In a previous post, we looked at Equine Rhinitis Virus A or ERV Type A in horses. We also mentioned Type B in passing. In this post we explain the differences between ERV Type A and B.
But first a recap…
What Is Equine Rhinitis Virus?
Equine Rhinitis Virus (ERV) is a contagious viral infection that affects horses, primarily targeting the respiratory system. The virus belongs to the family Picornaviridae and comes in two distinct strains, Type A and Type B.
ERV in general is known to cause a range of respiratory symptoms in affected horses, including nasal discharge, fever, coughing, and nasal congestion. While the severity of symptoms varies depending on the strain and individual horse’s immune response, ERV can lead to discomfort and temporary impairment of respiratory function.
For this reason, a timely diagnosis and appropriate treatment management regimes are essential for mitigating the impact of ERV on the individual horse and preventing its spread within horse populations.
With that in mind, what are the differences between Equine Rhinitis Virus A vs. B, and what sets them apart?
What Sets ERV Type A And B Apart?
Type A ERV
This is by far the more severe of the 2, and can have a very significant impact on equine health.
Horses infected with Type A ERV often display pronounced symptoms, including significant nasal discharge, fever, and respiratory distress. This strain can also lead to swollen lymph nodes, severe nasal congestion, and occasional lower leg swelling. In essence, Type A ERV is a serious illness, and requires veterinary care and attention.
Type B ERV
Type B ERV is less severe. While horses infected with Type B may still experience many of the same symptoms such as:
- nasal discharge,
- fever, and
- respiratory discomfort,
They tend to be less severe than Type A, and consequently easier to treat and manage.
What Are The Symptoms of Equine Rhinitis Virus B?
Similar to Type A, Type B rhinitis virus can cause a range of symptoms in affected horses. As mentioned however, they are typically less severe if the horse has Type B.
Nasal Discharge
One of the hallmark indicators of rhinitis, nasal discharge in horses with either type of ERV varies in consistency and colour.
Fever
Horses with both types of ERV present with an elevated body temperature, symptomatic of the body’s inflammatory response to the virus.
Respiratory Distress
Horses with either type may exhibit nasal congestion, audible breathing sounds, increased respiratory rate, and visible discomfort during respiration.
Ocular Symptoms
Some cases may present concurrent eye discharge, suggesting upper respiratory tract involvement.
Sneezing and Coughing
Irritation of the respiratory tract often triggers bouts of sneezing and dry coughing.
Reduced Appetite and Performance
Nasal congestion and respiratory discomfort can lead to decreased appetite, energy levels, and performance.
Swelling and Redness
Severe cases i.e. Type A ERV, may present with swollen and red nasal mucous membranes, indicating significant inflammation.
What Are The Causes of Equine Rhinitis Virus B?
Viral Infection:
Equine rhinitis virus B, along with its A counterpart, are both caused by common viral pathogens that affect horse populations.
Environmental Factors
Poor stable hygiene, inadequate ventilation, and exposure to infected horses can encourage the spread of the virus.
Allergens
Sensitivity to dust, pollen, and other allergens may trigger allergic rhinitis in susceptible horses.
Inhalation of Foreign Bodies
Particles such as grass seeds or dust can irritate the nasal passages, leading to inflammation.
Secondary Infections
Prolonged nasal discharge can predispose horses to secondary bacterial or fungal infections.
Managing Equine Rhinitis Virus B
Effective management strategies are essential for mitigating the impact of type B rhinitis virus:
Symptomatic Relief
Non-steroidal anti-inflammatory drugs (NSAIDs) and nasal decongestants can alleviate inflammation and respiratory discomfort.
Antiviral and Antibiotic Therapy
Targeted antiviral and antibiotic treatments may be necessary to combat viral and bacterial infections, respectively.
Environmental Control
Improving stable ventilation, minimizing dust exposure, and implementing proper hygiene protocols reduce the risk of viral spread.
Supportive Care
Steam inhalation therapy and humidification help soothe nasal irritation and promote healing.
Preventive Measures
Vaccination against common respiratory pathogens and vigilant monitoring of horses for early signs of infection are both important and effective preventive measures.
Spotting the Differences Between ERV Type A And B
Equine Rhinitis Virus (ERV) Type A and Type B present with subtle differences in their clinical presentation, severity of symptoms, and potential complications. However, it’s always best to talk to your vet for an accurate diagnosis.
Symptom Severity
Type A: Symptoms of ERV Type A tend to be more severe, with pronounced nasal discharge, fever, respiratory distress, and potential swelling and redness of nasal mucous membranes.
Type B: In contrast, ERV Type B symptoms are typically less severe, presenting with milder nasal discharge, fever, and respiratory discomfort compared to Type A.
Nasal Discharge
Type A and B: Both types of ERV can cause nasal discharge, but the consistency and color may vary. Type A may exhibit more profuse and varied discharge compared to Type B.
Respiratory Distress
Type A and B: Both types may lead to respiratory distress, including nasal congestion, audible breathing sounds, increased respiratory rate, and discomfort during respiration. However, these symptoms are usually less severe in Type B cases.
Ocular Symptoms
Type A and B: Concurrent eye discharge may occur with both types and is often similar in terms of presentation.
Appetite and Performance
Type A and B: Reduced appetite, energy levels, and performance can occur with both types, but may be less pronounced in Type B cases.
Swelling and Redness
Type A: Severe cases of Type A ERV may present with swollen and red nasal mucous membranes, reflecting significant inflammation.
Type B: This symptom is less commonly observed with Type B ERV.
Why Knowing Which Is Which Matters
Understanding the differences between Type A and Type B ERV enables accurate diagnosis and targeted treatment. As it is less severe, Type B ERV cases do not typically require the same type of aggressive treatment Type A ERV cases do.
Severity of Symptoms
Type A typically presents with more severe symptoms, requiring more aggressive treatment strategies compared to Type B, which may necessitate milder interventions.
Medication Selection
Different types of ERV may respond differently to specific medications. For example, Type A cases with severe inflammation may require stronger anti-inflammatory drugs compared to Type B cases with milder symptoms. Similarly, targeted antiviral and antibiotic therapies may be indicated based on the specific viral strain and secondary infections present.
Supportive Care Needs
Supportive care measures, such as steam inhalation therapy and humidification may vary depending on the severity and nature of respiratory distress. Accurate diagnosis around the type of ERV present ensures appropriate supportive care measures are implemented to address the specific needs of the affected horse.
Preventive Measures
Understanding the specific type of ERV involved allows for targeted preventive measures, such as vaccination against common respiratory pathogens.
Vaccination protocols may also differ based on the prevalence and severity of each ERV type within a particular geographic region or equine population.
Environmental Management
Environmental control measures, such as improving stable ventilation and minimising dust exposure, may be tailored to deal with the predominant ERV type circulating in a given area. Accurate diagnosis means accurately targeted interventions can be carried out to minimise viral spread and prevent future outbreaks.
Final Thoughts About Understanding Equine Rhinitis Virus A vs B
Equine Rhinitis Virus A vs B may share a viral family tree and many symptoms, but they are distinct branches with unique characteristics. However, although Type B is typically less severe than Type A, veterinary assistance should be sought as a matter of course for an accurate diagnosis.
