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NAVLE EXAM PRACTICE EXAM 2024 |
200+ QUESTIONS AND CORRECT
ANSWERS WITH RATIONALES |
ALREADY GRADED A+ | LATEST
VERSION (JUST RELEASED)
A number of older cows in a Texas herd are losing condition rapidly with a corresponding drop in milk production. Two pregnant animals have aborted. Affected animals are off feed, uncoordinated and out of breath after exertion. On physical exam, affected cows have a rapid bounding pulse and pale mucous membranes. One animal appears icteric with a temperature of 105°F (40.6°C). What is the most likely diagnosis? A - Eperythrozoon spp. B - Anaplasmosis C - Leptospira icterohaemorrhagiae D - Theileriosis E - Babesia bigemina ------CORRECT ANSWER---------------B This clinical picture of anemia, icterus and collapse is that of bovine anaplasmosis, a tick-borne obligate intraerythrocytic bacterium in the order Rickettsiales. Babesiosis has a similar distribution and presentation, but UNlike anaplasmosis, look for hemoglobinuria. Babesia look like little hoops or "pears" inside red cells. Eperythrozoon is a related blood parasite, but both inside and outside the red cells.
Which one of the following conditions occurs in the Fall in temperate climates, among cattle moved from poor pasture to lush pasture? A - Rumenal hyperkeratosis B - Vagal indigestion C - Vena caval thrombosis and metastatic pneumonia D - Verminous bronchitis (Husk) E - Acute bovine pulmonary emphysema and edema ------CORRECT ANSWER---------------E Acute bovine pulmonary emphysema and edema (ABPEE) is associated with Fall onset, occurring 5-10 days after changing cattle from poorer to better, often lush, pasture. Toxicity occurs because rumen micro-organisms convert L- tryptophan in lush pasture grasses to pneumotoxic 3-methylindole, which damages respiratory epithelial cells. Moldy sweet potato and Purple mint can cause a clinicopathologic syndrome that is indistinguishable from ABPEE. The toxic compounds are respectively, 4-Ipomeanol (Moldy Sweet Potato) and Perilla ketones (Purple Mint Toxicity. Pyrrolizidine alkaloid toxicity is caused by chronic ingestion of which one of the following plants? A - Astragalus spp. (locoweed) B - Lupinus spp. (lupine) C - Nerium spp. (oleander) D - Persea spp. (avocado) E - Senecio spp. (ragwort) ------CORRECT ANSWER---------------E Senecio spp. (ragwort). Common plants containing pyrrolizidine alkaloids (PA) are: Senecio vulgaris, S. jacobea, Amsinckia intermedius, Heliotropium europaeum, Crotolaria spectabilis.
The nystagmus usually improves markedly within 72 hrs and the cat will likely completely return to normal in the next 2-3 weeks without any medication. This cat most likely has idiopathic vestibular disease. For severe disorientation, consider sedatives (diazepam and acepromazine). Glucorticoids do not usually alter course of disease. Anti-emetics usually not effective. In cats where you cannot rule out otitis externa or media, antibiotic therapy is warranted. Which lesions are most commonly associated with Marek's disease? A - Edematous facial swelling with sinusitis B - Hemorrhagic skin lesions C - Nerve enlargement D - Wrinkled eggs E - Blood in the trachea ------CORRECT ANSWER---------------C Think of NERVE ENLARGEMENT with Marek's disease; Also distortion of the pupil, enlargement of feather follicles ("skin leukosis"=condemnation of carcass). May see one leg forward, one leg back, a transient paralysis. Think infectious laryngotracheitis (ILT) if there is blood occluding trachea on necropsy. Remember wrinkled eggs go with infectious bronchitis. Think infectious coryza with sinusitis, swelling under eyes. What is the most common cause of Horner's syndrome in dogs? A - Idiopathic B - Brachial plexus avulsion C - Neck bite wounds D - Otitis media E - Retrobulbar neoplasia ------CORRECT ANSWER---------------A
Horner's Syndrome is IDIOPATHIC in 50-93% of dogs (45% in cats). See four things with Horner's, ALL associated with an eye:
