Presentation and management of trapped neutrophil syndrome (TNS) in UK Border collies

Clinical findings, treatment and outcome of trapped neutrophil syndrome in Border Collies: 12 cases (2011-2022)

OBJECTIVES

This study aimed to evaluate clinical signs, diagnostic findings, treatment administered and short- (survival to 28 days) and long-term prognosis (survival >6 months) in dogs diagnosed with trapped neutrophil syndrome.

MATERIALS AND METHODS

Medical records of 12 dogs (10 Border Collies and two Border Collie Crossbreeds) homozygous for VPS13B gene mutation causing trapped neutrophil syndrome from seven veterinary institutions between January 2011 and June 2022 were evaluated retrospectively.

RESULTS

The most common clinical signs at the time of diagnosis were pyrexia, abnormal gait and gastrointestinal signs. Concurrent metaphyseal osteopathy and immune-mediated polyarthritis were common. Seven dogs had a segmented neutrophil count below, four dogs within and one dog above the analyser reference interval at presentation. Two dogs had a septic source identified and both were additionally identified to be homozygous mutant positive on DNA testing by polymerase chain reaction (PCR) for canine cyclic neutropenia. All dogs received at least one antimicrobial agent and 10 dogs received treatment with prednisone or prednisolone (median starting dose 1 mg/kg/day; range 0.5 to 2.5 mg/kg/day). Nine dogs were alive at 28 days and six dogs were alive at 6 months post-diagnosis.

CLINICAL SIGNIFICANCE

Trapped neutrophil syndrome should be suspected in young Border Collies with pyrexia, lameness and gastrointestinal signs. Neutropenia may not always be present and long-term survival is possible. A septic focus was not commonly identified in our population; however, our results suggest that if identified, testing for concurrent canine cyclic neutropenia should be considered.

Recognition and Diagnosis of Underlying Disease Processes in Bacterial Pneumonia

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.

Microscopic and molecular diagnoses of Giardia duodenalis in pet animals in Babylon Province, Iraq

Background and Aim

The breeding of pet animals, especially dogs and cats, in Iraq has increased recently. However, no epidemiological or molecular data exist regarding Giardia duodenalis infection in pet animals, particularly in Babylon Province. Therefore, this study aimed to detect G. duodenalis and its genotypes in pets using microscopic and molecular techniques.

Materials and Methods

For microscopic examination, 150 pet fecal samples (dogs = 75, cats = 75) were examined from October 1, 2022, to March 30, 2023. Fourteen isolates of G. duodenalis (7 per host) were genetically characterized using SSUrDNA gene sequencing.

Results

Microscopic examination revealed that the rates of G. duodenalis infection was 14.67% (11/75) and 12% (9/75) in dogs and cats, respectively. According to sex, the infection rate in dogs was 22.22% (8/36) for males and 7.69% (3/39) for females. Conversely, the infection rate in cats was 5.56% (2/36) for males and 17.95% (7/39) for females. The highest infection rates were recorded for animals under 6 months of age, with 16.67% (3/18) for dogs and 27.27% (3/11) for cats. In rural areas, the infection rate was higher than that in urban areas, with 17.65% (6/34) in dogs and 13.89% (5/36) in cats. For the molecular diagnosis, 14 isolates of G. duodenalis (7 per host) were genetically characterized using SSUrDNA gene sequencing. In dogs, the findings revealed specific genotypes, with D at 3/7 (42.86%) and C at 2/7 (28.57%). In addition, zoonotic genotype A was found in 2/7 (28.57%) of dogs. In cats, the specific assemblage F was present in 4/7 (57.14%), while zoonotic genotype A was found in 3/7 (42.86%).

Conclusion

This study is considered the first in Babylon Province to detect G. duodenalis genotypes in pet animals (dogs and cats), as some have zoonotic genotypes that could transmit infections to humans. The results of this study illustrate the epidemiological importance of this parasite in this region.

Multiorgan neutrophilic inflammation in a Border Collie with "trapped" neutrophil syndrome

Trapped neutrophil syndrome is a rare congenital disease recognized in Border Collies and is characterized by persistent neutropenia with myeloid hyperplasia. The mechanism of neutropenia has not been described. We document the case of a young Border Collie diagnosed with trapped neutrophil syndrome based on clinical features, blood and bone marrow evaluation, and presence of the associated homozygous mutation. Results from flow cytometric and storage studies suggested lower neutrophil survival time. The dog had substantial neutrophilic inflammation in multiple organs, indicating that neutrophils could leave the marrow and enter tissues, making the term "trapped" neutrophil syndrome a misnomer.

Trapped Neutrophil Syndrome in a Border Collie

A 10 wk old female border collie was presented for hemorrhagic diarrhea and pelvic limb lameness. Examination revealed pain and effusion in multiple appendicular joints and pyrexia. Clinicopathologic testing revealed moderate neutropenia as well as nondegenerate neutrophilic inflammation in multiple joints. Radiographs showed capsular joint swelling and heterogeneous metaphyseal lucencies in the distal radius, ulna, femur, and tibia. Genetic testing confirmed a mutation in the vacuolar protein sorting-associated protein 13B gene and a diagnosis of trapped neutrophil syndrome (TNS). Within 24 hr of initiating prednisone therapy (1 mg/kg, per os, q 12 hr), the dog was afebrile and nonpainful with normal ambulation. Lameness recurred twice over the next 5 mo. At 9 mo of age, diagnostics showed severe erosive polyarthritis of both stifles with an inflammatory leukogram and arthrocentesis findings consistent with septic arthritis, and the dog died despite antibiotic therapy. This is the first case of TNS described in the North American literature, and it is unique in that we had the opportunity to document progression of radiographic abnormalities over more than 6 mo. TNS should be considered in young border collies with signs suggestive of immune-mediated polyarthritis, septic arthritis, or hypertrophic osteodystrophy, combined with neutropenia or gastrointestinal signs.