What is the injection called for treating subcutaneous ticks in dogs?

Understanding Subcutaneous Tick Infestations in Dogs

What are Subcutaneous Ticks?

Subcutaneous ticks are arthropods that penetrate the dermal layer of a dog and migrate into the subcutaneous tissue, often remaining undetected for days or weeks. Unlike typical ectoparasites that attach to the skin surface, these ticks embed their mouthparts deep enough to avoid routine visual inspection, creating a concealed nidus that can elicit chronic inflammation and secondary bacterial infection.

The life cycle of a subcutaneous tick involves attachment, engorgement, and gradual migration through the connective tissue. During migration, the tick releases anticoagulant and immunomodulatory saliva, which suppresses local immune responses and facilitates prolonged feeding. Clinical signs may include localized swelling, palpable nodules, intermittent fever, lethargy, and anemia resulting from blood loss. Diagnosis relies on physical examination of nodules, ultrasound imaging to locate the embedded organism, and fine‑needle aspiration for microscopic confirmation.

Effective management requires systemic acaricidal therapy capable of reaching deep tissue. The injectable medication commonly employed is a macrocyclic lactone formulation, specifically ivermectin, administered at a dose of 0.2 mg/kg subcutaneously. Ivermectin penetrates vascular and interstitial compartments, paralyzing the tick’s neuromuscular system and leading to rapid death. Follow‑up treatment may include a second dose after 7–10 days to address any surviving larvae and prevent reinfestation. Supportive care—antibiotics for secondary infection, anti‑inflammatory drugs for tissue swelling, and routine tick prevention—completes the therapeutic protocol.

Symptoms of Subcutaneous Tick Infestations

Behavioral Changes

The injectable medication commonly employed to treat subcutaneous tick infestations in dogs is a moxidectin‑based formulation, marketed under names such as ProHeart 12. It is administered subcutaneously and provides systemic protection against several ectoparasites.

Behavioral alterations may appear during the first 24–48 hours after injection. Most changes are mild and transient; however, some dogs exhibit more pronounced responses that warrant observation.

Decreased activity or temporary lethargy
Increased restlessness or pacing
Reduced appetite or selective eating
Irritability, including growling or snapping when handled
Heightened grooming or scratching, possibly indicating mild pruritus
Rarely, disorientation or stumbling, suggesting transient neurologic effects

Most reactions resolve without intervention. Persistent or severe signs—such as continuous aggression, prolonged incoordination, or loss of appetite beyond 48 hours—should prompt immediate veterinary assessment. Monitoring the dog’s behavior during the initial post‑injection period helps differentiate normal drug‑related responses from adverse events requiring treatment.

Skin Manifestations

Subcutaneous tick infestations in dogs frequently present with distinct cutaneous signs. The lesions appear as firm, raised nodules beneath the skin, often grouped in clusters. Overlying hair may be sparse or absent, and the skin may exhibit erythema or mild swelling. Central punctate openings sometimes reveal the tick’s mouthparts, and serous or purulent discharge may develop if secondary infection occurs.

Administration of the injectable antiparasitic commonly used for these infestations can provoke additional skin reactions. Typical post‑injection manifestations include:

Localized erythema at the injection site
Small, transient papules or wheals surrounding the needle entry point
Mild edema that resolves within 24–48 hours
Rare hypersensitivity presenting as pruritic urticaria or systemic dermal eruption

Recognition of both the primary tick‑related lesions and the potential injection‑associated cutaneous effects enables prompt therapeutic adjustments and reduces the risk of complications.

Treatment Approaches for Subcutaneous Ticks

Overview of Injection Therapies

Types of Injectable Medications

The injection employed to treat subcutaneous tick infestations in dogs is a subcutaneous formulation of fluralaner, marketed as Bravecto Injectable. This product delivers systemic acaricidal activity for up to 12 weeks after a single administration.

Injectable antiparasitic agents fall into several pharmacological classes:

Macrocyclic lactones – ivermectin, milbemycin oxime, doramectin. Provide broad‑spectrum efficacy against nematodes and some ectoparasites; dosage and safety vary by breed and weight.
Isoxazolines – fluralaner (injectable), afoxolaner (injectable formulations under development). Target GABA‑gated chloride channels in arthropods, producing rapid tick kill and prolonged protection.
Phenylpyrazoles – fipronil injectable preparations, less common but effective against certain tick species when combined with other agents.
Organophosphates – diazinon injectable, limited use due to toxicity concerns; reserved for severe infestations when other options are unsuitable.

