Methionine
Also known as: Ammonil, Acimethin, Acimol, M-Caps, Methigel, Methio-Form, Methiotrans, Methnine, Neutrodor, Pedameth, Uracid, Uromethin, Uroeze
* **Administration:** Give this medication with meals or mixed directly into your pet's food to reduce stomach upset and enhance effectiveness. * > **Important Warning:** Do not give to kittens, and ensure kittens cannot access adult cat food that has been treated with this medication. * **Dietary Caution:** Do not combine this medication with prescription urinary diets (like s/d or c/d) unless specifically instructed by your veterinarian, as this can cause dangerous changes in blood acid levels. * **When to Call the Vet:** Contact your veterinarian immediately if your cat shows signs of weakness, loss of appetite, uncoordinated walking, or pale/bluish gums.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Urine acidification
- Urine acidification
- General / Ketosis
- Laminitis (purported)
- Senecio-induced liver damage
- Urine acidification (struvite dissolution)
- Struvite dissolution therapy (if diet and antimicrobials do not result in acid urine)
How it is given
Possible side effects
- Gastrointestinal distress (nausea, vomiting)
- Heinz-body hemolytic anemia (especially in cats)
- Methemoglobinemia
- Ataxia
- Cyanosis
- Metabolic acidosis
- Gastrointestinal upset (nausea, vomiting, diarrhea)
- Heinz body anemia (especially in cats at high doses)
- Worsening of hepatic encephalopathy in patients with liver disease
Cautions & contraindications
- Renal failure
- Pancreatic disease
- Hepatic insufficiency
- Preexisting acidosis
- Oxalate or urate calculi
- Kittens
- Pre-existing metabolic acidosis
- Severe liver disease or hepatic encephalopathy
- Urate, cystine, or calcium oxalate urolithiasis
- Young growing animals
- Pregnant or nursing animals
- > **Hepatic Warning:** If used in patients with frank hepatic insufficiency, methionine can cause increased production of mercaptan-like compounds and intensify the signs of **hepatic encephalopathy** (dementia or coma). * **Urolithiasis Risk:** Do not give to animals with oxalate or urate calculi, as these stones thrive in acidic environments. * **Dietary Overlap:** Unmonitored use concurrently with an acidifying diet (e.g., s/d, c/d) may easily lead to severe metabolic acidosis and signs of overdose. * **Age Restrictions:** Strictly not recommended for use in kittens due to high susceptibility to toxicity.
Drug interactions
- Aminoglycosides (gentamicin, amikacin): Urine acidification may diminish the effectiveness of aminoglycosides in treating bacterial urinary tract infections, as they are more effective in an alkaline medium.
- Erythromycin: Urine acidification may diminish the effectiveness of erythromycin in treating bacterial urinary tract infections.
- Quinidine: Urine acidification may increase the renal excretion of quinidine, potentially lowering its systemic levels.
- Other urinary acidifiers (e.g., ammonium chloride): Additive acidification leading to severe metabolic acidosis
- Urinary acidifying diets: Excessive lowering of urine pH and increased risk of metabolic acidosis
Frequently asked questions
What is Methionine used for in pets?
* **Administration:** Give this medication with meals or mixed directly into your pet's food to reduce stomach upset and enhance effectiveness. * > **Important Warning:** Do not give to kittens, and ensure kittens cannot access adult cat food that has been treated with this medication. * **Dietary Caution:** Do not combine this medication with prescription urinary diets (like s/d or c/d) unless specifically instructed by your veterinarian, as this can cause dangerous changes in blood acid levels. * **When to Call the Vet:** Contact your veterinarian immediately if your cat shows signs of weakness, loss of appetite, uncoordinated walking, or pale/bluish gums.
Is Methionine safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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