Figure 1: Testicular tumor in male rat (Rumpus).
Case history and photos

History

Rumpus, an agouti hooded male, was 2 years 2 months of age.
He was overweight but otherwise healthy. He suffered no significant health problems during his life.
Of significance: Rumpus is from the problematic Australian blue line and is half brother to Spritely who died of suspected lymphosarcoma at 7 months of age.

Clinical Signs

In December of 2004, we noticed one of his testicles seemed firmer than the other. Since we were unsure at the time if this was normal or not, we continued to keep watch.

On 17 January 05, the left testicle was definitely harder and appeared larger. Rumpus was taken to see our vet at this time.

Diagnosis

Possible tumor. R/O infection, inflammation, or torsion (?).

Orchiectomy (removal of testicle or testicles, also known as castration or neuter) recommended.

Treatment

On 18 January 05, surgery was undertaken and both testicles were removed in the event a mass was present.

The following are the surgical notes as written and submitted by Dr Larissa Ladyko:

“Desexed. Enlarged testicle removed. Large swollen testicle appeared to be cancerous, but didn’t extend out of testis. Other testicle appeared normal.
Fluids, Metacam and Baytril were given.
Baytril was to be continued for 5-10 days depending on how surgical area looks. Metacam provided for the first few days post-op, if needed.
Testicle examined under microscope – tumor confirmed, no infection or inflammation. Unable to determine at that time if tumor malignant or benign, but it was definitely confined only to left testicle.”

Outcome

Rumpus had a slow recovery, the surgery being very stressful for him. Within a few days of recovery we noticed a lump appear in the wound area.

It appeared to be just some scar tissue with inflammation – a keloid.

Continued Metacam for a few days and remained on Baytril as the lump reduced over the next 3 weeks. During this time Rumpus recovered well and was active and his normal self, although he had lost considerable weight and was starting to show minor hind leg weakness. One week after stopping Baytril an abscess formed in the area and was drained by our vet. He was again placed back on Baytril.

Follow-up

On 6 March 05, Rumpy had a sudden downturn. He was lethargic, breathing heavily and developed sudden onset of paralysis in hind legs. The vet suspected pain due to onset of spinal degeneration. He was given a steroid
and painkillers, but no response. Rumpus died peacefully later that day (at 2 years and 5 months of age).

Photos

Photos 1 & 2, below, show diseased testicles following removal.

Photos courtesy of Al and Robyn Arthur, of The Dapper Rat, http://www.dapper.com.au
Collaborated case history by: Dr Larissa Ladyko B.V.Sc, and Robyn Arthur.