DMN: practice questions (week 9)

dysphagia/esophageal diseases, US imaging of GIT, GDV, gastric surgery SA, acute + chronic V/D SA, equine gastric disorders

What is the structure marked with the blue arrow on the following longitudinal scan of the liver in a feline patient?

Gallbladder

What blood vessels surround the cranial + dorsal aspect of the left adrenal on abdominal scans?

Cranial mesenteric artery (CMA) + Celiac artery (CA)

Millie, an 8yo intact female MBD presented for a 3-day history of vomiting, polyuria, lethargy, & inappetence. Her last heat was 2 months ago. On presentation, she has dull mentation, temp is 104°F, HR 180 bpm, red MM, CRT <1 sec, & weak femoral pulses. Two 20 mL/kg fluid boluses result in temporary improvement in perfusion parameters, but they worsen again shortly afterward.

What is the most likely type of shock + most appropriate initial treatment in this case?

Septic/distributive shock → norepinephrine CRI

Batman, a 2yo MN Labrador Retriever presented 30 minutes after being hit by a car. On presentation, he is dull, temp is 99°F, HR 160 bpm, pale MM, CRT 3 sec, & weak femoral pulses.

What is the most likely type of shock + most appropriate initial treatment in this case?

Hypovolemic/hemorrhagic shock → fluid resuscitation

Caroline, an 8yo FS Great Dane presented for severe lethargy. She has a history of progressive weakness, exercise intolerance, & respiratory problems. On presentation, she is lethargic + tachypneic with increased respiratory effort, pale mucous membranes, cold extremities, weak + irregular pulses, & marked tachycardia. ECG shows atrial fibrillation. POCUS reveals marked cardiac dilation + poor contractility.

What is the most likely type of shock + most appropriate initial treatment in this case?

Cardiogenic shock → positive inotropic support; antiarrhythmic therapy + diuretics may be indicated

Rex, a 7yo MI German Shepherd presented for a 2-hour history of restlessness + unproductive vomiting. On presentation, he is QAR, HR 154 bpm, with pale pink MM, CRT 2 sec, weak femoral pulses, & cold extremities + ears. His abdomen is markedly enlarged + painful, with a tympanic sound on percussion.

What is the most likely type of shock + most appropriate initial treatment in this case?

Obstructive shock → fluid resuscitation + relief of the obstruction 

During a gastrotomy, which technique best minimizes the risk of contamination from gastric contents?

Pack off the stomach with moistened laparotomy sponges & place full-thickness stay sutures around the incision site

Which suture pattern is preferred for closure of procedures involving gastric outflow, such as pyloroplasty?

Appositional pattern

Which type of hiatal hernia involves movement of the gastroesophageal junction cranial to the diaphragm?

Type I - sliding hiatal hernia

Which gastric neoplasm is most commonly reported in dogs?

Gastric adenocarcinoma

What correctly describes linitis plastica associated with gastric carcinoma?

Diffuse infiltration & thickening of the stomach wall, resulting in a nondistensible stomach

When can oral food + water generally be initiated after gastric surgery in a patient that is not actively vomiting?

Approximately 12 hours after surgery

Why is the cysto-colic view of the AFAST procedure useful immediately before + during cystocentesis?

To confirm enough distension of the bladder + To exclude bladder pathologies as bladder masses

What are the steps involved in swallowing/deglutition?

1. Oral preparatory (voluntary)

2. Oral (voluntary)

3. Pharyngeal (involuntary)

4. Esophageal (involuntary)

What are the common complaints (clinical signs) from owners when their pet is presenting with dysphagia?

Pain, messy eating/dropping food, regurgitation, halitosis, pawing at mouth

What are the main viruses that may cause oral lesions in cats?

Calicivirus, Herpesvirus, FIV/FeLV, Rabies

What are the main viruses that may cause oral lesions in dogs?

Rabies + Distemper

What are some of the common benign masses that may cause dysphagia in companion animals?

