Prognostic indicators for survival of downer cattle treated using a flotation tank in a referral hospital: 190 cases (2000-2020).

BACKGROUND: Nonambulatory cattle present therapeutic challenges in addition to animal welfare concerns. Flotation therapy is a treatment option, but more information regarding prognostic indicators for survival is needed to guide use of this modality. HYPOTHESIS/OBJECTIVES: Evaluate historical and clinical variables assessed during hospitalization as prognostic indicators for survival in recumbent cattle undergoing flotation treatment in a referral hospital. ANIMALS: A total of 190 nonambulatory dairy cattle. METHODS: Retrospective case series. Medical records were analyzed from cattle undergoing flotation between 2000 and 2020. Univariable and multivariable logistic regression analyses were performed to assess the association of clinical variables with survival to discharge. RESULTS: Eighty-nine of 190 (47%) recumbent cattle survived to discharge. For each additional day of hospitalization, cattle were 1.10 (95% confidence interval [CI], 1.02, 1.21) times more likely to survive. Cattle unable to walk out of the tank after their first float session were 0.11 (95% CI, 0.04, 0.28) times less likely to survive compared to cattle that could and inappetent cattle were 0.22 (95% CI, 0.07, 0.63) times less likely to survive compared to cattle with normal appetites. Cattle diagnosed with coxofemoral luxation or toxemia were 0.11 (95% CI, 0.02, 0.65) and 0.16 (95% CI, 0.02, 0.90) times less likely to survive, respectively, compared to cattle with causes of recumbency that were undetermined. CONCLUSIONS AND CLINICAL IMPORTANCE: Walking out of the tank after the first float session, appetite, diagnosis, and days of hospitalization are associated with outcome in nonambulatory dairy cattle treated by flotation. These findings can be used to determine likely outcome and guide treatment, referral, or euthanasia decisions.

Assessing the effects of experimental bacterial challenge with Pasteurella multocida and ampicillin on the respiratory microbiota of pre-weaned Holstein calves.

The association between changes in the respiratory microbiota and Bovine Respiratory Disease (BRD) in dairy calves is not well understood. We investigated characteristics of the nasopharyngeal (NP) microbiota associated with BRD following Pasteurella multocida infection. We also evaluated the effect of ampicillin on the respiratory microbiota. Calves (n = 30) were inoculated with P. multocida and randomly allocated into an antibiotic group (AMP; n = 17) or placebo group (PLAC; n = 11) when lung lesions developed. Deep NP swabs (DNPS) were collected before and after challenge. Monitoring was performed daily until euthanasia at day 14. Swabs and tissue samples were collected for analysis. The V4 hypervariable region of the 16 S rRNA gene was amplified and sequenced on an Illumina MiSeq. Increased species abundance in the pre-challenge DNPS was associated with a decrease in cumulative respiratory disease over 14 days post-infection. While NP beta diversity was affected by infection, antibiotic therapy showed no effect on the alpha and beta diversity nor the relative abundance (RA) of genera in the NP tonsil, lymph node and lung microbiota. Antibiotic therapy was associated with an increased RA of NP Pasteurella spp. and a decreased RA of NP Prevotella spp. Common taxa among all samples included GIT-associated bacteria, which suggests a possible link between the GIT microbiota and respiratory microbiota in dairy calves.

Resolution of tracheal collapse and stenosis without surgical intervention in two Holstein calves.

CASE DESCRIPTION: A 4-month-old 127.5-kg (280.5-lb) Holstein heifer calf (patient 1) and a 4-month-old 174-kg (382.8-lb) Holstein bull calf (patient 2) of high genetic value were examined because of signs of respiratory tract disease (dyspnea, wheezing, and coughing) of 2 and 3 months' duration, respectively, that did not respond to antimicrobial and anti-inflammatory treatment. Patient 1 was born with assistance owing to malpresentation and dystocia. The birth of patient 2 was unobserved. CLINICAL FINDINGS: For both calves, results of a physical examination, CBC, serum biochemical analysis, thoracic radiography and CT, and nasotracheal endoscopy led to the diagnosis of tracheal collapse and stenosis secondary to perinatal rib fractures. Neither calf had evidence of substantial lower airway disease. TREATMENT AND OUTCOME: Both calves were discharged from the hospital with the recommendation that they be individually housed in cool, well-ventilated stalls with no access to headlocks. The clinical signs abated, and surgical intervention was not pursued in either patient. Both patients grew as expected and achieved reproductive maturity, with patient 1 becoming an oocyte donor and patient 2 being purchased by a commercial bull stud company. Patient 1 was reevaluated at 21 months old, and patient 2 was reevaluated at 26 months old. Results of follow-up thoracic radiographic (patient 1) and nasotracheal endoscopic (both patients) examinations indicated an anatomically normal trachea with no evidence of collapse or stenosis. CLINICAL RELEVANCE: This report was the first to describe successful resolution of tracheal collapse and stenosis secondary to perinatal rib fracture in dairy calves without surgical intervention.

Salmonella in Dairy Cattle.

As an infectious, contagious pathogen, Salmonella is probably rivaled by only bovine viral diarrhea virus in its ability to cause clinical disease, such as enteritis, septicemia, pneumonia, and reproductive losses. The increasing prevalence of Salmonella, particularly Salmonella Dublin, on dairies presents new challenges to producers and veterinarians. No current discussion of bovine salmonellosis is complete without acknowledging the increasing public health concern. Increasing antimicrobial resistance among enteric pathogens brings the use of antimicrobials by veterinarians and producers under ever stricter scrutiny. This article provides a comprehensive review of Salmonella etiology, prevalence, pathogenesis, diagnostics, treatment, and control.