Respi

Question 1

What is the best staining method for identification of mast cells in BALF ?

Answer 1

Recommendation for BAL cytology staining would be to use both the MGG and the Toluidine Blue staining method, relying on the Toluidine Blue for the enumeration of mast cells.

TB stain appears to be the most reliable staining method but is only able to identify mast cells, and thus must be supplemented by another staining method in order to fulfil a full differential cell count.
inclusion of both the MGG and the TB staining methods in the evaluation of BAL cytology

Reliability of cytological evaluation of mast cells from bronchoalveolar lavage uid in horses: Intraobserver agreement and mast cell identi cation
eve 2020

Question 2

Is oiled mixed hay feeding system effective in controlling the airway obstruction in SEA horses ?

Answer 2

Nutri-Foin Système, which incorporates soybean oil to mechanically processed hay, is an appropriate alternative to pelleted hay for the control of the airway obstruction in horses with SEA.

Pelleted hay and the hay treated with the Nutri-Foin Système similarly im
proved lung function, airway neutrophilia, mucus score and serum antioxidant enzyme kinetics over time.

Results: Pelleted hay and the hay treated with the Nutri-Foin Système s

Effects of a propriety oiled mixed hay feeding system on lung function, neutrophilic airway inflammation and oxidative stress in severe asthmatic horses
evj 2020

Question 3

Does intra-articular administration of methylprednisolone effective in improving the lung function of SEA horses ?

Answer 3

Methylprednisolone IA administration improves the lung function of severe asthmatic horses. However, this effect was mild and of a short duration.
MPA estimate a peak plasmatic concentration 6-7 hours after IA injection with serum concentrations below detectable levels by day 6.
Unlikely to affect performance 48h after IA administration.
No effect with IM injection.

Pulmonary response of severely asthmatic horses after intra-articular administration of methylprednisolone
evj 2021

Question 4

Which statement is true about severe equine asthma?
A- Angiogenesis contributes to thickening of the airway wall in asthmatic horses and was reversed by a 2-week treatment with corticosteroids.
B- Contrary to human, angiogenesis does not contribute to thickening of the airway wall in asthmatic horses
C- Angiogenesis contributes to thickening of the airway wall in asthmatic horses and was not reversed by a 2-week treatment with corticosteroids.
D- Angiogenesis contributes to thickening of the airway wall in asthmatic horses and was reversed by a 2-week treatment with bronchodilators.

Answer 4

C- Angiogenesis contributes to thickening of the airway wall in asthmatic horses and was not reversed by a 2-week treatment with corticosteroids.

number of vessels and vascular area were increased in the airway
walls of asthmatic horses in exacerbation. Differences observed between groups disappeared after 2 weeks of treatment with corticosteroids because of the increased number of vessels in
healthy horses.

Bronchial angiogenesis in horses with severe asthma and its response to corticosteroids
jvim 2021

Question 5

What is the clinical efficacy of nebulized dexamethasone sodium phosphate in the treatment of horses with severe asthma ? Are they side effects ?

Answer 5

Oral, but not nebulized dexamethasone is an
effective therapy for horses with severe asthma and both treatment modalities inhibit the hypothalamic-pituitary-adrenal axis.

Lung resistance improvement for oral. But cortisol decreased for both

Nebulized dexamethasone sodium phosphate in the treatment
of horses with severe asthma
jvim 2021

Question 6

What is the clinical efficacy of ciclesonide in the treatment of horses with severe asthma ? Are they side effects ?

Answer 6

Ciclesonide inhalation solution administered by the Aservo® EquiHaler® effectively reduced severity of clinical signs in a majority of horses with severe equine
asthma and was well tolerated.
Few systemic and local adverse events of ciclesonide were observed.

At least 30% reduction in clinical score.
No improvement of BAL cytology.
Clinical assessment !

Inhaled ciclesonide is efficacious and well tolerated in the treatment of severe equine asthma in a large prospective European clinical trial
evj 2021

Question 7

Which statement is true about lipidomic analysis of surfactant and plasma from horses with asthma ?
A- The most significant surfactant alterations were present in MEA (altered phospholipid content and composition)
B- The most significant surfactant alterations were present in SEA (altered phospholipid content and composition)
C- Serum SP-D concentrations were only significantly increased in MEA horses
D- Serum SP-D concentrations were significantly increased in MEA and SEA horses

Answer 7

Answer B
The most significant surfactant alterations were present in SEA (altered phospholipid content and composition).
Only SEA horses had significantly increased serum SP-D concentrations.

plasma lipidomic profile was altered significantly in asthmatic horses compared to age-matched controls. The plasma lipidomic profile also varied depending on the BALF inflammatory profile present.

Lipidomic analysis of surfactant and plasma from horses with asthma and age-matched healthy horses
AJVR 2022

Question 8

Which environment maximise the exposition to fungi ?
A- Pasture
B- Stabling
C- Truck

Answer 8

Stabling increases exposure to fungi.
Exposure to fungi could contribute to airway inflammation by increasing dectin-1 functional isoforms in BAL.

ß-glucans were found to bind predominantly to the innate cell-surface immune
receptor dectin-1. Dectin-1 is a C-type leptin receptor expressed predominantly by dendritic cells and macrophages/monocytes, but is also present on neutrophils, lymphocytes, and in bronchial and alveolar epithelial cells

Characterization of fungal exposure and dectin-1 expression in healthy horses and horses with severe asthma
AJVR 2022

Question 9

Which statement is true about severe equine asthma?
A- SEA is associated with lower airway innervation
B- SEA is associated with greater airway innervation
C- Airway innervation is modified only in SEA but not in MEA
D- Airway innvervation is not significantly different between SEA and control horses.

Answer 9

Severe asthma in horses is associated with greater airway innervation, possibly contributing to airway smooth muscle remodeling and exacerbating severity of the disease.

Severe asthma in horses is associated with increased airway innervation
jvim 2024

Question 10

What are the benefits of soaked hay in SEA horses ?
A- Soaked hay decreases respirable particles, but does not improve lung function.
B- Soaked hay decreases respirable particles and lung resistance
C- Soaked hay decreases respirable particles for 6 hours
D- 2 hours of soaking are necessary to reduce respirable particles from hay

Answer 10

Soaking hay for 10 or 30 minutes reduces respirable particles by up to 90% for a period of 1 to 2 hours.
Soaked hay can decrease lung resistance and control airway obstruction in horses with severe asthma.
In the study : soaked hay was immersed for 45 minutes and dried out hay was discarded between meals.

Effects of soaked hay on lung function and airway inflammation in horses with severe asthma
jvim 2024

Question 11

Which bronchodilator has the best efficacy and fewer side effects in horses with SEA ?

Answer 11

Comparison between hyoscine butylbromide (HBB) = N-butylscopolammonium bromide (ESTOCELAN®) and salbutamol (VENTOLINE®).
Both drugs have a similar bronchodilator potency but with a longer duration for salbutamol. Gastrointestinal and cardiovascular side effects were noted only with HBB, suggesting the preferential use of salbutamol to relieve bronchoconstriction in horses with asthma.

From 5 to 30 minutes after HBB administration, the heart rate accelerate

Comparative study of the bronchodilator efficacy and adverse effects of salbutamol and hyoscine butylbromide in horses with severe asthma
jvim 2024

Question 12

Which statement is true about microarray molecular mapping of horses ?
A- Microarray profiling cannot identify specific allergenic components associated with SEA.
B- Microarray profiling can identify specific allergenic components associated with SEA, with a variability of sensitization profiles between geographical locations.
C- Microarray profiling can identify specific allergenic components associated with SEA in horses, regardless of location.
D- Microarray profiling can identify specific allergenic components associated with SEA, with a variability of sensitization profiles between seasons.

Answer 12

B- Microarray profiling can identify specific allergenic components associated with SEA in horses, with a variability of sensitization profiles between geographical locations.
Significant regional variations in IgE-sensitization profiles influenced by environmental factors

Microarray molecular mapping of horses with severe asthma
jvim 2024

Question 13

A 12-year-old mare presents with chronic coughing, increased respiratory rate, and exercise intolerance. On endoscopy, you observe a smooth, pink to white surfaced mass partly occluding a mainstem bronchus. What is the most likely diagnosis, and what diagnostic step would you take to confirm it?

