Closure-related complications after median sternotomy in cats: 26 cases (2010-2020).

OBJECTIVES: The aim of this study was to determine closure-related complications and outcome after median sternotomy (MS) in cats. METHODS: This was a retrospective, multicentric study. The medical records of cats undergoing MS from six referral hospitals were reviewed (2010-2020). Data retrieved included signalment, history, presenting complaints, surgery, patient outcomes and complications. Follow-up was performed via patient records and email/telephone contact with both owners and referring veterinarians. Descriptive statistics were performed. RESULTS: Data on 36 cats were collected; four were excluded due to insufficient follow-up and six died less than 5 days after surgery. Twenty-six cats survived to discharge (survival rate 81%). Three cats had a full sternotomy (FS) performed and 23 cats a partial sternotomy (PS). Of the cats that underwent a PS, six included the manubrium (PSM) and three included the xyphoid process. For 14 cats, the length of sternotomy was unknown. Sternotomy closure was performed with suture in all cats. Two cats (7.7%) developed closure-related complications, both after PSM, during the long-term follow-up, one mild, slightly displaced sternal fracture and one severe, sternal dehiscence (without skin wound dehiscence) requiring revision surgery. No seroma, surgical site infection or wound dehiscence occurred. The most common reason for MS was the presence of a thoracic mass (17/26; 65%), with thymoma being the most common (11/17; 65%). CONCLUSIONS AND RELEVANCE: MS has a low closure-related complication risk in cats when compared with dogs. Complications in cats present differently to what has been previously described in dogs.

Postattenuation neurologic signs after surgical attenuation of congenital portosystemic shunts in dogs: A review.

The development of postattenuation neurologic signs (PANS) is a poorly understood and potentially devastating complication after surgical attenuation of congenital portosystemic shunts in dogs. Postattenuation neurologic signs include seizures but also more subtle neurologic signs such as depression, behavioral changes, tremors, and twitching. They most commonly occur within 7 days postoperatively and are typically unrelated to hyperammonemia, hypoglycemia, or electrolyte disturbances. This narrative review summarizes the findings of 50 publications from 1988-2020 that report occurrence of PANS. While most published reports included only dogs affected by postattenuation seizures (PAS), others included dogs with any form of PANS. Overall, PANS (including PAS) affected 1.6%-27.3% of dogs, whereas incidence of PAS ranged from 0%-18.2%. The etiology of PANS remains unknown; however, several theories have been proposed. Risk factors include preoperative hepatic encephalopathy, increasing age, and possibly certain breeds and extrahepatic shunt morphology. There is increasing evidence that prophylactic antiepileptic drugs do not prevent PANS. Treatment is centered around controlling neurologic signs with antiepileptic drugs and providing supportive intensive care. The 30-day survival rate in studies that included a minimum of four dogs affected by PANS was 0%-100% (median, 50.0%) and 0%-75.0% (median, 37.5%) for those with PAS. Mortality associated with PANS was typically related to occurrence of generalized seizure activity. Prognostic factors positively associated with short-term survival included having a history of preoperative seizures and development of focal seizures only. If affected dogs survived to discharge, survival for several years was possible, and the majority of neurologic signs manifested as part of the phenomenon of PANS appeared to resolve.

Long-term outcome and quality of life of dogs that developed neurologic signs after surgical treatment of a congenital portosystemic shunt: 50 cases (2005-2020).

OBJECTIVE: To determine survival time and quality of life of dogs that developed postattenuation neurologic signs (PANS) after surgical treatment of a single congenital portosystemic shunt and survived at least 30 days and identify whether neurologic signs present at the time of discharge would resolve or reoccur. ANIMALS: 50 client-owned dogs. PROCEDURES: Medical records were retrospectively reviewed, and follow-up data relating to neurologic signs and seizure activity were obtained. Owners were asked to complete a questionnaire related to the presence of neurologic signs, including seizures, and their dog's quality of life. RESULTS: Thirty of the 50 (60%) dogs had postattenuation seizures with or without other nonseizure neurologic signs, and 20 (40%) had neurologic signs other than seizures. Neurologic signs had fully resolved by the time of discharge in 24 (48%) dogs. Signs resolved in 18 of the remaining 26 (69%) dogs that still had PANS other than seizures at the time of discharge. Seizures reoccurred in 15 of the 30 dogs that had postattenuation seizures. Twenty-seven of 33 (82%) owners graded their dog's long-term (> 30 days after surgery) quality-of-life as high. Forty-five (90%) dogs survived > 6 months. Most (29/43 [67%]) neurologic signs (other than seizures) present at the time of hospital discharge resolved. CLINICAL RELEVANCE: Findings highlighted that survival times of > 6 months and a high QOL can be achieved in most dogs with PANS that survive at least 30 days. Most neurologic signs other than seizures resolved within 1 month postoperatively. Half of the dogs with postattenuation seizures had a reoccurrence.