-Granuloma, Sialocele/Ranula (tongue)

-Peripheral odontogenic fibromas, Canine peripheral ameloblastomas (gums)

What are some of the common malignant tumors that may cause dysphagia in companion animals?

SCC, Melanoma, Fibrosarcoma

How should you treat a sialocele (damaged salivary gland/duct) as well as obstructive lesions to the salivary glands such as masses (carcinoma) or sialoliths in companion animals?

Surgical correction

What is the non-painful swelling of the salivary glands in companion animals that responds well to Phenobarbital treatment?

Sialadenosis

What is the self-limiting virus of the cheek + gums in companion animals that can bleed if traumatized & a vaccine can help minimize its spread?

Papillomavirus

A dog presents with repeated swallowing, food coming out through the nose, & gagging. Where can you most likely localize the reason for this dysphagia?

Pharynx

Where do we most commonly find esophageal foreign bodies in companion animals?

Thoracic inlet, Base of heart, Caudal esophagus (just cranial to diaphragm)

A dog presents with regurgitation as the only clinical sign. Where can you most likely localize the reason for this dysphagia?

Esophagus

A dog presents with food dropping from the mouth, painful chewing, & excessive salivation. Where can you most likely localize the reason for this dysphagia?

Oral/facial lesions

What are the main differentials for a dog who cannot transport food/liquid down the esophagus due to a structural or functional problem?

Megaesophagus, Lower esophageal sphincter achalasia (LES), Dysautonomia

What are the main differentials for a dog that seems in pain when transporting food/liquid down the esophagus due to irritation or inflammation?

Esophagitis (secondary to vomiting), Esophageal ulcer, Mass

A dog presents with dysphonia, gagging, & inspiratory stridor. Where can you most likely localize the reason for this dysphagia?

Larynx

What types of GI conditions require emergency intervention in companion animals?

-Conditions causing dyspnea → obstructive/compressive FB

-Hypovolemic shock → GI hemorrhage

-Acute abdomen/non-productive retching

What are the biggest things that may cause Gastroesophageal reflux disease (GERD) in companion animals?

Vomiting, Anesthesia, Atropine, Acepromazine

A dog presents with regurgitation, extension of the head/neck, ptyalism, repeated swallowing attempts, pain, depression, & anorexia. You narrow the diagnosis down to esophagitis. What are some of the things that could be causing this animal’s esophagitis (inflammation of the esophagus?

FB, GERD, Drugs (Doxycycline), Spirocerca lupi

How can we treat esophagitis in companion animals after diagnosing via endoscopy or esophagram?

-If GERD → H2 receptor antagonists/PPI/Sucralfate

-Small frequent soft meals low in fat + fiber via tube

-Pain mgmt

What are the treatment options for companion animals with an esophageal stricture (severe inflammation affecting the muscularis layer)?

Balloon catheter dilation, Bougienage, Stents, or Surgical resection

What is the immune mediated, paraneoplastic condition where antibodies are produced against the nicotinic acetylcholine receptors found at the neuro-muscular junction?

Myasthenia gravis

What is the most common type of hiatal hernia, seen mainly in brachycephalic breeds or Shar peis, diagnosed via survey radiographs or contrast study?

Sliding/axial

What is the disease typically seen in large breed dogs 1-3yrs old that presents as temporal/masseter pain (opening/closing the jaw) & how is it typically treated?

Masticatory myositis → prednisolone

-see hyperglobulinemia, anemia, increased CK, + proteinuria

What esophageal procedure is described by an incision into the esophageal lumen?

Esophagotomy

What esophageal procedure is described by partial resection of the esophagus?

Esophagectomy

What esophageal procedure is described by the creation of an opening in the esophagus to place a feeding tube?

Esophagostomy

What type of muscle do horses have in their esophagus?

Upper 2/3 is striated, lower 1/3 is smooth

What is the most common clinical sign for esophageal disease in horses?