Answer 13

The most likely diagnosis is a granular cell tumor.

To confirm, a large tissue biopsy should be obtained, possibly via a tracheostomy at the thoracic inlet to enable access with larger instruments such as uterine biopsy forceps. Small mucosal pinch biopsies may result in false negatives.

2024 vetclinic Tumors of the Respiratory Tract

Question 14

An 8-year-old gelding presents with inappetence, weight loss, and ventral thoracic edema. On auscultation, you note muffled lung sounds in the ventral thorax.

What additional clinical signs might you expect, and what diagnostic test would be most useful for confirming your suspicion of thoracic lymphoma?

Answer 14

Additional signs may include tachypnea, dyspnea, jugular venous distension, and pulsation.
Thoracocentesis with cytological analysis of the pleural fluid would be most useful for confirming thoracic lymphoma, as neoplastic cells are frequently present in the effusion.

2024 vetclinic Tumors of the Respiratory Tract

Question 15

A 20-year-old grey horse presents with bilateral periocular swelling unresponsive to antibiotics and corticosteroids. On examination, you note mild submandibular lymphadenopathy.

What other clinical signs would support a diagnosis of melanoma, and what simple diagnostic test could you perform to confirm your suspicion?

Answer 15

Other clinical signs supporting melanoma include:
- multiple black nodule-like masses in various locations, particularly the:
- ventral tail, perianal region, and external genitalia. A fine needle aspiration of one of the masses for cytological examination could confirm the diagnosis of melanoma.
Horner syndrome also described.

2024 vetclinic Tumors of the Respiratory Tract

Question 16

A 15-year-old horse presents with respiratory distress, depression, and signs of pleural pain. Ultrasound examination reveals multiple soft tissue irregular cauliflower-like masses adherent to the pleura. What is your presumptive diagnosis, and what diagnostic procedure would you recommend to confirm it?

Answer 16

The presumptive diagnosis is mesothelioma. To confirm, an ultrasound-guided trucut biopsy or thoracoscopy would be recommended, as cytology of pleural fluid can be challenging to interpret for this condition.

2024 vetclinic Tumors of the Respiratory Tract

Question 17

4 different types of melanoma?

Answer 17

melanocytic nevi,
discrete dermal melanoma,
dermal melanomatosis,
anaplastic malignant melanoma

2024 vetclinic Tumors of the Respiratory Tract

Question 18

A horse undergoes auscultation using a novel digital auscultation device (DAD).Which finding would be most suggestive of severe asthma exacerbation?
A) Normal breath intensity and duration
B) Occasional crackles during inspiration
C) Frequent wheezes, crackles, and increased breath intensity
D) Decreased breath sounds in all lung fields
E) Intermittent rattles during expiration

Answer 18

Correct answer: C) Frequent wheezes, crackles, and increased breath intensity

Wheezes, crackles, rattles, and breath intensity were significantly more frequent,
higher in sEA+=adventitious sounds

2023 Breath characteristics and adventitious lung sounds in healthy and

Question 19

A horse with moderate asthma is treated with nebulized dexamethasone (15 mg daily) for 13 days, but kept in a dusty environment.
Which of the following outcomes is most likely?

A) Significant improvement in airway cytology
B) Downregulation of all inflammatory cytokines
C) Upregulation of IL-5, IL-6, IL-17, IL-12, and TNF-α
D) No change in cytokine expression
E) Complete resolution of clinical signs

Answer 19

Correct answer: C) Upregulation of IL-5, IL-6, IL-17, IL-12, and TNF-α

Nebulized administration of dexamethasone was associated with increased expression of inflammatory cytokine mRNA.
There was no improvement in inflammatory airway cytology associated with either dexamethasone or saline treatment.

A CONSORT-guided, randomized controlled clinical trial of nebulized administration of dexamethasone and saline on lower airway cytokine mRNA expression in horses with moderate asthma
jvim 2024

Question 20

A 12-year-old Warmblood gelding in France presents with severe equine asthma. Based on the study’s findings, which of the following statements is most accurate regarding allergen sensitization profiling?
A) Allergen sensitization profiles are likely to be identical to those found in North American horses
B) Microarray profiling is unlikely to provide useful information for this horse
C) The horse is likely to show sensitization to Hev b 5.0101, Cyn D, Der p 2, and Rum cr
D) Mathematical modeling of allergen profiles will have poor discriminatory power for this horse
E) Environmental factors have minimal influence on the horse’s allergen sensitization profile

Answer 20

C) The horse is likely to show sensitization to Hev b 5.0101, Cyn D, Der p 2, and Rum cr

PLS-DA models showed high discriminatory power in predicting SA in horses
from Canada (area under the curve [AUC] 0.995) and France (AUC 0.867) but poor discriminatory power in horses from the United States

Key components:
* Geographical location influences allergen sensitization profiles in horses with severe asthma
* Microarray profiling can identify specific allergenic components

2023 Microarray molecular mapping of horses with severe asthma

Question 21

In a study of horses with smoke-induced mild asthma, what was the primary factor associated with improved aerobic capacity?
A) Administration of dexamethasone
B) Administration of salbutamol
C) Reduction in ambient particulate matter concentration
D) Increased exercise intensity
E) Combination of all treatments

Answer 21

Correct answer: C) Reduction in ambient particulate matter concentration

The study found that improved air quality (reduced PM2.5) was the single most important factor in enhancing aerobic capacity, with no additional benefits observed from dexamethasone or salbutamol administration.

Efficacy of dexamethasone, salbutamol, and reduced respirable particulate concentration on aerobic capacity in horses with smoke-induced mild asthma
jvim 2020

Question 22

In a large-scale clinical trial of horses with severe equine asthma, which of the following statements best describes the efficacy of inhaled ciclesonide compared to placebo after 10 days of treatment?
A) Ciclesonide showed no significant difference in treatment success rate compared to placebo
B) Ciclesonide demonstrated a 30% higher treatment success rate than placebo
C) Ciclesonide improved pulmonary function but not clinical signs
D) Ciclesonide was effective only in horses with moderate clinical signs
E) Ciclesonide caused significant adverse effects, limiting its clinical use

Answer 22

Correct answer: B) Ciclesonide demonstrated a 30% higher treatment success rate than placebo

Results: The treatment success rate in ciclesonide-treated horses was 73.4% (80/109) after 10 (±1) days of treatment, being significantly higher than in the placebo group with 43.2% (48/111; P < 0.0001).
Few systemic and local adverse events of ciclesonide were observed

2020 Inhaled ciclesonide is efficacious and well tolerated in the
treatment of severe equine asthma in a large prospective
European clinical trial

Question 23

A 10-year-old horse presents with mild respiratory signs. PCR testing of a nasal wash sample detects Nicoletella semolina. Based on the findings of this study, how should this result be interpreted?
A) N. semolina is definitely the cause of the respiratory signs
B) N. semolina is likely an incidental finding unrelated to the clinical signs
C) The horse should be treated with antibiotics targeting N. semolina
D) Further testing is needed to determine if N. semolina is contributing to disease
E) N. semolina is never found in healthy horses

Answer 23

Correct answer: B) N. semolina is likely an incidental finding unrelated to the clinical signs
N. semolina was commonly detected in both healthy and asthmatic horses, suggesting its presence alone does not indicate pathogenicity.

Nicoletella=pasteurella

2021 Nicoletella semolina in the airways of healthy horses and horses
with severe asthma

Question 24

In a study of airway remodeling in horses with mild/moderate asthma, which of the following changes was NOT observed compared to control horses?
A) Epithelial hyperplasia
B) Thickened lamina propria
C) Smooth muscle hypertrophy
D) Increased submucosal inflammatory cells
E) Smooth muscle fibrosis

Answer 24

Correct answer: C) Smooth muscle hypertrophy
This question tests understanding of the key airway remodeling changes observed in mild/moderate equine asthma, highlighting that while smooth muscle fibrosis was increased, hypertrophy was not specifically reported in this study.
Tissue remodeling of the bronchial lamina propria, epithelium, and smooth muscle was present in horses with MEA.

