Signalment:  “Schatzie” Miniature Schnauzer, FS, 3 years old

 

https://puppydogweb.com/gallery/miniatureschnauzers/miniatureschnauzer_hibbler.jpg

 

History: Schatzie was presented for the complaint of polyuria/polydipsia. She was obtained from a breeder when she was 10 weeks of age, and was spayed at 9 months of age after having 1 heat cycle. Schatzie was acting completely healthy and normal up until this spring when her owners that she was drinking and urinating a lot. Additionally, her coat quality decreased and stopped growing as it normally was before. The owners monitored Schatzie's polyuria and polydipsia at home for about 2-3 months until she was presented to her regular veterinarian for workup. Bloodwork was normal other than a low sodium level, that was measured to be 127 mmol/L. Schatzie has been otherwise healthy and has a great appetite. Schatzie's water consumption has been monitored and has been around 700-750 ml in a 24 hour period. Salt has been added to her diet at 1/4 teaspoon 1-2x daily and she seems to perk up slightly when give this. However, Schatzie occasionally vomits after salt administration. She also has occasional diarrhea. No coughing or sneezing has been noted.  She has traditionally been fed a raw diet, but this past week she has had home cooked meals.

 

General: BAR T:102.0°F    Pulse:  88 /min   Resp: 24 /min  Wt: 7.8 kg  BCS: 6 /9     MM Color: pink    Refill: <2 sec Eyes: Corneas are clear, no ocular discharge, pupils/PLRs are equal and responsive, normal conjunctiva.

Fundic exam: Not done

Ears: No inflammation, no exudate noted

Oral cavity: Pink mucous membranes, normal capillary refill. No masses seen. Teeth: Mild dental tartar.

Lymph nodes: Normal, no peripheral lymphadenopathy noted. Heart: No murmurs or arrhythmias, pulses strong and synchronous.

Respiratory system: No nasal discharge, no tracheal sensitivity. Lungs clear on auscultation. Abdomen: Normal, soft, non-painful, no masses or organomegaly noted.

Rectal exam: Not done

Urogenital: Grossly normal spayed female Musculoskeletal: Normal

Neurological: Normal mentation, normal gross exam

Skin and hydration: Normal hydration. Fur is wiry and dry.

Pain Assessment scale(0= no pain or discomfort , 10= highest intensity) :  0 /10

Patient (Reference Range, units)

•       Red blood cells 6.96 (5.5-8.5 x 10^6/ul)
•       Hgb    16.2 (12-18 g/dl)
•       PCV    49.7 (35-52%)
•       Platelets  291 (200-900 x10^3/ul)
•       WBC   8.25 (6-17 x10^3/ul)
•       Segmented Neutrophils 6.60 (3-11.5 x10^3/ul)
•       Lymphocytes  1.16 (1.0-4.8 x10^3/ul)
•       Monocytes 0.33 (0.2-1.4 x10^3/ul)
•       Eosinophils  0.17 (0.1-1.0 x10^3/ul)

Patient (Reference Range, units)

•       Serum creatinine  0.8 (0.5-1.5  mg/dl)
•       BUN  14 (6-30 mg/dl)
• `     Total Protein 5.9 (5.1-7.0 g/dl)
•       Albumin 3.3 (2.5-3.8 g/dl)
•       Globulin  2.6 (2.1-4.5 g/dl)
•       Calcium 9.8 (7.6-11.4 mg/dl)
•       Phosphorus 2.9 (2.7-5.2 mg/dl)
•       Sodium          132 (141-152 mmol/L)
•       Potassium    4.2 (3.9-5.5 mmol/L)
•       Chloride        100  (107-118 mmol/L)
•       Glucose 124  (68-126 mg/dl)
•       Alk phos        10 (7-92 U/L)
•       ALT                 28 (8-65 U/L)
•       GGT    1 (0-7 U/L)
•       Total bili 0.1 (0.1-0.3 mg/dl)
•       Cholesterol   184 (129-297 mg/dl)
•       Triglycerides 48 (32-154 mg/dl)
•       Bicarbonate 15 (16-24 mmol/L)

Sample obtained by cystocentesis

•       USG   1.040
•       Color yellow, sl turbid
•       pH       8.5
•       Protein           Trace
•       Glucose         Neg
•       Blood                         neg
•       Microscopic No abnormalities on urine sediment exam other than amorphous crystals

Plasma osmolality (Posm): 274.9 and 280  (Reference: 280-310 mOsm/kg) on 2 occasions.

