VMC 221: Veterinary Immunology and Serology (1+1)

CLINICAL TYPE-I HYPERSENSITIVITY REACTIONS

• Milk Allergy
• Food allergy 
• Atopic dermatitis 
• Drug or vaccine hypersensitivity
• Allergies to parasite etc.

Milk allergy

• Jersey cattle may become allergic to the α casein of their own milk which is synthesized in the udder and if milking is delayed the increased intramammary pressure forced the protein into blood stream. This results into anaphylactic reaction, urticaria and death.

Food allergy

• Certain ingested protein (eggs, fish, dairy products, beef etc) are not fully absorbed and the peptide antigen reach mast cells within few minutes which results in pruritic skin reaction ( papules and erythematous) and also vomiting and diarrhea. This type of reactions is common in dogs and cats.

Atopic dermatitis

• It is a chronic multifactorial syndrome with inflammation and itching reaction on the skin. Commonly it is due environmental allergy due to dust, pollens, molds, animal dander etc and observed in dogs, cats, horses and goats. Initially there may be diffused erythema, licking and scratching results in hair loss, papules, scaling and crusting. Some dogs may develop otitis externa.

Allergies to vaccines or drugs

• Allergies have been recorded to killed foot and mouth disease, rabies and CBPP vaccines. Penicillin allergy may be induced in animals either by therapeutic exposure or by ingestion of penicillin contaminated milk. The penicillin molecule is degraded in vivo into penicilloyl group. This binds to proteins and provokes an immune response.

Allergies to parasites

• Allergies reported to tapeworms, fly bites, mites etc.  Responses to Demodex mites and components of flea saliva may cause Type IV hypersensitivity.