**1. MIOSIS (constricted pupil)
- PROTRUSION 3rd eyelid (nictitans)
- ENOPHTHALMOS (sunken eye)
- PTOSIS (drooped eyelid), +/- anisocoria. Remember "My 3rd Sunken Toe" (Miosis, 3rd lid protrudes, Sunken eye, Ptosis). Diagnose Horner's syndrome by history, with 3 of 4 signs. Look for CLASSIC INCREASED anisocoria in the dark. Other diagnostic tests depend on where suspect primary disease. If you can get a primary diagnosis, (ie: Guttural pouch mycosis, brachial plexus avulsion,otitis media, etc.) must treat that.** Which one of the following diseases have been linked with the variant form of Creutzfeldt-Jakob disease (vCJD) in humans? A - Bovine spongiform encephalopathy B - Q fever C - Sporadic bovine encephalomyelitis D - Equine West Nile virus encephalitis E - Eastern equine encephalomyelitis (EEE) ------CORRECT ANSWER------ ---------A Bovine spongiform encephalopathy (BSE) suddenly appeared in the mid 1980's in the UK, likely due to changes in the practice of feeding meat and bone meal of sheep origin. In 1997, it was confirmed that Creutzfeldt-Jakob disease was associated with the bovine disease. Sporadic bovine encephalomyelitis (SBE), caused by Chlamydia pectoris (also called Chlamydophila pecorum), is not known to cause disease in humans.
Stump pyometra can also cause PU-PD, but the dog usually is ill and does not have the cutaneous atrophy. A 10 year old Quarterhorse gelding pastured in the northeastern United States is presented for weakness and depression. The owner reports that the horse's urine is an unusually dark brown color. On physical exam, the horse is tachycardic and tachypneic. The mucous membranes are a dark yellowish brown. The horse's plasma has a pink tinge. A CBC, blood smear, biochemistry panel, and urinalysis indentify intravascular hemolytic anemia, hemoglobinemia, methemoglobinemia, and hemoglobinuria. Erythrocytes are seen on the blood smear with Heinz bodies and eccentrocytosis. Ingestion of which one of the following plants is most likely to cause of this spectrum of clinical signs in this case? A - Tetradymia spp (Horsebrush) B - Quercus spp (Oak) C - Acer rubrum (Red maple) D - Veratrum spp (Skunk cabbage) E - Xanthium spp (Cocklebur) ------CORRECT ANSWER---------------C Ingestion of Acer rubrum (Red maple) is most likely the cause of hemolytic anemia and the resultant pathology in this horse. Wilted or dry leaves and bark of red maple trees contain oxidants which damage red blood cell (RBC) membranes, resulting in the formation of Heinz bodies and eccentrocytes. Acute intravascular hemolysis, hemoglobinemia, methemoglobinemia, hemoglobinuria, and methemoglobnuria follow. Clinical signs of toxicity include: weakness, depression, tachypnea, tachycardia, icterus, cyanosis, and brown discoloration of blood and urine.
Post mortem findings include: icterus, splenic hemosiderosis, splenomegaly, swollen dark red-blue black kidneys with red-brown tubular casts, and a swollen brown liver. Toxicity is often fatal. If the horse survives the hemolytic crisis, renal failure may develop due to pigmenturia. Treatment is supportive care: IV fluids, oxygen, and blood transfusions. A herd of ewes has had an abortion storm in which 80% of animals are affected, all stages of gestation are affected, and lambs that are born are very weak. On the placentas, cotyledons have white foci of necrosis. Which one of the following choices is the primary differential diagnosis? A - Listeria monocytogenes B - Brucella C - Chlamydiosis D - Histophilus ovis E - Toxoplasma gondii - -----CORRECT ANSWER---------------E Toxoplasma gondii infection can cause severe abortion storms in sheep. Clinical signs pathognomonic of T. gondii are bright to dark red cotyledons with white foci of necrosis; the intercotyledonary areas of placenta are normal. With Brucella and Histophilus ovis the abortion rate is much lower. Abortion caused by Listeria spp. is associated with the feeding of silage. A chicken farm has had several ill and dead birds over the past week.
