Page 110 Lecture Notes - Veterinary Neonatal Immunology, Infectious Diseases, and Oncology (Vocabulary Flashcards)

Vocabulary flashcards covering passive transfer, neonatal isoerythrolysis, ehrlichial diseases (granulocytic and Potomac horse fever), diagnostic tests, and common equine tumors.

Failure of passive transfer (foals)

Foals fail to acquire maternal antibodies from colostrum, leaving them immunocompromised and at risk for fatal infections (e.g., Pneumocystis carnii); adequate passive transfer is defined by total protein >800 mg/dL.

Pneumocystis carnii

Unusual organism that can cause fatal infections in foals with failure of passive transfer.

Adequate passive transfer

Total protein >800 mg/dL indicating sufficient transfer of maternal immunoglobulins to the foal.

ELISA (SNAP) test

Rapid (about 5 minutes) test used to detect antibodies and assess passive transfer in foals.

Total Protein (TP) by refractometer

Measurement used to infer immunoglobulin levels; not highly sensitive but usable when other tests aren’t available.

Zinc sulfate turbidity test

A quick assay to assess immunoglobulin content in foal serum for passive transfer evaluation.

Radioimmunodiffusion (RID)

Most accurate test for detecting immunoglobulin transfer (IgG) but requires about 24 hours.

Neonatal isoerythrolysis (NII)

Hemolytic disease in foals caused by maternal antibodies against foal RBC antigens (Aa and Qa) transferred via colostrum.

Aa antigen

Equine red blood cell antigen involved in NII; stallion positive and mare negative can lead to foals at risk.

Qa antigen

Another equine red blood cell antigen involved in NII; contributes to alloimmune anemia when mare is negative and foal inherits it.

Multiparous mare

A mare that has given birth more than once; higher risk for NII due to prior antigen exposure and antibody production.

Epitheliochorial placenta

Placental type in horses that prevents in utero transfer of antibodies; colostral antibodies acquired after birth.

Granulocytic ehrlichiosis

Infection by Ehrlichia equi that resides in neutrophils/eosinophils; characterized by morulae in cells and typically mild signs.

Ehrlichia equi

Causative agent of granulocytic ehrlichiosis; an intracellular bacterium of neutrophils/eosinophils.

Morulae

Intracytoplasmic inclusion bodies seen in granulocytic ehrlichiosis (morulae are clustered bacteria within leukocytes).

Potomac horse fever

Disease caused by Ehrlichia risticii (Neorickettsia risticii); intracellular in monocytes with leucopenia and monocytosis.

Ehrlichia risticii (Neorickettsia risticii)

Agent causing Potomac horse fever; intracellular organism that resides in monocytes/macrophages.

Paired serum titers

Diagnostic approach for Potomac horse fever requiring a four-fold rise between acute and convalescent titers (or a titer decrease) for confirmation.

PCR (Potomac horse fever)

Polymerase chain reaction testing of blood or feces; a sensitive and specific modern diagnostic method for PHF.

Tetracycline

Antibiotic effective against intracellular and rickettsial organisms; rapid clinical response expected within 24–48 hours.

Oxytetracycline

Drug of choice for Potomac horse fever; typically given for 7–10 days.

Seminoma

Common unilateral testicular tumor in horses; firm, enlarged testicle that can be locally invasive and reduce sperm production.

Granulosa-theca cell tumor

Common unilateral ovarian tumor in mares; benign and secretes steroids that suppress cycling by inhibiting gonadotropins.