This handy update for practitioners details traditional and contemporary diagnostic tools as well as abnormalities encountered during the course of pregnancy. Early diagnosis is valuable for breeders of working or show dogs and for medical therapy before mid-gestation or pregnancy termination via ovariohysterectomy. The traditional method of digital palpation has a short accuracy window and is only 87% to 88% accurate in the second trimester of pregnancy, 73% accurate for negative pregnancy, and 12% accurate for litter size. Newer, noninvasive imaging techniques have made better diagnoses possible with varying degrees of accuracy. Real-time ultrasonography allows for correct assessment of pregnancy status, fetal number and viability, and investigation of the uterus and extrareproductive abdominal structures (a full bladder makes a good caudal abdominal marker). At present there are no accurate, commercially available serologic tests for pregnancy diagnosis in dogs. Even if proposed tests become available, it will be unlikely that they will be able to yield litter number or much other related information.

Abnormalities during pregnancy include progesterone-induced insulin resistance, which can lead to diabetes mellitus, requiring insulin regulation; pregnancy toxemia resulting from anorexia, requiring supplemental nutrition; and large litters, requiring cesarean section. Causes of pregnancy loss can include Brucella canis and canine herpesvirus infection, trauma, genetic abnormalities in pups, inadequate nutrition of the dam, hypothyroidism, and hypoluteoidism (corrected by progesterone supplementation if blood concentrations fall below 5 ng/ml before the last week of gestation).

COMMENTARY: Veterinarians would do well to secure the means for accurately diagnosing and monitoring canine pregnancy, an especially valuable service for breeder clients and clients with working dogs.

Pregnancy diagnosis and abnormalities of pregnancy in the dog. Kustritz MVR. PROC WILD WEST VET CONF, 2003, pp 774-781.