Selection of an injectable medication requires consideration of species‑specific sensitivity, age, weight, and concurrent health conditions. Fluralaner injection distinguishes itself by a single, long‑acting dose that eliminates the need for repeated handling, making it the preferred choice for managing subcutaneous tick burdens in canine patients.

Mechanism of Action

The injectable drug administered to dogs for subcutaneous tick infestations contains a potent ectoparasiticide that targets the nervous system of the arthropod. After intramuscular or subcutaneous delivery, the active molecule circulates systemically, reaching the dermal and subdermal layers where attached ticks reside.

Mechanism of action:

The compound binds to ligand‑gated chloride channels (GABA‑gated and glutamate‑gated) on tick neurons.
Binding blocks the flow of chloride ions, causing continuous neuronal excitation.
Persistent excitation leads to uncontrolled muscle contraction, paralysis, and rapid death of the parasite.
Systemic exposure ensures that feeding ticks are affected even before they detach, preventing further transmission of pathogens.

Pharmacokinetic properties support efficacy: peak plasma concentrations occur within 2–4 hours, and therapeutic levels persist for several days, covering the typical feeding period of embedded ticks. The drug’s selective affinity for invertebrate receptors minimizes toxicity to the canine host while delivering reliable eradication of subcutaneous infestations.

Common Injectable Medications Used

Ivermectin

Ivermectin is an injectable macrocyclic lactone employed to eradicate subcutaneous tick infestations in canines. Commercial preparations include IverVet, Ivomec, and generic veterinary formulations, all administered by subcutaneous injection.

The drug acts on glutamate‑gated chloride channels in arthropods, inducing hyperpolarization, paralysis, and death of ticks embedded beneath the skin. Systemic absorption ensures coverage of both attached and migrating stages.

Typical dosing parameters are:

0.2 mg Ivermectin per kilogram of body weight
Single injection for acute infestations, with repeat dosing at 30‑day intervals for persistent exposure
Administration in the dorsal lumbar region, using a sterile 1‑ml syringe

Safety considerations require exclusion of dogs with the MDR1 gene mutation, notably Collies, Australian Shepherds, and related breeds, due to heightened neurotoxicity risk. Veterinary supervision is essential to verify correct dosage, monitor for adverse reactions, and integrate the injection into a broader ectoparasite control program.

Selamectin

Selamectin is the injectable antiparasitic agent indicated for the control of subcutaneous tick infestations in dogs. Delivered as a spot‑on preparation, it spreads systemically after application to the skin, reaching the subcutaneous layer where it eliminates feeding ticks. The product is marketed under names such as Revolution and Stronghold.

Key characteristics:

Spectrum of activity – effective against Rhipicephalus and Dermacentor species that reside beneath the skin, as well as fleas, heartworm larvae, ear mites, and certain intestinal nematodes.
Mechanism – interferes with neurotransmission in arthropods by binding to glutamate‑gated chloride channels, causing paralysis and death of the parasite.
Dosage – administered once monthly at a weight‑based dose of 6 mg/kg; each application treats the entire animal for 30 days.
Administration – applied directly to the dorsal cervical region; the solution spreads across the skin and is absorbed into the bloodstream, reaching subcutaneous tissues without the need for an intramuscular injection.
Safety profile – well tolerated in dogs over 8 weeks of age and weighing at least 2 lb; adverse events are rare and typically limited to mild skin irritation at the application site.
Regulatory status – approved by the FDA and EMA for canine use, with labeling specifying tick species covered and contraindications for pregnant or lactating females.

Selamectin therefore represents the recommended injectable solution for managing subcutaneous tick burdens in canine patients, providing broad parasite coverage with a convenient monthly dosing schedule.

Moxidectin

Moxidectin is the injectable antiparasitic formulated for the control of subcutaneous tick infestations in dogs. It belongs to the macrocyclic lactone class and exerts its effect by binding to glutamate‑gated chloride channels in arthropod nerve and muscle cells, causing paralysis and death of the parasite.

Typical administration involves a single subcutaneous injection of the veterinary‑approved concentration (e.g., 0.1 mg/kg). The dose provides systemic protection for up to 30 days, covering the life cycle of common tick species such as Rhipicephalus sanguineus and Dermacentor variabilis.

