A number of parasites can affect dogs, but some are specifically adapted to inhabit the sensitive tissues of the respiratory system. Among these, certain mites target the nasal passages, where their presence can cause irritation and varied clinical signs. This type of infestation is a common, contagious condition that affects dogs worldwide. Understanding these specific mites and the symptoms they cause is important for owners seeking to maintain their pet’s health.
Understanding Canine Nasal Mites
Canine nasal mites are parasites of the species Pneumonyssoides caninum, which is an arachnid. These organisms reside on the mucosal lining of the nasal cavities and sinuses. They are non-burrowing and feed on shedding skin cells lining the nasal passages.
Adult mites measure 0.6 to 1.5 millimeters in length and are typically light yellow or tan. They possess long legs and an oval-shaped body. Despite their size, they are sometimes visible to the unaided eye as tiny specks near the nostril area.
Transmission occurs primarily through direct nose-to-nose contact between dogs. Indirect transmission is also possible, as the mites are highly mobile and can survive off a host for several weeks. This risk increases in environments with dense canine populations like kennels or boarding facilities.
All known life stages, including egg, larva, nymph, and adult, occur within the host’s nasal passages or sinuses. The presence of these mites causes inflammatory lesions in the olfactory mucosa, the tissue responsible for the sense of smell. While all breeds and ages are susceptible, large breeds and dogs over three years old may be diagnosed more frequently.
Recognizing Signs of Infestation
The irritation caused by the mites leads to a range of observable clinical signs in affected dogs. The most common manifestation is sneezing, as the dog attempts to forcefully expel the organisms. This is often accompanied by reverse sneezing, a condition called paroxysmal respiration, where the dog rapidly pulls air inward through the nose, making a loud snorting or honking sound.
Mites can also trigger a nasal discharge, which may be clear or contain mucus. The irritation sometimes leads to nosebleeds, known as epistaxis. Other signs include restlessness, labored breathing, and persistent shaking or pawing at the head due to discomfort in the nasal area.
The inflammatory reaction in the olfactory mucosa can impair a dog’s ability to pick up scents. This reduced sense of smell is noticeable, particularly in working or hunting dogs. While these symptoms suggest infestation, many dogs may be asymptomatic carriers showing no signs.
Veterinary Diagnosis and Treatment
Diagnosis often begins with the veterinarian observing clinical signs, as symptoms can mimic those of other upper respiratory conditions. Definitive diagnosis requires visualizing the mites directly within the nasal cavity or identifying them in collected samples.
The most effective method for direct visualization is rhinoscopy, which involves examining the nasal passages with a flexible endoscope while the dog is under general anesthesia. Another diagnostic technique is nasal flushing, where a sterile solution is used to flush the nasal passages. The resulting fluid is collected and examined under a microscope for the presence of mites.
In some cases, a veterinarian may choose an empirical treatment trial. This involves administering antiparasitic medication based solely on clinical signs, with the expectation that symptoms will resolve if mites are the cause.
Although no drugs are specifically approved for canine nasal mites, several antiparasitic medications have been reported as effective. These medications belong to the class of macrocyclic lactones, including drugs like milbemycin oxime, ivermectin, and selamectin. Treatment typically involves multiple doses over several weeks to ensure all life stages of the mite are eliminated. The prognosis is generally excellent, with symptoms resolving after treatment.