For cat owners, nothing is quite as frightening as being told your cat needs to be anesthetized for a procedure. Anesthesia, defined as a "loss of feeling or sensation," is commonly used in veterinary practices, and provides an essential tool for surgical or other painful procedures. Anesthesia is expected to be used when your cat is spayed or neutered. But, it helps to have a better understanding of some of the commonly used types of anesthetics, how they work, and their potential drawbacks. It'll help you make the best decisions when it comes to sedating your cat.
Sedation Before Anesthesia
Cats are generally given sedatives or tranquilizers before anesthesia. These drugs will sedate and calm your cat so it can be given a mask or tracheal tube required for inhalant anesthesia. The medication also allows for a smaller amount of general anesthetic to help to minimize vomiting and foster a quicker recovery period. Sedating drugs are generally administered intravenously. If your veterinarian uses ketamine, for example, the drugs can be injected. Injectable anesthetics are often used for relatively quick procedures, such as C-sections, spaying, or neutering.
Injectable anesthetic agents fall into three main groups: barbiturates, dissociative anesthetics, and nonbarbiturate hypnotics. Each of these agents has its pros and cons. Talk to your veterinarian about the risks of using certain anesthetics for your cat's procedure. The doctor can ease your mind about the type of anesthetic that'll be used and why.
Barbiturates (thiopental, thiamylal, and methohexital): Cats that are older, obese, or have compromised hepatic and renal functions typically require a higher dosage for better metabolism of barbiturates. Barbiturates have the potential to cause respiratory depression if given in excessive doses and the extra dosage could prolong recovery.
Ketamine: Ketamine is a disassociated anesthetic widely used as both a pre-anesthetic drug and in combination with other drugs, such as acepromazine. It can be used as full anesthesia for some procedures. It's generally considered safe, although some people believe that certain breeds of cats may be at risk with its use. Ketamine is not recommended for cats suffering from renal disease (kidney) or hepatic lipidosis (a liver condition), and certain other conditions. Ketamine can depress your cat's cardiac and respiratory function with the potential of causing excess fluid in the lungs.
Propofol: Propofol is a nonbarbiturate hypnotic. It’s also called PropoFlo, Rapinovet, and Dipravan. Propofol is the "injectable of choice" for certain veterinary procedures, as it's quick-acting, offers a rapid recovery period, and rarely causes drug aftereffects. However, propofol is not recommended for cats with certain liver diseases, since it is primarily metabolized via the liver. Typically, propofol has minimal effects on your cat's cardiovascular system. However, this drug may cause breathing problems when given to your cat too quickly, or cause cardiac arrest if your cat is given an overdose.
What Is Acepromazine?
You may hear your vet mention acepromazine, which is the most commonly used sedative for animals. It’s used in conjunction with an anesthetic protocol. Acepromazine isn't recommended for cats with CNS (central nervous system) lesions, and it can sometimes cause hypothermia.
Isofluorane revolutionized veterinarian anesthesia. The inhalant is safer for older and more compromised cats, offers rapid recovery of a cat after surgery, and it's not likely to induce nor exacerbate a heart arrhythmia. Since isofluorane lost its patent, it's becoming less expensive than newer inhalants. It's also still considered the anesthetic of choice in veterinary medicine for pregnant cats (including C-sections) and felines with heart problems. On the other hand, isoflurane can lead to respiratory or cardiovascular depression. Another inhalant drug, halothane, may also lead to cardiopulmonary depression and a risk of malignant hypothermia in some feline breeds/strains.
There's always a potential risk when using any anesthesia. Ask your veterinarian to do a pre-anesthetic blood screening. This precaution will help your veterinarian determine the best anesthetic or combination of anesthetics for your cat. Ask your veterinarian for if your cat requires heart monitoring and/or oxygen assistance for additional safety during a procedure involving anesthesia.