According to the AVMA's Principles of Veterinary Medical Ethics (2 008 revision) "Ethically, the information within veterinary medical records is considered privileged and confidential. It must not be released except by court order or consent of the owner of the patient. Veterinarians should secure a written release to document that request." A 5 year old domestic short-haired spayed female cat is presented with the complaints of anorexia, chronic vomiting, and weight loss. Physical examination reveals icterus, dehydration, and fever. Thickened small intestinal loops are appreciated with abdominal palpation, and serum biochemistry shows increased bilirubin and liver enzymes. The cat is diagnosed with extrahepatic biliary obstruction with accompanying cholangitis and inflammatory bowel disease. Which one of the following normal anatomic features may predispose cats to this triad of diseases? A - Narrowing of the duodenum distal to the entry of the common bile and pancreatic ducts B - Common opening of the pancreatic and common bile ducts into duodenum C - Enlarged duodenal papilla in comparison to other species D - Decreased proportion of alpha-smooth muscle actin in muscle fibers of the wall of the gall bladder in cats E - Decreased diameter and increa ------CORRECT ANSWER---------------B In cats, there is a common opening of the pancreatic and common bile ducts into the duodenum. It is thought that this may predispose them to ascending cholangitis and pancreatitis after vomiting associated with inflammatory bowel disease, resulting in extrahepatic biliary obstruction. Other possible etiologies of EHBO include neoplasia, biliary stricture, duodenal obstruction, diaphragmatic hernia, and parasitic infection.
In all cases, there is a lack of bile entry into the intestinal tract, leading to decreased absorption of fat and fat soluble vitamins such as vitamin K, potentially resulting in coagulopathies. Except in transient cases that are related to acute pancreatitis, surgical intervention to relieve the obstruction is required as well as appropriate supportive care, antimicrobial treatment, and vitamin K administration. Most of a litter of European wild boar at a zoological park have died. The surviving piglets are in lateral recumbency with a frothy nasal discharge. Necropsy of the piglets reveals pulmonary edema and copious fluid in the trachea and bronchi along with grayish- white necrotic foci on the myocardium. Which one of the following diseases is the most likely diagnosis? A - Edema disease B - Encephalomyocarditis C - Glasser's Disease D - Porcine Respiratory and Reproductive Syndrome E - Pseudorabies ------CORRECT ANSWER---------------B Encephalomyocarditis virus (EMCV) is caused by a cardiovirus in the family picornaviridae. Confusingly, the virus is named for its effects on mice. Think of rodents and exotic zoo mammals with EMCV. Pig-to-pig contact, contamination of swine feed and water by rodents or ingestion of dead rodents may cause disease. See pulmonary edema and copious transudate in the respiratory tract, causing cardiac failure. Zoo outbreaks of EMCV have included lions, African elephants, rhinos, hippos, sloths, llamas, antelope and nonhuman primates. An outbreak of lion deaths at a Florida zoo in the USA occurred after feeding them the carcass of an African elephant that had died of EMCV. Edema disease is a neurologic disease caused by a hemolytic Escherichia coli producing Shiga toxin e2 and F18 pili resulting in high mortality in recently-weaned pigs.