Nonsurgical reduction of prolapsed colocolic intussusception in 2 puppies.

OBJECTIVE: To describe the nonsurgical management of prolapsed colocolic intussusception in 2 puppies. CASE SUMMARY: Two 3-month-old male intact puppies (Pug and Labrador Retriever) developed intussusceptions that had prolapsed from the anus after they had suffered from tenesmus with soft feces or diarrhea. Reduction of the prolapsed tissue was performed and colocolic intussusception was diagnosed ultrasonographically in 1 dog. Rectal manipulation and saline enema were performed in both dogs, and reduction of the intussusception was confirmed endoscopically or ultrasonographically. Bupivacaine and prednisolone foam enemas were administered to reduce tenesmus. Abdominal ultrasonography the following day in 1 dog confirmed a normal appearing colon. No further tenesmus was noted in 1 dog; the other had a brief rectal prolapse after an episode of tenesmus that was manually reduced. Intussusception had not recurred 4 months and 1 year following manual reduction procedures. NEW OR UNIQUE INFORMATION PROVIDED: This is the first report of successful nonsurgical management of colocolic intussusception in a companion animal. Nonsurgical management is a first-line treatment of intussusception in children and could be considered in dogs with colocolic intussusception. Further investigation is required to define specific aspects, including rectal manipulation, saline enema, or anesthesia, that aid in resolution of this type of intussusception.

Pubic fractures secondary to extended transpelvic urethrostomy in a cat.

OBJECTIVE: To report the occurrence and describe the management of pubic fractures after the use of an extended transpelvic urethrostomy (TPU) to treat postprostatic intrapelvic urethral obstruction and laceration in a cat. ANIMAL: One 6-year-old domestic short-haired cat. STUDY DESIGN: Case report. METHODS: A cat was presented with urethral obstruction and laceration confirmed by positive contrast retrograde urethrography. Temporary urinary diversion was performed. An attempt was made to perform perineal urethrostomy, but the cranial location of the laceration precluded this technique. An extended TPU was performed, which required removal of 30% to 60% greater length of pelvic bone than has been previously described. RESULTS: Bilateral pubic ramus fractures occurred 1 week after surgery, from which the cat clinically improved with cage rest, and exhibited evidence of healing according to computed tomography after 8 weeks. CONCLUSION: Extended TPU used to treat postprostatic intrapelvic urethral laceration may lead to pubic fractures postoperatively. CLINICAL SIGNIFICANCE: It may be prudent to rest any cat that has had a TPU or extended TPU to reduce fracture risk.

Prognostic factors for short-term survival of dogs that experience postattenuation seizures after surgical correction of single congenital extrahepatic portosystemic shunts: 93 cases (2005-2018).

OBJECTIVE: To identify prognostic factors for short-term survival of dogs that experience seizures within 7 days after surgical correction of single congenital extrahepatic portosystemic shunts (cEHPSS). STUDY DESIGN: Multi-institutional retrospective study. SAMPLE POPULATION: Ninety-three client-owned dogs. METHODS: Medical records at 14 veterinary institutions were reviewed to identify dogs that underwent surgical attenuation of a single cEHPSS from January 1, 2005 through February 28, 2018 and experienced postattenuation seizures (PAS) within 7 days postoperatively. Logistic regression analysis was performed to identify factors associated with 1-month survival. Factors investigated included participating institution, signalment, shunt morphology, concurrent/historical conditions, presence of preoperative neurologic signs, presence of preoperative seizures, aspects of preoperative medical management, surgical details including method and degree of shunt attenuation, type of PAS (focal only or generalized ± focal), drugs administered as part of the treatment of PAS, and development of complications during treatment of PAS. RESULTS: Thirty (32.3%) dogs survived to 30 days. Seventy-six (81.7%) dogs experienced generalized PAS. Factors positively associated with short-term survival included having a history of preoperative seizures (P = .004) and development of focal PAS only (P = .0003). Most nonsurvivors were humanely euthanized because of uncontrolled or recurrent seizures. CONCLUSION: Dogs that experienced PAS that had a history of preoperative seizures and those that experienced focal PAS only had significantly improved short-term survival. CLINICAL SIGNIFICANCE: The results of this study provide information that will help in the counseling of owners who seek treatment for PAS after surgical correction of cEHPSS. © 2020 The American College of Veterinary Surgeons.