Key characteristics:

Pharmacokinetics: Rapid absorption, peak plasma levels within 4–6 hours, prolonged elimination half‑life supporting monthly dosing.
Spectrum of activity: Effective against adult ticks, larvae, and nymph stages; also active against heartworm larvae and certain gastrointestinal nematodes.
Safety profile: Well‑tolerated in healthy adult dogs; contraindicated in collie‑type breeds due to MDR1 gene sensitivity.
Regulatory status: Licensed for canine use in the United States, European Union, and several other regions; available under brand names such as Merial® and ProHeart® 6.

Veterinarians select moxidectin when a systemic, long‑acting solution is required to eliminate ticks residing beneath the skin, ensuring rapid parasite clearance and reducing the risk of tick‑borne disease transmission.

Administration of Injections

Veterinarian's Role

The injection used to treat subcutaneous tick infestations in dogs is a macrocyclic lactone formulation, most commonly ivermectin administered subcutaneously. This medication targets the nervous system of ticks, leading to rapid paralysis and death.

Veterinarians perform several critical tasks in this therapeutic process:

Confirm the presence of ticks through physical examination and, when necessary, laboratory identification.
Determine the appropriate drug, dosage, and administration route based on the dog’s weight, age, health status, and potential drug interactions.
Deliver the injection using aseptic technique, observe the animal for immediate adverse reactions, and document the procedure in the medical record.
Advise owners on post‑treatment monitoring, including signs of neurological side effects such as ataxia, tremors, or hypersensitivity.
Provide a comprehensive prevention plan, recommending regular tick control products, environmental management, and scheduled health checks.

By integrating accurate diagnosis, precise drug delivery, and thorough client education, veterinarians ensure effective elimination of ticks while minimizing risk to the animal.

Dosage and Frequency

The subcutaneous tick‑treatment injection most frequently prescribed for dogs is a long‑acting formulation of a macrocyclic lactone, marketed under names such as Bravecto® injectable or a similar afoxolaner‑based product.

Standard dosing is calculated on body weight. For dogs weighing 5–10 kg, the recommended volume is 0.5 mL; for 10–20 kg, 1.0 mL; for 20–30 kg, 1.5 mL; and for animals over 30 kg, 2.0 mL. Each milliliter delivers a concentration of 10 mg/mL of the active ingredient, providing a total dose of 5 mg/kg.

The injection is administered as a single subcutaneous dose. Protective efficacy against subcutaneous tick infestations persists for up to 12 weeks; therefore, re‑administration is advised at 90‑day intervals to maintain continuous coverage.

Key points:

Dose: 5 mg/kg, expressed in volume according to weight categories above.
Frequency: one injection every 12 weeks (approximately three months).
Route: subcutaneous injection, preferably in the scruff of the neck.
Monitoring: observe the injection site for swelling or irritation; report adverse reactions promptly.

Potential Side Effects and Precautions

Allergic Reactions

Allergic reactions are a primary safety concern when administering the injectable agent designed to eliminate subcutaneous tick infestations in dogs. Immediate hypersensitivity manifests within minutes to hours, presenting as facial swelling, urticaria, vomiting, or collapse. Delayed responses appear 24–72 hours post‑injection, characterized by pruritic dermatitis, erythema, and lameness. Diagnosis relies on clinical observation and, when necessary, serum tryptase measurement to confirm mast cell activation.

Pre‑treatment assessment should include a thorough history of prior drug sensitivities, concurrent medications, and underlying immune disorders. Premedication with antihistamines or corticosteroids reduces the incidence of acute reactions in high‑risk patients. During administration, the injection must be given subcutaneously in a calm environment, with the animal monitored for at least 30 minutes for signs of anaphylaxis.

If anaphylaxis occurs, immediate intervention follows established protocols: intramuscular epinephrine (0.01 mg/kg), intravenous antihistamines, and supportive oxygen therapy. Secondary care may involve fluid resuscitation and monitoring of cardiovascular status. For delayed hypersensitivity, symptomatic relief includes oral antihistamines, corticosteroid courses, and topical soothing agents. Persistent or severe dermatologic lesions warrant dermatology referral and possible allergy testing to identify specific antigenic components of the medication.

