Diazepam for cats: Uses, risks, and safety guidelines

In this article:

• What is diazepam used for in cats?
• Safety
• Dosages
• Alternatives

In this article

• What is diazepam used for in cats?
• Safety
• Dosages
• Alternatives

Most people have heard the brand name Valium. Diazepam is the generic version. Veterinarians commonly use it as a sedative, anxiety treatment, seizure medication, and muscle relaxant in cats and dogs. It’s often used on an as-needed basis, but veterinarians are cautious about giving cats diazepam on a daily basis. Some cats can experience life-threatening liver injury when taking daily oral diazepam. It’s a rare occurrence, but veterinary medicine can’t explain why it even happens at all. Some veterinarians may refuse to use it as a daily medication in cats. 

What is diazepam used for in cats?

Diazepam is a common veterinary drug that is a first-line treatment for active seizures, though its use as a daily maintenance treatment for seizures is debated. 

In addition to seizures, veterinarians may prescribe diazepam on an as-needed to keep cats calm during anxiety-inducing situations such as a vet visit or traveling. 

It can be an effective treatment for general anxiety, behavioral problems, urethral obstruction, and urine spraying, but its use as a daily treatment for these problems is controversial.

Less commonly, some veterinarians may use it as an appetite stimulant in cats that are not eating, but it’s not their first choice. Some veterinarians may use it as a tranquilizer for veterinary procedures to calm the cat before administering anesthetics.

Seizures

Diazepam is the most common medication used to calm seizures in cats, particularly long-acting seizures or seizures that won’t stop (status epilepticus). Diazepam is a benzodiazepine, a family of drugs that slow down the nervous system. 

When a cat is having seizures, the veterinarian will give a diazepam intravenous bolus (single injection) along with other drugs called anticonvulsants. They will continue to inject diazepam every five minutes until the seizures stop. If that doesn’t work, they may start an intravenous constant-rate infusion of diazepam or use other drugs to stop the seizure. 

Doctors commonly use diazepam as a seizure maintenance treatment in people to prevent seizures. Veterinarians generally avoid diazepam as a seizure maintenance treatment in both dogs and cats. In dogs, the drug doesn’t last long. In cats, there’s a small risk of serious liver injury.

Anxiety

Diazepam quickly tranquilizes an animal, so veterinarians commonly use it as a one-time treatment to pacify an animal in stressful situations. It works when caregivers can anticipate a potentially panic-provoking situation like taking a cat on a trip or right before a vet visit. Doses need to be given at least a half hour before the cat undergoes stress.

Veterinarians may use it as an ongoing anxiety or problem behavior treatment. It’s also effective at reducing urine spraying or urine marking, behavioral problems that are closely related to anxiety. However, chronic, daily use of diazepam in cats is controversial, so its use for anxiety and urine marking has diminished over the years. 

Urethral obstruction

The urethra is a long tube that passes urine from the bladder out of the body. When the urethra is obstructed, the cat is partly or totally unable to empty the bladder. It’s a common problem in male cats. Urethral obstruction may affect 1.5%–9% of cats at some time in their lives. The standard treatment involves emergency veterinary care, catheterization, medications, and brief hospitalization.

After emergency treatment, the cat may need further care with anesthetics, pain relievers, or muscle relaxants. Diazepam is a skeletal muscle relaxant and was once a first-line treatment for urethral spasms in cats, but its use in cats is less common now because of the risk of liver injury. 

Is diazepam safe for cats?

Diazepam is commonly used in cats but may not be safe for every cat. Diazepam is never given to cats that have had an allergic reaction to diazepam. 

Veterinarians are cautious about giving cats daily doses of diazepam because of the small risk of liver injury and hepatic failure. The liver can start failing within a few days of starting diazepam and quickly prove fatal. Veterinarians do not know why this happens. They can’t predict which cats are vulnerable. When daily diazepam is prescribed to a cat, the only way to keep the cat safe is to perform a blood test at the beginning of treatment and again after a few days to monitor liver function.

Veterinarians are also cautious about using diazepam in cats that are aggressive or have slow breathing. 

Diazepam is a controlled substance and may not be safe for people if used inappropriately. If prescribed for a cat, do not give it to other people. Keep it securely out of the reach of children and pets.

Side effects of diazepam in cats

Diazepam’s most common side effects in cats are behavior changes including:

• Irritability
• Depression
• Bizarre behaviors

Other common side effects include:

• Lethargy
• Increased appetite

Diazepam’s most serious side effect in cats is liver damage, though this is rare. Caregivers should carefully monitor the cat for signs of liver problems and take the cat to the veterinarian if they occur. These include:

• Lethargy
• Loss of coordination
• Loss of appetite
• Yellowing of the eyes, skin, or mucus membranes

These symptoms usually occur within a few days of starting daily diazepam doses.

