Metronidazole (Flagyl®)


Metronidazole has several uses in veterinary medicine.  It is effective against Giardia parasites.  It is employed in the treatment of many forms of diarrhea, including diarrhea caused by colitis and inflammatory bowel disease.   It aids in the treatment of certain liver disorders.  Metronidazole is an antibiotic that may be used in the treatment of certain types of bacterial infections.



Lactulose is a very effective laxative that is commonly used in veterinary medicine.   It is frequently used in the treatment and prevention of constipation in pets.

Lactulose also is used to treat some types of liver disease. 


Lactulose is available as a liquid suspension for oral administration.  Lactulose may be administered as an enema by veterinarians.

Prednisone, Cortisone and other Steroids


Corticosteroids are a class of medicines related to cortisone.  Cortisone is a naturally occurring hormone.

Corticosteroids should not be confused with anabolic steroids.  Anabolic steroids promote body and muscle growth.  Corticosteroids are used in pets to treat inflammation, allergies, itching, immune system irregularities, pain, back or spinal trauma, and eye, ear, or skin problems.

Mineral Oil-Based Laxatives and Hairball Remedies ( Including Laxatone® and Petromalt®)


Laxatone® and Petromalt® are commonly prescribed to prevent and eliminate hairballs in cats.  They are laxatives that promote the passage of intestinal contents through the rectum as feces.  Although the two products (and other, similar products) primarily are marketed as hairball remedies, they also are used to treat and prevent constipation.

Cimetidine (Tagamet®), Ranitidine (Zantac®), and Famotidine (Pepcid®)


Cimetidine, ranitidine, and famotidine are related medicines.   They are in a class of drugs called H2 blockers.  They have similar effects and uses in veterinary medicine.

H2 blockers cause decreased production of stomach acid.   In pets, these medicines are prescribed mainly to treat or prevent gastrointestinal upset (vomiting, diarrhea, or lack of appetite).  They also may be used to prevent or treat ulcers or irritation of the esophagus, stomach, or intestines.

Doxycycline (Vibramycin®)


Doxycycline is an antibiotic related to tetracycline.   It is effective against a variety of organisms, and is often used to treat bacterial infections. It is the antibiotic of choice for many diseases (such as Lyme disease) that are spread by ticks and some diseases caused by organisms known as Mycoplasma.  It is commonly employed in the treatment of respiratory infections and fever of unknown origin in cats.

Albon® (Sulfadimethoxine)


In veterinary medicine, sulfadimethoxine is used primarily to treat coccidia (Isospora) in puppies and kittens.  Courses of sulfadimethoxine generally last from 3 to 21 days.

Sulfadimethoxine also may be used as an antibiotic, but this is not common in veterinary medicine.

Sulfadimethoxine is currently considered an inferior treatment option for coccidia.  A different drug, ponazuril, is preferred.

Levothyroxine (Soloxine® and Thyro-Tabs®)


Levothyroxine is used to treat hypothyroidism in dogs. It works by supplementing the dog's production of thyroid hormone. The effect is temporary. Most dogs with hypothyroidism require lifelong treatment with levothyroxine.


Levothyroxine most commonly is administered as an oral pill once or twice daily.

Side Effects

Side effects of levothryoxine are rare but can include gastrointestinal upset.



Insulin is a drug that is used in the treatment of diabetes in dogs and cats. It requires special handling and storage, it must be given by injection, and it carries the risk of overdose. Despite these disadvantages, insulin is the most commonly used drug in the treatment of diabetes. Without insulin, most diabetic cats and dogs will suffer severe or fatal complications of the disease.

Form and Storage of Insulin