Airway remodeling in horses with mild and moderate asthma
jvim 2022

Question 25

A 12-year-old Warmblood gelding is diagnosed with equine multinodular pulmonary fibrosis (EMPF) based on lung histopathology. Thoracic radiographs show severe caudodorsal lung changes and enlarged tracheobronchial lymph nodes. Lung biopsy qPCR reveals a high EHV-5 viral load. Based on the findings of this study, which of the following statements is most accurate regarding prognosis and treatment?

A) The horse has a good long-term prognosis if it survives to hospital discharge
B) Corticosteroid treatment is unlikely to improve short-term survival
C) The severity of radiographic changes is a reliable predictor of survival time
D) Treatment with corticosteroids may improve the odds of short-term survival
E) The high EHV-5 viral load indicates a poor prognosis for short-term survival

Answer 25

Correct answer: D) Treatment with corticosteroids may improve the odds of short-term survival

short-term survival (discharge) 57%,
long-term survival (6 months) 14%.
Short-term survival associated (higher) with corticosteroid treatment
Short term survival NOT associated with EHV5 viral load or severity of pulmonary lesions on thoracic radiographs – requirement of histopathologic diagnosis for inclusion (more severe disease)

Prognostic indicators and long-term survival in 14 horses with EMPF

Question 26

What was the most common finding in the bronchoalveolar lavage fluid (BALF) cytology of horses with EMPF compared to horses with asthma?

A) Neutrophilia
B) Eosinophilia
C) Macrophage atypia
D) Lymphocytosis

Answer 26

Answer: C) Macrophage atypia

Rationale: Macrophage atypia was observed in 67% of EMPF cases, a finding that was significantly more common compared to asthmatic horses (8%).

Clinical findings and outcome predictors for multinodular pulmonary fibrosis in horses: 46 cases (2009-2019)

Question 27

Which of the following was associated with a worse prognosis for horses with EMPF?

A) Low respiratory rate
B) Higher blood lymphocyte count
C) High respiratory effort and tachypnea
D) Higher BALF neutrophil count

Answer 27

Answer: C) High respiratory effort and tachypnea

Rationale: Increased respiratory effort and tachypnea were common in EMPF cases, but high respiratory rates were associated with a poorer prognosis, as shown by the survival analysis.

Clinical findings and outcome predictors for multinodular pulmonary fibrosis in horses: 46 cases (2009-2019)

Question 28

A 10-year-old Warmblood mare presents with a 3-week history of weight loss, increased respiratory effort, and tachypnea. Upon clinical examination, she has a respiratory rate of 42 breaths per minute, and a fever of 39°C is noted. Radiographic and ultrasonographic studies show interstitial lung changes consistent with EMPF. Bronchoalveolar lavage fluid (BALF) cytology is performed and reveals macrophage atypia. Testing for Equine Herpesvirus 5 (EHV-5) is positive. The horse is treated with corticosteroids.

Question:
Based on the clinical findings and test results, which of the following is the most likely prognostic outcome for this mare?

A) High likelihood of survival beyond 3 months
B) Prognosis is likely poor despite corticosteroid treatment
C) Fever will likely resolve after corticosteroid treatment
D) The horse will most likely recover without further interventions

Answer 28

B) Prognosis is likely poor despite corticosteroid treatment
Rationale: Although corticosteroid treatment is commonly used, it was not shown to improve 3-month survival in EMPF horses. The combination of clinical signs, BALF cytology findings, and EHV-5 positivity suggests a poor prognosis for this mare, consistent with the conclusion of the study.

Survival > 3 months if:
- lower median respiratory rates 30 vs. 41
- higher BALF lymphocyte:neutrophil ratios 4.7 vs. 0.47
- higher blood lymphocyte counts (1.25 vs. 0.90

Clinical findings and outcome predictors for multinodular pulmonary fibrosis in horses: 46 cases (2009-2019)

Question 29

In a horse presenting with nasal discharge and suspected sinusitis, how can molecular characterization of the sinus microbiome help differentiate between primary and dental-related sinusitis, and how might this information guide treatment decisions?

Answer 29

Dental-related sinusitis shows higher microbial diversity and a greater proportion of obligate anaerobic bacteria.
Primary sinusitis typically has lower diversity, often dominated by a single species (frequently Streptococcus equi).

Antimicrobial resistance genes and fungal components were found exclusively in dental-related sinusitis cases.

Equine sinusitis aetiology is linked to sinus microbiomeby amplicon sequencing

Question 30

In healthy horses, how does the bacterial and fungal microbiota composition of the pharynx compare to that of the lower respiratory tract (proximal and distal trachea),?

Answer 30

The bacterial and fungal microbiotas of the pharynx were found to be more similar in composition to those of the proximal and distal trachea compared to any other sampling site in the upper respiratory tract of healthy horses.
.
For fungal communities, there was significant overlap among the pharynx, arytenoid, proximal trachea, and distal trachea, with no significant differences detected between these locations after correcting for multiple comparisons.

Fungal species richness and diversity were highest in the nostrils

The study found more spatial heterogeneity in bacterial composition compared to fungal communities throughout the respiratory tract.

2022 Topography of the respiratory, oral, and guttural pouch bacterial and fungal microbiotas in horses

Question 31

In a 10-year-old barrel racing horse presenting with respiratory noise during competition, what is the most likely upper airway obstruction to be found on overground endoscopy, and at what point in the exercise test would you expect to observe it?

Answer 31

Based on the study results, the most likely upper airway obstruction to be found would be nasopharyngeal collapse, which was observed in 49% of horses with UAOs.
Regarding the timing, the paper reports that UAOs were more frequently observed during the low-speed phase of exercise (55% of UAOs) compared to the high-speed/high-intensity phase (22% of UAOs).
- NasoPharyngeal Collapse → 49%
- Palatal instability → 42%
- Intermittent DDSP → 39%

This emphasizes the importance of performing overground endoscopy at different exercise intensities to fully assess upper airway function in barrel racing horses.

Upper airway endoscopy in exercising horses: Findings in 164 barrel racing horses with respiratory clinical signs and/or poor performance. 2023

Question 32

In healthy horses undergoing general anesthesia for elective procedures, how do thoracic ultrasound findings compare before anesthesia and 3 hours post-recovery, and what implications does this have for interpreting post-anesthetic thoracic ultrasound exams?

Answer 32

Controverses
The study found no significant differences in thoracic ultrasound findings between pre-anesthesia and 3 hours post-recovery in healthy horses. This suggests that any significant changes observed on thoracic ultrasound within 3 hours post-anesthesia in clinical cases are more likely to represent true pathology rather than normal post-anesthetic changes. These findings can help clinicians differentiate between normal post-anesthetic findings and potential complications like atelectasis or pneumonia when interpreting thoracic ultrasounds in the immediate post-anesthetic period.

General anesthesia does not induce ultrasonographic changes in the pleura of healthy adult horses anesthetized for elective magnetic resonance imaging

Question 33

How do lung ultrasound findings change in healthy horses following general anesthesia, and what factors are associated with more pronounced post-anesthetic lung ultrasound changes?

Answer 33

Controverses.

The study found significant increases in I-lines, B-lines, and coalescent B-lines on lung ultrasound following general anesthesia in healthy horses, with peak changes at 2 hours post-anesthesia.
Factors associated with more pronounced post-anesthetic lung ultrasound changes included longer total procedure time and abnormal cardiorespiratory values during anesthesia.

Perioperative lung ultrasonography in healthy horses undergoing general anesthesia for elective surgery”

Question 34

Equine rhinitis viruses (ERAV and ERBV): which types of infection? Clinical signs? Diagnostic modalities?

Answer 34

Picornavirus :
- ERAV (Aphthovirus), formerly known as equine rhinovirus 1,
- ERBV (Erbovirus), formerly known as equine rhinovirus 2, are capable of affecting both the lower and upper airways.

In young performance horses, ERAV has been associated with the development of inflammatory airway disease.
Both natural and experimental infections of seronegative horses with ERVs have been considered to be a cause of fever, anorexia, seromucoid nasal discharge, coughing, lymphadenopathy and occasionally lower limb swelling

Difficulties in virus isolation

very short shedding time following the development of clinical signs

Serology, using acute and convalescent serum samples, has remained a diagnostic pillar when ERAV is suspected but detection via qPCR has yielded negative results

Challenges in navigating molecular diagnostics for common equine respiratory viruses 2021

Question 35

What is the significance of determining EIV clade affiliation?

