old exam 1 scenarios Flashcards
A 2-year-old MC Yorkshire Terrier is presented for progressive weight loss and diarrhea. The owners report a 3 month history of intermittent soft stools that is now consistent. The dog’s appetite was good but now increasingly intermittent. Feces are yellow to light brown, sometimes greasy, and always voluminous. There is no reported blood, mucus, or straining. A CBC and biochemistry panel show lymphopenia, moderate hypoalbuminemia, and hypocholesterolemia. Fecal floats were negative and there was no response to a hypoallergenic diet, probiotic, or a 2 week course of antibiotics. TLI, folate, and cobalamin were all within normal limits.
what is the Dx?
Lymphangiectasia
A 2-year-old MC Yorkshire Terrier is presented for progressive weight loss and diarrhea. The owners report a 3 month history of intermittent soft stools that is now consistent. The dog’s appetite was good but now increasingly intermittent. Feces are yellow to light brown, sometimes greasy, and always voluminous. There is no reported blood, mucus, or straining. A CBC and biochemistry panel show lymphopenia, moderate hypoalbuminemia, and hypocholesterolemia. Fecal floats were negative and there was no response to a hypoallergenic diet, probiotic, or a 2 week course of antibiotics. TLI, folate, and cobalamin were all within normal limits.
Lesion?
Full thickness biopsies of the intestine show marked dilation of lymphatics in both the mucosa and submucosa. There is little to no increase in cells within the lamina propria or submucosa.
A 2-year-old MC Yorkshire Terrier is presented for progressive weight loss and diarrhea. The owners report a 3 month history of intermittent soft stools that is now consistent. The dog’s appetite was good but now increasingly intermittent. Feces are yellow to light brown, sometimes greasy, and always voluminous. There is no reported blood, mucus, or straining. A CBC and biochemistry panel show lymphopenia, moderate hypoalbuminemia, and hypocholesterolemia. Fecal floats were negative and there was no response to a hypoallergenic diet, probiotic, or a 2 week course of antibiotics. TLI, folate, and cobalamin were all within normal limits.
Mechanism?
The primary mechanism of diarrhea is osmotic due specifically to malabsorption of dietary fat.
A week after dealing with an outbreak of calf diarrhea, your partner develops what she describes as “impressive” high volume, watery diarrhea and “stomach cramps”. The signs have already lasted another week, and she’s had trouble staying hydrated. The calves had similar clinical signs. There was no blood or significant straining. Most were at least 10 days of age and none were older than about 4-5 weeks. The calves were treated symptomatically and management changes were recommended. Most calves recovered after 7-14 days and now seem fine. She is hoping for a similar outcome, but has already lost 5 pounds.
Dx?
Cryptosporidiosis
A week after dealing with an outbreak of calf diarrhea, your partner develops what she describes as “impressive” high volume, watery diarrhea and “stomach cramps”. The signs have already lasted another week, and she’s had trouble staying hydrated. The calves had similar clinical signs. There was no blood or significant straining. Most were at least 10 days of age and none were older than about 4-5 weeks. The calves were treated symptomatically and management changes were recommended. Most calves recovered after 7-14 days and now seem fine. She is hoping for a similar outcome, but has already lost 5 pounds.
Lesion?
Villi are short and blunt, and crypts are hyperplastic. The epithelium is intact, but in many sections numerous small round protozoa are attached to the luminal surface of enterocytes.
A week after dealing with an outbreak of calf diarrhea, your partner develops what she describes as “impressive” high volume, watery diarrhea and “stomach cramps”. The signs have already lasted another week, and she’s had trouble staying hydrated. The calves had similar clinical signs. There was no blood or significant straining. Most were at least 10 days of age and none were older than about 4-5 weeks. The calves were treated symptomatically and management changes were recommended. Most calves recovered after 7-14 days and now seem fine. She is hoping for a similar outcome, but has already lost 5 pounds.
Mechanism
A primary mechanism of disease likely involves diminished activity of membrane-bound digestive enzymes. This reflects the effect of the organism on the intestinal microvilli. Malabsorption due to overall diminished intestinal absorptive surface area also plays a central role in the pathophysiology.
A 7-year-old MC Greyhound has had intermittent diarrhea and vomiting for the past year. His appetite remains mostly good but there is now significant weigh loss so that his body condition score is now 2/9. The vomitus may or may not contain food, but there is no blood. Feces have gone from soft to watery. The signs seem to wax and wane but the owners report 2-4 episodes per day during bad periods. Repeated fecal floats for parasites have been negative and there was no response to antibiotics. There has been some improvement since starting a highly digestible, single protein diet. The signs improved considerably in response to high dose corticosteroids, but the owners were unhappy with the side effects. The only abnormalities on CBC, biochemistry panel, and U/A have been hypoalbuminemia and hypoglobulinemia, both of which have worsened over the past 4 months. TLI, folate, and cobalamin are normal.
Dx
Inflammatory Bowel Disease
A 7-year-old MC Greyhound has had intermittent diarrhea and vomiting for the past year. His appetite remains mostly good but there is now significant weigh loss so that his body condition score is now 2/9. The vomitus may or may not contain food, but there is no blood. Feces have gone from soft to watery. The signs seem to wax and wane but the owners report 2-4 episodes per day during bad periods. Repeated fecal floats for parasites have been negative and there was no response to antibiotics. There has been some improvement since starting a highly digestible, single protein diet. The signs improved considerably in response to high dose corticosteroids, but the owners were unhappy with the side effects. The only abnormalities on CBC, biochemistry panel, and U/A have been hypoalbuminemia and hypoglobulinemia, both of which have worsened over the past 4 months. TLI, folate, and cobalamin are normal.