Documentation of any adverse event is essential for future treatment planning. Alternative tick control strategies—such as oral acaricides, topical formulations, or environmental management—should be considered for dogs with confirmed drug hypersensitivity. Regular follow‑up examinations ensure resolution of allergic manifestations and verify the effectiveness of tick eradication.

Breed Sensitivities

The medication administered to eliminate subcutaneous ticks in dogs is an injectable acaricide, most commonly ivermectin. Genetic variations affect how this drug is processed, making some breeds highly susceptible to adverse reactions.

Breeds with documented sensitivity include:

Collies
Shetland Sheepdogs
Australian Shepherds
Old English Sheepdogs
Border Collies
German Shepherds (occasionally)
Mixed breeds carrying the MDR1 mutation

In these dogs, standard doses can cause neurotoxicity, manifested as tremors, ataxia, or seizures. Veterinary protocols require a reduced dosage or the selection of an alternative injectable such as moxidectin, which exhibits a safer profile for MDR1‑deficient animals.

Before treatment, a veterinarian should:

Verify the dog’s breed or mixed‑breed heritage.
Perform a genetic test for the MDR1 mutation when breed risk is high.
Adjust the injection volume according to the test results.
Monitor the animal for signs of toxicity for at least two hours post‑administration.

For breeds lacking the MDR1 mutation, the conventional ivermectin dosage remains effective and well tolerated. Nonetheless, all dogs should receive a full clinical assessment to rule out concurrent conditions that could amplify drug sensitivity.

Overdose Risks

The injectable acaricide employed to eliminate subcutaneous ticks in dogs carries a narrow therapeutic margin; exceeding the recommended dose can provoke severe systemic toxicity. Acute overdose typically manifests within minutes to hours as tremors, ataxia, and heightened reflexes, reflecting central nervous system excitation. Gastrointestinal irritation appears as vomiting, diarrhoea, and abdominal pain, while cardiovascular compromise may include tachycardia, hypotension, and arrhythmias. Renal and hepatic dysfunction may develop secondary to metabolic overload, evident through reduced urine output, jaundice, and elevated serum enzymes.

Veterinary intervention for suspected overdose should include:

Immediate cessation of the offending product.
Administration of activated charcoal to limit further absorption.
Intravenous fluid therapy to maintain perfusion and support renal clearance.
Anticonvulsant medication (e.g., diazepam) for seizure control.
Cardiac monitoring and, if necessary, anti‑arrhythmic agents.
Laboratory evaluation of liver and kidney parameters to guide supportive care.

Preventive measures focus on strict adherence to the label‑specified dosage, calculated on the basis of exact body weight, and verification of the formulation prior to injection. Re‑evaluation of dosing protocols is warranted for breeds with known sensitivities or for animals receiving concurrent medications that may potentiate neurotoxic effects. Prompt recognition and treatment of overdose significantly improve prognosis and reduce the risk of permanent organ damage.

Prevention and Long-Term Management

Integrated Tick Control Strategies

Topical Treatments

Subcutaneous tick infestations require systemic intervention, typically delivered by an injectable formulation known as moxidectin (commercially ProHeart 6). While injection provides long‑lasting protection, topical acaricides remain a viable option for immediate control and for owners who prefer non‑injectable methods.

Topical products act on the skin surface and are absorbed through the dermis to reach embedded ticks. They are formulated as spot‑on liquids, sprays, or shampoos and contain ingredients that disrupt tick nervous systems or inhibit development. Commonly used agents include:

Fipronil – spot‑on solution, 4‑week efficacy against attached and migrating ticks.
Permethrin – spray or dip, rapid knock‑down of ticks, 2‑week protection.
Selamectin – spot‑on formulation, 4‑week activity, effective against several tick species.
Imidacloprid + Moxidectin – combination spot‑on, 4‑week protection, synergistic action.

Application follows a precise protocol: the measured dose is applied directly to the dorsal neck region, ensuring contact with the skin while avoiding the face and eyes. Dogs should be restrained briefly to prevent licking until the product dries. Repeat treatment intervals align with the product’s labeled duration, typically every 28 days.

Safety considerations include verifying the dog’s weight to calculate the correct dose, checking for hypersensitivity to active ingredients, and avoiding use on puppies below the minimum age specified by the manufacturer. Topical treatments do not replace injectable moxidectin when a veterinarian recommends systemic protection for high‑risk environments, but they serve as an effective adjunct or alternative for owners seeking a non‑injectable approach.

