Priapism is a condition in male animals in which the penis is erect for more than four hours and is constantly engorged after the cause of the sexual excitement is no longer apparent.1 Penile desiccation and ischemic necrosis may develop as a result of chronic external exposure of the organ and subsequent stagnation of blood.
Benjamin H. Cassutto, DVM
In dogs, there is no standard medical treatment for this condition. If the underlying cause of the priapism cannot be corrected and the penis becomes irreparably damaged, perineal urethrostomy and penile amputation must be performed. However, in people, terbutaline, a beta-adrenergic agonist, has been used to successfully treat priapism.2-4 In this article, I describe the successful pharmacologic treatment of priapism in two dogs with a combination of anticholinergic therapy and terbutaline.
CASE REPORT 1
A 1-year-old miniature pinscher was presented to our hospital for treatment of priapism of three days' duration.
The owner had adopted the dog from a shelter one month earlier, and preventive care (vaccinations, deworming) had been performed before adoption. The dog was then neutered at the same facility. Instead of sutures, tissue glue was used to close the skin incision initially, and the dog had to be operated on again after reopening its incision.
One week later, the owner left the dog and an intact bitch together in the house. During that time, the patient was constantly after the female, mounting it and trying to breed. When the owner returned home, she removed the patient from the bitch and noticed that the patient was lethargic and its penis was completely out of the sheath and not able to be replaced. According to the owner, the dog was still eating but was polydipsic.
On physical examination, the dog was in excellent body condition and weighed 6 lb (2.7 kg), but it was depressed, dehydrated (6% to 8%), and febrile (103.9 F [39.9 C]). Oral examination revealed moderate dental tartar and tacky mucous membranes. On inspection of the genitalia, the penis was erect and out of its sheath. It was becoming desiccated and dirty and was unable to be replaced in its sheath. Examination of the surrounding area revealed a swelling just below the area of the bulbous penis. The incision from the neutering procedure was healing appropriately. The penis and incision did not seem painful. The rest of the physical examination results were unremarkable.
Initial diagnostic tests
The dog was hospitalized, and a complete blood count (CBC), serum chemistry profile, and urinalysis were performed (Table 1). The CBC revealed anemia, leukocytosis, monocytosis, and thrombocytosis. The serum chemistry profile results revealed azotemia, hyperamylasemia, and hyperglobulinemia. The urinalysis revealed hematuria, protienuria, and cocci.
Table 1 Abnormal Laboratory Findings
Radiographic examination of the spinal cord was recommended since it is indicated in suspected cases of priapism, but the owner declined any further tests.
The primary differential diagnosis for priapism is paraphimosis, which is protrusion of the nonerect penis from the prepuce. This condition was considered to be unlikely in this case because the penis was erect and the arousal or sexual stimulation was no longer present.