Urine Osmolality (Uosm): simultaneously with latter Posm measurement: 1416 mOsm/kg (Reference: variable)

3-view Thoracic Radiographs (no images to show)

• There is a dorsal soft tissue membrane beginning just caudal to the laryngeal cartilages and extending through the level of the thoracic inlet. This membrane results in up to 50% narrowing of the tracheal lumen.
• The lungs and pleural space are normal
• No evidence of intrathoracic lymphadenopathy
• The heart measures at the upper end to slightly above normal range (11 VHS on right lateral view, 10.6 VHS on left lateral view). On the VD view there is a bulge in the cardiac silhouette in the region of the right atrium.  Pulmonary vasculature appears normal.
• Included skeletal structures are normal

Diagnostic Interpretation by Radiologist:

• Trachea - redundant tracheal membrane (tracheal collapse)
• Heart - normal shape variant, alternatively true
• Right-sided cardiomegaly (consider pulmonary hypertension [although no pulmonary arterial enlargement noted], tricuspid endocardiosis, etc)

Procedure with T1w (pre and post contrast), T2w, transverse, dorsal and sagittal planes as well as FLAIR and T2* GRE in transverse plane.

 

Radiologist Interpretation:

Head:

• Dentition/oral cavity: Normal
• Nasal cavity/frontal sinuses: Normal
• Nasopharynx/laryngopharynx: Normal
• Orbit/globe: Normal
• External/middle/inner ear: Normal

Calvarium/Brain:

• There is moderate bilateral symmetrical dilation of the lateral ventricles with no mass effect or dilation to the third or fourth ventricles noted.
• There is mild bulging of the caudoventral cerebellum through a focal concave region of the caudal fossa at the foramen magnum that is absent. No other evidence of syringomyelia noted.

Lymph nodes: Medial retropharnygeal lymph nodes are mildly enlarged.

Extra-cranial structures: Normal

Overall Diagnostic Interpretation:

Brain:

•       Incidental moderate dilation of the lateral ventricles
•       Mild caudal occipital malformation with mild herniation (likely incidental)    

Lymph nodes: Mildly reactive, less likely metastatic

ACTH Stimulation Test

•       Baseline cortisol concentration:  75 (58-144 nmol/L)
•       60 min Post-ACTH (IV Administration) cortisol concentration: 350 (225-425 nmol/L)

Your total case analysis should not exceed 2000 words, so feel free to use lists and bulleted outlines when logical, and be sure to emphasize primarily evidence that supports your thinking about this case.  There is NO one way to organize your analysis, but seek to answer all of the following questions along the way.

1. Problems: List the 3 most serious clinical problem(s) in this case, and defend your reasoning.

2. Differentials: Focusing on the complaint of polyuria/polydipsia, and the findings in this case, and focusing upon central nervous system, endocrine and renal organ systems, search the literature and identify at least 2 major differential diagnoses for Schatzie, defending your choices with clearly identified evidence from the case and information from the literature.

3. Evidence from Case Observations: Identify the clinical observations in this case to support your problem list and differential diagnosis list, and defend why you believe that these are relevant to the case.

4. Understanding: 

a. Is Schatzie actually polydipsic? If so, how can you tell? If unclear, what additional evaluation would you recommend?

b. Explain the relationship between Posm and the plasma biochemistries, and Uosm and the urine specific gravity.

c. Explain the possible pathophysiological changes that could result in the electrolyte results.

d. Why was the MRI performed?

e. What other diagnostic tests would be valuable in this case?

f. If unmanaged, what kind of additional clinical signs would you expect?

g. Propose at least 2 ways to manage this dog’s problems.

h. Describe at least two basic science principles important to the case and explain their connection to the animal’s problems.

5. Conclusions/Self-Reflection: Identify and explain at least 2 personal learning issues from the exercise. Focus on issues relevant to the current level of your studies.

6. References: Provide references that helped you with understanding of this case. Note: Seek to go beyond lecture notes, textbooks and review articles by seeking primary research references highly relevant to the case. Whomever reads your analysis should be able to find the reference if they are interested. This includes web references, which should be made into active links in Scholar.

Use the following format for references

Journal article: Last Name of First Author, Initial (Year of Publication): Title of article. Journal Name Volume: First Page. PubMed ID # or link (make the link an active one in Scholar).

Textbook: Last Name of First Author, Initial (Year of Publication): Title of chapter. Editor of Book Last Name, First Initial:

Textbook Name. First Page Number.

Web Reference: Last name & Initial of first author if known, title of piece, year published if known, active web hyperlink.

Example: Unknown, Canine Influenza in Dogs, AVMA website, https://www.avma.org/KB/Resources/FAQs/Pages/Control-of-Canine-Influenza-in-Dogs.aspx