Sean E. Hulsebosch

Background: Androgen-dependent cystinuria has been described in intact male dogs. Castration has been recommended to reduce urinary cystine excretion. Hypothesis/Objectives: Urinary cystine/creatinine concentration will significantly decrease in dogs with suspected androgen-dependent (Type III) cystinuria after castration and will be associated with a lack of sonographic evidence of urolithiasis. Animals: Six intact male dogs with cystine uroliths. Methods: Prospective, observational study. Urinary amino acid/creatinine concentrations and abdominal ultrasound were evaluated at baseline (T0), 30 days (T30), and 90 days (T90) after castration and urolith removal. No dietary change was recommended unless urolith recurrence was noted. DNA was evaluated for the cystinuria-associated marker for Type III cystinuria. Results: The median decline in urinary cystine/creatinine (uCys/creat) concentration from T0 to T30 was 577 nmol/mg (IQR, 415–969; p = 0.03), from T0 to T90 was 798 nmol/mg (IQR, 580–989; p = 0.03) and from T30 to T90 was 34 nmol/mg (IQR, 19.5–443; p = 0.03). Two dogs had small (2.5–3 mm) uroliths at T30, which resolved in one of them at T90. Both dogs with ultrasonographic evidence of recurrence at T30 were positive for the cystinuria-associated genetic marker, although no signs of lower urinary tract disease were noted in either dog. Three of 6 enrolled dogs were homozygous positive for the genetic marker. Conclusions and Clinical Importance: Castration should be considered for intact male dogs with cystine urolithiasis.

Background: Insulin-treated diabetic cats frequently achieve transient remission. The glucagon-like peptide-1 receptor agonist, exenatide extended-release (exenatide-ER), preserves β cell function in people with type 2 diabetes mellitus (DM). Objectives: Investigate the effect of exenatide-ER on the duration of diabetic remission in cats. Animals: Twenty-two client-owned cats with recent diabetic remissions. Methods: Placebo-controlled, single-blinded study. Cats were assigned randomly to receive exenatide-ER (0.13 mg/kg) or saline injection SC, once monthly for 2 years or until DM relapsed. Cats were fed low-carbohydrate diets; weight control was actively supervised. Paired t-tests and Mann–Whitney were used to compare pre- versus post-study characteristics within groups and between group outcomes, respectively. Results: Treatment groups (placebo, N = 10; exenatide-ER, N = 12) were similar in age, sex, and body weight upon inclusion. Thirteen cats completed the 2-year study without diabetic relapse. Nine cats (placebo, n = 4; exenatide-ER, n = 5) exited prematurely. Three of these exited because of DM relapse (placebo: N = 1, day 212; exenatide-ER: N = 2, days 553 and 558). There was no difference in remission duration between treatments (placebo: 669 [121–721]; exenatide-ER: 662 [28–735] days, p = 0.9). Median body weight decreased in both groups at study exit (placebo: −0.6 kg [−1.3 to +0.3], p = 0.03; exenatide-ER: −0.2 kg [−1.2 to +0.5], p = 0.02). Hemoglobin A1c remained unchanged on exenatide-ER (−0.05% [−6.9 to +2.1]) but increased on placebo (+2.3% [−1.7 to +4.4]; p = 0.03). Conclusions and Clinical Importance: Exenatide-ER contributed to the maintenance of glycemic control as reflected by hemoglobin A1c but did not affect remission duration. Management might have contributed to the extended remission duration.

Bacterial pneumonia can present in both dogs and cats as either acute or chronic disease, and clinical signs may suggest respiratory or systemic impairment. Aspiration pneumonia, a common form of disease, can be caused by esophageal or laryngeal disease, vomiting, or altered mentation, such as with CNS disease or general anesthesia. Bacterial pneumonia can also develop due to inhaled airway foreign bodies, reduced local immune function, or impaired clearance of respiratory secretions. Rapid identification of the etiology and associated risk factors for pneumonia can help veterinarians develop a targeted therapeutic plan and prevent recurrence of disease.

Sibling female and male Chihuahuas were evaluated for a 9-month history of tachypnea that failed to respond to fenbendazole, doxycycline, amoxicillin-clavulanate, and prednisone. Physical examination identified tachypnea, hyperpnea, and harsh bronchovesicular lung sounds. Fundic examination disclosed diffuse chorioretinitis, manifested as multifocal chorioretinal granulomas in the female dog and occasional chorioretinal scars in the male dog. Thoracic radiographs indicated moderate to severe interstitial to broncho-interstitial infiltrates in both dogs. Serum and urine antigen and antibody testing in the female dog failed to identify infectious agents, but cytologic assessment of hepatic lymph node, liver, and splenic aspirates identified Pneumocystis trophozoites. Infection was confirmed in both dogs by 28S rRNA PCR sequencing from multiple tissue samples. The female dog responded well to trimethoprim-sulfamethoxazole, but the male dog was euthanized because of liver failure, presumably related to antimicrobial treatment.