Answer 35

Determining EIV clade affiliation is important for epidemiological monitoring, understanding outbreaks, and updating vaccine strains to improve protection against clinical disease.
H3N8 Florida sublineage, clade 1 in North America, Africa, Japan;
clade 2 in Europe, China, India

Challenges in navigating molecular diagnostics for common equine respiratory viruses 2021

Question 36

Why is it important to use a multigene approach for EHV-1 detection?

Answer 36

A multigene approach is crucial to reduce the risk of false negatives, as recent outbreaks have identified a new H752 genotype that may be missed by single-gene allelic discrimination assays.
SNP at position 2254 of DNA polymerase gene correlates with EHM
D752 genotype (G2254) associated with neurological outbreaks
N752 genotype (A2254) associated with non-neurological outbreaks
14-24% of EHM isolates do not have neuropathogenic marker
New H752 genotype (C2254) recently identified

Challenges in navigating molecular diagnostics for common equine respiratory viruses 2021

Question 37

How does quantitative PCR help in diagnosing EHV-4 infections?

Answer 37

Quantitative PCR helps differentiate between lytic and non-replicating EHV-4, with high viral loads indicating active infection and presence of clinical signs.

Challenges in navigating molecular diagnostics for common equine respiratory viruses 2021

Question 38

What does a positive qPCR result for EAV typically indicate?

Answer 38

A positive qPCR result for EAV generally suggests clinical infection in horses.

Challenges in navigating molecular diagnostics for common equine respiratory viruses 2021

Question 39

Why is testing for EHV-2 and EHV-5 not recommended in horses with upper respiratory tract diseases?

Answer 39

Testing is not recommended due to the high detection rate in healthy horses, which makes interpretation of positive results difficult in the context of respiratory disease.

Challenges in navigating molecular diagnostics for common equine respiratory viruses 2021

Question 40

What is a key challenge in diagnosing ERAV infections?

Answer 40

A key challenge in diagnosing ERAV infections is the very short shedding time following the development of clinical signs, making PCR detection difficult and necessitating the use of serology for diagnosis.

Challenges in navigating molecular diagnostics for common equine respiratory viruses 2021

Question 41

Is there any difference in microbiota and mycobiota between nasopharyngeal cicatrix and healthy horses?

Answer 41

6 fungal genera (Alternaria, Bipolaris, Microascus, Spegazzinia, Paraconiothyrium, Claviceps)
1 bacterial genera (Staphylococcus) were significantly different

The fungal genus Bipolaris had increased abundance in nasopharyngeal cicatrix syndrome (NCS) affected horses and on NCS affected farms. Therefore, Bipolaris warrants further investigation.
Pythium insidiosum was absent in the nasopharyngeal wash of all horses, irrespective of health status.

Nasopharyngeal bacterial and fungal microbiota in normal horses and horses with nasopharyngeal cicatrix syndrome
jvim 2021

Question 42

In horses with chronic guttural pouch infection unresponsive to medical management, what could you advise?

Answer 42

Transpharyngeal diode laser fenestration appears to be an effective and well-tolerated treatment for chronic guttural pouch infection in horses. The procedure resulted in complete resolution of clinical signs in 12 out of 13 horses, with the one exception having concurrent equine asthma syndrome. All owners expressed satisfaction with the outcome.
This technique offers several advantages over traditional surgical approaches:
It can be performed on standing, sedated horses, avoiding risks of general anesthesia.
It avoids potential iatrogenic nerve damage associated with transcutaneous approaches.
There is no need for postoperative wound management.
The procedure was uncomplicated to perform and had minimal complications.
While this study did not directly compare the technique to other surgical approaches, the high success rate (92.3%) and owner satisfaction suggest it may be preferable to more invasive methods.

Clinical outcome of horses with guttural pouch infection following transpharyngeal fenestration 2022

Question 43

In a horse presenting with bilateral guttural pouch mycosis and severe neurological signs but no evidence of hemorrhage, what treatments do you consider?

Answer 43

Salpingopharyngostomy and topical oxygen therapy (TOT) are both potential treatments for guttural pouch mycosis, each with its own advantages:
Salpingopharyngostomy:
Creates a fistula between the pharynx and guttural pouch, introducing varying gas levels that may inhibit fungal growth.
Can be performed as a single procedure, requiring no further treatments or hospitalization.
Allows for simultaneous treatment of bilateral cases with a single opening in the dorsal pharyngeal recess.
Does not significantly alter temperature or humidity within the guttural pouch.

Topical oxygen therapy (TOT):
Involves placing an indwelling catheter in the affected guttural pouch and administering oxygen at 15 L/min, four times daily for 1-2 weeks.
Showed promising results with fungal plaque regression after a minimum of two treatments.
Reported resolution or significant improvement in 10/12 neurological disorders, compared to 9/18 cases with transarterial coil embolization.
May be used as an adjunct treatment or primary treatment in non-bleeding cases.
In terms of efficacy, TOT shows promising results for neurological sequelae resolution, while salpingopharyngostomy aims to create an environment less hospitable to fungal growth.
Practically, salpingopharyngostomy offers the advantage of being a single procedure without need for prolonged hospitalization, whereas TOT requires multiple treatments over 1-2 weeks.
The choice between these treatments may depend on factors such as the severity of neurological signs, the presence of bilateral disease, and the ability to hospitalize the horse for an extended period.
In some cases, a combination approach might be considered, with TOT performed initially, followed by salpingopharyngostomy if needed.

Treatment of guttural pouch mycosis with salpingopharyngostomy 2023

Question 44

In a young horse presenting with severe neurological signs including neck pain and abnormal head carriage, but no evidence of hemorrhage, how would you approach the diagnosis and treatment?

Answer 44

1. Perform endoscopy of both guttural pouches to look for fungal-like plaques. In this case, endoscopy revealed fungal-like plaques in the medial compartment of both guttural pouches.
2. Obtain samples from the plaques for fungal culture to confirm the diagnosis. The paper reports that Aspergillus was cultured from the samples.
3. Consider debridement of the mycotic plaques, though this may be challenging if the plaques are strongly adherent.
4. Perform laser salpingopharyngeal fistulation under standing sedation.
5. Initiate treatment with oral potassium iodide. The colt in this case received potassium iodide at a dose of 20 mg/kg bwt per os s.i.d.
6. Monitor for potential complications such as bacteremia, which occurred in this case and was treated with appropriate antibiotics based on culture and sensitivity.
7. Conduct serial endoscopic evaluations to monitor resolution of the fungal plaques. In this case, complete resolution was observed 4 months post-operatively.
8. Follow up on neurological signs, as the paper reports minimal neurologic deficits remained 6 months post-operatively.

Successful combination treatment of bilateral guttural pouch mycosis with salpingopharyngeal fistulation and potassium iodide 2023

Question 45

In harness racehorses diagnosed with iDDSP via exercising endoscopy, how does laryngeal tie-forward surgery affect racing performance compared to pre-surgical performance, and what factors influence the success of the procedure?

Answer 45

Laryngeal tie-forward surgery generally improves racing performance in harness racehorses diagnosed with iDDSP:

1. Performance index increased in 67% of experienced racehorses postoperatively.
2. 66% of horses established or improved their racing speed mark after surgery.
3. As a group, performance index increased by 0.5 points and racing speed improved by 0.83 seconds postoperatively.

Factors influencing the success of the procedure include:
1. Individual variation: Some horses (25%) did not show a decline in performance index before diagnosis, suggesting iDDSP affects horses differently.
2. Presence of complex upper respiratory tract disorders: 43% of horses had additional disorders, which may impact outcomes.
3. Age: The study found a non-linear relationship between age and performance index.
4. Breed: While both Standardbreds and Norwegian-Swedish Coldblooded Trotters showed improvement, there were some differences in outcomes between breeds.

The degree of basihyoid-cricoid distance shortening during surgery did not significantly affect postoperative performance.
Additionally, there was a 21% recurrence rate of iDDSP within 2 years post-surgery, indicating that long-term follow-up is important.