Effect of prophylactic treatment with levetiracetam on the incidence of postattenuation seizures in dogs undergoing surgical management of single congenital extrahepatic portosystemic shunts.

OBJECTIVE: To report the incidence of postattenuation seizures (PAS) in dogs that underwent single congenital extrahepatic portosystemic shunt (cEHPSS) attenuation and to compare incidence of PAS in dogs that either did or did not receive prophylactic treatment with levetiracetam (LEV). STUDY DESIGN: Multi-institutional retrospective study. POPULATION: Nine hundred forty dogs. METHODS: Medical records were reviewed to identify dogs that underwent surgical attenuation of a single cEHPSS from January 2005 through July 2017 and developed PAS within 7 days postoperatively. Dogs were divided into 3 groups: no LEV (LEV-); LEV at ≥15 mg/kg every 8 hours for ≥24 hours preoperatively or a 60 mg/kg intravenous loading dose perioperatively, followed by ≥15 mg/kg every 8 hours postoperatively (LEV1); and LEV at <15 mg/kg every 8 hours, for <24 hours preoperatively, or continued at <15 mg/kg every 8 hours postoperatively (LEV2). RESULTS: Seventy-five (8.0%) dogs developed PAS. Incidence of PAS was 35 of 523 (6.7%), 21 of 188 (11.2%), and 19 of 228 (8.3%) in groups LEV-, LEV1, and LEV2, respectively. This difference was not statistically significant (P = .14). No differences between groups of dogs that seized with respect to investigated variables were identified. CONCLUSION: The overall incidence of PAS was low (8%). Prophylactic treatment with LEV according to the protocols that were investigated in our study was not associated with a reduced incidence of PAS. CLINICAL SIGNIFICANCE: Prophylactic treatment with LEV does not afford protection against development of PAS. Surgically treated dogs should continue to be monitored closely during the first 7 days postoperatively for seizures.

Cell-mediated immune responses to COPV early proteins.

Cell-mediated immunity plays a key role in the regression of papillomavirus-induced warts and intra-epithelial lesions but the target antigens that induce this response are not clear. Canine oral papillomavirus (COPV) infection of the oral cavity in dogs is a well-characterized model of mucosal papillomavirus infection that permits analysis of the immune events during the infectious cycle. In this study we show that during the COPV infectious cycle, systemic T cell responses to peptides of several early proteins particularly the E2 protein, as assayed by delayed type hypersensitivity, lymphoproliferation and IFN-gamma ELISPOT, can be detected. The maximal response occurs in a narrow time window that coincides with maximal viral DNA replication and wart regression: thereafter, systemic T cell responses to early proteins decline quite rapidly. Vaccination using particle-mediated immunotherapeutic delivery (PMID) of codon-modified COPV E2 and E1 genes induces strong antigen-specific cell-mediated immune responses in the vaccinated animals. These data show that therapeutic immunization by PMID with codon-modified E2 is completely effective, that to E1 is partially protective, that this correlates with the intensity of antigen-specific cell-mediated immune responses and, further, they emphasize the importance of these responses and the route of immunization in the generation of protective immunity.

Therapeutic immunisation with COPV early genes by epithelial DNA delivery.

