Clopidogrel is a prescription antiplatelet medication used in veterinary medicine to prevent blood clots in cats. Known by the brand name Plavix, this drug works by affecting platelets, which are the blood cells responsible for clotting. Its use is a preventative measure prescribed by veterinarians for cats identified to be at risk for specific clot-related conditions.
Why Cats Are Prescribed Clopidogrel
The primary reason a veterinarian prescribes clopidogrel is to prevent a condition called arterial thromboembolism, or ATE. This event occurs when a blood clot, also known as a thrombus, travels through the arteries and becomes lodged, blocking blood flow. For many cats, this risk is directly linked to underlying heart disease, most commonly hypertrophic cardiomyopathy (HCM). HCM causes the muscular walls of the heart to thicken, which can disrupt normal blood flow and create an environment where clots are more likely to form.
A common manifestation of ATE is the “saddle thrombus,” where a clot lodges at the point where the aorta splits to supply blood to the rear legs. This blockage cuts off circulation, leading to sudden paralysis, pain, and coldness in the hind limbs. Clopidogrel is administered to cats with conditions like HCM to reduce the chances of such a clot forming in the first place.
Administration and Dosage
Clopidogrel is an oral medication, administered as a tablet once daily. The exact dosage, such as the standard 18.75 mg per cat, is determined by the veterinarian based on the individual animal’s condition and health status. Administering the pill can be a challenge for cat owners because the drug is bitter, which can cause cats to drool excessively or refuse the medication altogether.
Veterinarians often recommend specific strategies for administration. One method is to hide the tablet inside an empty gelatin capsule, which masks the taste. Another option is using specially formulated pill pockets or other palatable treats designed to conceal medications. For cats that consistently resist pilling, a veterinarian may suggest a compounding pharmacy, which can prepare the medication in a more tolerable form, such as a flavored liquid or a smaller, coated chewable tablet.
Potential Side Effects and Monitoring
While clopidogrel is well-tolerated by most cats, owners should monitor for potential side effects. The primary risk is bleeding, as the medication is designed to inhibit clotting. Owners should watch for signs such as:
- Nosebleeds
- Blood in the urine or stool
- Unusual bruising
- Any minor cut that continues to bleed for a prolonged period
The appearance of digested blood in the stool, which can look like coffee grounds, requires immediate veterinary attention.
Other side effects can include gastrointestinal upset. Some cats may experience vomiting, diarrhea, or a loss of appetite after starting the medication. Giving the tablet with a small amount of food may help reduce this discomfort. Anemia has also been noted as a potential issue for cats on long-term therapy. If any of these side effects are observed, owners should stop giving the medication and contact their veterinarian for guidance.
Drug Interactions and Precautions
Owners must provide their veterinarian with a complete list of all other medications, supplements, and vitamins their cat is taking before starting clopidogrel. Combining clopidogrel with other medications that affect bleeding, such as nonsteroidal anti-inflammatory drugs (NSAIDs), can heighten the risk of bleeding complications. Similar risks exist when used with other anticoagulants like warfarin or heparin.
If a cat requires any planned surgical or dental procedure, the owner must inform the veterinarian that the animal is on clopidogrel. The medication may need to be stopped for a period before the procedure to reduce the risk of excessive bleeding. Use of the drug may also require care in animals that have existing liver or kidney disease.