A 6-year old intact male domestic short haired cat presents with acute onset exophthalmos of the right eye in the past 2 days. He is painful on palpation around his eye and head. The eye can be retropulsed with minimal resistance. He has not been eating in the past day and has a rectal temperature of 103.4F (39.7 C). What is the most likely diagnosis? A - Orbital neoplasia B - Retrobulbar abscess C - Anterior uveitis D - Glaucoma ------CORRECT ANSWER---------------B The answer is a retrobulbar abscess. Acute, painful exophthalmos is usually due to retrobulbar abscessation. These lesions are usually painful and may be swollen. These animals are frequently systemically ill with fever and leukocytosis. Causes of retrobulbar abscesses include penetrating wounds, foreign bodies, spread from dental or sinus infection, and hematogenous spread. Glaucoma does not cause exophthalmos, although, chronically it can cause buphthalmos which may appear similar. Anterior uveitis also does not cause exophthalmos. You are an associate veterinarian paid a base salary of $55,000 annually, plus a 8 % bonus based on receipts above your monthly production goal of $23,000. Bonuses are paid quarterly. Your last three month's production were: $23,000, $28,000, and $27,000. How much is your quarterly bonus? A - $ B - $ C - $ D - $ E - $900 ------CORRECT ANSWER---------------C $ If $23,000 is the monthly production goal, then the month you brought in $23,000 does not count towards a bonus.
In the second month, $ 28,000 = $5000 above goal In the third month $ 27,000 = $4000 above goal Total above production goal = $5000+$4000= $ $9000 X (0.08 bonus rate) = $720. Many practices use a combination system with a base salary and a production-based bonus if you bring in more than a monthly production goal, but no penalty if you are below that monthly goal, which is good if you are a new graduate, and helps in low traffic months at the clinic. A 10-year old female spayed Siamese cat presents for a new lump the owner found a month ago. She was spayed last year before she was adopted from the shelter. The owner states that the lump has grown over the last month, and it doesn't seem to bother the cat. On exam, the 2 cm lump is located on the left 2nd mammary gland, and no other lumps are noted. The lump is freely moveable, and chest radiographs are clear. What is the chance that this tumor is malignant? A - 5% B - 50% C - 20% D - 85% - -----CORRECT ANSWER---------------D 70 - 90% of all feline mammary tumors are malignant. Spaying a cat before 6 months of age reduces the risk for mammary tumors by 7 fold. The statistics for dogs is a 50:50 chance of malignancy for a single mammary mass. This 25 year old Quarter Horse mare is presented for evaluation in July in the northern hemisphere. She is diagnosed with pituitary pars intermedia
A 10-year old German Shepherd presents to you with the complaint of licking the anal area and scooting. On examination, you find numerous ulcerated tracts in the perianal area that are draining purulent fluid. What is the diagnosis? A - Perianal fistula B - Clostridial colitis C - Anal sac abscess D - Anal sac impaction ------CORRECT ANSWER---------------A The correct answer is perianal fistula. This is seen mainly in older German Shepherds, and licking the anus is a common presenting complaint. The key finding is the presence of multiple draining tracts in the perianal region that can actually be quite deep. Damage to the left recurrent laryngeal nerve is associated with "roaring" in horses. The left recurrent laryngeal nerve is a branch off of which cranial nerve? A - Glossopharyngeal (CN 9) B - Facial (CN 7) C - Trigeminal (CN 5) D - Hypoglossal (CN 12) E - Vagus (CN 10) ------CORRECT ANSWER---------------E Damage to the recurrent laryngeal nerve (a branch of the Vagus (CN 10)) causes laryngeal hemiplegia - a paralysis of the abductor muscle (dorsal cricoarytenoid muscle) controlling the glottic cleft in the larynx. This allows the vocal fold (usually left side) to evert into the lumen of the larynx, obstructing airflow, leading to a roaring sound, and most importantly, slowing the horse. Oral administration of which of these drugs has been implicated as a cause of esophageal strictures in cats?