Ptyalism (hypersalivation) → from nostrils

What are some of the main differentials for ptyalism/dysphagia in horses that must be ruled out prior to assessing the esophagus for a diagnosis?

-Oral cavity abnormalities

-Guttural pouch abnormalities

-CN abnormalities → Prehension (VII), Mastication (CN V, VII, XII), Swallowing (CN IX, X)

What is the most dangerous disease of the guttural pouch as they can erode arteries & cause life-threatening nosebleeds in horses, diagnosed via endoscopy?

Fungal mycosis

What are the main clinical signs associated with a horse diagnosed with choke (esophageal obstruction)?

Frothy nasal discharge, feed coming from nostrils/mouth, ptyalism, gagging/retching, coughing

What should we use to sedate a horse when performing a diagnostic evaluation for a potential choke diagnosis?

Xylazine (a2 agonist)

-also ensure head is lower than point of shoulder

What medications can be used to relax the upper vs. lower esophagus while performing diagnostics for a horse with potential choke?

-Upper 2/3 (striated) → Oxytocin

-Lower 1/3 (smooth) → Buscopan

A 22yo Thoroughbred mare is presented for bilateral green nasal discharge, retching, coughing, & inappetance noted after her evening meal. The owner recently switched this mare to a pelleted diet because of her poor dentition. A slight swelling is noted in the proximal-left jugular groove, just caudal to the ramus of the mandible. Based on the presumed diagnosis, what is the best initial treatment protocol?

Withhold food + water, give sedatives + oxytocin, & recheck in 2 hours

If you have already attempted to sedate + provided analgesia, passed a NG tube, & pumped water while keeping the horse’s head low in a persistent case of choke with no resolution, what should you try next?

Place horse in stall → NPO, IV fluids + electrolytes, sedatives/relax esophagus, give time

-sometimes surgery is necessary

If a horse presents with a prolonged choke (>48hrs), how should we treat the horse?

Broad spectrum abx, NSAIDs, Sucralfate, Refeeding considerations (easily digestible feed, no grain/concentrates)

What are some of the secondary complications of choke in horses?

Aspiration pneumonia, esophageal stricture (linear or circumferential), esophageal rupture

If a horse presents with congenital megaesophagus, which breed are we most likely evaluating?

Friesian

What is the proper systematic “scan approach” when performing an abdominal ultrasound on companion animals?

Cranial → caudal, Clockwise/anti-clockwise

-Liver → spleen → LK + adrenal → bladder → GIT → pancreas →RK + adrenal → LNs + blood vessels → peritoneal + retroperitoneal spaces

On ultrasound, what shape is the gallbladder on longitudinal vs. transverse scans in a dog?

Longitudinal: tear-drop shaped

Transverse: round

How is the gallbladder different in cats than in other species?

Occasionally will be bi-lobed

-also can see more of the biliary tree upon US of gallbladder in cats (cystic duct)

When biliary sediment/sludge is not an incidental finding in dogs, what are some things that may have caused this mixture of precipitated crystals, glycoproteins, cellular debris, & mucin?

Stagnant biliary flow or Gallbladder dysmotility

What might biliary sediment/sludge along with gallbladder wall thickening be a result of in cats?

Inflammatory biliary disease (cholecystitis)

What could be the consequence of a gallbladder mucocele in middle aged-older small to medium breed dogs (dachshunds!), formed by accumulation of thick, mucin-laden bile in the gallbladder?

Ischemic necrosis of the GB → opportunistic bacterial infection → bile peritonitis

What are some of the differential diagnoses that may cause diffuse thickening of the wall of the gallbladder in small animals, associated with clinical signs such as fever, vomiting, weight loss, & icterus?

-Cholecystitis

-Portal hypertension

-Extracholecystic inflammation → acute hepatitis, pancreatitis, peritonitis

-RS heart failure, renal failure, neoplasia

-Anaphylaxis (AFAST)

What is the main sign that there is increased wall thickness of the gallbladder in small animals upon ultrasound?

