Selamectin-Sarolaner in Dogs & Cats
Generic: Selamectin/Sarolaner
Selamectin/Sarolaner is a potent, broad-spectrum, prescription-only topical parasiticide designed for the simultaneous prevention and treatment of external and internal parasites in dogs.
This medication is intended for dogs and cats.
Overview
Selamectin/Sarolaner is a multi-action antiparasitic product formulated for topical application, combining two distinct chemical classes to provide comprehensive protection against a wide array of pests. This medication combines Selamectin, an avermectin that acts as an endectocide, with Sarolaner, a member of the isoxazoline class known for its rapid and sustained efficacy against arthropods. By merging these two potent molecules into a single monthly dose, veterinarians provide a streamlined approach to managing parasite exposure in canine patients. It is specifically engineered to address the complex lifecycle of various pests that affect a dog's health, ranging from microscopic mites to blood-feeding fleas and ticks.
Clinically, this combination is used to maintain year-round health by disrupting the transmission cycles of parasites that can cause significant distress or illness. While Ivermectin and Milbemycin Oxime have long been staples in heartworm prevention, the addition of the sarolaner component elevates the product's ability to eliminate systemic flea and tick infestations effectively. It serves as an essential tool in preventative medicine, reducing the risk of secondary conditions caused by parasite bites, such as flea allergy dermatitis or tick-borne diseases. Furthermore, it avoids the need for multiple medications, which is a significant advantage over using a standalone product like Spinosad or Afoxolaner when internal parasite control is also required.
The administration of this medication is vital for pets living in environments where parasites are endemic. Unlike Fenbendazole, which is primarily used for intestinal deworming, this topical combination offers a systemic approach to both surface and internal protection. By controlling the population of fleas and ticks at the source, it helps limit the environmental contamination of a pet owner’s home. It remains a standard of care for dogs requiring a robust defense against heartworm disease, common intestinal parasites, and the biting insects that act as vectors for more dangerous pathogens.
What It Treats
- Heartworm Disease: Prevention of Dirofilaria immitis infection by killing larval stages.
- Fleas: Treatment and prevention of Ctenocephalides felis infestations.
- Ticks: Treatment and control of infestations from Dermacentor reticulatus, Ixodes ricinus, and Rhipicephalus sanguineus.
- Sarcoptic Mange: Treatment and management of Sarcoptes scabiei infestations.
- Ear Mites: Treatment and control of Otodectes cynotis infections.
- Intestinal Worms: Treatment and control of roundworm and hookworm infections.
How It Works
The medication functions through a dual-mechanism approach. Selamectin works by binding to glutamate-gated chloride channels in the nerve and muscle cells of susceptible parasites, increasing chloride ion permeability and causing hyperpolarization. This leads to flaccid paralysis and the subsequent death of the parasite. This component is highly effective against juvenile heartworms, certain mites, and internal worms. Sarolaner acts as a non-competitive antagonist at the gamma-aminobutyric acid (GABA) receptors and glutamate receptors of the arthropod nervous system. Because it is highly selective for the nervous systems of insects and acari (mites and ticks) compared to mammals, it causes uncontrolled, excessive neuromuscular activity that rapidly kills the pest. When applied topically, the drugs are absorbed into the bloodstream and distributed to the skin and tissues, providing continuous protection for the duration of the monthly treatment cycle.
Dosage
The dosage is strictly weight-dependent and must be determined by a veterinarian based on the specific body mass of the dog. Users should strictly follow the product labeling provided by the veterinarian and should never split doses between animals or attempt to use cat-specific formulations on dogs. If a dose is missed, it should be applied as soon as possible and the monthly schedule resumed.
Administration
The medication is a topical solution applied directly to the skin of the dog, typically at the base of the neck or between the shoulder blades. The hair should be parted so that the medication is applied directly to the skin rather than the fur to ensure proper absorption. The animal should not be bathed for at least two hours following application to ensure the product has fully dried and been absorbed into the lipid layer of the skin.
Storage
Store in the original packaging at room temperature between 20°C and 25°C (68°F to 77°F). Keep the product out of the reach of children and pets. Do not freeze or expose to excessive heat, as this can compromise the chemical stability of the active ingredients.
Contraindications
This medication should not be used in dogs with a known hypersensitivity to either selamectin or sarolaner. It is not intended for use in sick, debilitated, or underweight dogs without a thorough veterinary examination to ensure their system can tolerate the treatment. Caution is advised when administering to dogs with a history of neurological disorders, such as seizures or epilepsy, as the mechanism of action involves the nervous system of the parasite and can rarely affect the host. Additionally, this product must not be used on cats or other small mammals unless explicitly labeled for that species, as specific dosages and ingredients differ significantly. Because the product is absorbed through the skin, it should not be applied to broken, irritated, or infected skin, as this may lead to systemic absorption levels that differ from those intended for therapeutic use.
Interactions
While generally safe when used as directed, potential interactions exist with other compounds that affect neurotransmission. Caution should be exercised if the dog is concurrently receiving other avermectin-class drugs, as this can increase the risk of neurological side effects. Because this product is a topical, there are fewer systemic interactions compared to oral medications like [Fluralaner](/medications/fluralaner-in-dogs-and-cats), yet owners should still inform their veterinarian of any ongoing treatments, particularly those for epilepsy, sedatives, or other antiparasitics.
Side Effects
- Application site alopecia (hair loss)
- Localized erythema (redness) or pruritus (itching) at the site of application
- Gastrointestinal distress such as vomiting or diarrhea
- Lethargy or decreased appetite
- Neurological signs in rare cases, such as tremors or ataxia, particularly in sensitive individuals
- Hypersensitivity reactions
Sources & References
Frequently Asked Questions
This information is educational only and not a substitute for professional veterinary advice. Always consult a licensed veterinarian before starting or changing any medication.
