A retrospective study on dystocia in the cat, evaluation of 111 cases.

Dystocia affects on average 3-8% of all pregnancies in purebred cats. Nonpedigree cats are also affected, but the incidence is unknown. The causes of dystocia and the optimal treatment are largely unexplored in cats. The aims of the present retrospective study were to describe feline dystocia cases and to evaluate kitten mortality in relation to factors associated with dystocia in cats. Medical records of 111 cases (107 queens) treated for dystocia from 2017 to 2024 were retrieved from client files at the University Animal Hospital in Uppsala, Sweden. At the initiation of treatment, 276 kittens remained in utero or in the birth canal. The total kitten mortality rate, including that of kittens born before treatment but excluding four kittens that were euthanized at the owner's request, was 40.9%. The mortality of kittens born after treatment was 44.1%, excluding four kittens euthanized at the owner's request. Two queens died, one of which was euthanized at the owner's request. Among all the cases, 91 (82.0%) were surgically treated, with caesarean section, or en bloc resection in two patients. Ovariohysterectomy was performed in 47.2% of the queens that were surgically treated. Medical treatment was initiated in 30 patients, and was successful in 11 of them, and 19 were further surgically treated after only partial or no success. The success rate of medical treatment was thus 36.7%. Eight queens were hypocalcaemic. Maternal hyperglycaemia was present in 65.5% of the cases and significantly increased the risk of kitten mortality. The estimated duration of second-stage labour before admission did not affect kitten mortality. Disturbed labour (total or partial uterine inertia) was the most common cause of dystocia. Feline dystocia was associated with high kitten mortality but low mortality in queens. Most queens with dystocia were treated surgically, but medical treatment with calcium and/or oxytocin was efficient in cases with non-obstructive dystocia, and ≤ 3 foetuses remaining. Hypocalcaemia may contribute to dystocia in a minority of cases. Maternal hyperglycaemia increased the risk of mortality before discharge. Diagnosing dystocia may be challenging in cats, as there is no clear association between the length of the parturition process and mortality.