LAM I Exam II Material Flashcards
What drug is most often used initially in non-strangulating colic cases?
Flunixin Meglumine
T/F: Nervous and tense horses seem to be predisposed to developing DDSP
True
likely by natural head/neck position when in this state of behavior
A middle-aged or older afebrile horse with recurrent seasonal episodes of expiratory dyspnea/distress is the classic presentation for what respiratory disorder in horses?
recurrent airway obstruction (RAO)
What laryngeal hemiplegia (LH) treatment option can be performed if the owner is only really worried about the noise associated with the disorder?
ventriculectomy, ventriculocordectomy
reduces noise and stabilizes arytenoid cartilage; does not improve airway mechanics as well as other procedures
T/F: In Type II IAD, eosinophils make up greater than 2% of the total cell count
False
- In Type II IAD, mast cells make up greater than 2% of the total cell count*
- In Type III IAD, eosinophils make up greater than 3% of the total cell count*
What age group is most affected by laryngeal hemiplegia?
all ages are affected, but incidence is highest in young horses (2-3 yr old racehorses)
T/F: CBC and serum chemistry is typically normal in cases of recurrent airway obstruction (RAO)
True
T/F: Laryngoplasty is indicated for treatment of laryngeal hemiplegia in grade IIIB, IIIC, and IV affected horses
True
What is your diagnosis?
left laryngeal hemiplegia
In Type III IAD, eosinophils make up greater than ____% of the total cell count
> 3% of total cell count
In Type III IAD, eosinophils make up greater than 3% of the total cell count
Which is the predominant cell type in the BAL of horses with RAO?
Neutrophils
When strangles begins to spread and become more generalized than just the lymph nodes draining the throat, this is termed:
bastard strangles
- Metastasis to lymph nodes throughout body, most commonly to lung, mesentery, liver, spleen, kidney, brain
- Typically involves the abdomen (Can lead to local and diffuse peritonitis – adhesions and ileus)
- Difficult to treat, long-term antimicrobial therapy – often results in death of affected horse
What is the most likely diagnosis for the picture shown?
Epiglottic entrapment
EE is an upper airway condition that can produce exercise intolerance, respiratory noise, & occasional coughing (especially when eating)
What is the predominant cell type encountered in Type III IAD?
What is the preferred treatment option?
eosinophils
Treat with corticosteroids
What are the two types of DDSP? Which is more common?
intermittent and persistent
intermittent (IDDSP) is more common
If you see Curshmann Spirals in the BAL evaluation of a horse with overexpanded lung fields, what would you expect to find on pulmonary auscultation?
expiratory wheeze
The question is describing a horse with RAO.
On thoracic auscultation of a depressed tachypneic horse you hear loud breath sounds over the dorsal lung fields. At approximately the level of the point of the shoulder breath sounds completely disappear and you hear louder heart sounds throughout the thorax from this point ventrally.
Based on these physical findings, what is the most likely diagnosis?
Pleuropneumonia
What is the predominant cell type encountered in Type II IAD?
What is the preferred treatment option?
Mast cells
Treat with cromolyn sodium (mast cell stabilizer)
What is the drug of choice for treatment of all complicated strangles cases?
Penicillin
T/F: High populations of neutrophils, eosinophils, and mast cells are characteristic for recurrent airway obstruction (RAO)
False
Neutrophilic inflammation (35-50% of total cells) is characteristic for RAO. Eosinophils and mast cells are NOT characteristic of this disease
What corticosteroid should you use in a horse with RAO and mild dyspnea at rest?
prednisolone
Transferrin is the carrier protein responsible for iron transport and distribution in the body. It can be measured by evaluation of __________
TIBC
Total Iron Binding Capacity
Which one of the following is not a part of strangles control on a horse farm?