Interactions of diazepam with other pet medications

To avoid possible drug interactions, tell the veterinarian about all the drugs, supplements, and herbal products the cat is receiving, especially:

• Drugs that make the cat sleepy or lethargic such as opioids, barbiturates, or anticonvulsants
• Supplements or herbal products that make the cat sleepy such as CBD or melatonin
• The anxiety treatments amitriptyline or fluoxetine
• The stomach acid medications omeprazole or cimetidine
• The antibiotic erythromycin
• Azole antifungals such as ketoconazole or itraconazole
• The steroid dexamethasone
• The heart drugs digoxin, quinidine, or amiodarone
• Antacids
• Mineral oil

Diazepam dosage for cats

Diazepam dosages vary by condition:

• For acute seizures: 0.5–1 mg/kg intravenous injection
• For situational anxiety: 0.25–0.5 mg/kg given by mouth on an as-needed basis
• For functional urethral obstruction: 1–2.5 mg given every eight hours 

When caregivers administer diazepam to their pet at home, they can use either a human or veterinary formulation, usually tablets or oral solutions.

Rectal diazepam can be used during an active seizure. The veterinarian may use rectal diazepam during an emergency. It’s unlikely, but a veterinarian could suggest that a caregiver use a home diazepam rectal seizure kit or diazepam rectal gel (formerly available as brand name Diastat) to manage an ongoing seizure at home. This is uncommon and will require some instruction.

Can cats overdose on diazepam?

A diazepam overdose can be fatal in a small animal. No maximum dosage for cats has been defined, but a dose of 500 mg/kg can rapidly kill a cat.

A caregiver should immediately call an animal poison control center or take the cat to a veterinarian if the cat has been given too much diazepam or shows signs of diazepam toxicity, including:

• Significant drowsiness
• Slow reflexes
• Slow heart rate
• Low blood pressure
• Confusion
• Disorientation
• Involuntary muscle movements
• Coma

Can I give my cat diazepam every day?

Diazepam can be given to cats every day, but there is a small risk that daily diazepam doses can induce life-threatening liver failure in a cat. Veterinarians don’t know why this happens, and they are unable to predict which cats will be affected.

Because of this risk, some veterinarians may not use daily diazepam in a cat. Those that do will perform blood tests at the start of treatment and a few days later to determine if the drug is affecting the cat’s liver. Veterinary literature does not suggest continued liver testing after the first few days, so daily diazepam may be safe for cats after that initial treatment period. 

How to give your cat diazepam

• Only use diazepam in a cat when prescribed by a veterinarian.
• Follow all the veterinarian’s instructions. 
• Do not give the cat extra medicine. If it doesn’t seem to be working, talk to the prescriber.
• To calm a cat before a stressful event, give the diazepam dose at least 30 minutes before the event happens.
• If the veterinarian prescribes daily doses, do not stop giving the cat doses until talking to the veterinarian. The dose may need to be gradually decreased to prevent withdrawal symptoms.
  • The only exception is if the cat starts showing signs of liver damage. In that case, call the veterinarian immediately or take the cat to a veterinary hospital. 
• Ask the veterinarian what to do in case a dose is missed.
• Give diazepam tablets or oral solution with food or on an empty stomach.
• If you don’t know how to dose a cat with a tablet or oral solution, have a veterinary technician show you the correct technique.
• Diazepam tablets are scored so they can be split into two smaller doses. If the veterinarian prescribes a dose requiring half a tablet, ask the veterinary professional how to split the tablet correctly.
• Doses of diazepam oral solution should always be measured with the calibrated oral syringe supplied with the medicine. Do not use kitchen measuring devices or tableware.
• Store diazepam at room temperature in a light-protected container.

Diazepam alternatives for cats

Veterinarians use diazepam as a first-line treatment for active seizures. A veterinarian will supplement this treatment with longer-acting anti-seizure drugs such as an anticonvulsant or barbiturate. If repeated diazepam injections don’t work, the veterinarian may switch to a diazepam infusion or try another benzodiazepine. In the worst cases, the veterinarian may need to use anesthesia to stop the seizure. 

For anxiety, veterinarians primarily use diazepam to treat situational fear in cats. It works very quickly but only lasts a short time. Alternative treatment options include lorazepam, gabapentin, trazodone, clonidine, or acepromazine. 

For urine spraying, the optimal treatments are conservative treatments such as environmental changes and pheromone sprays. When medications are needed, diazepam is effective, but there’s always a small chance that daily dosing will harm the cat’s liver. Other medication treatment options include selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, or Wellbutrin (buspirone).

For urethral spasms in cats with urethral blockage, diazepam is used as a muscle relaxant. To avoid daily diazepam dosing, veterinarians can use other muscle relaxants including smooth muscle relaxants called alpha blockers or skeletal muscle relaxants. Not all muscle relaxants used in people are used in cats.

Summary

Diazepam is safe and effective when used as needed to treat active seizures and to calm cats in scary situations. Diazepam is also effective as a daily drug in treating urine marking, anxiety, and urethral obstruction, but veterinarians are cautious because some cats may experience life-threatening liver damage. If the veterinarian prescribes daily diazepam, ask about ways to keep the cat safe from liver problems.