A - Doxycycline B - Azithromycin C - Diazepam D - Potassium bromide ------CORRECT ANSWER---------------A The correct answer is doxycycline. There is also evidence that clindamycin can cause stricture formation. For this reason, it is recommended that after pilling a cat with doxycycline, it is followed with a small volume (5-10 mls) of water. A 5 year old female spayed Cocker Spaniel is presented with a strange expression. Her right ear and lip appear to droop. There is ptosis O.D. (right eye) and the dog is drooling on the exam table. What anatomic structure is damaged? A - Right side inner ear B - Left side inner ear C - Trigeminal nerve D - Facial nerve E - Left side medulla, motor tract ------CORRECT ANSWER---------------D Think of facial nerve paralysis (CN 7) with a unilaterally droopy face. Remember the facial nerve is motor to the muscles of facial expression (explaining the right side drooped ear, lip and eyelid) and innervates the lacrimal and salivary glands. Loss of innervations can lead to a dry eye, and possibly to exposure keratitis if animal losses ability to close eyelid from damage to facial nerve innervation of the orbicularis oculi muscle. Idiopathic in 75% of canine cases (25% of cats). Can also see these signs with middle ear damage (from otitis media), from facial nerve trauma (ear surgery in dogs, or pressure from halter buckles in anesthetized horse), or neoplasia. Think more of a dropped jaw with trigeminal nerve neuropathy (CN 5-dogs, horses).
A 10-year old male intact Doberman mix dog is presented with one testicle that is grossly enlarged and nonpainful and the other atrophied. What condition(s) are expected to be seen in association with this presentation? A - Benign prostatic hypertrophy, constipation B - Hypothyroidism C - Increased aggression, territoriality D - Feminization syndrome E - Penile hypertrophy, hirsutism ------CORRECT ANSWER---------------D Feminization syndrome. Nonpainful unilateral testicular swelling in an old dog should make you think of neoplasia, especially an estrogen-secreting sertoli cell tumor, which can cause feminization syndrome. See gynecomastia, penile atrophy, pendulous prepuce, attraction of other males, blood dyscrasias, +/-bone marrow depression (via high estrogen), bilateral alopecia. Remember that cryptorchidism increases risk of sertoli cell tumor: About 25 - 29% of sertolis develop feminization syndrome and ~ 70% of intra- abdominal testicular tumors, regardless of type, cause feminization syndrome. May see prostate hypertrophy with sertoli, but it is due to squamous metaplasia, not the classic (and common) benign prostatic hypertrophy (BPH). Hypothyroidism and BPH are common older dog conditions, but not associated with unilateral testicular hypertrophy. Remember that sex hormones are also secreted by the zona reticularis of adrenal cortex and can see feminization or virilism with excess secretion. Tommy, a 4-year old male neutered domestic short hair, presents to you for frequent urination. Urinalysis reveals 4+ struvite crystals. An abdominal radiograph shows a 1 cm round calculus in the bladder. Tommy does not have a urethral blockage, and urine culture is negative. The owner says surgery to remove this stone is not an option due to finances. Which of the following would be the most important treatment for Tommy?
A - Potassium citrate B - Alkalinizing diet C - Clavamox D - Acidifying diet E - Metacam ------CORRECT ANSWER---------------D This cat most likely has a struvite bladder stone. This cannot be determined without a stone analysis, but based on the signalment of the patient, the crystalluria, and the radiograph, this is the most likely type. These types of stones typically form in urine with a high pH. Therefore, an acidifying diet would be appropriate for stone dissolution. Calcium oxalate stones are the most common type of stone to form in acidic urine. For this type, an alkalinizing diet would be the most appropriate. Clavamox would only be indicated if this cat had a urinary tract infection sensitive to this antibiotic. This cat had a negative urine culture. Metacam can be used short-term to help with pain and inflammation associated with the cystitis from this condition but unfortunately Metacam is no longer recommend for use in cats in the United States. Potassium citrate is a supplement that can be given in addition to an alkalinizing diet to prevent the formation of calcium oxalate stones. This would be contraindicated in this case. What is the primary factor associated with pregnancy toxemia in ewes and goats? A - Young age at parturition B - Clostridium perfringens C - Polioencephalomalacia D - Inadequate nutrition E - High sulfur, Low thiamine diet ------CORRECT ANSWER---------------D Pregnancy toxemia in ewes and goats is a severe form of ketosis most associated with inadequate nutrition and TWINS in OLDER animals. Can
