Urinary Tract Disorder IN FOALS Flashcards
Signs of Urinary Tract Problems in foals
- Azotemia in the first 24 hours
- Lack of urination
- Dribbling urine from the urachus
- Abnormal posturing
Normal Time for first normal colt urination
6-8 hours postpartum
Normal time for first filly urination
- 10-12 hours postpartum
Initial urine concentration
- Dilute or concentrated
Foal urine concentration after 24-48 hours
- Hyposthenuric
- AKA specific gravity <1.008
- If it’s not this in a foal, the foal isn’t nursing enough
- Mare’s milk is mostly water
Azotemia in neonatal foals possible indicators if foal is less than 7 days of age?
- Placental insufficiency
- Pre-renal failure
Other causes of azotemia in foals
- Acute kidney injury (AKI)
- Obstructive disease
- Congenital renal disorders
- Uroperitoneum
Normal umbilical anatomy of the foal
- see the picture on your desktop
What structure does the umbilical vein become?
- Falciform ligament
What structures do the umbilical arteries become?
- Round ligaments of the bladder
Umbilical ultrasound
- Image type: transverse/longitudinal
- Where is it located?
- Transverse image
- Cranial to urinary bladder
- Caudal to external umbilicus
What would it mean if the urachus was black?
- That means that it’s patent
Urachal diverticulum
- Image type: transverse/longitudinal
- Can be seen on longitudinal view
- Cranial to left
- Occasionally occurs
Clinical signs with urachal diverticulum
- Straining to urinate
Patent urachus signs
- Dribbling urine from umbilicus
Patent urachus and umbilical infection
- Can be a preliminary feature of umbilical infection
Treatment for patent urachus
- Surgical or medical
- Must fix underlying problem, treat urine scald with skin protectants (can pool underneath the skin)
- Systemic antimicrobials excreted in the urine in high concentrations
- Surgery to remove umbilicus (sometimes hope that getting up and not laying in urine will close it up without surgery)
Uroperitoneum causes
3, and which is most common?
- Ruptured bladder* (most common)
- Ureteral rupture
- Urachal leak
Clinical pathologic abnormalities for uroperitoneum
- Serum sodium: decreased
- Serum creatinine: increased
- Serum potassium: increased
Diagnosis of uroperitoneum
- Ultrasound
- Abdominocentesis
- Peritoneal fluid creatinine will be 2x serum creatinine
Treatment of uroperitoneum
- Surgical typically
- Can try to treat medically with Foley catheter in place
Uroperitoneum cases
- see the cases in the lecture
- Not producing urine
- Abdomen increases in size often
- Straining to urinate
- Can be obtunded
- May not be nursing
- Often diagnosed with CBC/Chem/ultrasound
What is the emergency with uroperitoneum?
- NOT surgical repair
- Treating the hyperkalemia is
- You MUST manage that before going in surgically
How to correct hyperkalemia?
- Drainage of peritoneal urine accumulation
- Fluid therapy - LRS or 0.9% NaCl with Dextrose (2.5-5%)
Omphalophlebitis structures that can be involved?
- Arteritis
- Phlebitis
- Urachitis
- Combinations
Diagnosis of omphalophlebitis
- Ultrasound may help
- Try to accurately assess the internal structures to determine the extent of surgery needed
Umbilical abscess locations
- Umbilical vein
- Umbilical abscess
- Subcutaneous abscess
- Omphaloarteritis
Umbilical infection in the umbilical vein challenges
- Can be quite difficult
- Poor vascular entry of antimicrobials
- ## Sometimes extends to the liver - difficult to remove surgically
Treatment of omphalophlebitis
- Choose antimicrobial with good penetration
- Thick vascular and abscess walls
- Thick purulent exudate
- Culture via swab if possible
- Antibiotics
- Can treat medically, but may need to remove the umbilicus too
What antibiotics work best for omphalophlebitis initially?
- Rifampin + TMS or chloramphenicol
- Chloramphenicol can cause aplastic anemia in people
What should you consider when evaluating an umbilical hernia?
- How large?
- How many fingers? (1 or 2 generally okay; more might be a concern)
- What do you palpate within the hernia?
- GI viscera
- Peritoneal fluid
- Omentum
Evaluating a hernia with ultrasound
- Look for bowel and small intestine
- Omentum
- Fluid
- If entrapped fluid or incarcerated intestine (measure wall thickness; intestinal distension; evaluate peristalsis)
Treatment of hernia variables
- Depending on size may mean surgical treatment right away or surgical treatment later
Inguinal hernia signalment
- young colts
Typical timeline for inguinal hernia
- Present at birth or several days later
- Can be unilateral or bilateral
Predisposing factors for inguinal hernias (3 we talked about)
- Large inguinal rings (Tennessee Walking Horse; Standardbred; Draft breeds)
- Trauma
- Increased abdominal pressure (straining)
Indirect inguinal hernia definition
- Intestines pass through the intact vaginal ring
- Contained within the parietal layer of the vaginal tunic
Are indirect inguinal hernias usually reducible or non-reducible?
- Usually reducible
Urgency of indirect inguinal hernias
- Not usually life-threatening
Treatment of indirect inguinal hernias
- Typically resolve with manual reduction within a few days
- Can even put a diaper on them to try and squish everything back in
Direct inguinal hernia definition
- Parietal vaginal tunic or peritoneum in vaginal ring region TEARS
- Intestines become positioned under the skin
- See images
Direct inguinal hernias reducible/non-reducible
- Typically not reducible
- Large amount of intestine involved
Urgency of treating direct inguinal hernias
- SURGICAL EMERGENCY
How would you usually identify an inguinal hernia?
- usually noted by observation or palpation
Clinical signs of indirect inguinal or umbilical hernia
- No apparent clinical signs
Clinical signs of direct inguinal or umbilical hernia
- May notice direct inguinal hernia where intestines appear under skin
- very painful and colicky
When do inguinal hernias need to go to surgery?
- If strangulation occurs
- Inability to reduce hernia
- Increase in hernia size
- Increase in heat, pain, firmness on palpation
- Development of colic
Treatment of indirect inguinal hernias
- Conservative initially
- Small hernias usually correct without treatment
- IMPORTANT to instruct owners to monitor size of hernia and reduce frequently
What size hernia are unlikely to resolve on their own?
- Umbilical >5 cm in diameter are more prone to complications and less likely to resolve on their own
When is elective surgery indicated for hernias?
- > 7-10cm or ones that have not resolved by 7-10 months of age
- Or if strangulating hernia suspected, a prompt surgical treatment is required
Ectopic ureters how common?
- Not at all
Normal ureter anatomy
- Ureters start at the renal hilus
- Penetrate dorsal wall of the bladder at the trigone
- Trigone is just cranial to the neck of the bladder
Internal urethral sphincter
- Segment in proximal portion of urethra where a smooth muscle layer is augmented with fascicles of skeletal muscle
- forms a functional sphincter
Control of internal urethral sphincter
Voluntary
Ectopic ureters
- One or both ureteral ostia empty into the bladder, urethra, or some point distal to the functional sphincter
- Sometimes ureters empty into uterus or vaginal tract
Diagnosis of ectopic ureters
- Urine dribbling
- Definitive diagnosis made by ultrasound or cystography
Treatment of ectopic ureters
- Reconstructive surgery
- Or if unilateral, a nephrectomy
- rarely successful
