from a tissue sample (post mortem), Reportable

 Treatment: No specific, supportive care

 Prevention:  Yearly vaccination, may be more frequent depending on location

Risk-Based Vaccines

Selected for use based on risk assessment performed by, or in consultation with, a licensed veterinarian. Use may vary between individuals, populations, and/or geographic regions.

1.Equine Herpesvirus (Rhinopneumonitis)

2.Equine Influenza

3.Strangles- Streptococcus equi

Equine Herpesvirus (Rhinopneumonitis)

Causative agent: Equine herpesvirus 1 (respiratory, reproductive, and neurologic forms) Equine herpesvirus 4 (respiratory), Latent virus: Hides from the immune system, Spread by respiratory secretions

Clinical signs: Fever, Nasal discharge, Lethargy/Depression, Neonatal death, Late‐term abortion, Neurologic disease

Diagnosis: PCR or Postmortem

Treatment: Isolation and supportive care

Prevention:  Frequent vaccination of young horses, horses that travel/show, and horses used for breeding; No vaccine is effective against neurologic form of EHV-1!

Mare vaccine protocol to prevent abortion is to vaccinate at 5^th, 7^th, and 9^th month of gestation

Equine Influenza

Causativ Causative agent: Orthomyxovirus that mutates readily, spread through respiratory secretions

 Clinical signs: Fever, anorexia, weight loss, mucopurulent nasal discharge, increased respiratory rates, and retropharyngeal lymphadenopathy

 Diagnosis: Presumptive, virus isolation, immunoassay, immunofluorescence, PCR, and antibody detection

 Treatment: Supportive, isolation from other horses

 Prevention: Frequent vaccination of young horses, horses that travel/show, and horses used for breeding

Strangles

 Causative agent: Streptococcus equi, highly contagious- can be carried by humans, equipment, feed buckets

 Clinical signs: Sudden fever, mucopurulent nasal discharge, and abscessation of the submandibular and retropharyngeal lymph nodes

 Diagnosis: Culture, PCR, and serology

 Treatment: Antibiotic therapy and lance and flush, isolation, disinfection of equipment, stall, buckets

 Prevention:  Intranasal vaccine- modified live vaccine- WILL CAUSE ABSCESS IF GIVEN IM! Based on risk

 Best immunity is exposure- antibody production, lifelong immunity

Modified Live vaccines

Cause a rapid immune response with fewer boosters required, but typically not as long-lasting immunity, caution with pregnant animals

Killed vaccines

Slower immune response, may require more boosters, but long-lasting immunity, safer for pregnant animals

Salmonella

 Causative agent: Salmonella agona, S. newport, S. anatum, S. Krefeld, S. typhimurium.

 Clinical signs: Carrier (stressed develop signs);mild clinical (anorexia, pyrexia; depression; soft watery stools;and acute clinical (watery, foul smelling diarrhea, abdom pain severe depression, anorexia, signifneutropenia.

 Diagnosis: repeated fecal cultures, neutropenia, and clinical signs

 Treatment: Supportive, Quarantine

Equine Protozoal Myeloencephalitis (EPM)

 Causative agent: Sarcocystis neurona or Neospora hughesi, horse ingests possum feces containing protozoa

 Clinical signs: Neurologic deficits, asymmetric muscle atrophy and cranial nerve abnormalities

 Diagnosis: Neuro exam, IFA antibody titer, serum and CSF

 Treatment: Antiprotozoal drugs (Ponazuril, long-term sulfa antibiotics), supportive, and vitamin E

Equine Infectious Anemia

 Causative agent: Retrovirus

 Clinical signs: Pale mucous membranes, petechiae, icterus, neurological signs, thrombocytopenia, and anemia

 Diagnosis: Serological testing, AGID, cELISA, Vira-CHECK ELISA, or Synthetic antigen ELISA

 Treatment: Reportable, euthanasia, or quarantine

Rain Rot

 Causative agent: Dermatophilus congolensis

 Most common in high humidity/temps

 Clinical signs: Crusty scabs or matted tufts of hair, yellow or green pus under scab, often on head, neck, chest

 Diagnosis: Culture and identification

 Treatment: Antimicrobial therapy on lesions