Aims To describe the radiographic prevalence and severity of canine hip dysplasia (CHD) in dogs undergoing tibial plateau levelling osteotomy (TPLO) for cranial cruciate ligament deficiency (CCLD); to evaluate the association between CHD and osteoarthritis (OA) severity; to determine whether the level of CHD or OA in the most severely affected hip was associated with ipsilateral vs contralateral CCLD; and for dogs that had one documented case of CCLD, whether the level of CHD severity in the most severely affected hip was associated with time to opposite-side CCLD. Methods Medical records from 466 client-owned dogs treated with TPLO for CCLD at a single referral centre between September 2021 and December 2022 were reviewed retrospectively. Pre-operative radiographs were assessed for CHD and OA severity. The relationship between the most severely affected hip and operated stifle was recorded as ipsilateral or contralateral. Prevalence estimates, breed-specific distribution analyses, multivariable logistic and ordinal models, and Cox proportional hazards models were used to evaluate associations between CHD severity, OA severity, ipsilateral vs contralateral CCLD, and time to opposite-side CCLD. Results The radiographic prevalence of CHD was 169/466 (36.3 (95% CI = 31.9-40.6)%). Among dysplastic dogs, 74.0% showed radiographic evidence of OA. CHD severity was strongly associated with OA severity (OR per one-category increase in CHD severity score 22.91 (95% CI = 14.87-35.32); p < 0.001). Increasing CHD severity was associated with higher odds of CCLD occurring in the stifle contralateral to the most severely affected hip (OR per one-category increase in CHD severity score 3.70 (95% CI = 1.88-7.91); p < 0.001). CHD severity showed little evidence of association with time to opposite-side CCLD (HR per one-category increase in CHD severity score 0.93 (95% CI = 0.73-1.17); p = 0.52). Conclusions CHD was common among dogs undergoing TPLO for CCLD in this referral population. Compared to dogs with mild CHD, dogs with more severe CHD were more likely to develop CCLD in the stifle contralateral to the most severely affected hip. However, in dogs that had been treated for CCLD, CHD severity was not associated with time to any subsequent opposite-side CCLD. These observational findings should be interpreted with caution. Clinical significance Identification of CHD in dogs undergoing TPLO may assist clinical assessment of pelvic limb function and long-term management. Prospective studies are needed to clarify the relationships between CHD and CCLD concerning CCLD rupture relative to the most dysplastic hip.
CASE HISTORY:On two occasions, increased perinatal losses were reported in two beef cattle herds under extensive rearing conditions in Buenos Aires province, Argentina, during the winter calving season of 2025. CLINICAL FINDINGS:Affected calves were born weak, unable to stand and suckle, and died within 1-3 days of birth. Cumulative incidences of 10% (33/330) and 3.9% (12/305) were recorded, with 100% case fatality. PATHOLOGICAL AND LABORATORY FINDINGS:Necropsies were performed on three calves: two from Outbreak 1 (one calf died within 1 day of birth and one within 3 days) and one calf that died within 1 day of birth from Outbreak 2. Grossly, in all three calves, pelvic limbs and sublumbar muscles exhibited multifocal-to-coalescent pale whitish discolouration, interspersed with haemorrhage. Microscopically, skeletal muscles presented polyphasic degeneration and necrosis of myofibres with calcified deposits within the sarcoplasm. Low Se concentrations (<0.75 mg/kg) were detected in the livers of all three calves, while Cu and Zn concentrations were within reference ranges. No evidence for the involvement of infectious agents was detected. Low Se concentrations were observed in serum samples from 18 dams from Outbreak 1 and nine from Outbreak 2. Mineral analysis of available feed from both farms showed low Cu concentrations in both outbreaks and elevated S concentrations in Outbreak 2. DIAGNOSIS:Nutritional myopathy (NM) in beef calves, presumed to be associated with Se deficiency in calves born to Se-deficient dams. CLINICAL RELEVANCE:Se deficiency was the most likely cause of NM, but high dietary SO4-2 and S concentration in Outbreak 2 may have interfered with dietary Se absorption. Our study highlights that NM should be considered as a potential cause of perinatal losses.
