That is the main diagnosis that apparently killed my bird, Wasp.
"Hydro" (excessive water) "pericardium" (lining of the heart cavity). This leads to a condition called tamponade. I learned that in ACLS (Advanced Cardiac Life Support). The heart of all animals, including hawks and humans, sits inside a protective sack, called the pericardium. If a disease process causes an increase in fluid inside this protective membrane, the heart cannot beat, cannot refill with blood, and the organism dies. This is what I witnessed myself on the morning of Saturday, July 12. Between the time I noticed there was a problem, and his death, about a half hour transpired. It was quick.
Two days prior to the events of Saturday morning, July 12, he appeared normal, and ate a good sized meal. Because of my work schedule, I did not look in on him on Friday, July 11, opting to feed him the following morning with training. Rich tells me he was heard inside his mew on Friday, squawking as he does. I have been slowly bringing Wasp back down to response weight, with the goal to do some summer hunting with him. Because he is a small hawk, flying at 570 grams, give or take just a little, he did not fly well in the very frigid winter we had this last year. I have held back his molt. I wanted to give him more experience on birds, and then hoped to fly him on young rabbits once the season for them opened.
I felt last year that the response weight of 570 grams seemed rather sharp for him, but that was the weight he had to be at for motivation. I had response from him, and now have been working to build up some muscle and stamina. My efforts have been stymied by the incredible hatchout of black flies and midges we have had this summer. This seems to be significant, for reading the necropsy report, this is highly likely what caused the hydropericardium.
On Saturday morning, as I entered his mew, he was quiet, which is unusual for this bird. Both he and Sassy are rather talkative. That is, Sassy is talkative, and I think she taught Wasp to be so as well. He was on his night roost, hunched over and looking very subdued, lethargic, and unconcerned about his surroundings. He has been particularly spooky as I've been reducing his weight, refusing to stay on my fist, refusing to come to me unless I have food. I cannot know if he has been ill for awhile, or if this was a sudden, acute situation. I couldn't ask him how he has been feeling, and he didn't inform me that he had chest pain, or an inability to breathe . . . which is the sensation tamponade would produce.
Upon lifting him off his perch, his feet went limp, which to my experience is a very bad thing. I had no idea what the problem could be, and questioned whether or not it could be very low condition, as I have been reducing his weight. I brought him into the house, and carefully gave him two droppers of a high sugar solution, making sure to deposit into the crop, and avoid the trachea. I then called the Raptor Center. I received voice mail, and left a message. Someone would call me back shortly, as there is someone in the clinic on weekend mornings, per the voicemail message. He would die on me before they called back. He did manage to free his foot from the towel binding him and grab my hand for one last squeeze. It was a goodly handshake . . . a final handshake. He died shortly after that.
When someone from the Raptor Center called me back I asked them about preserving the body for necropsy. I wanted to know WHY he died, as he had shown no signs prior to this day. I was advised to refrigerate, and not freeze. I wrapped him up in a smaller towel, and placed him in the refrigerator. I would not be able to submit his body for necropsy until Monday, two days away. It was a little weird the next couple days opening the refrigerator, and see those talons sticking out of the towel on the bottom shelf.
We are very fortunate here in Minnesota to have one of the pre-emminent raptor hospitals in the University of Minnesota. I have taken Sassy to the Raptor Center for surgery, as well as she and Hit Girl a couple years ago for health certificates prior to travel to a NAFA meet. Across the street from the Raptor Center is the Veterinary Diagnostic Laboratory. For a fee of $95 they would chop Wasp all up and take a very close look at him to try to determine what agent or infection or condition caused his too premature death. It has taken 10 days, but I now have his report.
The report begins with a rundown of each anatomical system. Most indicated nothing of note. Overall, his mucous membranes were pale, which could mean anemia. His Body Condition Score was 2 out of 5, with 1 = emaciation/ 5= obese. I knew he was thin, but 570 grams had been his flight weight last year. The cardiovascular system indicated severe hydrothorax. His liver was enlarged and redish. His spleen was enlarged and marble in appearance.
Histopathology, or microscopic analysis of tissue biopsies, found evidence of a microorganism suggestive of Leucocytozoon in the liver (more on that later). It was also found in the spleen. There was also evidence of a microorganism called Haemoproteus in the liver. System-wide, he was found to have Escherichia coli, non-haemolytic.
The Diagnosis indicates: Hydropericardium (this is the first and major cause of death); Spleen - Splenitis, lymphoplasmacytic, diffuse, moderate and diffuse reticuloendothelial hyperplasia with splenomegaly; Liver - Hepatitis, lymphocytic and histiocytic, multifocal, moderate, and widely disseminated intrahepatocellular and intraendothelial Apicomplexa microorganism suggestive of Leucocytozoon and bacterial emboli, with hepatomegaly.
The veterinary diagnostician indicates cause of death is unclear. It is his opinion that the presence of the Leucocytozoon should not have caused the bird's death. He noted that the bird was underweight.
So . . . where does that leave me? At least I can know that it was not anything obvious that I had done to him. Yes, he was underweight, but I was using the same techniques that I have used on all of my birds, and none have ever died of starvation. The presence of the microorganism Leucocytozoon and Haemoproteus interested me to look into it. The vector for these parasites are: 1. Black Flies, and 2. Blood-sucking mosquitos and midges, in that order. Go figure!
Both Wasp and Sassy are kept inside a screen mew. I have not been giving them any weathering time due to the current abundance of these biting insects. However, Wasp has been out of his protective mew while getting training, and there is always the possibility some follow inside when I come and go into their mew. How do you protect against something that is ubiquitous? And, was Wasp's underlying condition so compromised that he was unable to deal with these infections, leading to an inflamed liver and spleen, and then hydropericardium.
I am discouraged and dissapointed in his loss, but don't think anything obvious was wrong with his care. I am a bit disgusted after all my efforts last year, and money, to acquire a second Harris Hawk to be a companion to Sassy, that I am left now only with an inconclusive death report.
Sometimes, having responsibility for these magnificent animals can be very painful . . . when your best efforts only result in loss.