Onsior Cat: Uses, Dosing Basics, and Safety

Onsior Cat is a veterinary prescription pain and inflammation medicine containing robenacoxib, a nonsteroidal anti-inflammatory drug (NSAID). This page explains how Onsior 6 mg tablets for cats are typically used, along with dosing basics, safety concerns, and practical handling information. It is written to support informed discussions with a veterinarian and to help with day-to-day medication organization.

What Onsior for Cats Is and How It Works

Onsior contains robenacoxib, an NSAID used in cats to help reduce pain and inflammation. It works by inhibiting cyclooxygenase enzymes involved in prostaglandin production (prostaglandins are chemical messengers that contribute to pain, swelling, and fever). Robenacoxib is often described as more COX-2 selective than some older NSAIDs, which may influence how it is used in veterinary practice, but safety still depends on the individual cat’s health status and other medications. CanadianInsulin functions as a prescription referral service and may confirm prescription details with the prescriber.

Some patients explore Ships from Canada to US as an option when regulations allow and a valid prescription is available. For context on how this site explains medication mechanisms in general, see Mechanism Of Action Explained and Common Diabetes Medications. Those examples are not veterinary dosing guides, but they show the same label-first approach used here.

Who It’s For

Veterinarians may prescribe robenacoxib for short-term management of pain and inflammation in cats, including certain musculoskeletal conditions and perioperative pain control, depending on the approved labeling in the jurisdiction. Cats with chronic mobility issues are sometimes evaluated for osteoarthritis and other joint disorders, and pain control may be one part of a broader plan that can also include weight management and environmental changes.

Onsior 6 mg tablets for cats are not appropriate for every cat. NSAIDs are typically avoided or used with extra caution in cats with a history of gastrointestinal ulceration or bleeding, significant kidney disease, significant liver disease, dehydration, or known NSAID hypersensitivity. Use in very young kittens, pregnant cats, or nursing cats may be restricted by the product label. For condition-specific background and browsing, you can review the hubs for Feline Musculoskeletal Pain and Feline Osteoarthritis.

Dosage and Usage

Onsior tablets are given by mouth and are generally used as a once-daily treatment for a short course, following the veterinary label and the prescriber’s directions. Many cats receive NSAIDs for only a few days, such as around a procedure or during an acute flare of pain, because prolonged use can increase the chance of adverse effects. The prescriber may consider the cat’s body weight, age, hydration status, kidney and liver function, and concurrent medications when choosing a regimen.

Quick tip: Keep a simple log of date, time, and dose given to reduce double-dosing risk.

Tablet administration details vary by label and by clinical situation. Follow the veterinary instructions for whether the dose should be given with food and whether tablets may be split; do not change the form of the tablet unless the prescriber advises it. If a dose is missed or vomited, a veterinarian can advise on the safest next step based on timing and symptoms. For a general example of how this site summarizes “label basics” for dosing schedules (not for cats), see Semaglutide Dosage Chart.

Strengths and Forms

In many markets, Onsior for cats is supplied as an oral tablet with a 6 mg strength. Packaging and tablet appearance can vary by country and distributor, and availability may change over time. Some regions also have a robenacoxib injectable formulation intended for veterinary use, which is typically administered by a clinic for specific surgical or hospital indications.

Onsior 6 mg tablets for cats are commonly described as a fixed-strength tablet designed to make short-course dosing simpler for many cats. Because the tablet strength is fixed, veterinarians may rely on weight-based label guidance to decide whether this product is suitable for a given cat. If you are comparing veterinary products on the site, the Pet Medications hub is a browseable list of options and forms.

Storage and Travel Basics

Store tablets at controlled room temperature unless the package labeling states otherwise. Keep the medicine in its original blister or container to help protect it from moisture and to preserve the lot number and expiration date. Do not use tablets that look swollen, discolored, or crumbly, and keep all pet medications out of reach of children and animals that were not prescribed the drug.

When traveling, bring enough doses for the planned schedule plus a small buffer, and keep the prescription label available in case a clinic needs to verify the medication. Avoid leaving medicines in hot cars, direct sun, or damp environments such as bathrooms. If you manage medications for multiple family members, using separate labeled bags for each patient can reduce mix-ups. For a general travel-planning framework (not veterinary-specific), see Travel With Zepbound.