Halo sign/effect ± surrounding fluid

This is a longitudinal sonographic image of the gallbladder in a 4yo FS DSH presenting with fever, abdominal pain, & elevated liver enzymes. What do the findings indicate?

Thickened gallbladder wall

What organs surround the pancreas to locate it when performing ultrasonography in small animals?

Stomach + Descending duodenum

What is the normal echogenicity of the pancreas compared to surrounding fat on ultrasound in small animals?

Isoechoic

A dog with suspected acute pancreatitis presents to you. You decide to perform an ultrasound to confirm. What sonographic changes do you expect to find?

Enlarged + hypoechoic parenchyma, hyperechoic mesentery

-”irregular hypoechoic + hyperechoic areas” → necrosis or edema, hyperechoic only → fibrosis

What three concurrent conditions mean a cat has “triaditis”?

Pancreatitis + IBD + Hepatic lipidosis

This is a longitudinal sonographic image of the left limb of the pancreas in a 4yo FS DSH presenting for a long-standing history of lethargy + reduced appetite. On presentation the cat was icteric. What are the sonographic findings?

Hypoechoic pancreas + Hyperechoic mesenteric fat

What structures surround the left adrenal gland to make it easier to locate on ultrasound?

-Ventral to aorta

-Just cranial to left renal artery

-Left kidney

What structures surround the right adrenal gland to make it easier to locate on ultrasound?

-Caudal vena cava

-Right kidney

What is the maximum dorsoventral width of the left adrenal gland before it indicates adrenal enlargement (PDH/ADH)?

7.4mm

These are longitudinal sonographic images of the left + right adrenal glands in a 12yo FS Golden Retriever presenting with dysuria, reduced appetite, & lethargy. The maximum width of the caudal pole of the right adrenal was 7mm, while the left adrenal was 6.5mm. What do the findings suggest?

Normal size + echogenicity of the adrenals

What is the normal echogenicity of the fat surrounding most organs in the abdomen upon ultrasound in small animals?

Coarse echotexture & low-moderate echogenicity w/ hyperechoic speckles

What are the main plants that may cause mild to moderate GI signs in small or large animals upon ingestion, such as mild abdominal pain, diarrhea, dehydration, & colic?

Iris, Daffodil, Pokeweed

What are the main plants that start by causing severe GI signs, but will eventually affect other organs such as the liver, heart, kidneys, etc.?

Sago Palm, Oleander, Bracken Fern, Oak, Pig Weed

What is the toxic plant that can cause mouth irritation (erythema + swelling), excessive salivation, & vomiting/diarrhea due to an oily glycoside called ranunculin that is converted by plant enzymes to protoanemonin, eventually leading to liver damage + secondary photosensitization as well as hematuria & red coloration of milk in production animals?

Ranunculus sp. (Buttercup)

-trx with palliative care

What is the toxic plant that is associated with severe hemorrhagic diarrhea leading to hypovolemic shock, decreased BP, weakness, collapse, & copious thick/ropy salivation due to consumption of the plant’s seeds?

Ricinus communis (castor bean/lectins)

Which species are most severely affected by Senna seed toxicity, which leads to tenesmus, anorexia/depression/recumbency, cardiac insufficiency, & muscle weakness due to skeletal + cardiac muscle degeneration?

Pigs + Chickens

What fruit is most commonly responsible for causing phytobezoars (impaction of fruit in stomach/SI or rumen) in animals, leading to severe colic, absence of gut motility, increase in HR, perforations of gastric ulcerations, or peritonitis?

Diospyros sp. (Persimmon)

How can we treat a GI impaction caused by Persimmon?

-Administer oral mineral oil

-Mechanical breakup via endoscope or dissolve via cellulase enzyme (or coca cola)

-Surgical intervention if stubborn

Which toxin is responsible for inhibiting ribosomal protein synthesis?