- Quarantine new arrivals to stable
- Prophylactic antibiotics for close contacts
- Isolate clinically affected animals
- Clean water and feed buckets, utensils, hands
- Identify / isolate persistent carriers
Prophylactic antibiotics for close contacts
What would you expect to see on CBC in a horse with bacterial pneumonia secondary to equine influenza?
neutrophilic leukocytosis with hyperfibrinogenemia
T/F: Fever and lymphadenopathy are major clinical signs associated with strangles
True
Fever is the first clinical sign and is maintained as lymphadenopathy develops and abscesses mature
T/F: Horses with DDSP will often present with a “roaring” noise
False
- Horses with DDSP will often present with a “gurgling” noise. The noise is generated by air turbulence in inspiration and expiration, mostly EXPIRATORY component*
- During expiration air is expelled into the nasopharynx (normal) and oropharynx (abnormal) thus resulting in puffing of cheeks*
- Approximately 30% of DDSP cases do not make a noise *
With which subtype of equine herpesvirus would you expect to see the highest incidence of abortion?
EHV-1
In contrast to EHV-4 (which is mostly limited to the respiratory tract), EHV-1 establishes a lymphocyte-associated viremia, which is responsible for the delivery of virus to the pregnant uterus and other tissues
Name the two types of DDSP. Which is the most common?
intermittent and persistent
Intermittent is the most common. It is a significant performance-limiting condition in the horse and is only seen during exercise
What is the best treatment option for HyPP horses during acute episodes with severe hyperkalemia?
IV Ca gluconate
What are the two most important factors for management of a horse with recurrent airway obstruction (RAO)?
- keep outside at all times
- wet down/soak hay
T/F: Perivascular jugular injections are thought to be a common potential cause of right laryngeal hemiplegia
True
If you have a horse with recurrent unilateral nasal discharge that worsens when its head is lowered, what should your top differential be?
guttural pouch empyema
Clinical signs wax and wane with antimicrobial and anti-inflammatory use. The discharge is generally non-odorous, white, and opaque.
What is your diagnosis?
arytenoid chondritis
Most frequently seen in thoroughbred racehorses and suspected to be caused by frequent trauma to the arytenoid cartilages (recurrent NG intubation)
What type of rhabdomyolysis is more likely to be present in a 2-4 year old “high strung” Filly that is used as a weekend rider?
Type I
Type I is associated with limited exercise
What dietary change may help in the treatment of both polysaccharide storage myopathy (PSSM) and recurrent exertional rhabdomyolysis (RER)?
- Increase the grain component of the ration
- Increase the amount of protein supplement
- Increase selenium and vitamin E supplementation
- Reduce the amount of grain and increase the amount of fat
Reduce the amount of grain and increase the amount of fat
What horse breed is most at-risk for developing a rectal tear as the result of rectal palpation?
Arabians
- Rectal tears usually occur between 10 and 2 o’clock (dorsal aspect of rectum), 25-30 cm from anus, cranial to the peritoneal reflection at the pelvic inlet*
- This is thought to be due to an inherent weakness of the intestinal wall in this area, due partly to the direct penetration of short terminal arteries on either side of the mesenteric tenia and partly to the lack of serosa on this segment of bowel where it is enclosed by the mesorectum.*
- Gross.*
The method shown is a conservative treatment option for what respiratory disorder in horses?
dorsal displacement of the soft palate (DDSP)
The tongue-tie prevents caudal retraction of the larynx, hopefully increasing the contact surface of the palate and epiglottis
Dictyocaulus anfieldi (lungworm) infection is clinically indistinguishable from RAO. How do you differentiate between the two on TTW?
lungworm infection will have have eosinophils
RAO manifests as a neutrophilic inflammation
You may also see the actual parasite on TTW or BAL
T/F: Clinical signs of epiglottic entrapment (EE) include exercise intolerance, inspiratory and expiratory noise, cheek puffing, and chronic cough (especially when eating)
False
Clinical signs of epiglottic entrapment (EE) include exercise intolerance, inspiratory and expiratory noise, and chronic cough (especially when eating), but do not include cheek puffing.
