Page 8 - Clinical Connections - Spring 2023
P. 8

RVC RESEARCH    STUDY    VETERINARY SERVICES       RVC.AC.UK
         Exotics
        UNUSUAL PERSISTENT URACHAL REMNANT
        IN A GUINEA PIG





              three-year-old guinea pig was   to the possibility of Encephalitozoon cuniculi   These findings were most consistent with
              referred to the RVC Exotics and   infection. CT of the skull and the whole body   cystitis, cystolithiasis and persistent urachal
        A Small Mammals Service with an     was performed for further investigation.  remnant  and/or  vesicourachal  diverticulum.
        eight-week history of vocalising when   The  urinary  bladder  was  uniformly  soft   No cause for the neurological episode was
        urinating, progressing to haematuria and   tissue attenuating, and the wall could   identified.
        dysuria.                            not  be  delineated  from  the  lumen.  Two   The  patient  was  taken  to  surgery  a  few
          A few weeks before referral, an ultrasound   irregular calculi were identified in the lumen,   days later. Following premedication with
        of  her  bladder  was  performed,  revealing   measuring approximately 1 × 1 and 5.7 ×   methadone and midazolam, anaesthesia
        a focal area of bladder wall thickening and   3.8 mm. These were located about 0.4 cm   was induced with isoflurane in oxygen. Lateral
        the presence of sediment within the bladder   from the outer surface of the dependent wall,   and dorsoventral abdominal radiographs
        lumen. Clinical signs resolved after a 10-  suggesting marked thickening of the bladder   revealed a small area of radiopaque material
        day  course  of  meloxicam  and  enrofloxacin   wall.                   within  the  ventral  bladder,  but  no  defined
        but  there was a subsequent recurrence of   A separate, irregular mineral-dense, poorly   uroliths.
        haematuria and treatment was repeated.  defined structure was identified adjacent to   Lidocaine  and  bupivacaine  were
                                            the apex of the urinary bladder. This structure   used to perform an incisional block,
        First referral to the RVC           was surrounded by a soft tissue dense linear   and  subcutaneous  Hartmann’s  with
        On presentation the patient appeared tense   band connecting the apex of the urinary   hyaluronidase  was  administered  as
        on caudal abdomen palpation and vocalised   bladder to the ventral abdominal wall.   intravenous access was unsuccessful.  A
        when the bladder was palpated.  A 5mm                                   ventral  midline  coeliotomy  was  performed.
        subcutaneous soft swelling was palpated at                              Multiple adhesions were found between the
        the ventral midline of the caudal abdomen, in                           bladder and abdominal wall.
        the region of the umbilicus.                                              A thickened tubular structure was found
          A blood sample was taken from the cranial                             extending from the bladder towards the
        vena cava for complete blood count and                                  umbilicus,  consistent  with  a  persistent
        biochemistry.  There  were  no  significant                             urachus.  This was dissected from other
        findings.  Abdominal  radiographs  showed                               tissues, excised with a small portion of
        no evidence of urolithiasis, and ultrasound                             bladder  wall  and  submitted  for  histological
        examination of the urinary tract was within                             evaluation.
        normal limits. Cystocentesis was not                                      A 1 × 1 cm partially mineralised
        possible  as  the bladder  was  empty,  but  a                          haematoma was found within the bladder
        free catch sample obtained later revealed                               lumen, consistent in size and position with
        a specific gravity of 1.010 and a moderate                              the structure seen on the radiographs. The
        presence of blood on dipstick. Microscopy                               histology samples were consistent with a
        showed no evidence of active infection. She                             persistent urachal remnant.
        was discharged with ongoing meloxicam.
          Clinical  signs  were  controlled  by  the                            Recovery
        referring  vet  over  the  next  three  months,                         The patient made a good recovery from the
        with various courses of treatment, including                            procedure and was discharged three days
        meloxicam  and  enrofloxacin,  trimethoprim                             later with oral meloxicam and gabapentin,
        sulfamethoxazole, intermittent  pentosan                                and a 10-day course of trimethoprim
        polysulfate sodium, gabapentin and an                                   sulfamethoxazole. She was weaned off pain
        N-acetyl-D-glucosamine and hyaluronic acid                              medications in the weeks following surgery.
        supplement.                                                             No relapse of clinical signs was noted at nine
                                                                                months after surgery.
        Return to the RVC
        The patient had an acute neurological
        episode  four  months  after  the  first  referral,
        with lethargy, an abnormal head position and
        possible  seizure  noted  by  the  owner.  She                                 For the RVC Exotics and Small Mammals
                                                                                     Service, please call: 020 7554 3528
        recovered within 24 hours.  Treatment was                                      Email:
        started with fenbendazole for 28 days, due   Urachal remnant (arrow)         londonreferrals@rvc.ac.uk








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