Ricin

How can we treat an animal with Capsicum (pepper) toxicity, which shows symptoms of oral irritation at the site of contact, hypersalivation, or V/D if large amounts are ingested?

Cool water irrigation, administer mineral/vegetable oils (coconut oil)

What are the ornamental plants that cause immediate swelling of the lips/tongue/mouth, hypersalivation, mild/severe pain, & conjunctivitis due to release of oxalate crystals (raphides) from the stem + leaves as the animal eats?

Deiffenbachia sp. (dumbcane), Epipremnum sp. (golden pothos/devil’s ivy), Philodendron sp.

-trx with sedation, NSAIDs, soft food, + steroid ointment for eyes

What is the toxic plant that causes sneezing with greenish salivation (spewing sickness) as well as vomiting, eventually leading to liver degeneration in sheep + goats due to lactones & pseudoguaianolides?

Helenium (sneezeweeds) + Hymenoxys (bitterweeds)

What is the toxic fungus found on red clover that produces slaframine (indolizidine alkaloid), leading to slobber’s disease in horses?

Rhizoctonia leguminicola

What are the toxic plants that contain that toxin grayanotoxin which binds to voltage-gated sodium channels on membranes, causing a delay in closing of the channels leading to weakness, depression, regurgitation (projectile - asp. pneum.), etc. in sheep + goats?

Rhododendron sp. + Kalmia sp.

What is the primary toxic component of Zigadenus sp. (death camas), which increases the permeability of sodium channels of nerve cells, leading to continuous firing followed by decreased excitability, which shows clinical signs such as profuse frothy salivation, hyperexcitability followed by severe weakness, grinding of the teeth, etc.?

Zygacine alkaloid

Which type of medications can cause gingival hyperplasia in small animals?

Calcium channel blockers (amlodipine, nifedipine)

What should you always avoid doing as a treatment method for chemical ingestion in small animals?

Gastric lavage/stomach emptying

What clinical sign is most seen in horses after ingesting red clover infested with the fungus Rhizoctonia leguminicola?

Slobbers (ptyalism)

What antibiotic can induce severe colitis in horses associated with major changes in the intestinal microflora (Clostridium difficile)?

Erythromycin

What is the substance that Blister beetles secrete that acts as a blistering agent to animals hidden within alfalfa bales, leading to ulcerations/erosions & causing horses to submerge their muzzle in water for prolonged periods?

Cantharidin

-poor to guarded prognosis for affected animals, death usually within 3-18 hours of onset

What releases a Bufotoxin, causing CNS (hallucinogenic), CVR (digoxin-like), hyperthermia, + GI symptoms in those that come into contact with it?

Bufo toad

What are some of the items that may cause zinc poisoning in animals if ingested, starting with GI symptoms & eventually moving into liver/kidney damage as well as anemia?

Nuts, Bolts, Staples, Nails, Zippers, Toys, Pennies, Jewelry, Lotions

A dog with a history of ingesting a rodenticide presents with vomiting, dark tarry feces containing blood, PU/PD, seizures, & abdominal pain. What specifically in the rodenticide is responsible for causing this toxicity?

Vitamin D

What is the toxic dose of macadamia nuts in dogs, meaning they will need GI decontamination?

1 nut per 2lbs

What can even small quantities of xylitol cause if ingested by small animals?

Life-threatening hypoglycemia

What time frame is considered acute in regards to vomiting + diarrhea?

2-3 weeks

If a dog is presenting with melena (dark tarry stool), where is the site of the GI bleed?

Mouth-jejunum (small bowel signs)

If a dog is presenting with hematochezia (bright red stool), where is the site of the GI bleed?

Jejunum-rectum (large bowel signs)

What are some of the potential differentials for a small animal presenting with melena?

Ulcer, Parasitism, IBD, Neoplasia, Extra-GI (thrombocytopenia, addison’s, renal dz, epistaxis)

What are some of the potential differentials for a small animal presenting with hematochezia?

Inflammatory dz, Parasitism, Polyp, Colonic neoplasia