Side Effects and Safety

Like other NSAIDs, robenacoxib can cause gastrointestinal side effects. Some cats may vomit, have diarrhea, show reduced appetite, or seem quieter than usual during treatment. Mild stomach upset may improve after the course ends, but ongoing symptoms should be reported to a veterinarian because dehydration can worsen risk in cats receiving NSAIDs.

More serious reactions are less common but require urgent evaluation. Warning signs can include black or tarry stool, blood in vomit or stool, severe lethargy, collapse, yellowing of the gums or eyes, marked increase or decrease in drinking or urination, or facial swelling and hives. Onsior 6 mg tablets for cats should be stopped only under veterinary direction if serious signs occur, because the clinician may need to assess hydration and organ function promptly.

Why it matters: Cats can decompensate quickly with dehydration or reduced kidney perfusion.

Risk is influenced by the cat’s baseline kidney and liver function, concurrent illness, and other drugs. Some cats—especially older cats—may have screening blood work before NSAID use or periodic monitoring during repeat courses. If you want a general example of how long-running side effects are discussed in other medication categories on the site, see Long Term Side Effects.

Drug Interactions and Cautions

Drug interactions are an important reason to provide a complete medication list to the veterinarian. NSAIDs are commonly avoided in combination with other NSAIDs or corticosteroids (steroids) due to increased gastrointestinal ulceration risk. Caution can also be warranted with certain diuretics, ACE inhibitors, and other agents that may affect kidney blood flow, especially if the cat is ill, dehydrated, or has underlying kidney disease.

Onsior 6 mg tablets for cats may also require added caution if a cat is receiving anticoagulant or antiplatelet medications, has a bleeding disorder, or has a history of gastrointestinal disease. Because cats can hide pain and illness, changes in appetite, stool quality, energy, and water intake are practical at-home signals to track and report. Before anesthesia or dental procedures, clinics often review recent NSAID exposure to reduce overlapping risks during perioperative care.

Compare With Alternatives

Veterinarians have several options for feline pain management, and the best choice depends on diagnosis, duration, and comorbidities. Other NSAIDs may be used in cats in certain jurisdictions, but labeling differences matter, and some products are not appropriate for feline patients. In addition, a clinician may choose non-NSAID medications when kidney disease, dehydration risk, or gastrointestinal vulnerability makes NSAID use less suitable.

For osteoarthritis-related pain, some cats may be considered for non-NSAID approaches, including monoclonal antibody therapy (a targeted immune protein treatment) in markets where it is available, or multimodal plans that combine environmental changes with carefully selected medications. Opioid analgesics may be used for acute pain under veterinary supervision, particularly after surgery, while adjuvant agents like gabapentin may be considered for specific pain patterns. A veterinarian can explain expected benefits, monitoring needs, and what to do if pain control seems inadequate.

Non-drug supports can also matter. Litter box access, ramps, soft bedding, and reducing jump height can lower daily discomfort. For broader navigation across related items and educational context, the Feline Osteoarthritis hub can help you compare categories of options that may be discussed in clinic.

Pricing and Access

Onsior is generally a prescription product for cats, and access starts with a veterinarian’s assessment and written directions. Coverage varies by plan if a pet insurance policy is involved, and some households evaluate cash-pay approaches when coverage is limited. CanadianInsulin does not dispense medications directly; where permitted, dispensing is handled by licensed third-party pharmacies.

Several practical factors can affect how a prescription is processed, including the prescribed course length, local regulatory requirements, and whether the prescription needs clarification (for example, strength, quantity, or directions). If you are coordinating care between clinics, keeping a consistent medication list can prevent duplication of NSAIDs or unintended overlaps with steroids. When a household is managing Onsior 6 mg tablets for cats without insurance, asking the clinic about the shortest effective labeled course and appropriate monitoring can be a reasonable part of the conversation.

Documentation requirements may differ by jurisdiction, especially when cross-border fulfilment is considered. Cross-border fulfilment may be considered depending on documentation, eligibility, and jurisdiction. For non-time-limited site information that may relate to available programs, see Program Details.

Authoritative Sources

FDA reference database for approved animal drugs: Animal Drugs @ FDA.

Clinical background on NSAIDs and precautions in veterinary medicine: Merck Veterinary Manual NSAIDs Overview.

When medication transport is needed, systems may use prompt, express, cold-chain shipping for temperature control.

This content is for informational purposes only and is not a substitute for professional medical advice.