Cheek puffing is associated with DDSP
T/F: Strangles is a highly contagious disease associated with infection by S. zooepidemicus
False
Strangles is a highly contagious disease associated with infection by Streptococcus equi
T/F: PSSM is the result of the autosomal recessive inheritance of defective glycogen synthase
False
PSSM is the result of the _autosomal dominant_ inheritance of defective glycogen synthase
What is the major target cell for EIA?
macrophages
T/F: Adult interstitial Pneumonia is invariably fatal in horses
True
- Chronic, progressive disease occurring rarely in the adult horse. Clinical signs are indistinguishable from COPD, however horses are unresponsive to conventional therapy for COPD. This condition is invariably fatal and the exact etiology remains unknown, however, toxins have been suspected by some investigators*
- Disease is confirmed by LUNG BIOPSY*
T/F: Purpura hemorrhagica is an important complication seen in strangles, both with natural occurring infection as well as the vaccination
True
T/F: In cases of recurrent airway obstruction (RAO), the degree of neutrophilia is helpful in determining the severity of disease
FALSE
What is the predominant cell type encountered in Type I IAD?
What is the preferred treatment option?
Neutrophils
Treat with alpha-interferon
What is the preferred treatment protocol for a horse with RAO in severe distress?
inhalant bronchodilators and systemic steroids
probably injectable dexamethasone and inhalant albuterol
In Type II IAD, mast cells make up greater than ____% of the total cell count
> 2% (some cases up to 25%)
In Type II IAD, mast cells make up greater than 2% of the total cell count
T/F: Laryngeal hemiplegia (LH) is associated with a ‘roaring’ noise on expiration
False
Laryngeal hemiplegia (LH) is associated with a ‘roaring’ noise on inspiration
What corticosteroid should you use in a horse with RAO and moderate to severe dyspnea at rest?
dexamethasone
The most common cause of anemia in large animals is that associated with decreased red cell production, more particularly:
anemia of chronic disease
Accumulation of purulent material is termed:
empyema
T/F: A “tie-back” or laryngoplasty is a treatment option for the upper airway disease shown below
True
The image shows laryngeal hemiplegia
T/F: Viruses and bacteria are implicated in the pathogenesis of inflammatory airway disease (IAD)
True
How long is the incubation period for equine influenza?
1-3 days
therefore you can often expect many horses to be at same stage of the disease concurrently
With regard to equine influenza, what is the term used to describe the gradual alteration in HA and NA antigens due to random mutation, often limiting vaccine efficacy?
antigenic drift
What is the most common physiologic arrhythmia in the horse?
2nd degree AV block
With regard to equine influenza, what is the term used to describe the emergence of a new strain caused by sudden change in HA that has no apparent relation to HA of previously identified influenza strains, and may result from recombination of two virus strains?
antigenic shift
T/F: Horses with strangles will typically have no clinical signs except for fever for the first few days post-infection
True
During this time, the bacteria is multiplying
With which subtype of equine herpesvirus would you expect to see the highest incidence of respiratory disease?
EHV-4
What is your diagnosis?
dorsal displacement of the soft palate (DDSP)
T/F: If a horse with strangles is eating okay and is not depressed, it may be best to let the disease run its course
True
In this situation, it is recommended to accelerate maturation of abscesses, aid drainage of lymph nodes using hot packs, etc
What age group of horses is typically at higher risk of developing strangles?
younger horses (YEARLINGS)
What is the drug of choice for benign atrial fibrillation in horses?
Quinidine
Would you expect to see respiratory distress at rest in a horse with DDSP?
