Side Effects of Diazepam in Dogs

Diazepam is the veterinary formulation of Valium, a benzodiazepine tranquilizer and central nervous system depressant. It acts directly on the brain and is clinically effective for dogs as a sedative, a muscle relaxant and an anticonvulsant. In her article, "Diazepam for Veterinary Use," veterinarian Barbara Forney explains that diazepam is used in dogs to reduce anxiety and treat behavioral problems, such as "separation anxiety, fear of loud noises or thunderstorms, territorial or social aggression between animals, urine marking or spraying and hair loss due to excessive licking or grooming."

  1. Physical Side Effects

    • Because it's a muscle relaxant, diazepam's common side effects include weakness, loss of coordination and clumsiness. Some dogs may also experience increased appetite.

    Gastrointestinal Side Effects

    • Some dogs will experience vomiting, loss of appetite or diarrhea while taking diazepam.

    Side Effects Related to Addiction and Withdrawal

    • Long-term treatment can lead to dependence resulting in undesirable behavior changes once the drug is discontinued. Diazepam may be addictive, so dogs should be eased off diazepam gradually to reduce the risk of serious withdrawal symptoms. According to Sharon Crowell-Davis, DVM, sudden termination of diazepam can result in ̶0;rebound, the resumption of symptoms more intense than prior to treatment. When discontinuing, the common rule of thumb is to decrease the dose no faster than 25 percent each week."

    Side Effects Related to Pregnancy and Lactation

    • Diazepam crosses the placenta and is present in mother's milk, so pregnant and lactating dogs should only take the medication if the benefits outweigh the risks. The drug is teratogenic in humans during the first trimester of pregnancy, so beware of the potential for canine birth defects.

    Side Efects Related to Drug Interaction

    • Avoid using diazepam with other tranquilizers, narcotics, barbiturates, antihistamines and antidepressants, as it's a central nervous system depressant. Patients also taking digoxin should be monitored for signs of toxicity since diazepam can increase digoxin's effects. Antacids delay the absorption of diazepam, but this is easily managed by separating the medications by at least two hours. Doctors Foster and Smith suggest dog owners consult their veterinarian "before using diazepam with vitamins and supplements ̷0; and other drugs since interactions may occur."

    Overdose Side Effects

    • A diazepam overdose can significantly depress the central nervous system. If you see signs of increased sedation, difficulty breathing, loss of coordination or stumbling, disorientation, depression, decreased reflexes or coma, contact your veterinarian immediately.

    Side Serious Side Effects Related to or Causing Other Conditions

    • Use diazepam with extreme caution in dogs that have liver or kidney disease, have narrow angle glaucoma, are dehydrated or anemic, have difficulty breathing or are geriatric or obese. Contact your veterinarian if your pet experiences jaundice, pale gums, low platelets or an increased tendency to bruise or bleed while being treated with diazepam.

    Allergic Reaction as Side Effect

    • Contact your veterinarian or an emergency vet clinic immediately if your pet experiences an allergic reaction to diazepam. Symptoms may include facial swelling, hives, itchiness and scratching, diarrhea, vomiting, shock, seizures, pale gums, cold limbs or unconsciousness.

    Mental Status and Behavioral Side Effects

    • Some dogs may exhibit behavior such as excitement or aggression after taking diazepam, even when the drug is used to calm aggressive tendencies. While the medication may help with fear-induced aggression, learned inhibition of aggressive behavior may be lost, so use diazepam with caution. It's important to monitor working animals, such as military, police and service dogs taking the medication, as sedation and disorientation are also possible. Dogs taking diazepam may exhibit increased friendliness, anxiety, hallucinations, insomnia, amnesia, difficulty learning, depression or lethargy. Some dogs become disoriented and may wander around the house whining.