What is Hepatozoonosis?
Hepatozoonosis in canines stems from a singular-celled entity known as a protozoan. The illness manifests in two primary forms: Hepatozoon canis, transmitted by the Brown Dog tick, and Hepatozoon americanum, associated with the Gulf Coast tick.
Infection in dogs can arise when they ingest ticks carrying the pathogen or consume infected wild animals. Canines that frequently hunt or eat animals they find outdoors, or those residing in regions with significant Brown Dog or Gulf Coast ticks populations, are more susceptible. Typically, signs of the disease become evident between 4 to 10 weeks post-tick ingestion.
Regions like Texas, Louisiana, Alabama, Georgia, Mississippi, Oklahoma, Tennessee, and Florida in the south and south-central parts of the US experience a higher prevalence due to the abundance of Gulf Coast and Brown Dog ticks.
If caused by H. Americanum, Hepatozoonosis can lead to severe health decline and might be life-threatening in months without intervention. However, human caregivers need not worry, as the condition doesn't affect them.
Symptoms of Hepatozoonosis in Dogs
Infections from H. canis are often milder. Given that these microorganisms favor the immune system hubs (like lymph nodes and bone marrow) and the organs responsible for blood storage (like the spleen), symptoms commonly manifest as swollen lymph nodes, pallid gums, and fatigue. Some animals with H. canis might exhibit subtle symptoms or none at all.
On the other hand, H. americanum infections can lead to pronounced symptoms if left untreated. These may comprise:
- Elevated temperature
- Diminished weight
- Pain in the muscles or bones
- Muscle atrophy
- Eye discharge
Pet owners might initially observe that their dogs are hesitant to get up, display rigidity in movement, and appear fatigued from fever. Over time, these dogs might exhibit heightened sensitivity to touch (hyperesthesia) and might resort to scratching or even self-harm. If the infection progresses, muscle loss in the dog can become evident.
Causes of Hepatozoonosis in Dogs
Contrary to most illnesses from ticks that spread via bites, hepatozoonosis spreads when a dog ingests an infected tick. Besides, dogs might get infected by consuming the remains of wild animals tainted with these ticks. Newer research indicates that dogs can contract the infection from consuming a wild creature harboring the disease, regardless of whether they ingest the tick.
The silver lining is that this ailment doesn't spread directly between dogs.
Diagnose Of Hepatozoonosis in Dogs
Identifying hepatozoonosis in dogs begins with a detailed account of the pet's daily activities, geographical surroundings, and recent encounters with ticks. To further pinpoint the diagnosis, various procedures might be employed:
- Thorough physical check-up
- Evaluation of the complete blood profile
- Blood chemical profiling
- Examination of urine samples
- PCR diagnostic procedure
- Sampling and examination of muscle tissue
A vet will typically search for signs of anemia in blood samples and heightened levels of neutrophils, a particular white blood cell variety. On rare occasions, the blood sample might directly reveal the presence of the pathogenic protozoan. Through radiographs, bone anomalies are observed. All these diagnostic measures are essential in differentiating hepatozoonosis from other ailments manifesting similar signs, like diskospondylitis, meningitis, canine distemper, polyarthritis, and other tick-induced illnesses in dogs.
After these preliminary assessments, a vet will typically dispatch a sample for a PCR diagnostic procedure, aiming to detect the DNA of the protozoan in the dog's bloodstream. Occasionally, a muscle tissue biopsy is crucial to ascertain the presence of the protozoan, given it's the primary habitat of the organism within the host.
Treatment of Hepatozoonosis in Dogs
While hepatozoonosis doesn't have a definitive cure, treatments available can mitigate symptoms and extend the affected dog's lifespan. Therapeutic measures encompass rehydration, nourishing with a high-caloric diet, and administering non-steroidal anti-inflammatory drugs to counter inflammation and manage pain.
Medications targeting the protozoa are often prescribed, enhancing the duration and quality of the dog's life. Two main therapeutic strategies are prevalent. The first and more widespread approach involves a trio of drugs, commonly denoted as TCP:
- T represents trimethoprim-sulfadiazine (an antibiotic)
- C stands for clindamycin (another antibiotic)
- P is for pyrimethamine (an anti-parasitic agent)
Another treatment avenue involves the use of ponazuril, a solo anti-parasitic agent.
Veterinarians typically advise a prolonged treatment regime using decoquinate (an anti-parasitic that can be blended with meals), given twice daily over two years, to diminish the likelihood of symptom recurrence.
Although this regimen doesn't entirely eradicate the protozoa from a dog's system, it significantly reduces their count, minimizing inflammation and related symptoms. After ceasing decoquinate, a symptom resurgence is probable since remissions usually span only 2-6 months. Without treatment, the dog's physical condition deteriorates, leading to muscle atrophy and potentially resulting in fatality within a few months.
For cases involving H. canis infection, the treatment typically centers around the anti-protozoal drug, imidocarb, administered bi-monthly over several months. Free from other ailments, healthy canines may eventually be rid of the protozoan with diligent care.
Recovery of Hepatozoonosis in Dogs
The trio therapy is typically recommended for 14 days. If the canine exhibits positive reactions to the treatment by the end of this period, there should be enhanced mobility and reduced pain. Dogs have been on decoquinate treatment for extended periods, and it's widely believed that this regimen prolongs life and ensures a better quality of existence. Nonetheless, it's crucial to highlight that hepatozoonosis doesn't have a complete cure, requiring continuous management throughout a dog's life.
Prevention of Hepatozoonosis in Dogs
The most reliable method to ward off Hepatozoonosis is ensuring your dog doesn't consume ticks. Several dependable tick prevention solutions can be recommended by your vet, typically given every 1 to 3 months.
Further preventive measures encompass:
- Implementing tick protection throughout the year, especially in high-risk regions.
- Restricting your dog from preying on wild animals in tick-prone zones.
- Ensuring your home and outdoor spaces remain tick-free might necessitate expert pest control services.