No
- Horses with DDSP may not have any obvious clinical signs, especially at rest*
- Respiratory distress usually occurs during the last half of the race*
T/F: Horses affected with atrial fibrillation are likely to manifest syncope
False
Horses affected with ventricular tachycardia are likely to manifest syncope
Name the bacterial agents associated with guttural pouch empyema:
Streptococcus equi and Streptococcus zooepidemicus
The term ‘idiopathic laryngeal hemiplegia’ is only used to refer to _____-sided laryngeal hemiplegia
left
The term ‘idiopathic laryngeal hemiplegia’ is only used to refer to left-sided laryngeal hemiplegia
Which is the drug of choice for treatment of ventricular tachyarrhythmias in the horse?
Lidocaine
The Cornell Collar is a conservative treatment option for what upper airway disease?
DDSP
The Cornell DDSP collar holds larynx in place such that displacement does not occur (positioning larynx more rostrally and dorsally)
T/F: A “tie-back” or laryngoplasty is a treatment option for the upper airway disease shown below
False
The image shows dorsal displacement of the soft palate (DDSP). Laryngoplasty is NOT a treatment option for DDSP.
_Laryngeal tie-forward_ is a treatment option for DDSP
Moving aborally through the equine large colon, what structure will follow the pelvic flexure?
left dorsal colon
You are evaluating a 17-year-old Paint gelding found thrashing, pawing, and throwing himself to the ground for the last 6 hours. On rectal palpation you note presence of many tightly distended, bandless “loops of sausages” in caudal abdomen.
T/F: From this description, this horse has a strangulating small colon disease
False
- From this description, this horse has a strangulating small intestinal disease*
- There are two palpable areas of the GI tract that may feel like “loops of sausages”: the small colon and the small intestine. If the structure has a BAND, it must be the small colon. Otherwise, it is the small intestine*
A 2-year-old Standardbred racing colt is diagnosed with inflammatory airway disease. He has received multiple treatments and appears to respond best to alpha interferon.
What cell type do you expect to be most significantly increased in this horse’s BAL?
Neutrophils
The question is desribing Type I inflammatory airway diseases. These are most commonly encountered with mild neutrophilia (5-20%) and respond best to alpha-interferon
What is your diagnosis?
epiglottic entrapment (EE)
What is the most reliable means for diagnosis of recurrent exertional rhabdomyolysis (RER)?
muscle biopsy
observation of centralized nuclei (rather than the normal peripheral fiber location)
Polysaccharide storage myopathy (PSSM) is a degenerative myopathy characterized by a point mutation in the __________ gene
glycogen synthase 1
Polysaccharide storage myopathy (PSSM) is a degenerative myopathy characterized by a point mutation in the glycogen synthase 1 gene
What is the most likely diagnosis in this horse?
inflammatory airway disease (IAD)
Note the mucopurulent exudate (“mucus trail”)
What type of rhabdomyolysis is more likely to be present in an endurance horse or high competition horse?
Type II
Type II is associated with protracted exercise
Name the preferred surgical treatment option for the disorder shown below:
Transendoscopic laser correction
Epiglottic entrapment (EE) is shown in the image
With regard to recurrent airway obstruction (RAO) in horses, is resistance to airflow greatest during inspiration or expiration?
expiration
small airways collapse during expiration due to high pleural pressure, resulting in excessive expiratory effort and an end-expiratory wheeze
With regard to strangles, when is the disease most contagious?
After rupture, drainage of lymph nodes
This usually occurs 7-14 days after infection
What respiratory noise is typically expected with this presentation in a horse?
roaring
Laryngeal hemiplegia is pictured
What is the most common pathologic arrhythmia in the horse?
atrial fibrillation
Chondroids are associated with what disorder in the horse?