AIMS:To measure blood ionised calcium (iCa) and lactate (L-lac) concentration, relative plasma volume index (rPV) and oxygen saturation (SpO2), in a small number of dairy cows showing clinical signs of milk fever, and to report the effects of IV administration of calcium borogluconate combined with hypertonic saline solution (HSS), compared with calcium borogluconate alone, on iCa, rPV and SpO2. METHODS:A convenience sample of 10 Holstein dairy cows from multiple dairy farms showing clinical signs consistent with milk fever and having an iCa concentration ≤ 1.05 mmol/L was enrolled. Blood biochemistry, SpO2, and heart rate measurements were performed, and rPV was calculated with reference to the plasma volume at enrolment as the baseline. Cows were sequentially assigned to treatment groups in alternating order. The combination group (n = 5) received 3 L of 7.2% HSS mixed with 500 mL of 25% calcium borogluconate. The control group (n = 5) received 500 mL of 25% calcium borogluconate alone. Measurements were performed before treatment, immediately after treatment, and 24 hours later. RESULTS:Before treatment, the mean iCa concentration in cows with milk fever (n = 10) was 0.59 (SD 0.14; reference range: ≥1.05) mmol/L, the L-lactate concentration was 3.23 (SD 2.02; reference range: 0.31-1.51) mmol/L, and SpO2 was 94.4 (SD 1.8; reference range: 96-100)%. iCa concentrations increased after treatment in both groups. Immediately after treatment, rPV was 141.2 (95% CI = 131.7-150.7)% in the combination group and 120.3 (95% CI = 110.8-129.8)% in the control group, with higher values observed in the combination group. At 24 hours, rPV remained above baseline in both groups, although there was no difference between groups. Immediately after treatment, SpO2 was 99.4 (95% CI = 96.6-102.2)% in the combination group and 90.6 (95% CI = 87.8-93.4)% in the control group, with higher values observed in the combination group. Even at 24 hours after treatment, SpO2 remained increased relative to pre-treatment values in the combination group. In contrast, no increase in SpO2 was observed in the control group throughout the observation period. CONCLUSIONS:Milk fever was associated with increased blood lactate concentrations and peripheral hypoxaemia, which may suggest circulatory compromise related to hypocalcaemia. Compared with calcium therapy alone, calcium therapy combined with HSS increased rPV immediately after treatment and further improved SpO2. CLINICAL RELEVANCE:Adjunctive HSS may provide short-term circulatory support in cows with milk fever receiving standard calcium treatment under commercial farm conditions.
AIM:To evaluate the efficacy of an inactivated, whole-cell Leptospira borgpetersenii serovar Tarassovi vaccine for prevention of urinary shedding of L. borgpetersenii strain Pacifica, in naturally challenged cattle. METHODS:Three dairy farms in Northland, NZ, endemically infected with Pacifica, participated in a randomised controlled trial. Female calves (n = 291), aged 3-7 weeks, were randomly allocated in equal proportion to vaccinated and control groups. Two doses of test vaccine or saline were administered 4 weeks apart, then booster doses at 6 and 18 months. Blood and urine samples were collected once or twice between weeks 71 and 93, for determination of Tarassovi serology and shedding of pathogenic Leptospira by urine PCR, with subsequent amplicon sequencing of PCR-positive samples. For each farm separately, and pooled results from Farms 1 and 2, the proportion of animals shedding Leptospira in each group was compared statistically, and vaccine efficacy (VE) calculated. RESULTS:A strong serological response to Tarassovi was demonstrated following two vaccine doses. Between weeks 81 and 93, when study heifers were 17-20 months old, a high proportion of unvaccinated controls were seropositive to Tarassovi (100%, 89% and 83% on Farms 1-3, respectively), consistent with exposure to Pacifica on each farm. On Farm 1, 13/30 (43%) controls and 0/29 vaccinates were shedding pathogenic Leptospira in urine, representing VE of 100% (95% CI = 73-100%; p < 0.001); Pacifica was confirmed in eight control animals, also representing efficacy of 100% (95% CI = 49-100%; p = 0.005). On Farm 2, 6/73 (8%) controls and 1/72 (1%) vaccinates were shedding pathogenic Leptospira; however, the difference was not significant (p = 0.116). On Farms 1 and 2 combined, 19/103 (18%) controls and 1/101 (1%) vaccinates were shedding pathogenic Leptospira, representing VE of 95% (95% CI = 70-100%; p < 0.001). On Farm 3, one unvaccinated control was found to be shedding, and no vaccinates. No other serovars of Leptospira were identified on any farm by urine PCR. CONCLUSIONS:The Tarassovi vaccine conferred a very high level of protection (95-100% efficacy) against urinary shedding of L. borgpetersenii strain Pacifica in cattle, following two doses in calves and booster vaccinations at 6 and 18 months. CLINICAL RELEVANCE:Given the serious zoonotic risk of leptospirosis, and the emergence of Pacifica as an important strain in NZ cattle, incorporation of an effective Tarassovi vaccine in standard leptospiral vaccination programmes is highly recommended.