Lesion?
Villi are diffusely short, blunt, and infiltrated with cells that broadened the lamina propria. The epithelium appears intact. The infiltrate is a mixture of lymphocytes and plasma cells that are confined to the mucosa.
A 7-year-old MC Greyhound has had intermittent diarrhea and vomiting for the past year. His appetite remains mostly good but there is now significant weigh loss so that his body condition score is now 2/9. The vomitus may or may not contain food, but there is no blood. Feces have gone from soft to watery. The signs seem to wax and wane but the owners report 2-4 episodes per day during bad periods. Repeated fecal floats for parasites have been negative and there was no response to antibiotics. There has been some improvement since starting a highly digestible, single protein diet. The signs improved considerably in response to high dose corticosteroids, but the owners were unhappy with the side effects. The only abnormalities on CBC, biochemistry panel, and U/A have been hypoalbuminemia and hypoglobulinemia, both of which have worsened over the past 4 months. TLI, folate, and cobalamin are normal.
Mechanism?
Breakdown of immunologic tolerance to luminal antigens (bacterial and/or dietary components) is thought to be critical, perhaps resulting from alterations in the intestinal microflora or some disruption of the mucosal barrier
After just 2 weeks, a 1.5-year-old FS German Shepherd with chronic small bowel diarrhea and weight loss of approximately 6 weeks duration is responding very nicely to a course of oral antibiotics. Blood work sent to the TAMU GI lab revealed normal TLI but increased folate and decreased cobalamin. Extensive abdominal imaging, which included ultrasound, was unremarkable. A CBC, biochemical panel and U/A were similarly normal.
Dx?
SIBO
After just 2 weeks, a 1.5-year-old FS German Shepherd with chronic small bowel diarrhea and weight loss of approximately 6 weeks duration is responding very nicely to a course of oral antibiotics. Blood work sent to the TAMU GI lab revealed normal TLI but increased folate and decreased cobalamin. Extensive abdominal imaging, which included ultrasound, was unremarkable. A CBC, biochemical panel and U/A were similarly normal.
Lesion
There are typically no gross lesions in the intestines (except perhaps for soft to watery intestinal contents) and no significant microscopic lesions - including no evidence of mucosal damage and little to no inflammation.
After just 2 weeks, a 1.5-year-old FS German Shepherd with chronic small bowel diarrhea and weight loss of approximately 6 weeks duration is responding very nicely to a course of oral antibiotics. Blood work sent to the TAMU GI lab revealed normal TLI but increased folate and decreased cobalamin. Extensive abdominal imaging, which included ultrasound, was unremarkable. A CBC, biochemical panel and U/A were similarly normal.
Mechanism
It’s controversial how important this is as a primary cause of diarrhea. However, there may be several mechanisms of diarrhea in play, notably maldigestion due to sub-microscopic disruption of the intestinal brush border and microbial inactivation of bile acids in the intestinal lumen.
You are called to look at a problem with scours in a small herd of beef calves. The owner reports watery diarrhea in calves up to about 2 weeks of age. Signs in calves have started at anywhere from 2 to 11 days of age. Once diarrhea begins, it can last 6-10 days. There’s been no blood or straining, but the diarrhea is watery. All but one calf recovered but most required extensive therapy using a commercial electrolyte solution and esophageal feeder. 12 of the first 15 calves have been affected. 2 of the 12 had mild fevers and all were significantly dehydrated. The owner is hoping for some help as she’s got 20 more cows due to calf soon.
Dx
Rotavirus
and to a lesse extend Coronavirus
You are called to look at a problem with scours in a small herd of beef calves. The owner reports watery diarrhea in calves up to about 2 weeks of age. Signs in calves have started at anywhere from 2 to 11 days of age. Once diarrhea begins, it can last 6-10 days. There’s been no blood or straining, but the diarrhea is watery. All but one calf recovered but most required extensive therapy using a commercial electrolyte solution and esophageal feeder. 12 of the first 15 calves have been affected. 2 of the 12 had mild fevers and all were significantly dehydrated. The owner is hoping for some help as she’s got 20 more cows due to calf soon.
Lesion?
The lesion consists of villous atrophy and mild to (possibly) moderate inflammation that is neutrophilic in nature.
You are called to look at a problem with scours in a small herd of beef calves. The owner reports watery diarrhea in calves up to about 2 weeks of age. Signs in calves have started at anywhere from 2 to 11 days of age. Once diarrhea begins, it can last 6-10 days. There’s been no blood or straining, but the diarrhea is watery. All but one calf recovered but most required extensive therapy using a commercial electrolyte solution and esophageal feeder. 12 of the first 15 calves have been affected. 2 of the 12 had mild fevers and all were significantly dehydrated. The owner is hoping for some help as she’s got 20 more cows due to calf soon.
Mechanism?
Replication of this cytopathic pathogen is limited to the intestinal tract. Damage is usually mild because only mature enterocytes are affected. There may also be transient maldigestion of carbohydrates (like lactose) due to impaired disaccharidase activity in the brush border.
Two days after what seemed a successful minor orthopedic surgery, a 3 year old Thoroughbred stallion breaks with profuse, watery diarrhea and fever.
Dx?
Clostridium difficile or Clostridium perfringens
Two days after what seemed a successful minor orthopedic surgery, a 3 year old Thoroughbred stallion breaks with profuse, watery diarrhea and fever.
Lesion?
The primary lesion is acute, diffuse, severe, ulcerative colitis.
Two days after what seemed a successful minor orthopedic surgery, a 3 year old Thoroughbred stallion breaks with profuse, watery diarrhea and fever.
Mechanism
An essential part of the pathogenesis is production and secretion of potent cytopathic microbial exotoxins.