No method to predict which horses will respond most favorably to the procedure.

Outcome analysis of 95 harness racehorses with confirmed
dorsal displacement of the soft palate treated with laryngeal
tie-forward surgery
EVJ 2021

Question 46

In horses with recurrent laryngeal neuropathy, how does the activation pattern and fiber type recruitment of the sternomandibularis muscle, as determined by surface electromyography, support the potential use of the spinal accessory nerve for laryngeal reinnervation compared to the currently used first and second cervical nerve?

Answer 46

The sternomandibularis muscle shows increased activity with increasing exercise speed, particularly at gallop.
Muscle activation coincides with inspiration at gallop.
There is predominant recruitment of type I (slow-twitch, fatigue-resistant) muscle fibers during both feeding and exercise.
The muscle is activated at rest when horses are grazing.
These characteristics suggest the spinal accessory nerve could potentially address limitations of current laryngeal reinnervation techniques, such as reducing cricoarytenoideus dorsalis muscle fatigue and potentially shortening rehabilitation time.

Laryngeal reinnervation using the spinal accessory nerve: Electromyographic study of the sternomandibularis muscle 2022

Question 47

In Thoroughbred racehorses, how does high-load inspiratory muscle training (IMT) affect inspiratory muscle strength compared to conventional race training alone?

Answer 47

Based on the study results, high-load IMT significantly increases inspiratory muscle strength (IMSi) in race-fit Thoroughbreds beyond the improvements seen with conventional race training alone.

The high-load group showed a mean increase in IMSi from 26 cmH2O to 34 cmH2O after 10 weeks of IMT, while the low-load control group showed no significant change.

Training the equine respiratory muscles: Inspiratory muscle strength
EVJ 2022

Question 48

In horses with dynamic laryngeal collapse associated with poll flexion, does using a bitless bridle instead of a conventional snaffle bit bridle reduce the severity of upper airway obstruction during exercise?

Answer 48

A bitless bridle does not reduce the severity of dynamic laryngeal collapse (DLC) compared to a conventional snaffle bit bridle in affected horses.
There was no significant difference in inspiratory tracheal pressures during the poll flexion phase between the bitless bridle (-43.7 ± 15.6 cmH2O) and the snaffle bit bridle (-42.1 ± 10.8 cmH2O) (P=0.2).
All horses developed DLC in both bridles when exercised in poll flexion.
The change in mean inspiratory tracheal pressure between free and flexion phases was actually greater with the bitless bridle (-15.2 ± 12.3 cmH2O) compared to the snaffle bit bridle (-9.8 ± 7.9 cmH2O) (P<0.001).

Head and neck angles induced by rein tension , rather than the presence of a bit, appear to be the key factor in provoking DLC in susceptible horses.

Mean inspiratory pressure during the free phase was significantly (P < .001) more negative with the snaffle bit bridle (−32.3 ± 6.3 cmH2O), vs the bitless bridle (−28.5 ± 6.9 cmH2O).

A bitless bridle does not limit or prevent dynamic laryngeal collapse

Question 49

DDX of Upper Respiratory Diseases ?

Answer 49

• Rhinitis, sinusitis
• Progressive ethmoidal hematoma (PEH)
• Guttural pouch : mycosis, empyema, tympany
• Lymphoid pharyngeal hyperplasia
• Dorsal displacement of the soft palate (DDSP)
• Recurrent laryngeal neuropathy (RLN)
• Epiglottic entrapment
• Arytenoid chondritis
• Rostral displacement of the palatopharyngeal arch (rare)
• Nasopharyngeal cicatrix (rare)
• Neoplasia

Question 50

DDX of lower respiratory diseases

Answer 50

Infectious : cough +/- increase in respiratory effort, fever, lethargy, nasal discharge
- Bacterial broncho-pneumonia, pleuro-pneumonia
- Parasitic pneumonitis
- EMPF / EHV-5

Inflammatory : exercise impairment
- IAD
- RAO
- Parasitic
- MEED

Other :
- EIPH
- Neoplasia (primary or metastatic)

Question 51

When and how to diagnose DDSP in horses ?

Answer 51

DDSP results in a loud, vibratory expiratory noise with exercise. It is a common cause of poor performance in race horses and has a prevalence of 10% to 20%.

A definitive diagnosis is made, during **high-speed treadmill **examination, if the caudal border of the soft palate is seen dorsal to the epiglottis for more than 8 seconds.

Surgical advancement of the larynx (laryngeal tie-forward
procedure) demonstrated a success rate of 80% in racehorses.

Question 52

What are the grades of RLN in horses ?

Answer 52

RLN is a major cause of poor performance in racehorses and affects 1.6% to 8% of Thoroughbreds.
The prevalence in draft horses is nearly 42%, and the risk of RLN increases with increasing height in Belgians and Percherons.

Consensus on a four-level resting grading system :
- Grade I : all arytenoid cartilage mvt are synchronous and symmetrical, and full arytenoid abduction can be achieved and maintained.
- Grade II : asynchronous but full arytenoid abduction achieved and maintained
- Grade III : asynchronous or asymmetrical, and full arytenoid abduction not achieved and maintained
- Grade IV : immobility

Grading system at exercise :
- Grade A : full abduction during ispiration
- Grade B : abduction > resting position
- Grade C : abduction < resting position
- Grade D : collapse to the controlateral side

Surgery : tie-back (prosthetic laryngoplasty) → 48-68% success rate for racehorses

Question 53

DDX

Answer 53

• Metastatic neoplasia
• Fungal granulomas (Aspergillus spp, Histoplasma capsulatum (rare))
• Nodular interstitial pneumonia

Question 54

What is your clinical hypothesis with a horse that demonstrate pulmonary disease in the face of enterocolitis and severe neutropenia ?

Answer 54

Enteritis, colitis, and typhlocolitis are proposed to predispose horses to the development of systemic fungal dissemination. Gastrointestinal inflammation results in the disruption of the epithelial barrier, allowing for translocation of fungal organisms and subsequent systemic dissemination.

For this reason, horses that demonstrate evidence of pulmonary disease and have appropriate risk factors such as gastrointestinal disease, particularly if immunocompromised (marked neutropenia is present, corticosteroid adm°, PPID), fungal pneumonia should be considered.

Question 55

DDX of parasitic pneumonitis

Answer 55

• Parascaris equorum in foals and weanlings
• Dictyocaulus arnfieldi

Question 56

Adenovirus positive in horse, what do you know?

Answer 56

the most common viral cause of pneumonia isolated from foals and yearling’s is **EHV-1 **> EHV-5 > equine adenovirus.

Equine adenovirus is frequently detected in healthy foals and mares but rarely causes clinical disease including upper respiratory infections, pneumonia or diarrhoea
Fatal adenoviral pneumonia has been reported in Arabian foals with severe combined immunodeficiency syndrome
In severely immune deficient or suppressed animals, adenoviral infection may present as a bronchitis.

2022 Pathological approach to respiratory infections: Should
underlying immunodeficiencies be widely considered?

Question 57

You suspect a pneumonia on a foal (<1year old) which type of pathogen and which pathogen is most likely in charge ?

Answer 57

Bacterial pneumonia: 67.2% of pneumonia cases in young horses were attributed to bacterial agents.
Rhodococcus most likely

foal 0-1year:
Bacterial
* Rhodococcus equi
* Streptococcus equi ssp. zooepidemicus
* Actinobacillus equuli
* Klebsiella pneumoniae
* E. coli
* Staphylococcus sp.
* Bordatella bronchiseptica

yearling :1-5year
Bacterial
* Streptococcus equi ssp. zooepidemicus
* Streptococcus equisimilis
* Streptococcus sp.
* Pasteurella sp.
* Actinobacillus sp.
* Bordatella bronchiseptica
* E. coli
* Mycoplasma felis

87.7% of bacterial pneumonias occurred in horses under 6 months old.

2022 Pathological approach to respiratory infections: Should
underlying immunodeficiencies be widely considered?

Question 58

Why interstitial pneumonia is considered a syndrome rather than a disease?