Following challenge with COPV (canine oral papillomavirus), DNA plasmids encoding COPV L1, E1 or E2 protein were delivered into oral mucosal and cutaneous sites in beagles using particle-mediated immunotherapeutic delivery (PMID). Two weeks post-challenge, a priming dose of 8 microg DNA was delivered followed by a booster dose after a further two weeks. A group of control dogs were vaccinated using plasmid DNA encoding Hepatitis B virus surface (HBVs) gene. All of the control animals developed warts at the vast majority of sites (94%). All of the animals given wild type L1, E1, or E2 developed warts at most sites (88%, 75%, and 88%, respectively). The animals given codon optimised E2 however, were protected from wart growth with only one tiny lesion seen on a single animal that persisted for only a few days. The E1 codon optimised group was also significantly protected with a far lower number of smaller warts (48%) that persisted for a shorter duration. These data suggest that therapeutic immunisation by PMID with papillomavirus early genes is effective and emphasizes the importance of antigen load in the generation of protective responses to papillomavirus proteins.

Intraepithelial DNA immunisation with a plasmid encoding a codon optimised COPV E1 gene sequence, but not the wild-type gene sequence completely protects against mucosal challenge with infectious COPV in beagles.

DNA plasmids encoding the open reading frames of canine oral papillomavirus (COPV) nonstructural early genes E1, E2, or E7 protein were delivered into both oral mucosal and cutaneous epithelial sites in beagle dogs using particle-mediated immunotherapeutic delivery (PMID) technology. Control dogs were vaccinated with plasmid encoding either hepatitis B virus surface antigen (HBVs) or COPV L1. Using a prophylactic immunisation protocol, a priming dose of plasmid DNA was followed by a booster dose 6 weeks later. Four weeks after boost, all dogs were challenged with infectious COPV particles. Following viral challenge, as shown previously (M. A. Stanley et al., 2001, Vaccine 19, 2783-2792), mucosal papillomas developed in the negative-control HBVs vaccinated dogs, but all animals in the COPV L1 group were fully protected from disease development. In the early gene-vaccinated groups five of six in the E1-vaccinated dogs, two of six in E2-vaccinated dogs, and three of six in the E7-vaccinated beagles developed oral papillomas. Compared to the HBVs negative-control group the oral papillomas that did develop in the early-gene vaccinated beagles were significantly smaller, shorter in duration, and fewer in number. Taken together the disease burden was markedly reduced and this was statistically significant. In a second experiment one group of animals was vaccinated with plasmid encoding the wild-type COPV E1 gene, and a separate group was vaccinated with plasmid encoding a synthetic codon-optimised COPV E1 gene sequence. None of the codon-optimised E1-vaccinated animals developed papillomas at any challenge site. However, all animals vaccinated with wild-type E1 had papillomas. These data suggest that immunisation by PMID with papillomavirus early genes can significantly impact upon subsequent disease development and that full protection can be achieved using improved vectors encoding codon-optimised gene sequences perhaps emphasizing the importance of antigen load in the generation of protective responses to papillomavirus proteins.

Nasal dermoid sinus cysts in the dog.

OBJECTIVE: To describe the clinical and morphologic characteristics of nasal dermoid sinus cysts in the dog. STUDY DESIGN: Retrospective clinical study. ANIMALS: Six client-owned dogs. METHODS: Medical records (1995 to 1999) of 6 dogs that had a discharging sinus in the midline of the nose removed surgically were reviewed for signalment, physical examination, surgical and histopathologic findings, and outcome. RESULTS: Three golden retrievers, 1 springer spaniel, 1 cocker spaniel, and 1 Brittany spaniel with a history of intermittent discharge from a small opening in the midline on the bridge of the nose at the junction between the nasal planum and the skin were identified. The condition was unresponsive to antibiotic therapy, and previous surgical excision had been unsuccessful in 3 dogs. None of the dogs had any other congenital defects, and all dogs responded to complete surgical excision of the tract and cyst. On histopathologic examination of excised tissue, there were adnexal structures along a tract lined with stratified squamous epithelium, consistent with a developmental abnormality of ectodermal tissue. CONCLUSIONS: The lesions were diagnosed as nasal dermoid sinus cysts, similar to the congenital condition described in humans. Nasal dermoid sinus cysts are rare developmental defects related to abnormal development of the pre-nasal space and may extend into the cranial vault causing cerebral abscesses or recurrent meningitis. Complete surgical excision has a good prognosis. CLINICAL RELEVANCE: This is a new condition that should be added to the surgical differential diagnosis for a discharging sinus over the external nares in dogs.