Background: Severe muscle stiffness (SMS) in dogs with hypercortisolism (HC) is uncommon. Objectives: To evaluate signalment, presentation, treatments, and long-term outcomes of dogs with concurrent HC and SMS. Animals: Thirty-seven dogs. Methods: Medical records of dogs with HC and concurrent SMS were recruited from 10 institutions. Clinical information, test results, therapeutic responses, and survival times were reviewed. Results: All 37 dogs with HC and SMS had pituitary-dependent hypercortisolism (PDH); 36/37 weighed <20 kg. Signs and test results were typical of PDH aside from SMS, initially diagnosed in all 4 limbs in 9, pelvic limbs of 22, and thoracic limbs of 6 dogs. Hypercortisolism and SMS were diagnosed together in 3 dogs; HC 1-36 months before SMS in 23; SMS 1-12 months before HC in 11. Mitotane or trilostane, given to control HC in 36/37 dogs, improved or resolved HC signs in 28; SMS did not resolve, remaining static or worsening in 31/36 dogs, mildly improving in 5/19 dogs given additional therapies. Progression of SMS included additional limbs in 10 dogs and the masticatory muscles of 2. The median survival time from diagnosis of SMS was 965 days (range, 8-1188). Conclusions and Clinical Importance: Concurrent SMS and HC is uncommon, possibly affecting only dogs with PDH. Development of SMS might occur before or after diagnosis of HC. Apart from SMS, the clinical picture and survival time of these dogs seem indistinguishable from those of dogs with HC in general. However, while muscle weakness usually resolves with HC treatment SMS does not.

Background: For the treatment of diabetes mellitus (DM) in dogs, novel insulins with decreased injection frequency while maintaining safety and efficacy are desirable. Insulin fused with immunoglobulin-fragment-crystallizable (Fc) has an ultra-long plasma half-life because it recycles through cells, protected from proteolysis. Hypothesis: Glycemic control can be achieved in diabetic dogs with a recombinant fusion protein of a synthetic insulin and canine Fc (AKS-218d) administered subcutaneously once-weekly. Animals: Five client-owned dogs with naturally occurring DM. Methods: Prospective clinical trial in dogs with DM that were recruited from the UC Davis Veterinary Teaching Hospital and local veterinary clinics. Dogs previously controlled using intermediate-acting insulin q12h were transitioned to once-weekly injections of a preliminary construct identified as AKS-218d. The dose of AKS-218d was titrated weekly for 8 weeks based on clinical response and continuous interstitial glucose monitoring. Clinical signs, body weight, serum fructosamine concentrations, and mean interstitial glucose concentrations (IG) over the preceding week were compared between baseline (before AKS-218d) and during the last week of treatment. Data were compared using nonparametric paired tests. Results: Once-weekly AKS-218d, compared to baseline twice-daily insulin therapy, resulted in no significant changes in clinical signs, median (range) body weight (+0.4 kg [−0.5-1.1]; P = .6), fructosamine concentration (−75 mmol/L [−215 to +126]; P = .4), or mean IG (+81 mg/dL [−282 to +144]; P = .8). No adverse reactions were reported. Conclusion: Control of clinical signs, body weight, and maintenance of glycemia was achieved with this once-weekly novel insulin construct in 4 of 5 dogs.

OBJECTIVE: To report the fluoroscopic removal or repositioning of urinary tract implants in dogs and cats by use of an endovascular snare system (ESS) and to report procedural usefulness and complications in dogs and cats. ANIMALS: 3 cats and 14 dogs. PROCEDURES: A medical records review was performed to identify dogs and cats that underwent removal or repositioning of urinary tract foreign bodies or implants by use of an ESS with fluoroscopic guidance at a veterinary teaching hospital from 2013 to 2019. RESULTS: Dogs had a median weight of 25 kg (55 lb) with a range of 3.5 to 60.6 kg (7.7 to 133.3 lb), and cats had a median weight of 5 kg (11 lb) with a range of 4.2 to 5.4 kg (9.2 to 11.9 lb). By use of an ESS, 12 patients (2 cats and 10 dogs) underwent transurethral retrieval of retained vesicourethral implants or ureteral stents, 2 dogs underwent transurethral ureteral stent repositioning, 1 cat and 2 dogs underwent transnephric retrieval of ureteral stents, and 1 dog underwent cystoscopic-assisted transureteral ureteral stent retrieval. All procedures were successfully performed, and there were no associated procedural complications. CONCLUSIONS AND CLINICAL RELEVANCE: Retained vesicourethral implants or ureteral stents were successfully retrieved by use of an ESS in dogs and cats transurethrally or with an open or percutaneous transnephric approach and fluoroscopic guidance. These techniques should be considered as an alternative or adjunct to more invasive methods for implant retrieval or manipulation.

Struvite urolithiasis with bacterial urinary tract infection (UTI) is commonly reported in dogs; few data exist to describe successful dissolution protocols in dogs with naturally occurring disease. We hypothesized that a dry therapeutic urinary diet combined with targeted antimicrobial therapy can effectively dissolve presumptive struvite cystolithiasis in dogs with naturally occurring urease-producing bacterial UTI. Ten dogs with presumed infection-induced struvite cystolithiasis based on lower urinary tract signs (LUTS), radiodense cystoliths, and urease-producing bacterial UTI were enrolled. At enrollment, antimicrobials and dry therapeutic urinary diet were dispensed. In addition to lack of radiographic resolution of urolithiasis, dogs with persistent clinical signs were considered non-responders. There was no significant difference in pH between responders and non-responders; USG was significantly higher in the responder group. Recheck visits continued until radiographic dissolution or failure was documented. Five of the 10 dogs achieved radiographic dissolution of cystolithiasis within a median of 31 days (range 19–103). In the other 5 dogs, surgical urolith removal was necessary due to persistent LUTS (3 dogs within 2 weeks) or lack of continued dissolution noted radiographically (1 dog with numerous cystoliths failed at day 91; 1 dog failed by day 57 with questionable owner compliance). Dissolution of urinary tract infection induced struvite cystoliths can be accomplished in some dogs fed this dry therapeutic urinary diet in conjunction with antimicrobial therapy. Case selection could increase the likelihood of successful dissolution; however, if calcium phosphate is present, this could also prevent stone dissolution. If clinical signs persist despite diet and antimicrobials, stone removal is advised.