do antihistamines cause constipation
Medications that Cause Constipation. 1  Antihistamines. Antihistamines are prescribed for treatment of allergies in dogs. 2  Antacids. Antacids are used under the direction of a veterinarian for the treatment of stomach disorders, ulcers, heartburn and to lower high phosphorous levels in dogs with kidney failure. 3  Diuretics.