Answer 58

The aetiology of acute interstitial pneumonia has not been
clearly determined. A wide range of bacteria (eg Rhodococcus
(R.) equi, Klebsiella (K.) pneumoniae, Escherichia (E.) coli and
Streptococcus (Strep.) equi subspecies (ssp.) zooepidemicus)
and viruses, such as Equine herpesviridae (EHV) and equine
influenza virus (EIV) and Equine adenoviruses, have been detected
in foals with acute interstitial pneumonia but no common
denominator has consistently been identified. A few reports also
identified Pneumocystis (P.) carinii infection a s a c ause o f a cute
interstitial pneumonia, but these foals were mostly immunocompromised.
Additionally, various toxic substances have been
associated with acute interstitial pneumonia in adult horses and
other species.

2020 Acute interstitial pneumonia in foals: A severe, multifactorial
syndrome with lung tissue recovery in surviving foals

Question 59

Which of the following was NOT a commonly detected abnormality using the CRASH protocol in horses with clinical disease?
A) Pleural fluid
B) Lung consolidation
C) B-lines
D) Moderate-to-severe left-sided heart disease
E) Pericardial effusion

Answer 59

Answer: E) Pericardial effusion

2023 Feasibility of a point-of-care ultrasound protocol for cardiorespiratory evaluation of horses in different clinical settings

Question 60

What is the key difference in alveolar macrophage phenotype between horses with severe equine asthma and control horses at pasture?

Answer 60

At pasture, alveolar macrophages from horses with severe equine asthma showed significantly higher expression of IL-10 compared to control horses (4.35 ± 2.32 fold change, P<0.006). This elevated IL-10 expression persisted in SEA horses both at pasture and after natural challenge, while control horses only developed this phenotype after challenge.

2020 Alveolar macrophage phenotypes in severe equine asthma

Question 61

What is the clinical utility of electrical impedance tomography (EIT) ?

Answer 61

EIT generates images of the lungs based on impedance change.

EIT can detect:
- changes in airflow during histamine challenge (bronchoconstriction),
- subsequent albuterol adm° (bronchodilation),
- ventilation distribution in cardiogenic pulmonary disease.

EIT can discriminate flow variables after exercise between healthy and MEA/SEA horses, but differences between MEA and SEA were not observed.

Evaluation of histamine-provoked changes in airflow using electrical impedance tomography in horses
evj 21
Can bronchoconstriction and bronchodilatation in horses be detected using electrical impedance tomography?
jvim 2021
Electrical impedance tomography to measure lung ventilation distribution in healthy horses and horses with left-sided cardiac volume overload
jvim 21
Exercise-induced airflow changes in horses with asthma measured by electrical impedance tomography
jvim 2021

Question 62

Does nebulized dexamethasone treatment affect the respiratory microbiota, mycobiota, and equine herpesvirus levels in horses with mild asthma?

Answer 62

The study concluded that nebulized dexamethasone treatment affected the upper respiratory tract microbiota but not the mycobiota, which was overwhelmed by the effect of a sustained dusty environment.

Equine herpesvirus effects:
Increased EHV-2 DNA levels in nasal swabs (28-fold increase)
Decreased EHV-5 DNA levels

The authors emphasized the importance of environmental modification as part of the treatment strategy for asthma in horses.

2020 Effects of nebulized dexamethasone on the respiratory
microbiota and mycobiota and relative equine herpesvirus-1,
2, 4, 5 in an equine model of asthma

Question 63

Does moderate equine asthma alter the tracheal microbial populations compared to healthy horses, and is there evidence of bacterial overgrowth in these horses?

Answer 63

This study does not support the hypothesis that bacterial overgrowth is a common feature of chronic moderate asthma in horses.
Instead, it suggests that there may be a fundamental shift in the microbial populations, characterized by lower overall bacterial load and differences in the presence of certain bacterial species.
1. the** overall bacterial load was lower in asthmatic horses**
2. some bacterial differences:
Corynebacterium spp. were significantly more common in control horses.
Actinobacillus spp. were isolated only from horses with asthma and not from any control horses.
3. Streptococcus spp. were the most common bacteria isolated in culture and detected by qPCR in both groups, but there was no significant difference in their prevalence between asthmatic and control horses.
4. no association between microbial populations and clinical signs, tracheal mucus, or bronchoalveolar lavage fluid (BALF) inflammation.

The study suggests that the l**ower bacterial load in asthmatic horses could indicate dysbiosis **of the lower airways, either as a consequence of chronic inflammation or previous treatments, or as a perpetuating factor of inflammation.

2020 Tracheal microbial populations in horses with
moderate asthma

Question 64

Is there evidence of airway smooth muscle remodeling in horses with mild to moderate equine asthma (MEA), and if so, how does it differ from remodeling seen in severe equine asthma?

Answer 64

Evidence of airway smooth muscle remodeling in horses with mild to moderate equine asthma (MEA), but with some key differences compared to severe equine asthma:
1. MEA showed approximately 1.5 times** greater expression of the (+)insert SMMHC isoform** compared to controls. Overexpression suggests changes in the contractile apparatus that could contribute to airway hyperresponsiveness.

2. No significant difference was found in the proliferation rate of airway smooth muscle cells between MEA horses and controls (P=0.4). This differs from severe equine asthma, where increased proliferation is typically observed.
3. No significant difference in myocyte density was found between MEA horses and controls (P=0.3). This suggests that smooth muscle hyperplasia and hypertrophy may not be characteristic of this stage of the disease.
4. A positive correlation was found between pulmonary neutrophilia and PCNA expression in horses with neutrophilic inflammation (r=0.80, P=0.01).

2021 Airway smooth muscle remodelling in mild and moderate
equine asthma

Question 65

Can electrical impedance tomography (EIT) detect differences in airflow between healthy horses and horses with asthma before and after exercise?

Answer 65

Global peak expiratory flow (PEF_Global) and peak inspiratory flow (PIF_Global) were significantly higher in horses with SEA and MEA compared to controls after exercise.

PEF_Global **increased significantly after exercise in both SEA and MEA **horses, but not in controls.

PIF_Global increased significantly after exercise only in SEA horses.

Regional differences were observed, with more pronounced changes in ventral airflow after exercise in asthmatic horses.

No significant differences were found between groups before exercise or between MEA and SEA horses.

Cl: EIT could be a useful, non-invasive tool for assessing lung function in horses with asthma, especially for detecting subtle changes that may not be apparent at rest.

Exercise-induced airflow changes in horses with asthma measured by electrical impedance tomography

Question 66

Is there any difference in the fecal microbiota of horses with and without asthma ?

Answer 66

The intestinal microbiota of horses with asthma does not adapt in the same way to changes in diet and environment compared to the microbiota of healthy horses.

Fecal microbiota in horses with asthma
jvim 20

Question 67

What does the study suggest about the relationship between tracheal bacterial populations and clinical signs of moderate asthma in horses?

A) There is a strong correlation between specific bacterial populations and the severity of clinical asthma symptoms.
B) Microbial populations in the airways are directly associated with tracheal mucus and BALF inflammation in asthmatic horses.
C) No significant association was found between microbial populations and clinical signs, tracheal mucus, or BALF inflammation.
D) A higher bacterial load is associated with better control of asthma symptoms in horses.

Answer 67

Correct Answer:
C) No significant association was found between microbial populations and clinical signs, tracheal mucus, or BALF inflammation.

This question emphasizes the finding that despite the presence of certain potential pathogens in asthmatic horses, there was no direct link between bacterial populations and clinical signs or inflammation.
This study does not support that bacterial overgrowth is a common feature of chronic moderate asthma in horses.

Tracheal microbial populations in horses with moderate asthma
jvim 2020

Question 68

What was the effect of nebulized dexamethasone on the respiratory microbiota and mycobiota ?

Answer 68

Nebulized dexamethasone treatment affected the upper respiratory tract microbiota (decreased microbial diversity), but not the mycobiota, which was overwhelmed by the effect of a sustained dusty environment.

Effects of nebulized dexamethasone on the respiratory microbiota and mycobiota and relative equine herpesvirus-1, 2, 4, 5 in an equine model of asthma
jvim 2020

Question 69

What is the best forage between dry hay, streamed hay, haylage and pellets for asthmatic horses ?

Answer 69

Dust exposure was significantly higher with dry hay feeding, compared to steamed hay, haylage and pellets, and equivalent between haylage and pellets.