Oral Medications

Oral tick control agents for dogs provide systemic protection that eliminates parasites after they attach and begin feeding beneath the skin. These products are administered as chewable tablets or capsules, ensuring convenient dosing and rapid absorption.

Afoxolaner (brand NexGard) – a member of the isoxazoline class; single dose every 30 days; kills adult ticks and prevents attachment within 48 hours.
Fluralaner (brand Bravecto) – long‑acting isoxazoline; single dose every 12 weeks; effective against a broad spectrum of tick species, including those that embed subcutaneously.
Sarolaner (brand Simparica) – isoxazoline; monthly administration; rapid onset of action, eliminating feeding ticks within hours.
Lotilaner (brand Credelio) – isoxazoline; monthly dosing; high efficacy against Ixodes, Dermacentor, and Rhipicephalus species.

All oral formulations achieve therapeutic plasma concentrations that reach the dermal and subdermal tissues where ticks reside. Dosage is calculated on body weight and must be administered with food to enhance absorption. Contraindications include known hypersensitivity to isoxazolines and severe hepatic or renal impairment. Monitoring for neurological signs, such as tremors or ataxia, is recommended in breeds with known drug sensitivities.

When an injectable solution is required for subcutaneous tick infestations, veterinarians often select a parenteral formulation of moxidectin or ivermectin, which delivers a rapid systemic concentration. Oral agents remain the preferred choice for routine prophylaxis due to ease of administration, owner compliance, and the ability to target multiple ectoparasites concurrently.

Environmental Control

Environmental control reduces the risk of subcutaneous tick infestations that often require an injectable therapy in dogs. Effective measures focus on eliminating tick habitats, limiting host exposure, and interrupting the life cycle before ticks penetrate the skin.

Maintain short grass and clear leaf litter in yards and walking areas.
Remove brush, tall weeds, and debris where ticks hide.
Apply EPA‑registered acaricides to perimeters, following label directions for dosage and re‑application intervals.
Use tick‑inhibiting granules or sprays on kennels, shelters, and outdoor furniture.
Introduce natural predators, such as certain nematodes, to reduce larval populations.
Conduct monthly inspections of high‑risk zones and treat identified hotspots promptly.

Integrating habitat management with the prescribed injectable treatment maximizes efficacy, shortens recovery time, and lowers the probability of reinfestation. Regular veterinary follow‑up confirms that environmental interventions complement pharmacologic control, ensuring sustained protection for the animal.

Regular Veterinary Check-ups

Regular veterinary examinations provide the opportunity to assess a dog’s overall health and to identify parasitic threats before they become severe. During these visits, clinicians evaluate skin condition, perform blood work, and verify that preventive measures—including injectable treatments for subcutaneous tick infestations—are current.

The injectable medication used to address subcutaneous ticks is a moxidectin‑based formulation, commercially known as ProHeart. Administration occurs subcutaneously and offers extended protection against tick larvae that embed beneath the skin.

Key advantages of routine check‑ups:

Early detection of tick‑related lesions and secondary infections.
Timely administration of the moxidectin injection, maintaining therapeutic levels.
Comprehensive health screening (vaccinations, organ function, parasite load).
Personalized preventive plan based on breed, age, and environment.

Consistent veterinary visits ensure that the injectable tick treatment is delivered according to schedule, reducing the risk of chronic infestation and associated complications.

Monitoring for Reinfestation

Monitoring for reinfestation is a critical component of any protocol that employs an injectable acaricide for subcutaneous tick treatment in dogs. After administration, the dog should be examined regularly to detect any new attachment before the medication’s protective window expires. Early detection prevents secondary disease transmission and reduces the need for additional drug doses.

Veterinarians typically recommend the following schedule:

Initial examination 24‑48 hours post‑injection to confirm tick removal.
Follow‑up checks at 7‑day intervals for the first month.
Monthly inspections thereafter until the next scheduled injection.

During each inspection, owners should:

Perform a systematic skin sweep, focusing on common attachment sites such as ears, neck, and interdigital spaces.
Record the number, species, and location of any ticks found.
Report findings to the veterinary clinic promptly, especially if multiple ticks are observed or if the dog shows signs of irritation.

Consistent documentation enables the practitioner to assess the efficacy of the injectable product, adjust the treatment interval if necessary, and implement targeted environmental control measures to lower the risk of re‑exposure.