Dimapen is generally well tolerated; however, some animals may exhibit mild to rare adverse reactions:

1- Hypersensitivity Reactions (Allergic Reactions) : May occur in animals sensitive to penicillins oraminoglycosides.  Signs include:

Swelling at the injection site
Urticaria (hives)
Respiratory difficulty
Collapse (very rare, severe anaphylaxis)
 Immediate veterinary intervention is required in severe cases.

2- Local Reactions at Injection Site : Mild, transient swelling may occur—especially in horses, Typically resolves within a short period without treatment.

3- Systemic Reactions in Pigs (Rare) : Pigs may occasionally show Fever, Vomiting, Shivering and Incoordination.

4- Gastrointestinal + Renal Considerations : Because dihydrostreptomycin is an aminoglycoside Use caution in animals with compromised kidney function, as accumulation may increase toxicity risk. Toxic effects are rare when dosage guidelines are followed.

5- Effects During Pregnancy (Pigs) : Pregnant sows and gilts may rarely exhibit vulval discharge that could be associated with abortion. Use only under veterinary supervision during pregnancy.