Despite similar reduction in dust exposure, horses fed haylage displayed greater resolution of airway inflammation (lower BAL neutrophils) than those fed pellets and steamed hay.
Only haylage increased the ratio of anti-inflammatory to pro-inflammatory lipids while reducing BAL neutrophil proportions within 6 weeks (increased plasma omega-3 ?)

Effects of forages, dust exposure and proresolving lipids on airway inflammation in horses
AJVR 2021
Dust exposure and pulmonary in ammation in Standardbred racehorses fed dry hay or haylage: A pilot study
Vet J 21
Effects of low-dust forages on dust exposure, airway cytology, and plasma omega-3 concentrations in TB racehorses: A randomized clinical trial
JVIM 2023

Question 70

What are the 4 main medical causes of poor performance ?

Answer 70

• MEA
• EGUS
• Dynamic upper airway obstruction (DUAO)
• Myopathies

Medical causes of poor performance and their associations with fitness in Standardbred racehorses
jvim 2024

Question 71

Can I use serological or BALF IgE profiles to predict MEA ?

Answer 71

The concentrations of several allergen-specific IgE were higher in asthmatic horses (fungi (Aspergillus fumigatus), insects (Culicoides spp.), and latex (Hevea brasiliensis)).

The protein microarray performed better on BALF than serum for detection of asthma.
Serological IgE concentrations do not closely correlate with BALF concentrations and should be interpreted with caution.

Protein microarray allergen profiling in bronchoalveolar lavage fluid and serum of horses with asthma
jvim 23

Question 72

In bilateral BALF, does the pooled BALF sample perform better than the individual right and left samples ?

Answer 72

BALF mast cell count was higher in left lung compared to right lung and and compared to pooled samples.

Between the two techniques, 17 of the horses had changes in BAL cytology from control to airway inflammation or vice versa.

Pooled BAL sample was the least reliable for detecting airway inflammation, and was not representative of the overall lung condition.

Bilateral bronchoalveolar lavage cytology profiles in a warmblood horse population during a 1-year period
jvim 2024

Question 73

What did the study suggest about the potential use of neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker for equine asthma (EA)?

A) NGAL concentrations in both serum and BALF were equally effective in distinguishing between control and EA horses.

B) BAL NGAL concentrations increased with the severity of EA, with higher levels in severe asthma (SEA) compared to mild–moderate asthma (MEA).

C) NGAL concentrations were higher in serum than in BALF, and this difference was used to diagnose EA.

D) NGAL concentrations did not vary between different groups of horses (control, MEA, SEA), indicating it is not useful as a biomarker for EA.

Answer 73

Correct Answer:
B) BALF NGAL concentrations increased with the severity of EA, with higher levels in severe asthma (SEA) compared to mild–moderate asthma (MEA).

This question emphasizes the finding that BAL NGAL concentrations were significantly higher in horses with asthma compared to controls, and that NGAL concentrations in BAL fluid reflected the severity of the disease, making it a potential biomarker for equine asthma.

No differences were found in serum NGAL concentration between any of the groups.

Neutrophil gelatinase-associated lipocalin as a potential biomarker for equine asthma
evj 24

Question 74

What was the main finding of the study regarding the use of N-acetylcysteine (NAC) in horses subjected to head confinement during transportation?

A) NAC treatment significantly increased mucus accumulation and inflammation compared to the control group.
B) NAC treatment had no effect on mucus accumulation or inflammation in horses during head confinement.
C) The study found that NAC was only effective in reducing mucus accumulation but had no impact on inflammatory cell counts.
D) NAC treatment reduced mucus accumulation and inflammatory cell counts, particularly neutrophils, in horses subjected to head confinement.

Answer 74

Correct Answer:
D) NAC treatment reduced mucus accumulation and inflammatory cell counts, particularly neutrophils, in horses subjected to head confinement.

This question highlights the key finding that NAC treatment was effective in reducing both mucus accumulation and inflammatory cell counts and neutrophil % in horses with head confinement.

But higher macrophages.

The efficacy of N-acetylcysteine in decreasing airway inflammation and mucus accumulation in horses with 18 hours of head confinement
jvim 2024

Question 75

You are a veterinarian working with a group of racehorses. One of the horses, a 4-year-old Thoroughbred, has just completed a racetrack exercise, and you perform a post-exercise tracheobronchoscopy to assess for exercise-induced pulmonary hemorrhage (EIPH). The horse has a tracheobronchoscopy score of 0, showing no visible signs of hemorrhage. However, you are concerned about the possibility of EIPH and decide to follow up with a bronchoalveolar lavage (BAL) to measure the number of red blood cells (BALF RBC) in the lavage fluid.

Question:

Based on the study results, what would you expect regarding the relationship between the tracheobronchoscopy score and the BALF RBC number in this horse with a score of 0?

A) A tracheobronchoscopy score of 0 reliably rules out EIPH, and no follow-up is necessary.
B) A tracheobronchoscopy score of 0 means no EIPH, but the BALFRBC number is unlikely to be elevated.
C) A tracheobronchoscopy score of 0 does not exclude EIPH, and follow-up BALF RBC testing is recommended to rule out EIPH.
D) The BALF RBC number will be higher than 992/μL, even with a tracheobronchoscopy score of 0.

Answer 75

Correct Answer:
C) A tracheobronchoscopy score of 0 does not exclude EIPH, and follow-up BALFRBC testing is recommended to rule out EIPH.

Explanation:
The study found that while tracheobronchoscopy scores can indicate the presence of EIPH, false negatives are common, particularly with a score of 0. In these cases, the BALF RBC count may still be elevated, and therefore follow-up testing with BALF RBC is necessary to definitively rule out EIPH.
The study also showed that the sensitivity of tracheobronchoscopy for diagnosing EIPH was low (59%), while BALF RBC** ≥992/μL** had much higher sensitivity (93%), indicating that BALF RBC is a more reliable diagnostic test for EIPH.

Relationship between tracheobronchoscopic score and bronchoalveolar lavage red blood cell numbers in the diagnosis of exercise-induced pulmonary hemorrhage in horses
jvim 20

Question 76

What was the main risk factor identified for exercise-induced pulmonary hemorrhage (EIPH) in British National Hunt racehorses?

A) Age
B) Current airway inflammation
C) Increased time in training
D) Type of race

Answer 76

Correct Answer:
C) Increased time in training

Explanation:
The study found that increased time in training was significantly associated with an increased risk of both tracheal blood and significant haemosiderophages in tracheal wash fluid, both of which are indicators of EIPH. This suggests that prolonged training is a key risk factor for the development of EIPH in racehorses.

Current inflammation was associated with previous haemorrhage, but not current or future haemorrhage, suggesting that haemorrhage leads to inflammation but not that inflammation leads to haemorrhage.

Training related risk factors for exercise induced pulmonary haemorrhage in British National Hunt racehorses
evj 22

Question 77

Based on the study evaluating the presence of hemosiderophages in bronchoalveolar lavage fluid (BALF) in horses with respiratory disease, what is the main predictor for the presence of hemosiderophages in horses that do not have a history of intense exercise?

A) Severe equine asthma (sEA) is significantly associated with the presence of hemosiderophages in BALF.
B) Mild-to-moderate equine asthma is more likely to show hemosiderophages in BALF than severe equine asthma.
C) Age is the primary factor predicting the presence of hemosiderophages in BALF.
D) No clear association was found between asthma severity and the presence of hemosiderophages in BALF.

Answer 77

Correct Answer:
A) Severe equine asthma (sEA) is significantly associated with the presence of hemosiderophages in BALF.

Explanation:
Hemosiderophages were found in the BALF cytology in a subset of horses that perform light or no work and presented for respiratory signs. These cells were found more frequently in horses with sEA.

Bronchoalveolar lavage hemosiderosis in lightly active or sedentary horses
jvim 2023

Question 78

In the study assessing exercise-induced pulmonary hemorrhage (EIPH) in 2-year-old Thoroughbred racehorses, which of the following statements best describes the relationship between EIPH severity and furosemide administration?