Guttural pouch empyema (GPE)
When treating a horse with atrial fibrillation, it is important to take into consideration the duration of the arrhythmia. If the horse developed the arrhythmia within the past 72 hours, would you administer quinidine orally or intravenously?
intravenously
- Within 72 hrs of first developing, you can use IV formulation of quinidine
- If longer than 72 hrs duration use oral formulation
T/F: When performing an ultrasound on a horse with pleuropneumonia, gas bubbles are indicative of anaerobic organisms
True
T/F: Rhodococcus equi is a Gram-positive, pleomorphic rod that causes severe subacute to chronic bronchopneumonia and pulmonary abscessation in adult horses
False
Rhodococcus equi is a Gram-positive, pleomorphic rod that causes severe subacute to chronic bronchopneumonia and pulmonary abscessation in foals (up to 6 months of age). Adults and foals greater than 6 months of age seem to be protected from this disease
What is the antibiotic combination of choice for treatment of Rhodococcus equi?
Erythromycin and Rifampin
Keep in mind that Rhodococcus equi is difficult to treat. There is usually poor uptake of antibiotics into the cell, resulting in low intracellular concentration
What is the most common site for bacterial endocarditis in the equine?
mitral valve
Aortic insufficiency causes a (systolic/diastolic) murmur, whereas mitral insufficiency causes a (systolic/diastolic) murmur
aortic insufficiency causes a diastolic murmur
mitral insufficiency causes a systolic murmur
On Rhodococcus equi-endemic facilities, foals should be treated within first week of life with:
R. equi hyperimmune serum
You are called out to a farm to examine a 2-year old filly. The initial client complaint was decreased exercise tolerance. As you walk up to the horse you notice an audible inspiratory stridor, what is your most likely diagnosis?
- Idiopathic Laryngeal Hemiplegia
- Grade 4 EIPH
- Ethmoid hematoma
- Bilateral Laryngeal Hemiplegia
Bilateral Laryngeal Hemiplegia
Clinical signs in unilateral laryngeal hemiplegia cases are only seen during exercise
A 12 year old Arabian mare presents with severe respiratory distress. Upon examination you note definitive heave line and expiratory wheezes on lung auscultation. Mucous membranes appear slightly cyanotic. Treatment?
- Nebulized Beclamethasone
- Dexamethasone IV + Albuterol
- Inhalant albuterol & Beclamethasone
- Prednisolone + atropine
Dexamethasone IV + Albuterol (inhalant)
Which respiratory disease is caused by inhalation of a microorganism that multiplies in dirt, particularly that contaminated with horse feces
- S. equi var zooepidemicus pneumonia
- RAO
- Pleuropneumonia
- R. equi pneumonia
- S. equi var equi lymphadenopathy
R. equi pneumonia
T/F: Pleuropneumonia is often caused by the flare up of a pre-existing abscess in the lung due to stress
True
On auscultation of the lung, what is the first thing that will indicate to you that the horse may have pleuropneumonia?
- Percussion of the “fluid line”
- Cranioventral lung sounds
- Generalized lung sounds
- Absent lung sounds in cranioventral area
Absent lung sounds in cranioventral area
What are the three main infectious agents implicated in purpura hemorrhagica in the horse?
S. zooepidemicus, S. equi, and Influenza
Which of the following is not a type of treatment for VPC/Tachyarrhythmia:
- Rest to resolve myocardial damage
- Emergency case: Lidocaine (IV)
- Atropine IV
- Fluids to correct electrolyte abnormalities
Atropine IV
A horse is presented with acute decompensation after a rupture of the chordae tendinae. What is the associated condition?
mitral insufficiency
A 17-year-old Morgan stallion was found to have a grade III/VI holodiastolic, noisy murmur over the left heart base and slightly audible on the right side on yearly PE. The most likely diagnosis is:
- Tricuspid insufficiency
- Aortic insufficiency
- Mitral insufficiency
- VSD
- Atrial septal defect
Aortic insufficiency
T/F: On rectal palpation, the small intestine is not palpable in the normal horse
True
The small intestine is not palpable in the normal horse and finding either gas distended small intestinal loops or thickened small intestine is abnormal
How many bands are present on the small colon? How many are palpable per rectum?
2 are present; 1 is palpable
With regard to colic, what heart rate is compatible with a strangulating lesion?
>70-80 bpm