A) Prerace furosemide administration was associated with a higher likelihood of severe EIPH (grade ≥3) but did not affect EIPH occurrence.
B) EIPH severity (grade ≥3) was associated with poorer performance, as indicated by a lower speed index and finishing place.
C) Prerace furosemide administration decreased both the likelihood and severity of EIPH at most tracks.
D) EIPH severity was positively correlated with race distance and track surface, with longer races and dirt tracks increasing the likelihood of severe EIPH.

Answer 78

Correct Answer:
B) EIPH severity (grade ≥3) was associated with poorer performance, as indicated by a lower speed index and finishing place.

Explanation:
The study found that EIPH grade ≥3 was associated with poorer performance, as evidenced by lower speed index and finishing place. This indicates that severe EIPH has a negative impact on racehorse performance.
In contrast, prerace furosemide administration was associated with decreased likelihood, but not severity, of EIPH at most tracks.

Prevalence and severity of exercise-induced pulmonary hemorrhage in 2-year-old Thoroughbred racehorses and its relationship to performance
jvim 2024

Question 79

What are the clinical signs associated with paraneoplastic disease ?

Answer 79

• Fever
• Pruritus
• Anemia
• Hypercalcemia (Ca > 14 mg/dL)
• Hypertrophic osteopathy : most commonly associated with primary and metastatic pulmonary tumors

Question 80

What is the breathing pattern of tethered swimming horses?

Answer 80

A brief inspiration, followed by a period of apnoea with complete collapse of the URT including closure of the external nares, nasopharynx and rima glottidis and then a short, forced expiration.

Complete upper airway collapse and apnoea during tethered swimming in horses
evj 20

Question 81

What is the effect of inspiratory muscle training (IMT) ?

Answer 81

The study showed a lower grade of vocal fold collapse (6/9 horses), palatal instability (7/10 horses) and intermittent dorsal displacement of the soft palate (5/7 horses) post-IMT.

Inspiratory muscle training for the treatment of dynamic upper airway
collapse in racehorses: A preliminary investigation
Vet J 2021

Question 82

Based on the study investigating the effect of preoperative laryngeal function grade on postoperative performance following laryngoplasty and ventriculocordectomy (LPVC) in Thoroughbred racehorses with recurrent laryngeal neuropathy (RLN), which of the following statements is most accurate?

A) Horses with preoperative grade III.1 laryngeal function had significantly better earnings per start after LPVC compared to grade IV horses.
B) The severity of preoperative laryngeal dysfunction (grade III.2/III.3 vs. grade IV) had no effect on the likelihood of racing postoperatively.
C) Horses with preoperative grade III.2/III.3 laryngeal function were more likely to race postoperatively compared to grade IV horses.
D) Preoperative laryngeal function grade did not affect the time taken to race again after LPVC.

Answer 82

Correct Answer:
C) Horses with preoperative grade III.2/III.3 laryngeal function were more likely to race postoperatively compared to grade IV horses.

Explanation:
Laryngeal function grade may affect likelihood of racing after LPVC, but not earnings per start.

Grade III. 2/III.3 horses were more likely to race postoperatively than grade IV horses, and grade IV horses took a longer time to first race after LPVC.

The impact of grade of laryngeal function immediately prior to laryngoplasty and ipsilateral ventriculocordectomy on postoperative performance: 623 Thoroughbred racehorses (1998- 2013)
evj 2022

Question 83

Which of the following statements about respiratory disease in Ethiopian working horses is correct according to the study by Laing et al.?
A) Streptococcus zooepidemicus was significantly less common in horses with respiratory signs compared to controls
B) Viral pathogens like equine influenza virus played a major role in causing respiratory disease in this population
C) Risk factors for respiratory signs included strenuous work, drinking from stagnant water sources, and being housed on a cobbled floor
D) Horses with respiratory signs rarely had underlying lower airway pathology on examination

Answer 83

Correct answer: C) Risk factors for respiratory signs included strenuous work, drinking from stagnant water sources, and being housed on a cobbled floor

2020 Pathology, infectious agents and horse- and managementlevel
risk factors associated with signs of respiratory disease in
Ethiopian working horses

Question 84

Which of the following statements about Mycoplasma detection in horses with respiratory disorders is correct?
A) Mycoplasma felis was the predominant species detected in horses with respiratory signs
B) The prevalence of Mycoplasma spp. was significantly higher in bronchoalveolar lavage (BAL) samples compared to tracheal washes
C) There was no significant association between Mycoplasma detection and horse breed or age
D) M. equirhinis was the most commonly detected species and was significantly associated with respiratory signs

Answer 84

Correct answer: D) M. equirhinis was the most commonly detected species and was significantly associated with respiratory signs

2022 Detection of Mycoplasma spp. in horses with respiratory
disorders

Question 85

Which of the following statements about hyponatremia in horses with septic pneumopathy is correct according to the study by Migliorisi et al.?
A) Hyponatremia was more common in horses without systemic inflammatory response syndrome (SIRS)
B) There was no significant correlation between plasma sodium concentration and fibrinogen levels
C) Hyponatremic horses had a shorter duration of hospitalization compared to normonatremic horses
D) Hyponatremia was associated with higher rectal temperature, increased fibrinogen concentration, and presence of SIRS

Answer 85

Correct answer: D) Hyponatremia was associated with higher rectal temperature, increased fibrinogen concentration, and presence of SIRS

Presence or absence of pleural effusion did not influence severity of hyponatremia

2022 Hyponatremia in horses with septic pneumopathy

Question 86

What do you know about SAA and bacterial pneumonia?

Answer 86

Monitoring response to antimicrobial using SAA.
SAA decreases over course of clinical disease and correlated with clinical improvement of pneumonia, no significant correlation between SAA and other commonly monitored variables (WBC, fibrinogen)

2023 Utility of serum amyloid A in monitoring clinical response2023OK

Question 87

Which of the following statements best describes the effect of soaking hay on particulate matter (PM) exposure in horses, as demonstrated by the wearable real-time particulate monitor in this study?
A) Soaking hay had no significant effect on PM exposure
B) Soaking hay increased PM exposure by 50%
C) Soaking hay reduced PM exposure by more than 50%
D) Soaking hay only reduced PM10 exposure but not PM2.5 exposure

Answer 87

The correct answer is C) Soaking hay reduced PM exposure by more than 50%.

The study utilized a custom-built wearable particulate matter (PM) monitor called the Black Beauty (BB) to assess the effect of soaking hay on PM exposure in horses.
Results showed that feeding soaked hay significantly reduced both PM2.5 and PM10 exposures:
For PM2.5, short-term (20-min) exposure was reduced from 160 μg/m3 (dry hay) to 53 μg/m3 (soaked hay), and extended (8-h) exposure was reduced from 76 μg/m3 to 31 μg/m3.
For PM10, short-term exposure was reduced from 2829 μg/m3 (dry hay) to 970 μg/m3 (soaked hay), and extended exposure was reduced from 1581 μg/m3 to 488 μg/m3.

2024 A wearable real-time particulate monitor demonstrates that soaking hay reduces dust exposure

Question 88

Which of the following statements best describes the relationship between tracheobronchoscopic (TBE) scores and bronchoalveolar lavage fluid red blood cell (BALFRBC) numbers in diagnosing exercise-induced pulmonary hemorrhage (EIPH) in horses?
A) TBE scores and BALFRBC numbers are strongly correlated and equally sensitive
B) TBE scores are more sensitive than BALFRBC numbers in detecting EIPH
C) BALFRBC numbers are more sensitive than TBE scores in detecting EIPH
D) TBE scores and BALFRBC numbers are weakly correlated and equally sensitive

Answer 88

The correct answer is C) **BALFRBC numbers are more sensitive than TBE scores in detecting EIPH. **

The correlation between TBE score and BALFRBC number was significant but weak (P<.001; rs=0.42).

The sensitivity of TBE for diagnosing EIPH was poor (0.59; 95% confidence intervals [CI], 0.49-0.68), compared to BALFRBC number ≥992/μL (0.93; 95% CI, 0.88-0.96).
There were 75 instances where the TBE score equaled 0 although the BALFRBC number was ≥992/μL, indicating false negatives with TBE.

If the goal is to identify whether a horse is positive for EIPH, then BALFRBC number is the single test of choice because it has a much higher sensitivity (0.93 versus 0.59).